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Knockdown and lethal effects of eight commercial nonconventional and two pyrethroid insecticides against moderately permethrin-resistant adult bed bugs, Cimex lectularius (L.) (Hemiptera: Cimicidae)

Authors:
  • Sierra Research Laboratories, Modesto, CA USA
  • Sierra Research Laboratories, Inc.

Abstract

The common bed bug, Cimex lectularius (L.) (Hemiptera: Cimicidae) is undergoing a rapid resurgence in the United States during the last decade which has created a notable pest management challenge largely because the pest has developed resistance against DDT, organophosphates, carbamates, and pyrethroids, the latter class of insecticide being most commonly used today. Eight nonconventional insecticides Orange Guard (a.i., d-limonene), Natria Home Pest Control (a.i., soy bean oil and eugenol), RestAsure (a.i., sodium laurel sulfate, sodium chloride, and potassium sorbate), CedarCide (a.i. cedar oil), Essentria Broadcast Insecticide (a.i., 2-phenethyl propionate, rosemary oil, and peppermint oil), EcoSmart Organic Home Pest Control (a.i., 2-phenethyl propionate, clove oil, rosemary oil, peppermint oil, and thyme oil), Cirkil (a.i.,neem oil) and CimeXa (a.i., silica gel) were compared with two pyrethorids Bonide Bedbug Killer (a.i.,permethrin) and D-Force (a.i.,deltamethrin) as positive controls, and water for direct contact spray knockdown and lethal effects in the laboratory over 4 days. Orange Guard, CedarCide, Essentria, EcoSmart, and Cirkil provided extensive knockdown within 15 min (recovery was, at most, negligible), and caused 80 to 100% mortality within a day making them as effective as the two pyrethroids. CimeXa did not cause appreciable knockdown, but nearly complete mortality was achieved within a day. Product effects in terms of active ingredients and factors that might increase and decrease product effectiveness, such as cimicid aggregation behavior and residual effects, are discussed.
* Corresponding author: E-mail: bill@sierraresearchlaboratories.com
Knockdown and Lethal Effects of Eight Commercial
Nonconventional and Two Pyrethroid Insecticides against
Moderately Permethrin-resistant Adult Bed Bugs, Cimex
lectularius (L.) (Hemiptera: Cimicidae)
WILLIAM A. DONAHUE, JR.*1, ALLAN T. SHOWLER2, M. W. DONAHUE1,
B. E. VINSON1, LUCIA HUI3AND WESTE L.A. OSBRINK2
1Sierra Research Laboratories, 5100 Parker Road, Modesto, CA 95357, USA
2USDA-ARS KBUSLIRL, 2700 Fredericksburg Road, Kerrville, TX 78028,USA
3Alameda County Vector Control Services District, Department of Environmental Health, 1131
Harbor Bay Parkway, Alameda, CA 94502, USA
————————————————————————
Biopestic. Int. 11(2): 108-117 (2015)
ABSTRACT The common bed bug, Cimex lectularius (L.) (Hemiptera: Cimicidae) is undergoing
a rapid resurgence in the United States during the last decade which has created a notable
pest management challenge largely because the pest has developed resistance against DDT,
organophosphates, carbamates, and pyrethroids, the latter class of insecticide being most
commonly used today. Eight nonconventional insecticides Orange Guard (a.i., d-limonene),
Natria Home Pest Control (a.i., soy bean oil and eugenol), RestAsure (a.i., sodium laurel
sulfate, sodium chloride, and potassium sorbate), CedarCide (a.i. cedar oil), Essentria Broadcast
Insecticide (a.i., 2-phenethyl propionate, rosemary oil, and peppermint oil), EcoSmart Organic
Home Pest Control (a.i., 2-phenethyl propionate, clove oil, rosemary oil, peppermint oil, and
thyme oil), Cirkil (a.i.,neem oil) and CimeXa (a.i., silica gel) were compared with two pyrethorids
Bonide Bedbug Killer (a.i.,permethrin) and D-Force (a.i.,deltamethrin) as positive controls, and
water for direct contact spray knockdown and lethal effects in the laboratory over 4 days.
Orange Guard, CedarCide, Essentria, EcoSmart, and Cirkil provided extensive knockdown within
15 min (recovery was, at most, negligible), and caused 80 to 100% mortality within a day
making them as effective as the two pyrethroids. CimeXa did not cause appreciable knockdown,
but nearly complete mortality was achieved within a day. Product effects in terms of active
ingredients and factors that might increase and decrease product effectiveness, such as cimicid
aggregation behavior and residual effects, are discussed.
KEY WORDS : Cedar oil, d-limonene, essential oils, eugenol, mode of action, neem oil, peppermint
oil, rosemary oil, silica gel, sodium laurel sulfate
————————————————————————
0973-483X/11/108-117©2015 (KRF)
INTRODUCTION
The bed bug, Cimex lectularius (L.) (Cimicidae:
Hemiptera), is a flightless obligatory hematophagous
parasite of man, bats, poultry, and many domestic
animals (Usinger, 1966; Ebeling, 1975). Cimex
lectularius infestations cause emotional distress,
Mention of trade names or commercial products in this publication is solely for the purpose of providing
specific information and does not imply recommendation or endorsement by the U.S. Department of
Agriculture and by Alameda County Vector Control Services District, Department of Environmental Health.
2015 Donahue et al.: Effect of natural products on cimicidae 109
sleeplessness, and anxiety (Potter, 2006). Public
tolerance for C. lectularius bites in the United States
is almost zero, and litigation, especially involving
hotels, is becoming common (Potter, 2006, 2011). Over
the last decade, pest control professionals have
reported significant increases of C. lectularius
infestations in the United States and in developed
countries worldwide (Potter, 2006; Cooper, 2011).
Explanations for this resurgence include reduction
of baseboard spraying of synthetic pesticides for
cockroach control following the introduction of
effective baits in the early 1980s, resistance to
insecticides, loss of efficacious organophosphates
and carbamates as treatment options after enactment
of the Food Quality Protection Act (1996), increased
international travel, and lack of awareness by the
public and pest management professionals (Silverman
and Shapas, 1986; Shurdutet al., 1998; Potter, 2006;
Romero et al., 2007; Cooper, 2011). Cimex lectularius
has developed resistance against DDT,
organophosphates, carbamates, and pyrethroids, the
latter class of insecticide being most commonly used
today (Romero et al., 2007; Davies et al., 2012;
Koganemaru and Miller, 2013). The rapid resurgence
of C. lectularius in the United States during the last
decade has created one of the most difficult pest
management challenges in a generation (Potter, 2006;
Potter et al., 2008; Koganemaru and Miller, 2013) and
there is a critical immediate need for new insecticides
to achieve control.
As C. lectularius resistance to conventional
insecticides increases, alternative control tactics,
such as application of bioactive natural products that
often involve multiple compounds with different
modes of action warrant investigation and
development. Different modes of action in the same
nonconventional insecticide can reduce the risk of
insecticide resistance. Botanical products that
contain bioactive compounds are desirable for pest
management when they are effective and benign to
natural enemy populations (Schmutterer, 1990, 1995;
Ascher, 1993). Many are considered to be minimum-
risk pesticides and are exempt from Environmental
Protection Agency (EPA) registration under section
25(b) of the Federal Insecticide and Rodenticide Act
(Cloydet al., 2009). While some claims of success
using nonconventional insecticides against C.
lectularius are anecdotal, a limited number of
nonconventional insecticides, including botanically-
based formulations and desiccating powders, have
been scientifically assessed and were found to be
efficacious against C. lectularius (Anderson and
Cowles, 2012; Akhtar and Isman, 2013; Hinson et
al., 2014; Wang et al., 2014; Goddard and Maschek,
2015). Because the need for assessing rapid effects
of nonconventional insecticides is becoming more
apparent as C. lectularius resistance to conventional
insecticides continues to develop and C. lectularius
infestations spread and intensify, we assessed the
direct contact efficacy of eight nonconventional
commercial insecticides, each with different active
ingredients, for C. lectularius suppression by means
of knockdown and mortality.
MATERIALS AND METHODS
Assays were conducted at Sierra Research
Laboratories in Modesto, Stanislaus County, CA,
during March and April 2014. Sierra Research
Laboratories-WMB strain C. lectularius (L.), with
moderate permethrin resistance (10×) were used. The
treatment products were Orange Guard (EPA reg. no.
61887-1-AA, Orange Guard, Carmel Valley, CA) ready
to use (RTU) emulsion with the active ingredient
listed as being d-limonene (5.8%); Natria Home Pest
Control (EPA reg. exempt, Bayer, Environmental
Science, Research Triangle Park, NC) RTU emulsion
with active ingredients soy bean oil (3%) and
eugenol (0.25%); RestAsure (EPA reg. exempt,
RestAsure, St. Louis, MO) RTU emulsion with active
ingredients sodium laurel sulfate, sodium chloride,
and potassium sorbate (proprietary mixture);
CedarCide (EPA reg. exempt, CedarCide, Lewisville,
TX) RTU emulsion with active ingredients cedar oil
(5-20%) and hydrated silica (80-95%); Essentria
Broadcast Insecticide (EPA reg. exempt, Envincio,
Cary, NC) RTU aerosol with active ingredients 2-
phenethyl propionate (3%), rosemary oil (1.5%), and
peppermint oil (2%); EcoSmart Organic Home Pest
Control (EPA reg. exempt, Alpharetta, GA) RTU
emulsion with active ingredients 2-phenethyl
propionate (2%), clove oil (1%), rosemary oil (1%),
peppermint oil (1%), and thyme oil (0.5%); Cirkil RTU
110 Biopesticides International Vol. 11, no. 2
(EPA reg. no. 88760-1, Terramera, Buena Park, CA)
RTU emulsion with cold pressed neem oil as the
active ingredient (5.5% cold pressed neem oil);
CimeXa (EPA reg no. 73079-12, Rockwell Labs,
Kansas City, MO) with silica gel dust as the active
ingredient (100%); Bonide Bedbug Killer (EPA reg.
no. 4-358, Bonide Products, Oriskany, NY) RTU
emulsion with permethrin as the active ingredient
(0.5%) as a positive control; and D-Force (EPA reg.
no. 279-9554, FMC, Philadelphia, PA) RTU aerosol
with deltamethrin as the active ingredient (0.6%) as
another positive control to which the strain of C.
lectularius used in this study was not known to be
resistant. All of the treatments were obtained from
various retail sources, and the control was tap water.
Treatment units were each comprised of 10 adult
C. lectularius inside a 336-mL plastic cup (Kal-Clear
KC12S, Fabri-Kal, Kalamazoo, MI) on a cone coffee
filter at the bottom to absorb excess liquid. Plastic
Kal-Clear domed lids to the cups each had a 2.5-cm
diameter hole at the apex through which the
treatment formulations were sprayed using a 710-mL
Delta Orbital Sprayer (Delta Industries, King of
Prussia, PA) or aerosol can in which the product
was purchased. Application distance between the
sprayer nozzle was 15 cm for all of the treatments.
The amount of each product delivered by the sprayer
varied based on the formulation but complete
coverage was achieved in every instance. Orange
Guard was delivered in the amount of 1.8 mL/
replicate, CedarCide 2.2 mL/replicate, Essentria
Broadcast Aerosol 0.9 mL/replicate, EcoSmart Home
Pest Control 1.6 mL/replicate, Natria Home Pest
Control 1.7 mL/replicate, RestAsure 0.84 mL/replicate,
Cirkil 1.3 1.3 mL/replicate, CimeXa 0.1 g/replicate, D-
Force Aerosol 0.7 mL/replicate, Bonide Bedbug Killer
2.4 mL/replicate, and the control was comprised of
1.6 mL of water. Five minutes after treatment, the
insects in each cup were moved on to a 9.4-cm-diam,
1.5 cm deep plastic dish (Greiner Bio-One North
America, Monroe, NC) with a 7.5-cm-diam #2
Whatman (VWR, Westchester, PA) filter paper disc
inside as harborage and the dish was covered with a
flat lid. This procedure was replicated five times for
each of the 11 treatments, and the treatments were
arranged in a completely randomized experimental
design.
Knockdown (the inability of the bed bug to right
itself or move in an upright deliberate manner) and
recovery (process leading to restoration from
knockdown) were determined by counting numbers
of knocked down insects in each cup at 5, 15, 30, 45,
60, 120, and 240 min after treatment. Mortality (no
movement on being probed) was assessed as
numbers of dead insects at 1, 2, 3, and 4 days
following treatment.
The knockdown, recovery, and mortality assays
were each analyzed using one-way ANOVA and using
repeated measures with treatment and time as factors
and a treatment × time interaction (Analytical
Software, 1998). Mean separations were
accomplished with Tukey’s HSD (P < 0.05)
(Analytical Software, 1998). Because normality and
homogeneity of variance assumptions were not
violated, data were not log (x + 1)-transformed before
analyses.
RESULTS
Knockdown effects were detected (F = 21.95, df
= 76, 384, P < 0.0001). Within the first 5 min
CedarCide, EcoSmart, and Bonide caused complete
knockdown and similar results were obtained with
Orange Guard, Natria, Cirkil, and D-Force (Fig. 1)
(Table 1). RestAsure and Essentria achieved 52%
and 48% knockdown, but CimeXa failed to cause
more knockdown than the negative control
throughout the assay (Fig. 1). The most potent
knockdown-inducing products at 5 min maintained
high efficacy levels for the rest of the 4-h-long
knockdown assessment, and knockdown in the
Essentria treatment increased from 48 to 92% by 15
min (Fig. 1). Although knockdown in the Natria
treatment was not statistically different from complete
knockdown, it declined from a peak of 66% at 5 min
to 60% at 15 min and to 52% by 30 min (Fig. 1).
Similarly, RestAsure did not statistically differ at each
sampling time from the products that were>90%
effective and knocked down only 60% of the
cimicids (Fig. 1). Repeated measures detected a
treatment effect (F = 24.45, df = 10, 384, P < 0.0001),a
time effect (F = 6.04, df = 6, 384, P < 0.0001) occurred
between 5 and 15 min, and a treatment × time
interaction was detected (F = 7.35, df = 60, 384, P <
2015 Donahue et al.: Effect of natural products on cimicidae 111
0.0001). Three nonconventional insecticides
achieved > 90% knockdown within 5 min, one did so
within 15 min, and Orange Guard maintained 78%
knockdown throughout the 4-h-long assay (Table 1).
Recovery from knockdown did not occur in the
CedarCide, Essentria, EcoSmart, and the two
pyrethroid treatments, and it did not rise above 10%
in any of the other treatments that caused
knockdown (Fig. 1). Although treatment differences
were detected (F = 2.03, df = 32, 164, P = 0.0029),
Tukey’s HSD did not identify which means were
involved. Similarly, repeated measures detected
treatment differences (F = 2.18, df = 10, 164, P =
0.0375) that were not clarified by Tukey’s HSD. Time
did not affect recovery and a treatment × time
interaction was not detected.
Treatment influenced mortality (F = 17.55, df =
43, 219, P < 0.0001) during the 4-d sampling period
after the insecticides were applied. All of the
insecticides killed more cimicids than died in the
negative control (Table 2), but only CedarCide
caused 100% mortality and it did so by the end of
the first day (Tables 1 and 2). Essentria, Cirkil,
CimeXa, Bonide, and D-Force resulted in > 90%
mortality on the first day, and EcoSmart and Orange
Guard caused 88 and 76% mortality, respectively
(Tables 1 and 2). Natria and RestAsure killed 42%
and 46% of the cimicids on the first day, and neither
of them killed more than 52% by the end of 4 day
(Table 2). Mortality in the Orange Guard treatment
increased by 18.4% during the 4 day, becoming 87.5
and 73.1% more effective than Natria and RestAsure,
respectively (Table 2). Repeated measures detected
treatment differences (F = 19.42, df = 10, 219, P <
0.0001) resulting from the relatively low mortality in
the Natria and RestAsure treatments, and in the
negative control. Time effects (F = 11.89, df = 3,
219, P < 0.0001) occurred between the second and
third day when overall mortality increased by 3.9%.
A treatment × time interaction was detected (F =
2.43, df = 30, 219, P = 0.0003).
DISCUSSION
Desirable insecticides for cimicid control in the
home, hotels, and other locations where humans are
likely to encounter them will rapidly (within minutes)
halt biting activity and, possibly more slowly,
eliminate the pest. The two goals, knockdown and
elimination, can be accomplished separately and by
different means, or at the same time using one or
more insecticide. Elimination can occur in hours,
days, or weeks depending on the scale and
complexity of the infestation, and it can be achieved
by repellency (mainly aims to completely avert biting)
or mortality. Although neurotoxic pyrethroid
insecticides (Vijverberg and van den Bercken, 1990),
such as permethrin, are known for achieving rapid
knockdown and for their lethality to C. lectularius,
resistance has become increasingly problematic
Fig. 1. Mean (± SE) C. lectularius knockdown
at time intervals to 4 h (n = 5 replicates, one-way
ANOVA, Tukey’s HSD; a-d is abcd) for A) six
nonconventional insecticides and B) two
nonconventional insecticides, two pyrethroids, and
a control comprised of water (A and B data analyzed
together but presented separately to enhance
clarity).
0
2
4
6
8
10
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a
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a-d a-d a-d
a-d
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bcd
a-d
a-da-d
a-d
a-d
a-d
e
bcd
a-d a-d
a-d
a-d
a-d
a-d
Cirkil
CedarCide
Natria
RestAsure
CimeXa
Orange Gua rd
A. T reatmen ts
Mean no. C. Lectularius knocked down
Minutes
0
2
4
6
8
10
515 30 45 60 120 24
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D-Force at 5, 15, 30, and
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B. Treatments
Essentria
EcoSmart
Bonide
D-Force
Nega tive control
Mean no. C. Lectularius knocked down
112 Biopesticides International Vol. 11, no. 2
(Romero et al., 2007; Davies et al., 2012; Koganemaru
and Miller, 2013). When treating structures and
surfaces, effective cimicid control products should
also provide sufficient residual effects to continue
eliminating the pest over a substantial period of time
(weeks, months) following application (Hinson et al.,
2014) because cimicids are difficult to locate and
eliminate with low-residual direct sprays (Romero et
al., 2009). Commercial nonconventional insecticides
are available for purchase but few have been
compared in terms of efficacy, particularly products
with different modes of action.
The insecticides we tested contain different
active ingredients, some have different modes of
action, and a few have different active ingredients
and modes of action within the same product. Neem-
based products, such as Cirkil, often involve a variety
of bioactive compounds (e.g., salannin, salannol,
nimbinen, gedunin, and dirachtin derivatives)that can
induce a variety of insecticidal effects (e.g., growth
regulation, repellency, mortality from direct contact
and exposure to volatiles, sublethal reproductive
inhibition) against arthropods (Jones et al., 1989;
Schmutterer, 1990, 1995; Walter, 1999; Showler et al.,
2004; Greenberg et al., 2005). A commercial product
containing 70% clarified hydrophobic extract of neem
oil, however, was found to have negligible efficacy
against cimicids (Hinson et al., 2014). The strong
efficacy of neem-based Cirkil suggests that it has a
different blend of bioactive components.
RestAsure’s proprietary mixture of active
ingredients sodium laurel sulfate, sodium chloride,
and potassium sorbate are intended to repel,
desiccate, and kill, respectively. The active
ingredients have not been well established as
insecticides and potassium sorbate is best known
as an antibacterial and antifungal agent for
preserving food (Nikolov and Ganchev, 2011), and
sorbic acid was reported to have an insecticidal effect
in stored products (Dunkelet al., 1984; Dunkel and
Read, 1991).
A variety of essential oils have shown pest
control properties (Koul et al., 2008). Essentria’s 2-
phenethl propionate and two botanically-based
essential oils are indicated by the label as being an
octopamine blocker and repellent, and EcoSmart
contains 2-phenethyl propionate and four
botanically-based essential oils. The precise modes
of action of the various essential oils are not always
clear, but most essential oils are neurotoxic, involving
Table 1. Mean (± SE) peak percentage knockdown and mortality and time at which the peak was first
observed
TreatmentaKnockdown (%) Minutes Mortality (%) Hours
Orange Guard 82.0 ± 11.9 15 72.0 ± 16.2 96
CedarCide 100 5 100 24
Essentria 92.0 ± 5.8 15 94.0 ± 6.0 24
EcoSmart 100 5 96.0 ± 2.2 72
Natria 66.0 ±15.1 5 42.0 ± 12.8 24
RestAsure 60.0 ±15.1 15 56.0 ± 16.3 72
Cirkil 98.0 ±2.0 5 98.0 ± 2.0 24
CimeXa 34.0 ± 8.7 240 98.0 ± 2.0 24
Bonide 100 5 78.0 ± 17.4 24
D-Force 98.0 ±2.0 5 98.0 ± 2.0 24
Control 0 n/a 0 n/a
aOrange Guard, a.i.,d-limonene (5.8%); Natria Home Pest Control a.i., soy bean oil and eugenol (0.25%); RestAsure
a.i., sodium laurel sulfate, sodium chloride, and potassium sorbate (proprietary mixture); CedarCide a.i., cedar oil (5-
20%) and hydrated silica (80-95%); Essentria Broadcast Insecticide a.i., 2-phenethyl propionate (3%), rosemary oil
(1.5%), and peppermint oil (2%); EcoSmart Organic Home Pest Control a.i., 2-phenethyl propionate (2%), clove oil
(1%), rosemary oil (1%), peppermint oil (1%), and thyme oil (0.5%); Cirkil a.i.,neem oil (5.5% cold pressed neem oil);
CimeXa a.i., silica gel (100%); Bonide Bedbug Killer a.i., permethrin (0.5%) positive control; D-Force a.i., deltamethrin
(0.6%) positive control; water, negative control.
2015 Donahue et al.: Effect of natural products on cimicidae 113
acetylcholinesterase inhibition, competitive
obstruction of octopaminergic receptors, or
interference with GABA-gated chloride channels
(Mann and Kaufamn, 2012). Eugenol, from cloves
and other botanical sources, in Natria acts on
octopaminergic receptors (Khanikor et al., 2013) and
it has repellent knockdown and lethal effects on a
variety of herbivorous and phlebotomous arthropods
(Bhatnagaret al., 1993, Cornelius et al., 1997, Lee et
al., 1997, Obeng-Ofori and Reichmuth, 1997; Isman,
2000; Hummelbrunner and Isman, 2001; Thorsell et
al., 2006; Hieuet al., 2010; Velazquez et al., 2011b).
Peppermint, another essential oil, is mainly used in
arthropod control as a repellent (Thorsell et al., 2006;
Mkolo et al., 2011; Hieu et al., 2012), and rosemary
has been reported as being toxic to arthropods
(Velazquez et al., 2011a). Orange Guard’s d-limonene,
from citrus oil, destroys the wax coating of arthropod
respiratory systems and has been shown to kill a
variety of arthropods and to inhibit egg hatching in
some, including ticks (Coates et al., 1991; Lee et al.,
1997; Hummelbrunner and Isman, 2001; Raina et al.,
2007; Ferrarini et al., 2008). A commercial cimicid
control product with active ingredients clove oil,
peppermint oil, and sodium lauryl sulfate produced
100% cimicid mortality in 7–14 days depending on
the insect strain (Hinson et al. 2014). Another
commercial product with geraniol, cedar oil, and
sodium lauryl sulfate caused 92.5% cimicid control
in apartment buildings (Wang et al., 2014). A
different commercial product with phenethyl
propionate, soybean oil, and clove oil only provided
45% control in a chicken house (Goddard and
Mascheck, 2015). Cedar oil in CedarCide blocks
respiration and has neurological effects, including
toxicity and repellency (Panella et al., 1997; Dolan et
al., 2007), and some other essential oils, if delivered
in sufficient doses, can in the same way affect
respiration. Another commercial product containing
10% cedar oil, also provided 100% cimicid mortality,
within 1 h (Hinson et al., 2014). Soybean oil in Natria,
like most oils on arthropods, can also block
respiration (Bográn et al., 2006).
CimeXa, a dust formulation, destroys the waxy
Table 2.Mean (± SE) numbers of C. lectularius killed by contact (spray) application of eight natural product-
based and two pyrethroid insecticides after 1–4 days
Treatmenta Mortalityb
Days post treatment
123 4
Orange Guard 7.6 ± 1.2a-e 8.0 ± 1.0a-e 8.2 ± 0.9a-e 9.0 ± 0.5a-c
CedarCide 10a 10a 10a 10a
Essentria 9.4 ± 0.6a,b 9.4 ± 0.6a,b 9.4 ± 0.6a,b 9.4 ± 0.6a,b
EcoSmart 8.2 ± 0.4a-d 8.8 ± 0.4a-d 9.6 ± 0.2a,b 9.6 ± 0.2a,b
Natria 4.2 ± 1.3e,f 4.2 ± 1.3e,f 4.6 ± 1.2e 4.8 ± 1.4e,f
RestAsure 4.6 ± 0.6e 4.8 ± 1.5d,e 5.6 ± 1.6b-e 5.2 ± 1.6c-e
Cirkil 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a
CimeXia 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a
Bonide 9.6 ± 0.4a,b 9.4 ±0.4a,b 9.4 ± 0.4a,b 9.4 ± 0.4a,b
D-Force 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a 9.8 ± 0.2a
Control 0g 0g 0.4 ± 0.4fg 0.4 ± 0.4fg
aOrange Guard, a.i., d-limonene (5.8%); Natria Home Pest Control a.i., soy bean oil and eugenol (0.25%); RestAsure
a.i., sodium laurel sulfate, sodium chloride, and potassium sorbate (proprietary mixture); CedarCide a.i., cedar oil (5-
20%) and hydrated silica (80-95%); Essentria Broadcast Insecticide a.i., 2-phenethyl propionate (3%), rosemary oil
(1.5%), and peppermint oil (2%); EcoSmart Organic Home Pest Control a.i., 2-phenethyl propionate (2%), clove oil
(1%), rosemary oil (1%), peppermint oil (1%), and thyme oil (0.5%); Cirkil a.i.,neem oil (5.5% cold pressed neem oil);
CimeXa a.i., silica gel (100%); Bonide Bedbug Killer a.i., permethrin (0.5%) positive control; D-Force a.i., deltamethrin
(0.6%) positive control; water, negative control.
bValues followed by different letters are significantly different (P < 0.05), one-way ANOVA, Tukeys HSD.
114 Biopesticides International Vol. 11, no. 2
cuticle of the cimicid, resulting in dehydration
(Akhtar and Isman, 2013; Goddard and Maschek,
2015). Although cimicid control in a chicken house
reached only 46% when diatomaceous earth mixed
with the neonicotinoid insecticide dinotefuran was
used, CimeXa provided 100% control within 24 h
(Goddard and Mascheck, 2015). Because effective
dust-based desiccant products are not affected by
residue aging, Anderson and Cowles (2012)
concluded that they were superior to sprayable
pyrethroid products for cimicid control.
We found that Cirkil, CedarCide, Orange Guard,
Essentria, EcoSmart were as effective or nearly as
effective as the two pyrethroids, Bonide and D-Force,
in terms of achieving > 80% knockdown within 15
min and maintaining that level for the 2-h duration
of the knockdown assay. The same five
nonconventional insecticides achieved > 90% cimicid
mortality within 4 days, hence, all five were as
effective for knockdown and elimination as the
pyrethroid positive controls. The five
nonconventional products involved neem oil, cedar
oil, d-limonene, 2-phenethyl propionate, rosemary oil,
peppermint oil, clove oil, and thyme oil. Hence,
certain essential oils, neem constituents, and 2-
phenethyl propionate, which have a variety of modes
of action (e.g., octopamine receptor inhibition,
possibly other neurotoxic effects, and respiratory
interference or blockage can induce rapid knockdown
and relatively high mortality within days). Natria’s
and RestAsure’s moderate knockdown (50–60% with
relatively great variability) and 40–50% lethality
indicates that the eugenol, soybean oil, sodium lauryl
sulfate, sodium chloride, and potassium sorbate were
not sufficient for adequate knockdown and mortality
at the dosages and in the formulations used.
Repeated measures showed that in terms of
knockdown, Natria and RestAsure averaged 32 to
42.5% less, and mortality averaged 46.3 to 50% less,
than the more efficacious conventional and
nonconventional products, and that knockdown for
most products occurred within the first 15 min. While
CimeXa only caused negligible knockdown, it was
highly effective for killing bedbugs within 24 h.
Similarly, repeated measures showed that mortality
mainly occurred within 24 h and that there was a
slight (4%) average increase between the second and
third post-treatment days. Within the parameters of
our study, Cirkil, CedarCide, Orange Guard, Essentria,
and EcoSmart were best for rapid knockdown and
elimination, but CimeXa provided effective control
in one day absent rapid knockdown.CimeXa, and
other similarly effective dust-based products, might
gain a rapid knockdown effect by combining it with
another insecticide with strong knockdown capability.
Because this study involved contact knockdown
and lethal effects within a maximum of 4 days, the
full extent of possible effects of the tested products
were not measured. Neem, for example, can contain
many bioactive compounds (Jones et al., 1989;
Schmutterer, 1990, 1995; Walter, 1999) whose effects
were not observed in the context of the study.
Azadirachtin, the most widely recognized active
ingredient of neem-based insecticidal products, is
mostly regarded as an insect growth regulator that
affects insects during molts or other transitions in
developmental stages (Schmutterer, 1990, 1995;
Kraiss and Cullen, 2008), hence, Cirkil might not have
shown its full potential for eliminating cimicids.
Residual effects from contact with treated surfaces
were also not measured, nor was the contribution of
repellency to control, and horizontal transmission of
powder and botanical-based nonconventional
insecticides at aggregations has been shown to occur
in cimicids (Akhtar and Isman, 2013). Finally,
sublethal effects that might hinder reproduction (e.g.,
reduce fecundity, decrease egg hatch from treated
parent insects) were not considered. Some factors
that might have negatively influenced efficacy under
natural conditions were also not tested. As examples,
aggregation can reduce mortality from some
insecticides (Benoit et al., 2007), and long-term
effects of population dynamics can rekindle and
reintroduce problematic infestations (e.g.,
infestations can originate from a single mated female)
(Booth et al., 2012; Hinson et al., 2014).
The nonconventional products Orange Guard,
CedarCide, Essentria, EcoSmart, and Cirkil, displayed
the knockdown and elimination capabilities of a
desirable cimicid insecticide when applied as direct
contact sprays. Based on the active ingredients of
each product, d-limonene, cedar oil, and cold pressed
2015 Donahue et al.: Effect of natural products on cimicidae 115
neem oil were each effective. Because Essentria and
EcoSmart are blends of essential oils and specific
bioactive chemicals, the relative contributions of 2-
phenethyl propionate, rosemary oil, peppermint oil,
clove oil, and thyme oil to knockdown and mortality
were not established. A sixth nonconventional
product, CimeXa, comprised of silica gel, was
effective at eliminating the pest within a single day.
It is possible that the multiple modes of action of
most of the nonconventional products we tested,
some sufficiently benign to be exempt from EPA
registration, will delay or prevent the development
of resistance commonly associated with conventional
insecticides.
Acknowledgments. We thank Alameda County
Vector Control Services District, Department of
Environmental Health for financial assistance, and
Blake Wilson for critical review of an earlier draft.
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Accepted 2 December 2015
... fenitrothion) (Leong et al. 2020a). Other investigations have also found similar poor performance of commercial products for both C. lectularius , Donahue et al. 2015, Hinson et al. 2017) and C. hemipterus (Leong et al. 2020b). These findings suggest that existing commercial products based on synthetic chemicals face challenges in managing insecticide resistance in tropical bed bugs and that alternative approaches are needed to address this issue. ...
... As a result, product formulations are critical in enhancing the efficiency of essential oil products against pest insects apart from the active ingredients. Cedarcide also showed a quick knockdown effect within 5 min in a previous study against C. lectularius (Donahue et al. 2015). Moreover, Cedarcide was the only pesticide that achieved 100% mortality on the first day of treatment when compared with other insecticides (Orange Guard, Essentria, EcoSmart, Natria, RestAsure, Cirkil, CimeXa, Bonide, and D-Force) (Donahue et al. 2015). ...
... Cedarcide also showed a quick knockdown effect within 5 min in a previous study against C. lectularius (Donahue et al. 2015). Moreover, Cedarcide was the only pesticide that achieved 100% mortality on the first day of treatment when compared with other insecticides (Orange Guard, Essentria, EcoSmart, Natria, RestAsure, Cirkil, CimeXa, Bonide, and D-Force) (Donahue et al. 2015). Apart from Cedarcide, EcoSMART, which contains 2-Phenethylpropionate (PEP) that targets the octopamine receptor in fruit flies (Enan 2005), also proved effective against a moderately permethrin-resistant strain of C. lecturarius (Donahue et al. 2015). ...
Article
Insecticide resistance is widespread in global bed bug populations. Both common bed bugs and tropical bed bugs are pyrethroid-resistant among most field populations. Plant-based products and nonconventional pesticides offer minimal-risk strategies for managing bed bug resistance, but this strategy has yet to be formally evaluated in Cimex hemipterus (F.) (Hemiptera: Cimicidae). Here, several commercial plant-based formulations (Cedarcide, EcoRaider (also known as EcoVenger), EcoSMART, and Bio-D), a novel product, Provecta, and a pyrethroid insecticide, Pesguard FG161 were tested against pyrethroid-susceptible and resistant strains of C. hemipterus using direct spray, residual exposure, and egg dipping assays. Direct spray treatments outperform residual applications against all tested bed bug strains. Cedarcide exhibits the highest consistency in eliminating bed bugs, followed by EcoRaider, EcoSMART, and Provecta that outperform Bio-D and Pesguard FG161. In comparison to Pesguard FG161, all plant-based insecticide products and Provecta showed higher efficacy against pyrethroid-resistant strains. Although effective, product efficacy varies in terms of speed. Cedarcide kills all bed bugs within 1 min after spraying; however, other products can take up to 9 days to achieve 100% mortality. The efficacy of all products was reduced when evaluated on fabric surface (42%–65% mortality). Cedarcide and EcoRaider reduced egg hatchability by 37%–73% and 47%–70%, respectively. This study suggests that certain plant-based insecticides and an unconventional insecticide can serve as alternative direct spray treatments for managing tropical bed bugs, though their residual effects are limited.
... Silica aerogels are pesticide free, non-toxic to mammals, most effective against pesticide resistant species and stable at low and high temperatures [52,53]. Various types of silica aerogels-based insecticides (Table 3) [32,33,41,50,[61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80] are used for the control of ants, silverfish, fleas, mosquitoes, cockroaches, crickets, bedbugs, thrips, spiders, house flies, wasps and stored grain insect pests in stores, homes, hotels, restaurants, theaters, schools, hospitals and other places where food and human beings are present [33,44,50,[54][55][56][57][58]. SG-68 is very light and fluffy silica aerogel as well as SG-67 which is commercially available in the trade name of Dri-Die 67 ® is similar to SG-68. ...
... CimeXa is a silica aerogel-based dust which causes dehydration in insects [81,82]. It is considered very lethal to bed bugs and provides efficient control than the pyrethroid insecticides [61,75]. The bedbugs exhibited 100% mortality within 24 hours when the dust products such as Tempo dust, Drione and Syloid 244 (Silica aerogel) were applied to mattress and hardboards. ...
... It has also been reported that sorptive dusts were more efficient than abrasive materials [63]. Table 3 Types of commercially available silica aerogel-based insecticides and their targeted insect pests [32,33,41,50,[61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80]. ...
Chapter
Full-text available
Aerogels, composed of complex network of interlinked nanostructures, show 50% non-solid volume. Due to their unique properties, they are used as a carrier for active ingredients used to control agricultural pests as well as veterinary medicines. They can also be used as a carrier material for the application of entomopathogenic bacteria and viruses for the biological control of pests. Many aerogel-based formulations of herbicides, insecticides, acaricides, fungicides, bactericides, rodenticides, nematicides, piscicides and molluscicides effectively control the target pests. Practically, aerogels enhance the effectiveness of insecticides by increasing their penetrations. Furthermore, intensive research is required to develop latest aerogel-based pesticides with better utilization under effective integrated pest management programs in agriculture.
... CimeXa, a commercial silica gel-based desiccant dust, is more effective against bed bugs, Cimex lectularius (L.), than pyrethroidbased sprays (Benoit et al. 2009, Anderson and Cowles 2012, Donahue et al. 2015, Aak et al. 2016. The product also killed more larval and nymphal A. americanum than kaolin clay desiccant dustbased Surround WP, achieving 100% mortality within 24 h in the laboratory (Showler et al. 2018). ...
... Commercially available silica gel-based desiccant dust insecticides are used for controlling C. lectularius; CimeXa is more lethal than pyrethoid-based insecticides, albeit slower acting (Benoit et al. 2009, Anderson and Cowles 2012, Donahue et al. 2015, Aak et al. 2016. Silica gel-based desiccant dusts are also lethal against parasitic dipterans, including the North American malaria mosquito, Anopheles quadrimaculatus Say, southern house mosquito, Culex quinquefasciatus Say, yellow fever mosquito, Aedes aegypti (L.) (Micks 1960), and horn flies, Haematobia irritans irritans (L.) (Dorsey et al. 1966;A. ...
... Reduced need for frequent treatments with inert desiccant dust-based insecticides has the additional advantage of being likely to minimize re-entry into sensitive habitats with application equipment, decreasing both economic and environmental costs. Disadvantages of desiccant dusts include action that is slower than chemical toxins (Donahue et al. 2015), although mortality was complete against A. americanum larvae and nymphs by the 2-and 4-h sampling times, respectively, and complete mortality within hours was also reported by Showler et al. (2018Showler et al. ( , 2020a. While some desiccant dusts were associated with avoidance behavior by the red flour beetle, Tribolium castaneum (Herbst) (Ebeling 1995), deterrence of ixodids is not likely to be a negative feature because treatment of vegetation is anticipated to be directed as spot treatments against detected populations (Showler and Pérez de León 2020) (larvae are usually found in clusters, having emerged from a point-source egg mass). ...
Article
Ixodids (hard ticks) ingest blood from host animals, and they can transmit pathogenic organisms that induce medical and veterinary diseases. As resistance to synthetic conventional acaricides becomes more common, alternative tactics are coming under heightened scrutiny. Laboratory bioassays were used to assess the efficacy of CimeXa, a commercially available silica gel desiccant dust product, and Drione, a commercial product containing silica gel + pyrethrins and a synergist, piperonyl butoxide, against lone star tick, Amblyomma americanum (L.) (Ixodida: Ixodidae), larvae and nymphs. Both life stages were completely killed by CimeXa by 24 h, and Drione caused total larval mortality within 1 h when they were briefly immersed in the dusts and when they crawled across dust-treated substrate; nymphs were completely killed by 4 h after the same kinds of exposure. Mortality of A. americanum larvae and nymphs occurred after the pests crawled across dried aqueous suspensions of the products, but this was not as efficient and fast-acting as when the immature life stages were exposed to dry dusts. Further, dried aqueous suspensions of Drione were not substantially more lethal than dried aqueous suspensions of CimeXa. CimeXa and Drione will provide prophylactic control on vegetation and animals for as long as the silica gel remains without being physically removed. Both of the dust-based products will likely also be effective against other problematic ixodid species. Advantages and disadvantages, and potential uses, of desiccant dust-based acaricides are discussed.
... CimeXa is a silica aerogel-based commercial product that induces dehydration of arthropods by destroying their protective wax cuticle (Akhtar andIsman 2013, Goddard andMascheck 2015). The product is as lethal to bed bugs, Cimex lectularius (L.), as commercially marketed deltamethrin-and permethrin-based insecticides (Donahue et al. 2015), and diatomaceous earth mixed with the neonicotinoid dinotefuran (Goddard and Mascheck 2015). Dust-based desiccant products are more effective better than pyrethroid sprays (Anderson andCowles 2012, Donahue et al. 2015) for bed bug control. ...
... Silicon has mostly been used in agriculture as soil amendments to strengthen cell walls of plants, increasing their resistance to crop pests (Ukwungwu and Odebiyi 1985;Meyer 2002, 2003;Laing et al. 2006). Some applications of silica-based materials for insect control have been aimed against medical and veterinary pests such as bed bugs, C. lectularius (L.) (Donahue et al. 2015); the North American malaria mosquito, Anopheles quadrimaculatus Say, the southern house mosquito, Culex quinquefasciatus Say, and the yellow fever mosquito, Aedes aegypti (L.) (Micks 1960); horn flies, Haematobia irritans irritans (L.) (Dorsey et al. 1966); the poultry red mite, Dermanyssus gallinae (De Geer) (Schulz et al. 2014); the tropical rat mite, Ornithonyssus bacoti (Hirst) (Ebeling 1960); and deer tick, Ixodes scapularis Say, nymphs (Allan and Patrican 1994), all of which were effective by killing through desiccation. In laboratory bioassays and on vegetation in a natural habitat, CimeXa was effective at reducing ixodid larvae and nymphs (Showler et al. 2018). ...
Article
Ixodid ticks vector pathogens of humans, livestock, and wildlife, and occur in tropical and temperate regions worldwide. We used the lone star tick, Amblyomma americanum (L.) (Ixodida: Ixodidae), as a model for other ixodid species, including the southern cattle fever tick, Rhipicephalus (Boophilus) microplus (Canestrini) (Ixodida: Ixodidae). We assessed the lethality of CimeXa, an inert silica-based desiccant dust, and Drione, a silica-based desiccant dust with pyrethrin and piperonyl butoxide (PBO), against A. americanum larvae and nymphs on calves. CimeXa was highly lethal to larvae released onto shaved calf skin 72–96 h previously, and moderately toxic to nymphs. It did not affect immature life stages treated after they began feeding because desiccation was offset by ingestion of blood. Being inert, CimeXa can protect cattle from infestation before feeding occurs for a potentially indefinite period of time. Drione killed immatures within 24 h when released on treated skin and when applied to feeding ixodids because of the pyrethrin and PBO (PBO will also reduce resistance to pyrethrin if it develops). When CimeXa was applied to calves with the hair intact, ≈90% and ≈70% of A. americanum larvae and nymphs, respectively, were killed within 24 h and Drione killed 100% of each life stage. Drione also prevented and drastically reduced egg production and hatching. While CimeXa protects against infestation by immatures, Drione will also control ticks that are feeding. When pyrethrin and PBO in Drione eventually degrade, the silica aerogel carrier can continue to protect against infestation indefinitely.
... CimeXa, a finely divided silica aerogel powder, rapidly adsorbs the tick's wax layer, and it can also increase plant tolerance to pest infestation when applied to amend and improve soil texture and properties, which results in strengthening plant cell walls. Meyer 2002, 2003;Laing et al., 2006;Donahue et al., 2015;Showler and Harlien 2018). Ali (2016) reported that Particle film technology is a new technique to control for insects and diseases. ...
Research
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Two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is a great economic importance in Egypt that causing considerable damage to many crops. Some silicon formulations as kaolin, bentonite, aglev Si 300 & diatom as powder formulations, different forms of liquid formulation for potassium silicate and palmito formulation (plant extracts) as standard, were examined against Tetranychus urticae under laboratory conditions. The toxicity effect on adult females was determined. Also, acaricidal effects on some biological aspects of Tetranychus urticae were studied. The results demonstrated that the percentage of mortality increased as the concentration increase. palmito, diatom and kaolin gave the highest mortality rates followed by aglev Si 300, while the least effect found in bentonite on T. urticae adult females. The obtained results revealed that the best treatment for the rate of laying eggs at 100 % concentration was potassium salt for liquid formulations, diatom and aglev Si 300 for powder formulations. In general, liquid formulations were more effective on the oviposition rate for treated females than powder formulations. In egg incubation treatment, kaolin (100% conc.) gave the longest incubation period with an average (4.8 days), while the lowest average (3.4 days) was recorded with bentonite (75% conc.), which is the same rate as was found in the control. The best treatment for the egg hatch rate was bentonite (100% conc.), while the least effect was recorded with Kaolin (50% conc. Accordingly to the results of egg period, the best treatments were si El-Ghanem (100% conc.), bentonite (100% conc.), bentonite (75% conc.) and aglev Si 300 (100% conc.). The best treatments of larva period were bentonite (100% conc.), aglev Si 300 (100% conc.), diatom (100% conc.) and diatom (75% conc.). The present study revealed that some silicon formulations, such as diatom, kaolin, aglev Si 300, si El-Ghanem, kaolinated potassium silicate and potassium salt can be used alternatively as acaricides for potential mite management in integrated crop management.
... Although toxin-augmented desiccant dusts cause complete mortality in A. americanum larvae and nymphs within several hours, silica gel-and diatomaceous earth-based desiccant dusts still achieve 100% mortality within 24 h. In contrast with liquid contemporary, commonly used conventional synthetic insecticides (e.g., pyrethroids), CimeXa required additional hours to induce substantial C. lectularius mortality; on the other hand, CimeXa was one of the most efficacious pesticides assessed for C. lectularius control (Donahue et al. 2015). Exposure of larval and nymphal A. americanum to CimeXa in the laboratory caused 100 and 98% mortality, respectively, within 24 h . ...
Article
As resistance in economically and medically important ixodids (hard ticks, Ixodida: Ixodidae) to conventional synthetic toxin-based acaricides has become increasingly widespread, research efforts to identify alternative control tactics have intensified. Laboratory bioassays on the lone star tick, Amblyomma americanum (L.), as a model for other ixodid species, were conducted to assess the efficiency of Imergard WP perlite-based dust versus CimeXa, a silica gel-based insecticidal product that is highly effective against ixodid larvae and nymphs. Each of the two inert desiccant dusts immobilized A. americanum larvae and nymphs within 4–6 h, and killed 100% of the ixodids by 24 h after contact by brief immersion in dry dusts, and after they crawled ≈7.3 cm across a filter paper disc treated with the dusts. Contact by crawling on a dried aqueous film of the dusts, however, did not immobilize and kill the ixodids by 24 h. Similar to silica gel-based desiccant dust, dry perlite-based Imergard WP dust might prophylactically protect cattle and other animals from medically and agriculturally important ixodid pests. Perlite can potentially be stored indefinitely, it can retain its lethal properties for as long as adequate amounts remain on a substrate, and it might be acceptable for limited application in environmentally sensitive habitats.
... Silicon, the principal active ingredient in CimeXa, has been used to increase the resistance of crops against some pests when applied as a soil amendment to strengthen plant cell walls (Ukwungwo and Odebiyi 1985;Meyer 2002, 2003;Laing et al. 2006). Direct applications of silica-based materials against arthropod pests have involved those of medical and veterinary importance such as bed bugs, Cimex lectularius (L.) (Donahue et al. 2015); the North American malaria mosquito, Anopheles quadrimaculatus Say, the southern house mosquito, Culex quinquefasciatus Say, and the yellow fever mosquito, Aedes aegypti (L.) (Micks 1960); the poultry red mite, Dermanyssus gallinae (De Geer) (Schulz et al. 2014); the tropical rat mite, Ornithonyssus bacoti (Hirst) (Ebeling 1960); and deer (or black-legged) tick, Ixodes scapularis Say, nymphs (Allan and Patrican 1994); and lone star tick, Amblyomma americanum L., larvae, and nymphs in the laboratory, on vegetation in natural field conditions, and on cattle Harlien 2020). CimeXa, a finely divided silica aerogel powder, rapidly adsorbs the tick's wax layer into a voluminous matrix of pores present in the finely divided particles . ...
Article
The horn fly, Haematobia irritans irritans (L.) (Diptera: Muscidae), is an important bloodsucking ectoparasite of cattle throughout much of the world. The fly is mostly controlled using conventional synthetic insecticides but as concerns about resistance increase, alternative tactics have come under heightened scrutiny. Four desiccant dust products: Surround WP, a kaolin clay-based wettable powder; CimeXa, comprised of silica aerogel; Drione, silica aerogel + pyrethrins; and EcoVia, silica aerogel + thyme oil, were assessed for their lethal effects against horn fly eggs, larvae, pupae, and adults, under laboratory conditions. Although Surround WP and CimeXa did not prevent egg hatching and (when mixed with manure substrate) pupal development, the two products were associated with moderate reductions of emerged adults, and with complete adult contact mortality within 6 hr and 24 hr, respectively. Drione and EcoVia eliminated egg hatching, pupal development, and adults within 15 min to 1 hr, respectively, whether the flies were exposed to treated filter paper substrate or exposed by immersion in the dusts. Implications for horn fly control and advantages of inert desiccant dust formulations are discussed.
... In another laboratory study, CimeXa insecticide dust at the label rate produced 100% mortality in highly pyrethroid-resistant and insecticide-susceptible strains of bed bugs within 3-4 days [21]. Ninety-eight percent mortality was achieved after 1 day when silica gel dust, in a water solution, was applied to bed bugs that were moderately resistant to pyrethroids [22]. Forced exposure to silica gel dust, at a dose of 1.34 mg/cm 2 , caused > 95% bed bug mortality within 1 day [23]. ...
Article
Full-text available
Bed bug resistance to commonly used pesticide sprays has led to exploring new pesticides and other strategies for bed bug management. Non-chemical methods are effective in bed bug management; however, they do not provide residual protection. Compared to insecticide sprays, dust formulations are considered to provide longer residual control. We evaluated two bed bug management programs in apartment buildings. A building-wide inspection was initially conducted to identify bed bug infested apartments. Selected apartments were divided into two treatment groups: non-chemical plus silica gel dust treatment (10 apartments) and non-chemical treatment (11 apartments). After initial treatment, apartments were re-visited monthly for up to 6 months. During each visit, the total bed bug count per apartment was obtained by examining interceptor traps placed in the apartments and conducting a visual inspection. Mean bed bug count was reduced by 99% and 89% in non-chemical plus silica gel dust and non-chemical treatment, respectively. Non-chemical plus silica gel dust treatment caused significantly higher bed bug count reduction than the non-chemical treatment at 6 months. Bed bugs were eradicated from 40% and 36% of apartments treated with non-chemical plus silica gel dust treatment and non-chemical treatment, respectively.
... Studies have found that diatomaceous earths took up to 6 d to achieve 100% mortality in adult C. lectularius (Doggett et al. 2012, Agnew andRomero 2017). Compared against liquid formulations of conventional synthetic insecticides, such as pyrethroids, CimeXa, took hours longer to cause significant C. lectularius mortality, but it was also one of the most efficacious in terms of its lethality (Donahue et al. 2015). When A. americanum larvae and nymphs were exposed to CimeXa in the laboratory, 100 and 98%, respectively, mortalities were achieved within 24 h, and under windy field conditions, A. maculatus larvae and nymphs were reduced on vegetation by 94 and 100%, respectively, when the infested plants were examined 24 h after being dusted (Showler et al. 2018). ...
Article
With increasing development of resistance to conventional synthetic acaricides in economically and medically important ixodid species, interest in finding alternative control tactics has intensified. Laboratory bioassays were conducted, using the lone star tick, Amblyomma americanum (L.), as a model species, to assess the efficacy of a diatomaceous earth-based product, Deadzone, in comparison with a silica gel-based product, CimeXa. CimeXa is already known to be highly lethal against A. americanum larvae and nymphs. The two dust treatments were 100% effective against larvae and nymphs within 24 h after contact occurred by immersion in dry dusts and after crawling across a surface treated with the dry dusts. Contact by crawling on a dried aqueous film of the dusts, even at a concentration of 10%, was not as effective as exposure to the dusts in dry powder form. As has been demonstrated with CimeXa, it is likely that Deadzone will be capable of providing prophylactic protection of cattle from economically important one-host ixodids, such as the southern cattle fever tick, Rhipicephalus microplus (Canestrini), which vectors the causal agents of babesiosis. Diatomaceous earth can be stored indefinitely, will remain efficacious for as long as sufficient quantities remain on the substrate, it is a natural (organic) substance, and it might be amenable for limited use in environmentally protected habitats.
... Ecovia is a commercial, registered insecticide with two active ingredients: the desiccant dust silica gel and a botanical substance from thyme that impedes cell membrane permeability. Inert desiccant dust-based formulations of silica gel have been effective, in particular, for controlling bed bugs, Cimex lectularius (L.), through desiccation (Donahue et al. 2015). Silica gel is lethal to mosquitoes in the medically important genera Anopheles, Culex, and Aedes (Micks 1960), as well as to the horn fly, Haematobia irritans irritans (L.), a common pest of livestock (Dorsey et al. 1966). ...
Article
Full-text available
Ixodids suck blood from host animals and transmit pathogens that cause important medical and veterinary diseases. As synthetic conventional acaricide resistance becomes increasingly common, alternative tactics are likely to enhance control efforts. Laboratory bioassays assessed the lethality of CimeXa, a commercial silica gel desiccant dust, and EcoVia, a commercial product containing silica gel + thyme oil, against lone star tick, Amblyomma americanum (L.), larvae and nymphs. Both life stages were completely killed by CimeXa by 24 h, and EcoVia achieved total larval mortality within 1 h when they were initially immersed in the dusts and when they crawled across treated substrate. Larvae were killed faster than nymphs. Temporary immersion of A. americanum larvae and nymphs in aqueous suspensions of the dusts were less effective than exposure to the dusts applied dry. Larval and nymphal mortality associated with crawling on dried aqueous suspensions of the products was also not as strong as when the immature life stages crawled across substrate treated with dry dusts, and EcoVia was not more efficient than CimeXa. CimeXa and EcoVia can likely be used to protect cattle in a prophylactic context because silica gel does not degrade, and EcoVia might be effective at eliminating ticks that are feeding on cattle as well. We suggest that the two dust products be assessed for efficacy against other ixodid species, such as the southern cattle fever tick, Rhipicephalus microplus (Canestrini), which transmits the causal agents of babesiosis to cattle.
Article
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Bed bugs (Cimex lectularius L. and Cimex hemipterus F.) are among the most difficult urban pests to manage. Many essential oil-based bed bug control products that are considered reduced risk to mammals compared to synthetic insect neurotoxins have become commercially available, but their effectiveness as a stand-alone control method is unknown. This study assessed the field efficacy of an essential oil-based bed bug control product (EcoRaider; a.i. 1% geraniol + 1% cedar oil + 2% sodium lauryl sulfate) compared to a pyrethroid and neonicotinoid mixture spray (0.075% Temprid SC; a.i. beta-cyfluthrin + imidacloprid). After 12 weeks, the three treatments—EcoRaider, Temprid SC, and EcoRaider + Temprid SC caused 92.5 ± 2.7, 92.9 ± 3.0, and 91.7% ± 2.7% bed bug count reduction, respectively. No significant differences existed in the bed bug reduction among the treatments. Bed bugs were eliminated from only 22% of the treated apartments. Among those still with bed bugs, 76% of the residents did not know bed bugs were present. We documented the residents’ self-control practices and discussed the potential of using essential oil-based insecticides in bed bug management programs to minimize the health risks to building occupants and pets and to slow down the development of insecticide resistance.
Article
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Nikolov, A. and D. GANchev, 2011. In vitro antifungal examination of potassium sorbate towards some phytopathogens. Bulg. J. Agric. Sci., 17: 191-194 Potassium sorbate, a common food preservative, was tested under in vitro conditions according to its inhibi-tory activity towards economically important for Bulgaria phytopathogens. conidial (germ tube inhibition) and Thornberry (radial growth assays) tests were conducted in order to be determine such activity. The received results showed that potassium sorbate has a potential to be a developed as a protective fungicide against Monilia fructigena, Botrytis cinerea, Rhizoctonia solani, Phytophthora capsici and Alternaria solani.
Article
The common bed bug (Cimex lectularius L.) has recently surged in numbers internationally. A variety of plant-based, or "natural", products that are stated to kill or repel bed bugs are being marketed directly to consumers, even though the efficacy of many of these products remains poorly known. This study was conducted to determine whether some products advertised as natural are potential tools for management of bed bugs. Five natural-based products were applied as direct sprays to insecticide-susceptible (Harlan) and pyrethroid-resistant (Jersey City) strains of bed bug. Products that were most effective as direct sprays were chosen for residual-spray assays, which were compared with an industry-standard insecticide labeled for control of bed bugs. Both assays were conducted for a 2-wk period. For direct-spray assays, Green Bug® was the only product to produce 100% mortality within 1 min-1 hr (based on strain). Bed Bug Patrol® required 1-2 wk (based on strain) to produce 100% mortality, whereas all other products failed to exceed 70% mortality by the end of the 2-wk period. The two natural-based products (Bed Bug Patrol® and Green Bug®) selected for residual-spray assays failed to differ from the control. Zenprox® (0.25%) produced 100% mortality when applied to the insecticide-susceptible (Harlan) strain yet failed to differ from the control when applied to the pyrethroid-resistant (Jersey City) strain. These findings demonstrate that some natural-based products may be ineffective as residual spray applications for bed bug management.
Book
The most comprehensive and best illustrated treatment of the fascinating tropical neem tree (Azadirachta indica) and its unique substances. The extracts from the neem tree have an enormously broad range of applications. The main substance azadirachtin, a tetranortriterpenoid, influences the hormone system of insects, exerting thereby a pesticidal effect. Feeding activity, reproduction and flying ability of insects are also affected. It is biologically degradable and can be easily extracted from the seeds of the tree. Other important uses of neem tree products are: - antifertility and population control - cure of human diseases - manure and nitrification inhibitors - feeds for domestic animals - soap production With its exhaustive treatment of the neem tree and closely related plants, this book provides us with an impressive example of the varied uses of renewable resources. © 1995 VCH Verlagsgesellschaft mbH, Weinheim. All rights reserved.
Article
Natural chemicals have considerable potential for vector management because these chemicals are safer than conventional insecticides on account of their rapid environmental biodegradation and low toxicity to natural enemies, humans and other mammals and they suffer less from problems of registration difficulties. However, isolation and chemical characterization of the active compounds from plants with strong biological activities can be a tedious process compared to synthesizing new synthetic compounds because natural compounds are generally isolated in small amounts. In addition, the purity of natural products is highly variable and is dependent upon the extraction method, plant part, plant age, geographic origin and location, climate and the overall growth and health of the plant from which the chemical is extracted. Furthermore, the research and development of natural pesticides against insect vectors is constrained because of the perceived lack of economic return to the manufacturers on investment in insect vector control and also due to the difficulties in registration. Despite these difficulties, research in plant-derived pesticides has increased considerablly. In this paper we provide an overview of the compounds isolated from plants that have been evaluated for control of insect vectors of human and animal pathogens.
Article
Bed bugs are wingless hematophagous ectoparasites that have co-existed with humans since they first appeared in the caves of Mediterranean and Middle Eastern regions approximately 65 million years ago. Bed bugs are not known to transmit diseases, most probably due to the lack of sylvatic cycles. Historical control methods include some remedies, but also many useful control methods such as community-wide eradication efforts, insecticidal powders, fumigation, and rigorous cleaning. These intense eradication efforts combined with newly developed synthetic insecticides, such as DDT and malathion, almost eliminated bed bugs during the 1950s. However, there has been a resurgence in bed bug populations during the past 15 years. Recent molecular evidence suggests that bed bugs did not experience a genetic bottle neck, but rather existed in isolated populations. Today, bed bugs are found to have multiple modes of insecticide resistance including reduced cuticular penetration and up-regulation of ABC transporters (ATP-binding cassette protein transporters). Currently available chemical treatments are based on pyrethroid insecticides that are not effective against many insecticide resistant bed bugs, but fumigation and dust formulations have been found to be more effective. Non-chemical control methods are most useful in community-wide integrated pest management. Future bed bug control will most likely to rely on refining the currently available methods and focusing on the research with cooperative efforts.