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Studies on insect infestation in chocolates

DOI:10.1016/j.jspr.2006.02.001
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Khamrunissa Begum
Khamrunissa Begum
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P. Vanitha Reddy
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B.C. Leelaja
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Y. Rajashekar at Institute of Bioresources and Sustainable Development
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Abstract and Figures

The ability of stored-product pests including the cigarette beetle, Lasioderma serricorne, the sawtoothed grain beetle, Oryzaephilus surinamensis, the rust-red flour beetle, Tribolium castaneum, and the almond moth, Ephestia cautella, to infest chocolates under packaged and unpackaged conditions was investigated in the laboratory at 2571 1C and 6575% r.h. Four types of chocolates were investigated: milk, nut, dried fruit and nut, and wafer chocolates. Adults (beetles only, 20 per replicate) or eggs (30 per replicate) were released on unpackaged and packaged chocolates and infestation levels (number of living adults and larvae) were determined 45 days later. When adult beetles were released on unpackaged chocolates, the degree of infestation varied depending on the species and the type of chocolate.The highest infestation observed in the unpackaged chocolate was that of O. surinamensis in wafer chocolate (mean 138.4). When eggs were released on unpackaged chocolates, the most numerous species was E. cautella in dried fruit and nut chocolate (mean population ¼ 180.8). With packaged chocolates exposed to adults or eggs, insect infestation was nil or negligible (mean population<6.0). Although infestation levels were low, infestations were found in 50% of treatments over all. Damage to the packaging material along the folds or edges was observed in infested chocolates. The study has shown that milk, nut, dried fruit and nut, and wafer chocolates can support insect infestation and therefore, insect-proof packing of the chocolates and storage under hygienic conditions are important to avoid customers’ complaints.
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Journal of Stored Products Research 43 (2007) 118–122
Studies on insect infestation in chocolates
Khamrunissa Begum, P. Vanitha Reddy, B.C. Leelaja, Y. Rajashekar, S. Rajendran
Food Protectants and Infestation Control Department, Central Food Technological Research Institute, Mysore 570020, India
Accepted 22 February 2006
Abstract
The ability of stored-product pests including the cigarette beetle, Lasioderma serricorne, the sawtoothed grain beetle, Oryzaephilus
surinamensis, the rust-red flour beetle, Tribolium castaneum, and the almond moth, Ephestia cautella, to infest chocolates under packaged
and unpackaged conditions was investigated in the laboratory at 25711C and 6575% r.h. Four types of chocolates were investigated:
milk, nut, dried fruit and nut, and wafer chocolates. Adults (beetles only, 20 per replicate) or eggs (30 per replicate) were released on
unpackaged and packaged chocolates and infestation levels (number of living adults and larvae) were determined 45 days later. When
adult beetles were released on unpackaged chocolates, the degree of infestation varied depending on the species and the type of chocolate.
The highest infestation observed in unpackaged chocolate was that of O. surinamensis in wafer chocolate (mean 138.4). When eggs were
released on unpackaged chocolates, the most numerous species was E. cautella in dried fruit and nut chocolate (mean
population ¼180.8). With packaged chocolates exposed to adults or eggs, insect infestation was nil or negligible (mean population
o6.0). Although infestation levels were low, infestations were found in 50% of treatments over all. Damage to the packaging material
along the folds or edges was observed in infested chocolates. The study has shown that milk, nut, dried fruit and nut, and wafer
chocolates can support insect infestation and therefore, insect-proof packing of the chocolates and storage under hygienic conditions are
important to avoid customers’ complaints.
r2006 Elsevier Ltd. All rights reserved.
Keywords: Chocolates; Insect infestation; Ephestia cautella;Oryzaephilus surinamensis;Lasioderma serricorne;Tribolium castaneum
1. Introduction
Chocolate products in many forms and flavours are
relished by people of all ages for their sweetness and
richness in nutrition. The global confectionery market
including chocolate products has been estimated to exceed
$73.2 billion per annum and the annual global consump-
tion of chocolate confectionery has been estimated as 6.5
million tonnes (CAOBISCO, 2004). Chocolate is prepared
from a mixture of one or more of the following ingredients:
cocoa bean/ nib/ press cake, cocoa dust, sugars, cocoa
butter, milk solids and flavouring agents. Depending on its
composition, chocolate is known as plain chocolate, milk
chocolate, white chocolate, blended chocolate, bitter
chocolate or composite chocolate. Cocoa, the basic
ingredient in these chocolates varies from 20% to 60%.
The type of packaging material used for chocolates varies;
generally, aluminium foil, composite films, paper or plastic
trays are used. The packaged chocolates are known to keep
their quality up to 5 months when stored at 10–18 1C and
60–70% r.h. The actual storage period, however, may
extend for a longer duration in the distribution network/
retail market.
Insect infestation in chocolates may occur at any stage
from production to consumption. Insect infestations in and
around chocolate manufacturing facilities have been
reported in some countries (Bowditch and Madden, 1997;
Wohlgemuth, 1992). It is recommended that chocolate
products are stored in hygienic conditions in well-
ventilated locations at 18–20 1C and o50% r.h. (ICCO,
2000). In the retail market, however, hygiene varies and
accordingly the products are prone to infestation. When
insects are found in the chocolates, consumers often direct
their complaints to the manufacturer and the image of
the company is affected (Highland, 1984). Customers’
ARTICLE IN PRESS
www.elsevier.com/locate/jspr
0022-474X/$ - see front matter r2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.jspr.2006.02.001
Corresponding author. Tel.: +91 821 2513210; fax: +91 821 2517233.
E-mail address: somiah_r@yahoo.co.uk (S. Rajendran).
complaints about insect infestation in chocolates in the
retail market in both developed and developing countries
have been reported (Scheurer and Dubau, 1999).
Data on the infestability of different types of chocolates
under packaged and unpackaged conditions by insect pests
are lacking. Experiments, therefore, were conducted to
study the infestability of different types of chocolates under
packaged and unpackaged conditions by four common
stored-product insect pests viz., the rust-red flour beetle,
Tribolium castaneum (Herbst),the sawtoothed grain beetle,
Oryzaephilus surinamensis (L.), the cigarette beetle, Lasio-
derma serricorne (L.), and the almond moth, Ephestia
cautella (Walker), over a storage period of 45 days.
2. Materials and methods
2.1. Chocolates
Milk chocolate (ingredients: milk solids, cocoa butter,
cocoa solids, sugar, emulsifiers etc.), nut chocolate
(ingredients: almonds+other ingredients as in milk choco-
late), dried fruit and nut chocolate (ingredients: raisins,
cashew nuts, apricot kernels+other ingredients as in milk
chocolates) and wafer chocolate (ingredients: wheat flour,
hydrogenated vegetable oil, edible starches+other ingre-
dients as in milk chocolates) of the same brand were
obtained from the local market. The type of packaging
material used on the chocolates and their unit weight
varied. The chocolates were not checked for damage or
defects in the packaging materials prior to use in the
experiment. The moisture content of the chocolates as
determined by the toluene distillation method ranged from
1.1% to 3.2% (Table 1).
2.2. Insects
Tribolium castaneum and L. serricorne cultures were
maintained on whole wheat flour+5% yeast, O. surina-
mensis on broken wheat+rolled oats+yeast at a 5:5:1 ratio
and E. cautella on broken wheat+5% yeast+5% glycerol
in the laboratory at 25711C and 6575% r.h. From these
cultures, unsexed 1–2 week old adults of T. castaneum and
O. surinamensis and 2–3 day old adults of L. serricorne
were taken for infestation studies. For the collection of
eggs of T. castaneum, L. serricorne and O. surinamensis,
wheat flour was passed through an 85-mesh standard sieve
(pore size 180 mm). Into the sieved flour (200 g) c. 250
adults were released for oviposition for 48 h. At the end of
48 h, the adults were removed from the flour using standard
25- or 44- mesh sieves (pore sizes 600 and 335 mm,
respectively). The flour was subsequently sieved through
an 85-mesh sieve to separate the eggs, which were then
placed on the chocolates. To collect E. cautella eggs, newly
emerged adults were released into a metal cage having a
mesh bottom, which allows eggs to pass through. Eggs,
0–2 days old, were collected in a tray under the cage and
then placed on the chocolates. Viability of eggs of
individual species was checked as described in Rajendran
et al. (2004). Eggs (four replicates per species) were placed
individually in the wells of ELISA plates that were cut
into half so as to have only 48 wells and egg hatch was
observed under a binocular microscope, daily, until there
were no more emergences. Viability (% hatched) of eggs
was: T. castaneum (91.075.9), L. serricorne (79.2712.3),
O. surinamensis (86.877.8), and E. cautella (76.1714.5).
2.3. Infestation studies
The studies were carried out on chocolates (70–84 g per
replicate) under packaged conditions as well as without any
packaging materials. Chocolates were placed in bottles
(size 13 cm 9 cm) for 45 days at 25711Cand6575% r.h.
There were 2 sets of experiments. In the first set, adults (20
per replicate) were released on to chocolates with and
without packaging material. In the second set, 1–2 day old
eggs (30 per replicate) of the individual species were placed
on both unpackaged and packaged chocolates. There were
5 replicates for each type of chocolate. After the addition of
insects, the bottles containing chocolates and reference
diets were covered with pieces of cloth, tied with rubber
bands and held at 25711C for 45 days. At the end of 45
days, insect populations (live larvae and adults) in
chocolates were recorded. In packaged chocolates, when-
ever infestation was found, the packaging materials of the
ARTICLE IN PRESS
Table 1
Details of the types of chocolates used for the experiments
Chocolate type Unit weight (g) Moisture content
(%)
Packaging material used
Inner Outer
Milk chocolate 42 1.1 12 mm foil/25 mm polyethylene Printed paper
Nut chocolate 35 2.8 25 mm biaxially oriented
polypropylene
Printed carton
Dried fruit and nut chocolate 80 3.2 12 mm foil/25 mm polyethylene Printed paper
Wafer chocolate 15 2.4 Nil 12.5 mm polyethylene
terephthalate/metallisation/
17.5 mm biaxially oriented
polypropylene
K. Begum et al. / Journal of Stored Products Research 43 (2007) 118–122 119
chocolates were examined for the presence of damage or
defects.
2.4. Data analysis
Data on insect populations in the four types of
chocolates were transformed to logarithmic (for unpack-
aged chocolates) or O(x+0.5) (for packaged chocolates)
values and subjected to ANOVA followed by Duncan’s
New Multiple Range test to determine significant differ-
ences in infestation (of the individual species) between
chocolate types.
3. Results
In unpackaged chocolates, all four species could infest
but the degree of infestation varied between chocolate
types and insect species (Table 2). In general, populations
were greatest in dried fruit and nut chocolate. Where adults
were released in the chocolates, O. surinamensis (average
counts, 52–138) and L. serricorne (45–86) populations were
higher than T. castaneum (12–23). Oryzaephilus surinamen-
sis infestation levels in the chocolates were: waferodried
fruit and nutomilk ¼nut. No significant differences in the
levels of T. castaneum and L. serricorne infestation between
chocolate types were observed.
When eggs were used, high population levels of
E. cautella (180.8750.9) were noted in dried fruit and
nut chocolate. Among the beetle pests, high average counts
were recorded of O. surinamensis (5–27) and L. serricorne
(6–17). The levels of infestation when eggs of
O. surinamensis were placed in unpackaged chocolates
was: dried fruit and nutomilk ¼nut ¼wafer, whereas, for
L. serricorne as well as T. castaneum the infestation levels
were: milk ¼nut ¼dried fruit and nutowafer.
With packaged chocolates exposed to adults or eggs,
insect infestations were nil in 50% of the treatments and in
the remaining treatments very low infestation levels (mean
populationo6.0) were observed (Table 3). No significant
differences in the level of infestation between species and
between chocolate types were noted. No infestations were
found from T. castaneum adults released on wafer or nut
chocolates nor from eggs of either O. surinamensis or
E. cautella in dried fruit and nut, nut or wafer chocolates.
Damage to inner or primary packaging material (12 mm
foil/ 25 mm polyethylene) along the folds or edges was
observed in milk and dried fruit and nut chocolates infested
with the adults of O. surinamensis as well as L. serricorne
and with the eggs of E. cautella. Damage to the packaging
material (12.5 mm polyethylene terephthalate/metallization/
17.5 mm biaxially oriented polypropylene) along the seal
was also noticed in wafer chocolate infested with the adults
of O. surinamensis.
4. Discussion
Stored-product insects have different food preferences.
Chocolates contain various ingredients such as cocoa, tree
nuts, dried fruits and wheat flour that are favourable for
the growth and multiplication of insects. Lasioderma
serricorne is a major pest on cocoa and cocoa products
and can breed readily in all four types of chocolates in
addition to tobacco. Oryzaephilus surinamensis, a common
pest on processed foods and tree nuts, also breeds readily
on chocolates (Table 2). The omnivorous T. castaneum,
however, produced only low-level populations in the
chocolates tested. Population levels of E. cautella, a pest
on a variety of foodstuffs including cereals, cereal
products, cocoa, oilseeds, tree nuts and dried fruits were
ARTICLE IN PRESS
Table 2
Populations of Tribolium castaneum,Lasioderma serricorne,Oryzaephilus surinamensis and Ephestia cautella in unpackaged chocolates at the end of a
45-day storage period at 25711C
Insect No. of insects (mean7SD) recorded in different types of chocolates
c,d
Milk Nut Dried fruit and nut Wafer
Adults
a
Tribolium castaneum 23.078.7ax 17.4713.3ax 22.8710.8ax 11.672.6ax
Lasioderma serricorne 58.2723.0bx 45.2712.3bx 86.0715.5bx 79.0775.6bx
Oryzaephilus surinamensis 53.275.0bx 52.076.0bx 95.6720.3by 138.4722.5cz
Eggs
b
Tribolium castaneum 9.274.7aby 10.678.2ay 11.674.2ay 3.673.7ax
Lasioderma serricorne 16.075.1by 11.277.7ay 17.472.8aby 6.274.9ax
Oryzaephilus surinamensis 6.876.0ax 8.477.4ax 27.4710.0by 5.475.4ax
Ephestia cautella 18.674.1bx 71.6745.4by 180.8750.9cz 14.876.2bx
a
20 adults per each of 5 replicates released.
b
30 eggs per each of 5 replicates released.
c
Means in the same column of adults or eggs followed by different letters (a, b, c) differ significantly according to Duncan’s new multiple range test
(Po0.05).
d
Means in the same row of adults or eggs followed by different letter (x, y, z) differ significantly according to Duncan’s new multiple range test
(Po0.05).
K. Begum et al. / Journal of Stored Products Research 43 (2007) 118–122120
high on the chocolates particularly in fruit and nut as well
as nut chocolates.
The susceptibility of the ingredients used in chocolate
manufacture to insect pests such as E. cautella and the
Indian meal moth, Plodia interpunctella (Hu
¨bner) has been
studied (Locatelli and Garavaglia, 1995). It was noted that
raw hazel nuts used in the manufacture of chocolates were
more susceptible than the basic ingredients of the
chocolate.
Insect infestation in chocolates may depend on (1)
storage conditions, (2) storage temperature, (3) type and
thickness of the packaging materials, and (4) storage period
(Collins, 2003). The extent of infestation also depends on
the insect pest complex occurring in the premises. The
storage period of manufactured chocolates generally varies
from 3–6 months in the retail market. During longer
storage, more insects are likely to invade or penetrate the
packaging material causing more damage to the choco-
lates. The longer storage period facilitates insect develop-
ment to a life stage, i.e., larva or adult that is capable of
damaging the packaging material and/or the insects have
sufficient time to chew or damage the packaging material
(Kelly, 2004). Rapid turnover of the stocks will discourage
insect pest attack during storage (Anonymous, 1984).
Packaging plays an important role in maintaining the
shelf life of chocolates and as a physical barrier against the
entry of insect pests. The penetrability of the packaging
material by insect pests varies between species and among
the active stages of a particular species (Cline, 1978).
Stored-product insects have been classified as invaders and
penetrators of packed foodstuffs. Invaders (e.g. adults as
well as larvae of O. surinamensis) can gain entry into
the product through pinholes/punctures or imperfect
sealing, whereas penetrators (e.g. adults of L. serricorne,
larvae of E. cautella) with powerful mouthparts can
pierce or damage the packaging materials. In the current
study, damage to the packaging material along the folds or
edges due to insects (O. surinamensis, L. serricorne and
E. cautella) was noticed. In the present experiment on
packaged chocolates, out of a total 28 treatment combina-
tions, 50% of treatments had at least one infested replicate
(Table 3). Although infestation levels were low, any
infestation is important from a retailer or customer’s point
of view.
While examining the barrier properties of different
packaging materials that were used for chocolate products,
Schmidt (1979) observed that even aluminium foil was not
100% insect proof. In the present study, insects could
penetrate along the folds or edges of 12 mm aluminium foil
combined with 25 mm polyethylene packaging material in
milk and dried fruit and nut chocolates. Insect pests could
gain entry into the packaged products through minute
holes and defective sealing of the packaging material.
Sealing defects are likely to occur during manufacture of
chocolates. For the entry of insects (adults or larvae),
depending on the species, minute holes ranging from 560 to
1700 mm are enough for penetration (Cline and Highland,
1981). Due to variations in the extent of damage/defects in
the packaging materials of the four types of chocolates and
invasion potential of individual insect species, infestation in
packaged chocolates was sporadic in the present study
(Table 3).
Food aroma/volatiles escaping from defective sealing or
damaged packaging material may attract insects for
oviposition or feeding. In laboratory studies, Mowery et
al. (2002) showed that female adults of O. surinamensis
were attracted towards packaged products for oviposition.
In another study, it was noted that E. cautella females were
attracted towards the grain odour, which stimulated their
oviposition (Barrer and Jay, 1980). In laboratory tests on
insect resistance to packaging materials, it was shown that
P. interpunctella, an important pest on chocolate products,
could distinguish sealed packets with and without food
items for oviposition (Mullen, 1994).
ARTICLE IN PRESS
Table 3
Populations of Tribolium castaneum,Lasioderma serricorne,Oryzaephilus surinamensis and Ephestia cautella in packaged chocolates at the end of a 45 days
storage period at 25711C
Insect No. of insects (mean7SD) recorded in different types of chocolates
Milk Nut Dried fruit and nut Wafer
Adults
a
Tribolium castaneum 0.871.1 0 3.678.0 0
Lasioderma serricorne 0 0.270.4 1.671.8 5.479.9
Oryzaephilus surinamensis 5.8713.0 0 0.671.3 1.072.2
Eggs
b
Tribolium castaneum 1.872.2 0.270.4 0 0
Lasioderma serricorne 0 0 0.871.8 0.470.9
Oryzaephilus surinamensis 0.270.4 0 0 0
Ephestia cautella 1.873.6 0 0 0
No significant differences were observed between columns or rows of adults or eggs according to Duncan’s new multiple test (Po0.05).
a
20 adults per each of five replicates released.
b
30 eggs per each of five replicates released.
K. Begum et al. / Journal of Stored Products Research 43 (2007) 118–122 121
Insects such as T. castaneum (24 days as adults and 9–12
days as larvae) and L. serricorne (9 days as adults as well as
larvae) are highly tolerant of starvation (Cline, 1978;
Koura and El-Halfawy, 1973). Starved insects have a
greater tendency to attack packed products than normal
insects. In laboratory tests it was observed that starved
larvae are more aggressive in penetrating into the packa-
ging material (Cline, 1978). Therefore, in the absence of
any other food commodities, insects present in the vicinity
of chocolates would be more likely to penetrate the
packaging material of the products. In the present study
it was noted that a few adults of T. castaneum survived
during the storage period (45 days) probably by feeding on
the packaging material of the chocolates.
5. Conclusion
Chocolates have ingredients such as cocoa, tree nuts and
dried fruits and therefore are susceptible to insect infesta-
tion during storage. The present study has shown that all
four stored-product species tested could establish different
levels of infestation on four types of chocolates. In
packaged chocolates, however, only negligible levels of
infestation were established. To discourage infestation,
there must be rigorous quality checks on packaging
materials and their sealing during production and the
chocolates must be stored under hygienic conditions away
from infested foodstuffs.
Acknowledgement
The authors thank the Director, Central Food Techno-
logical Research Institute, Mysore, for encouragement and
support.
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ARTICLE IN PRESS
K. Begum et al. / Journal of Stored Products Research 43 (2007) 118–122122
... Cocoa is traded as dried cocoa beans in its primary form (Begum et al., 2007;Navarro et al., 2007;Joel et al., 2013), is attacked by many insect pests in storage, retail outlets and transit, especially in humid and warm tropical environments (Sivapragasam, 1990;Begum et al., 2007;Asimah et al., 2014) like Malaysia. Insects infestations of cocoa beans and other stored products mainly causes damage due to direct feeding on the commodity (Compton and Sherington, 1999;Lale, 2002;Sallam, 2008;Jonfia-Essien and Navarro, 2010), and indirectly as contaminants due to the presence of live or dead individuals and their waste materials (Obeng-Ofori, 2010;Jonfia-Essien and Navarro, 2010). ...
... Cocoa is traded as dried cocoa beans in its primary form (Begum et al., 2007;Navarro et al., 2007;Joel et al., 2013), is attacked by many insect pests in storage, retail outlets and transit, especially in humid and warm tropical environments (Sivapragasam, 1990;Begum et al., 2007;Asimah et al., 2014) like Malaysia. Insects infestations of cocoa beans and other stored products mainly causes damage due to direct feeding on the commodity (Compton and Sherington, 1999;Lale, 2002;Sallam, 2008;Jonfia-Essien and Navarro, 2010), and indirectly as contaminants due to the presence of live or dead individuals and their waste materials (Obeng-Ofori, 2010;Jonfia-Essien and Navarro, 2010). ...
... Within each group, containers were then, randomly allocated to series of infestation levels (0, 10, 20, and 30), and each series was replicated six times. Laboratory reared adult T. castaneum, 2e3wks old (Donahaye et al., 1996;Mahroof et al., 2003;Begum et al., 2007) were collected from the colony using an aspirator and introduced onto the cocoa beans in the plastic containers at an infestation level of 0, 10, 20 and 30 unsexed individuals (Mahroof et al., 2003;Boina and Subramanyam, 2004;Jonfia-Essien, 2006;Begum et al., 2007;Tefera et al., 2011;Ðuki c et al., 2016). The tops of the containers were covered with a muslin cloth to provide ample aeration for the insects during the experiment. ...
Damage potential of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) on cocoa beans: Effect of initial adult population density and post infestation storage time
Article
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The effect of different initial adult population densities of Tribolium castaneum (Herbst) at several post infestation storage times on the final adult population density, the percentage of damaged beans, the percentage of weight loss, and the weight of insect feeding residues on cocoa beans was investigated in laboratory experiments. Both factors interactively had highly significant (P < 0.01) effects on variables assessed. The highest mean final adult population density of 129.7 ± 4.6 was recorded in samples infested with the highest initial adult population density and stored for 150 d, while the least mean adult population density of 10.8 ± 0.54 was recorded on samples infested with the lowest initial adult population density in samples stored for 30 d. The highest percentage damaged cocoa beans 51.0 ± 1.21% was recorded in samples infested with the highest initial adult population density, while the least mean percentage damaged beans of 16.9 ± 1.26% was also recorded on samples infested with the lowest initial adult population density. Similar trends of means were recorded for all the remaining variables. Correlation between factors was significant and positive. Multiple and simple linear regressions analyses were also significant (P < 0.01) and all equations fitted the regression models and perfectly described the relationship between the independent and the dependent variables. Our results show that T. castaneum can impact negatively on both the quantity and quality of stored cocoa within just 30 days of infestation, with the impact increasing with increasing population density and post infestation storage time.
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... The cocoa bean, from which cocoa solids and cocoa butter are extracted, is the basis of chocolate which is commercially known as plain, milk, white, dark, blended, bitter or composite chocolate. Cocoa, the basic ingredient of these chocolates varies from 20% to 90% (Begum et al., 2007). The study has shown that milk, nut, dried fruit and nut, and wafer chocolates can support insect infestation and therefore, insect-proof packing of the chocolates and storage under hygienic conditions are important to avoid customers' complaints. ...
... Running to the biology of this species, it is known that it prefers soft commodities rather than hard ones (Back, 1926). Commercial chocolate products, as the ones that were tested in the present study, have ingredients such as cocoa, tree nuts, dried fruits, wheat flour and therefore are susceptible to insect infestation growth and multiplication during storage (Begum et al., 2007 ). Insect infestation in chocolates may depend on storage conditions, storage temperature, type and thickness of the packaging materials, and storage period (Collins, 2003 ). ...
Laboratory tests on the ability of Oryzaephilus surinamensis adults to locate different types of chocolate varying in quantity of cocoa
Article
Full-text available
  • Apr 2016
Results obtained by olfactometric trials on chocolate preferences of the sawtoothed grain beetle, Oryzaephilus surinamensis (L.) (Coleoptera Silvanidae), adults testing unpackaged commercial chocolate realized with different quantity of cocoa are reported. The following five chocolate types of the same brand were tested: chocolate with 30% cocoa; chocolate with 50% cocoa; chocolate with 70% cocoa; chocolate with 85% cocoa; chocolate with 90% cocoa. The present study has shown that adults of O. surinamensis could establish different levels of infestation on the five tested types of chocolates. The chocolate type with the less percentage of cocoa (30%) was found as the most preferable one by O. surinamansis compared with the other types tested. © 2016, Universita degli Studi di Bologna, Department of Agroenvironmental Sciences and Technologies. All right reserved.
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... The cocoa bean, from which cocoa solids and cocoa butter are extracted, is the basis of chocolate which is commercially known as plain, milk, white, dark, blended, bitter or composite chocolate. Cocoa, the basic ingredient of these chocolates varies from 20% to 90% (Begum et al., 2007). The study has shown that milk, nut, dried fruit and nut, and wafer chocolates can support insect infestation and therefore, insect-proof packing of the chocolates and storage under hygienic conditions are important to avoid customers' complaints. ...
... Running to the biology of this species, it is known that it prefers soft commodities rather than hard ones (Back, 1926). Commercial chocolate products, as the ones that were tested in the present study, have ingredients such as cocoa, tree nuts, dried fruits, wheat flour and therefore are susceptible to insect infestation growth and multiplication during storage (Begum et al., 2007 ). Insect infestation in chocolates may depend on storage conditions, storage temperature, type and thickness of the packaging materials, and storage period (Collins, 2003 ). ...
Controlling infestion of a chocolate factory by Plodia interpunctella by combining mating disruption and the parasitoid Habrobracon hebetor
Article
A field experiment of four years' duration was carried out to evaluate the efficacy of combining the mating disruption (MD) formulation Dismate (Russell IPM, UK) ZETA [(9Z,12E)-tetradecadienyl acetate], with the parasitoid Habrobracon hebetor against the Indianmeal moth Plodia interpunctella in a chocolate factory. The experimental period began early in 2011 and ended in late 2014. Begane Dismate dispensers were placed in the facility from 2011 to 2014 and H. hebetor was released in 2014. Pheromone-baited traps were used to monitor the flight activity of the male moths and oviposition Petri-dish traps were placed to assess the progeny production of P. interpunctella females. Following the start of MD, a decrease in the number of P. interpunctella males caught in monitoring traps was observed from 2011 to 2013. A further decline in the moth population was noted in 2014, when MD was combined with the release of parasitoids. The presence of larvae in the oviposition cups was occasionally observed throughout the monitoring period, from 2011 to 2014. This study demonstrates that the combined system of MD and parasitoids is an effective and reliable technique that can be used to successfully control P. interpunctella. This article is protected by copyright. All rights reserved.
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... Navel orange worms lay eggs while the almonds are still on the tree and the eggs incubate when the nuts are dried on-ground, which could hide and grow inside the kernels for long time and cause significant food safety risk in the final products. In recent years, insect damages or even live insects have been found in dried raw nuts or other products such as chocolates (Begum et al., 2007;Yu et al., 2018). Therefore, disinfestation of tree nuts is critical as well in preserving the product quality and safety. ...
Postharvest processing of tree nuts: Current status and future prospects—A comprehensive review
Article
Tree nuts are important economic crops and are consumed as healthy snacks worldwide. In recent years, the increasing needs for more efficient and effective postharvest processing technologies have been driven by the growing production, higher quality standards, stricter food safety requirements, development of new harvesting methods, and demand to achieve energy saving and carbon neutralization. Among all, the technologies related to drying, disinfection, and disinfestation and downstream processes, such as blanching, kernel peeling, and roasting, are the most important processes influencing the quality and safety of the products. These processes make up the largest contribution to the energy consumptions and environmental impacts stemming from tree nut production. Although many studies have been conducted to improve the processing efficiency and sustainability, and preserve the product quality and safety, information from these studies is fragmented and a centralized review highlighting the important technology advancements of postharvest processing of tree nuts would benefit the industry. In this comprehensive review, almonds, walnuts, and pistachios are selected as the representative crops of tree nuts. Current statuses, recent advances, and ongoing challenges in the scientific research as well as in the industrial processing practices of these tree nuts are summarized. Some new perspectives and applications of tree nut processing waste and by‐products (such as the hulls and shells) are also discussed. In addition, future trends and research needs are highlighted. The material presented here will help both stakeholders and scientists to better understand postharvest tree nut processing and provide technological recommendations to improve the efficiency and sustainability, product quality and safety, and competitiveness of the industry.
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... The cosmopolitan cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae), is one of the most damaging pests in food storage and the tobacco industry worldwide [1][2][3][4][5] and is of increasing importance for damage inflicted at heritage sites such as museums [6,7] and herbaria [8,9]. Adult beetles penetrate packaged commodities, leaving a neat round hole, which classifies this species in the category of "true penetrators" of food packages [10,11]. ...
Odorants of Capsicum spp. Dried Fruits as Candidate Attractants for Lasioderma serricorne F. (Coleoptera: Anobiidae)
Article
Full-text available
  • Jan 2021
The cigarette beetle, Lasioderma serricorne F. (Coleoptera: Anobiidae) is an important food storage pest affecting the tobacco industry and is increasingly impacting museums and herbaria. Monitoring methods make use of pheromone traps which can be implemented using chili fruit powder. The objective of this study was to assess the response of L. serricorne to the volatile organic compounds (VOCs) from different chili powders in order to identify the main semiochemicals involved in this attraction. Volatiles emitted by Capsicum annuum, C. frutescens, and C. chinense dried fruit powders were tested in an olfactometer and collected and analyzed using SPME and GC-MS. Results indicated that C. annuum and C. frutescens VOCs elicit attraction toward L. serricorne adults in olfactometer, while C. chinense VOCs elicit no attraction. Chemicals analysis showed a higher presence of polar compounds in the VOCs of C. annuum and C. frutescens compared to C. chinense, with α-ionone and β-ionone being more abundant in the attractive species. Further olfactometer bioassays indicated that both α-ionone and β-ionone elicit attraction, suggesting that these compounds are candidates as synergistic attractants in pheromone monitoring traps for L. serricorne.
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... Its control is made difficult by the beetle's longevity, being recorded to live for up to 7 months (Mason, 2015), and even up to 3-5 years in extreme cases (Howe, 1956;Kilpatrick et al., 2004). Females lay about 400 eggs either singly or in batches (Khamrunissa et al., 2006;Rees, 2007) and oviposition drops after 2 months (Mason, 2015). ...
Differential Response of Cultivar-Morphological Status Combination on Damage Severity of Stored Dates Infested with Oryzaephilus Surinamensis L (Coleoptera: Silvanidae)
Experiment Findings
Full-text available
  • Jan 2017
Three locally sourced date cultivars, Jigawa, Deglet Noor and Mali, were divided into those with and without calyces and infested with 10 pairs of 2-3 days old Oryzaephilus surinamensis to determine their differential response to insect activities and formulate a damage severity scale across 14 weeks. Mean damage severity period (weeks) revealed that date cultivars without calyx significantly (P<0.05) depredated faster than date cultivars with calyx as presence of calyx covering was found to confer protection against infestation and delayed rate of development. Deglet Noor with calyx recorded the longest mean of 11.8 weeks to ferment at damage scale 5, which was statistically different (P<0.05) from Jigawa cultivar without calyx with a mean of 9.0 weeks to reach same damage scale. The result shows significant differences (P<0.05) in the influence of O. surinamensis infestation on stored dates across time where the six date samples recorded varying time periods (weeks) for damage as arranged in decreasing order: Deglet Noor with calyx (DC) > Deglet Noor without calyx (DNC) > Mali with calyx (MC) > Mali without calyx (MNC) > Jigawa with calyx (JC) > Jigawa without calyx (JNC). Thus, the best cultivar-morphological status combination that showed longer quality date storability against O. surinamensis infestation was Deglet Noor cultivar with calyx (DC) while Jigawa cultivar without calyx (JNC) was the least.
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... Control of this beetle is made difficult by its longevity, being recorded to live up to 7 months (Mason, 2015), and some time up to 3-5 years in extreme cases (Howe, 1956;Kilpatrick et al., 2004). Females lay about 400 eggs either singly or in batches (Khamrunissa et al., 2006). Oviposition drops after 2 months (Mason, 2015). ...
Firmness and calyx covering an arsenal against Oryzaephilus surinamensis (Linné, 1758) (Coleoptera: Silvanidae) infestation in stored dates (Phoenix dactylifera L.)
Experiment Findings
Full-text available
  • Sep 2018
Three date cultivars were sourced from the open market, sterilized and infested with Oryzaephilus surinamensis L. in a no-choice infestation experiment to determine emergence and weight loss. Emergence of O. surinamensis in Jigawa cultivar with and without calyx was significantly higher (P≤0.05) than emergence in Mali and Deglet Noor with and without calyx, just as emergence in Mali cultivar without calyx was significantly (P≤0.05) higher than emergence in Deglet Noor with and without calyx. Based on cultivar, Deglet Noor gave the least emergence of O. surinamensis with the highest in Jigawa cultivar. There was a highly significant (P≤0.05) weight loss in Jigawa date cultivar compared with weight loss in both Deglet Noor and Mali date cultivars, and, dates without calyx had significantly higher (P≤0.05) weight loss compared with dates with calyx. Pulpy dates appeared to be the most susceptible cultivars whereas firm dates were the least susceptible date cultivars. Conclusively, the results showed that Deglet Noor cultivar with calyx had the least emergence of O. surinamensis as well as loss in weight and is therefore recommend to store owners for prolonged storage.
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... This study, following a series of complaints regarding insect contamination of chocolate-based foods, highlighted that PP was more resistant to penetration by insects compared to PVC, in agreement with the findings of Cline (1978b) and Highland and Wilson (1981). Another study focused on chocolate infestation by T. castaneum, O. surinamensis, L. serricorne and E. cautella (Begum et al., 2007) highlighted that dried fruit and nut chocolate (unpackaged) were more prone to infestation, while only sporadic cases of infestation of packaged foods could be observed during a 45-day trial. ...
Development of Insect-Repellent Food Packaging Materials
Chapter
  • Jan 2018
Packaging is the last defence of food against insect pests. Almost every package can be perforated by insects, which are attracted by the volatiles emanating from food. Consumers who come across contaminated packages hold the manufacturer responsible for the mishap, with dramatic consequences for the image of the company: hence, the food industry urges strategies to contain this risk. This chapter presents an in-depth analysis of the actual and past contributions on the theme, drawing a time-line of the studies carried out to date on packaging resistance to penetration by insects and on the development of insect-proof packages.
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... Its control is made difficult by the beetle's longevity, being recorded to live for up to 7 months (Mason, 2015), and even up to 3-5 years in extreme cases (Howe, 1956;Kilpatrick et al., 2004). Females lay about 400 eggs either singly or in batches (Khamrunissa et al., 2006;Rees, 2007) and oviposition drops after 2 months (Mason, 2015). ...
Differential Response of Cultivar-Morphological Status Combination on Damage Severity of Stored Dates Infested with Oryzaephilus Surinamensis L (Coleoptera: Silvanidae)
Article
Full-text available
  • Dec 2017
Three locally sourced date cultivars, Jigawa, Deglet Noor and Mali, were divided into those with and without calyces and infested with 10 pairs of 2-3 days old Oryzaephilus surinamensis to determine their differential response to insect activities and formulate a damage severity scale across 14 weeks. Mean damage severity period (weeks) revealed that date cultivars without calyx significantly (P<0.05) depredated faster than date cultivars with calyx as presence of calyx covering was found to confer protection against infestation and delayed rate of development. Deglet Noor with calyx recorded the longest mean of 11.8 weeks to ferment at damage scale 5, which was statistically different (P<0.05) from Jigawa cultivar without calyx with a mean of 9.0 weeks to reach same damage scale. The result shows significant differences (P<0.05) in the influence of O. surinamensis infestation on stored dates across time where the six date samples recorded varying time periods (weeks) for damage as arranged in decreasing order: Deglet Noor with calyx (DC) > Deglet Noor without calyx (DNC) > Mali with calyx (MC) > Mali without calyx (MNC) > Jigawa with calyx (JC) > Jigawa without calyx (JNC). Thus, the best cultivar-morphological status combination that showed longer quality date storability against O. surinamensis infestation was Deglet Noor cultivar with calyx (DC) while Jigawa cultivar without calyx (JNC) was the least.
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Vortex assisted-ionic liquid based dispersive liquid- liquid microextraction of low levels of nickel and cobalt in chocolate-based samples and their determination by FAAS
Article
In the study, a sim­ple and green vor­tex as­sisted-ionic liq­uid based dis­per­sive liq­uid liq­uid mi­croex­trac­tion (VA-IL-DLLM) com­bined with flame atomic ab­sorp­tion spec­trom­e­try (FAAS) was de­vel­oped for the ex­trac­tion and de­ter­mi­na­tion of nickel (Ni) and cobalt (Co) in choco­late-based sam­ples. An ul­tra-hy­dropho­bic ionic liq­uid (IL), 1-hexyl-3-methylim­i­da­zolium tris(penta­flu­o­roethyl)tri­flu­o­rophos­phate, [C6mim][FAP], was cho­sen as ex­trac­tion sol­vent. The method is se­lec­tively based on chelate for­ma­tion be­tween Ni(II)/ Co(II) ions and nin­hy­drin (2,2-di­hy­drox­yin­dane-1,3-dione) at pH 9.0, and then si­mul­ta­ne­ous ex­trac­tion of the formed com­plexes into the mi­cro-drops of IL, [C6mim] [FAP]. Ex­trac­tion pa­ra­me­ters (pH, the IL amount, chelat­ing lig­and con­cen­tra­tion, vor­tex time, vol­ume of dis­per­sive sol­vent, and ef­fect of in­ter­fer­ence ions) were eval­u­ated and op­ti­mized. Un­der op­ti­mized con­di­tions, the method was as fol­lows; lin­ear work­ing ranges were within the 1.0–350 μg L−1 and 0.7–400 μg L−1 for Ni and Co, re­spec­tively. The lim­its of de­tec­tions (3 × sblank/m, n:10) were 0.3 μg L−1 for Ni(II) and 0.2 μg L−1 for Co(II) with rel­a­tive stan­dard de­vi­a­tion <3.1% for real sam­ples. The method was val­i­dated by analy­sis of two stan­dard ref­er­ence ma­te­ri­als (SRMs), and re­cov­ery tests based on spik­ing at two lev­els. Lastly, the method was re­li­ably ap­plied for the de­ter­mi­na­tion of trace Ni and Co in choco­late-based sam­ples, with amounts in range of 1.5–192.7 μg L−1 and in range of 3.8–152 μg L−1, re­spec­tively.
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Lepidoptera and Coleoptera as pests of stored products in Berlin during 1991-1997
Article
  • Jan 1999
During 1991 to 1997 4078 samples sent in by public and private institutions were tested for their attack by arthropods. 5994 determinations were done. Seven the store damaging species of Lepidoptera were observed. Plodia interpunctella was the prime pest (305 determinations, mainly in cornflakes, muesli, sunflower seeds, nuts, feed, milk porredge and chocolate products). The percentage of P. interpunctella increased from 4,3% (1991) to 5.6%-8.4% (for 1993). Larvae and adults and pure larvae samples of P. interpunctella were mainly noticed from September to November. Pure adults samples could be counted for the most part from March to September. 27 the store damaging Coleoptera-species were determined. Stegobium paniceum was the prime pest (164 samples). 4% of the samples involved S. paniceum. Further mainly observed beetle-species were: Lasioderma serricorne (36 samples), Tenebrio molitor (in 75 samples) and Trogoderma angustum (134 samples).
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Laboratory observations on the ability of Ephestia cautella (Walker) (Lepidoptera: Phycitidae) to locate, and to oviposit in response to a source of grain odour
Article
Grain odour influenced oviposition behaviour was investigated amongst free-flying, gravid Ephestia cautella females. Females released into a 5 m3 or 10 m3 cage readily located, and oviposited in the vicinity of, small sources of diffusing grain odour or grain odour in an airstream. Oviposition increased at the odour source when 30% of an airstream carrying grain odour was replaced by CO2, whereas it decreased when 95% was replaced by N2, and did not change when 60% was replaced by either CO2 or N2. Females released into a wind-runnel responded to grain odour by increased frequency of upwind flight and by landing at the odour source. These responses are discussed in the context of grain stores sealed for treatment with controlled atmospheres or fumigants.
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Penetration of Seven Common Flexible Packaging Materials by Larvae and Adults of Eleven Species of Stored-Product Insects
Article
The ability of larvae to penetrate flexible packaging materials was determined for large and small larvae of 11 species of stored-product insects. These insects were confined individually, with or without food, in small pouches made of cellophane, polyethylene, paper, polyvinylchloride, aluminum foil, polyester, or polypropylene. Larvae of Oryzaephilus mercator (Fauvel), Cathartus quadricollis (Guérin-Méneville), and Cryptolestes pusillus (Schönherr) made no penetrations. Tribolium castaneum (Herbst) larvae were very weak penetrators. Only Tenebroides mauritanicus (L.) and Trogoderma variabile Ballion larvae penetrated all 7 materials. Larvae of the 5 other species, Dermestes maculatus De Geer, Lasioderma serricorne (F.), Ephestia cautella (Walker), Corcyra cephalonica (Stainton), and Plodia interpunctella (Hübner), penetrated 5 of the 7 materials. Foil, polyester, and polypropylene were generally the most resistant to penetration. Larvae of all species generally showed a much greater propensity to penetrate when confined without food. Many penetrations occurred within 24 h and most occurred within 1 wk. Some larvae that did not penetrate and subsequently transformed into adults made more penetrations as adults than as larvae. The locations of the penetrations in the vertically positioned pouches were predominantly in the bottom 1/2 of the pouches and in a zone 0–1 cm from the folds.
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Infestation of Chocolate‐based Products: Insects Responsible and Origins of Contamination
Article
In response to on-going consumer complaints regarding insect infestation of chocolate-based products manufactured at a factory in southern Australia, research was undertaken to determine the insects responsible for infestation and locate the points along the manufacture/distribution network where insect pests were most likely to be entering the produce. Phycitine moths were responsible for almost all cases of product infestation, with most infestation occurring after goods had been packaged. Methods of identifying storage environments suspected of unknowingly harbouring phycitine populations or of regularly handling infested goods are discussed. the detrimental consequences for the manufacturer, and for the processed food industry in general, of the presence of stored product insects in wholesale and retail outlets are also considered.
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Rapid determination of the effectiveness of insect resistant packaging
Article
A technique was developed to evaluate the usefulness of odour barriers and to determine the effect of package content in consumer size packages on resistance to infestation by insects. Female Plodia interpunctella (Hübner) could distinguish sealed packets containing food from non-food items as a suitable site for oviposition. Utilization ofthis technique will reduce the time needed to evaluate new materials for use in insect resistant packaging.
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Vorratsschädigende Lepidoptera und Coleoptera in Berlin während der Jahre 1991–1997—Überblick und Tendenzen
Article
  • Feb 1999
During 1991 to 1997 4078 samples sent in by public and private institutions were tested for their attack by arthropods. 5994 determinations were done. Seven the store damaging species of Lepidoptera were observed.Plodia interpunctella was the prime pest (305 determinations, mainly in cornflakes, muesli, sunflower seeds, nuts, feed, milk porredge and chocolate products). The percentage ofP. interpunctella increased from 4,3% (1991) to 5.6%–8.4% (for 1993). Larvae and adults and pure larvae samples ofP. interpunctella were mainly noticed from September to November. Pure adults samples could be counted for the most part from March to September. 27 the store damaging Coleoptera-species were determined.Stegobium paniceum was the prime pest (164 samples). 4% of the samples involvedS. paniceum. Further mainly observed beetle-species were:Lasioderma serricorne (36 samples),Tenebrio molitor (in 75 samples) andTrogoderma angustum (134 samples).
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Mechanisms Underlying Sawtoothed Grain Beetle ( Oryzaephilus surinamensis [L.]) (Coleoptera: Silvanidae) Infestation of Consumer Food Packaging Materials
Article
The sawtoothed grain beetle, Oryzaephilus surinamensis (L.), is an extremely destructive pest of packaged consumer food products. The beetle is not believed to chew directly through packaging materials, but to use openings or flaws in damaged or improperly sealed packages to gain entry. We investigated the behavioral mechanisms by which the sawtoothed grain beetle infests packages with flaws. Significantly more sawtoothed grain beetles infested consumer food packages that had been punctured with 0.4 mm diameter holes, to simulate packaging flaws that preclude adults, than when packages had no flaws. In a test arena, females laid more eggs into or near the hole in a plastic packaging film, when they were able to contact the food through the hole than when they could not contact the food. First instar larvae placed either 1 mm or 1 cm away entered holes when food was present, indicating that packages could become infested if eggs were laid near holes. In the absence of food, neither adults nor larvae responded to holes. This study has shown the importance of sound packaging in preventing insect infestation.
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Influence of phosphine on hatching of Cryptolestes ferrugineus (Coleoptera: Cucujidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae)
Article
  • Nov 2004
The hatching and mortality response of 0- to 48-h-old eggs of field strains of the stored-product insects Cryptolestes ferrugineus (Stephens), Lasioderma serricorne (F) and Oryzaephilus surinamensis (L) following phosphine fumigation for 24, 48 or 120 h at 27 (+/- 2) degrees C was investigated. Hatching was delayed and reduced in the first few days in a phosphine-resistant strain of C ferrugineus that was treated with 2.0-7.0 mg litre(-1) doses for 48 h (5-80% mortality) and with 1.0-2.0 mg litre(-1) for 120 h (44-84% mortality). In both the exposures there were significant increases in hatching on later days when compared with the corresponding controls. Developmental delay was, however, not evident in susceptible strains of C ferrugineus, L serricorne and O surinamensis that were exposed to phosphine for 24 h.
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Insect infestation and food packaging. Paper presented to the 16th Federation of Asian & Oceania Pest Managers Associations Convention and International Exhibition
  • M Kelly
Kelly, M., 2004. Insect infestation and food packaging. Paper presented to the 16th Federation of Asian & Oceania Pest Managers Associations Convention and International Exhibition, 25-26 November 2004, Mumbai, India. pp. 45-47.