Prospect of propolis from stingless bee, Heterotrigona itama as biological control of the subterranean termite, Coptotermes curvignathus

Abstract

This study applies a propolis from a stingless bee, Heterotrigona itama as an alternative to control the infestation of a subterranean termite, Coptotermes curvignathus . The objective of this study was to assess the antitermitic activity of stingless bee’s propolis as termiticide based on its repellency activity, contact toxicity effect as well as its ability to act as cellulase inhibitor. The bioactive components of the propolis in terms of the phenolics and flavonoids content were also determined. It was observed that the propolis is a termite’s repellent with a preference index of -0.73. Upon contact, it can kill 50% of the termite’s population within 1.5 hours with lethal concentration of about 16% (w/v). It’s extract also can inhibit cellulase activity of termites. Diameter of the clear zone on the CMC agar was found to be significantly reduced from 3.1 cm to 2.4 cm when 30% (w/v) propolis’s extract was added into the termite extract at the ratio of 1 to 4 (termite: propolis extract). In conclusion, from the results obtained, propolis from Heterotrigona itama has high potential to be used as an environmentally safe alternative to chemical termiticide.

Full text

IOP Conference Series: Earth and Environmental Science
PAPER • OPEN ACCESS
Prospect of propolis from stingless bee,
Heterotrigona itama
as
biological control of the subterranean termite,
Coptotermes curvignathus
To cite this article: H A Zakeri et al 2021 IOP Conf. Ser.: Earth Environ. Sci. 711 012018
View the article online for updates and enhancements.
This content was downloaded from IP address 178.171.65.8 on 24/03/2021 at 01:30

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution
of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Published under licence by IOP Publishing Ltd
The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
1
Prospect of propolis from stingless bee, Heterotrigona itama as
biological control of the subterranean termite, Coptotermes
curvignathus
H A Zakeri1,2*, M Kannan1, N M Kumar1, and W A Azmi1
1Faculty of Science and Marine Environment, Universiti Malaysia Terengganu (UMT),
21030 Kuala Nerus, Terengganu, Malaysia
2EnviroGroup, Biological Security and Sustainability (BioSES) Research Interest
Group, Faculty of Science and Marine Environment, Universiti Malaysia Terengganu
(UMT), 21030 Kuala Nerus, Terengganu, Malaysia
*E-mail: hazlina@umt.edu.my
Abstract. This study applies a propolis from a stingless bee, Heterotrigona itama as an
alternative to control the infestation of a subterranean termite, Coptotermes curvignathus. The
objective of this study was to assess the antitermitic activity of stingless bee’s propolis as
termiticide based on its repellency activity, contact toxicity effect as well as its ability to act as
cellulase inhibitor. The bioactive components of the propolis in terms of the phenolics and
flavonoids content were also determined. It was observed that the propolis is a termite’s repellent
with a preference index of -0.73. Upon contact, it can kill 50% of the termite's population within
1.5 hours with lethal concentration of about 16% (w/v). It’s extract also can inhibit cellulase
activity of termites. Diameter of the clear zone on the CMC agar was found to be significantly
reduced from 3.1 cm to 2.4 cm when 30% (w/v) propolis’s extract was added into the termite
extract at the ratio of 1 to 4 (termite: propolis extract). In conclusion, from the results obtained,
propolis from Heterotrigona itama has high potential to be used as an environmentally safe
alternative to chemical termiticide.
1. Introduction
Termites cause serious threats to the urban environment and farming field. They bring in great damage
to wooden structures and buildings as well to valuable crops and young forestry plantations. From more
than 2800 known species of termites, roughly 185 of them are considered as pests [1]. For example,
termites of the families Termitidae, Kalotermidae, Hodotermidae and Rhinotermitidae have instigated a
huge damage in industries involved in agriculture [2]. Of these families, the genus Coptotermes of the
Rhinotermitidae is said to be the pestiferous termites which contribute to 85% of the infestation and has
caused more economic impact compared to the other genus [2]. Coptotermes curvignathus or rubber
termite is the largest Coptotermes species in Asia and it has been known, among others, to infest rubber
[3]; oil palm [4]; and coconut [5]. All these species of trees are economically important in Malaysia.
Various strategies have been used to control the infestation of termites, thus, minimising the damages
and loss due to the termites feeding behaviour. Most of the strategies employed chemicals. These include
the use of chemical termiticides which contain active ingredients such as fipronil, bifenthrin,
chlorantraniliprole, cyantraniliprole, imidacloprid, chlorfenapyr, and indoxacarb [6, 7]. Nonetheless,
there are numerous detrimental impacts which resulted from the usage of chemical termiticides [8].

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
2
These chemically synthesized termiticides are hazardous to the environment and the cryptic life style
of termites makes their direct application difficult [9]. The use of termiticides of biological origin,
especially from botanical sources, has thus become increasingly popular nowadays to replace the
chemicals. For example, in the control of the termite C. curvignathus, extracts from Aquilaria
malaccensis [10], Scorodocarpus borneensis [11] and Cinnamomum parthenoxylon [12] were applied.
They are more environmentally safe, have low health risk, low in cost and are available abundantly.
However, there is poor understanding of the mode of action of the substances contained in the botanical
pesticides, which appears to differ according to the individual compounds [13].
Propolis or bee glue, is an essential combination of resins synthesized by bees from the compounds
gathered from many plant sections. Plants are known to possess bioactive compounds, such as phenolics
and flavonoids, that can be formulated in many applications. Even though propolis is popular among the
people as medicine, the bioactive compounds found in propolis can also be used as an alternative to
replace the chemical termiticides. A successful pesticide or termiticide may exhibit repellent activity
[14, 15, 16], toxic upon contact or ingestion [14, 15, 16] and starving the pest either by acting as
antifeedant [11, 17, 18] or inhibiting the cellulase activity [19, 20, 21].
In this study, we use propolis from a stingless bee, Heterotrigona itama against a subterranean
termite, C. curvignathus by observing the propolis repellent/attractant activity, its contact toxicity and
its ability to inhibit the activity of the termite’s cellulase. The quantitative analysis of bioactive
compounds, particularly of phenolics and flavonoids, in the propolis was also carried out. This is to
determine the prospect of propolis as an alternative to replace chemical termiticides.
2. Materials and Methods
2.1 Materials
The frozen sample of stingless bee’s, Heterotrigona itama, propolis was obtained from Taman Pertanian
Negeri, Sekayu, Kuala Berang, Terengganu Darul Iman, Malaysia. The propolis was stored at -80°C
until further use. A subterranean termite species, Coptotermes curvignathus, was collected from nests
located within the Universiti Malaysia Terengganu campus. The termites were placed in plastic
containers and fed with dry wood. Muslin cloth was used to cover the top of the containers.
2.2 Extraction and Preparation of Propolis from H. itama
A 200 g frozen sample of propolis was prepared as described by [22]. The frozen propolis was first
homogenized in an electric blender and macerated in 70% ethanol at a ratio of 1 g propolis to 9 mL
ethanol. Then, the ethanolic extract of propolis was left at a cool and dark area for 10 days. After 10
days, the extract was subjected to rotary evaporation at 60°C for 2h. The propolis extract obtained was
freeze-dried to a powder form. It was stored at -20°C until further analyses.
2.3 Determination of Total Phenolics and Total Flavonoids Content of Propolis Extract
Total phenolics content (TPC) of propolis was determined according to the Folin-Ciocalteu method as
explained in [23]. Firstly, a 0.1 g powdered form of propolis was dissolved in 1 mL of 55% ethanol to
get a 10% (w/v) propolis solution. An aliquot of 200 μL was taken from the stock and added to a 1 mL
Folin-Ciocalteu reagent. The mixture was then left at room temperature for 3 min. After 3 min, the
mixture was added to a 10% sodium bicarbonate. The final volume of the solution was adjusted to 10
mL using distilled water. Following that, the solution was left in the dark for 90 min. The absorbance of
the solution was then read at 725 nm using a UV-VIS spectrophotometer. TPC of propolis was
determined by comparing the absorbance with that of a standard curve constructed from various
concentrations of gallic acid. TPC was expressed as mg of gallic acid equivalents (GAE) per mL of
propolis.
Total flavonoids content (TFC) of propolis was determined according to the methods as described
by [23]. As with TPC, a 10% (w/v) propolis solution was used for analysis. A 200 μL of the solution
was then mixed with 5% (w/v) sodium nitrite and distilled water, and left at room temperature for 5 min.
After 5 min, a 10% (w/v) AlCl3 was added and left at room temperature for 6 min. Then, a 1M NaOH

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
3
was added to the mixture. The final volume of the solution was adjusted to 10 mL using distilled water.
The absorbance of the solution was then read at 510 nm using a UV-VIS spectrophotometer. TFC of
propolis was determined by comparing the absorbance with that of a standard curve constructed from
various concentrations of quercetin. TFC was expressed as mg of quercetin equivalents (QE) per mL of
propolis.
2.4 Repellency Activity of Propolis Extract against the Termite C. curvignathus
To determine whether propolis can repel the termites, a repellent activity assay was carried out according
to [24] with some modifications. Three different concentrations of propolis, 10%, 20% and 30% (w/v),
were first prepared by mixing the powdered propolis with 55% ethanol. Petri dishes containing
Whatman No. 1 filter papers cut into halves each were also prepared. One half of the filter paper was
treated with a 200 μL propolis while the other half of the paper was treated with 55% ethanol which
served as control. After the treated filter papers were dry, ten termites were placed at the centre of the
petri dish. The petri dish was then left in darkness. After 1h, the number of termites found on each half
of the filter paper was calculated. Percentage of repellency (PR) was determined using the following
formula [24]:
% of repellency (PR) = [(C – T) / (C + T)] * 100
where, C is the number of termites observed on the ethanol halves, and, T is the number of termites
observed on the propolis halves.
The preference index (PI) of the propolis was also calculated using this formula [25]:
Preference index (PI) = (%T - %C) / (%T + %C)
where, %T is percentage of termites on propolis halves and %C is percentage of termites on ethanol
halves. PI values between – 1.0 and – 0.1 indicate repellent extract, - 0.1 to + 0.1 indicate neutral extract
and + 0.1 to + 1.0 indicate attractant extract.
2.5 Contact Toxicity of Propolis against the Termite C. curvignathus
To determine whether propolis can kill the termites externally, a contact toxicity assay was carried out
according to [26] with some modifications in terms of the incubation conditions. Three different
concentrations of propolis, 10%, 20% and 30% (w/v), were first prepared by mixing the powdered
propolis with 55% ethanol. Termites were then briefly dipped into each of the concentrations plus the
control (a 55% ethanol). Ten termites for each propolis concentrations and control were placed onto
petri dishes separately and kept at room temperature in darkness. Each experiment was replicated five
times. The number of dead termites was then counted every 1h interval for 3h. Percentage of mortality
(PM) was calculated according to the following formula [24]:
% of Mortality (PM) = (No. of dead termites / Total no. of termites) * 100
The LC50 and LT50 of propolis against termites were also calculated using probit analysis from a graph
of percentage cumulative mortality vs propolis concentrations or time of treatment in hours.
2.6 Extraction of Total Soluble Proteins of the Termite C. curvignathus
Total soluble proteins (TSP) of termites were extracted according to the method as described by [27]
with slight modifications where 0.5 M Tris-HCl buffer was used instead of 0.1 M and the centifugation
time used was 10 min instead of 20 min. Termites were first weighed and blended using an electric
blender. The suspension was then homogenized in 0.5 M Tris-HCl buffer at pH 8.5. The mixture was
filtered and the collected filtrate was further centrifuged at 10000 xg and 4°C for 10 min. The supernatant
containing the TSP was then used as the cellulase source.

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
4
2.7 Cellulase Inhibition Assay of Propolis Extract
To determine whether propolis can inhibit the cellulase activity of termites, anticellulase assay was
carried out following the methods by [27] using carboxymethyl cellulose (CMC) agar. Crude protein
extract of termites (100 μL), a 10% (w/v) propolis extract (100 μL) and crude protein extract of termites
with propolis extract (100 μL) were loaded onto a hole of 1 cm in diameter punched using a cork borer
located on the CMC-agar plate. Four different ratios of crude protein extract of termites with propolis
extract were analysed: 1:1, 1:2, 1:3 and 1:4, (termite:propolis). The CMC-agar were incubated at 50°C
overnight. After incubation, the plates were stained with 0.1% Congo red for 15 min with shaking and
then washed away with 1M NaCl several times. Cellulase activity was observed by the formation of a
clearing zone or halo. The diameter of the clearing zone or halo was then measured in cm and compared.
2.8 Statistical Analyses
Mean values and standard error were determined from three replicates of each treatment. The
statistically significant differences between the treatments were analysed using a one-way ANOVA
followed by Tukey HSD post-hoc test at probability level of 0.05. The statistical software used was
Daniel’s XL Toolbox 7.2.13 Add-in for Microsoft Excel.
3. Results and Discussion
The present study used the ethanolic extract of propolis from a stingless bee, Heterotrigona itama. Total
phenolics content (TPC) and total flavonoids content (TFC) of this extract was found to be 11.6±0.06
mg GAE/mL and 14.3±0.03 mg QE/mL, respectively. According to [28], propolis from H. itama mainly
consisted of terpenoids, flavonoids, phenols, essential oils, steroids, saponin and coumarins. However,
the chemical composition of propolis reportedly depends on the specificity of the local flora at the site
collection and also the vegetation preference of stingless bee species [28]. Phenolics and flavonoids
active compounds have been known to display insecticidal activities. For examples, taxifolin, a
flavonoid compound from conifer acts as insecticide synergist by inhibiting the activity of glutathione
S-transferases in a Colorado potato beetle [29]; phenolic compounds including flavonoids extracted
from seeds of a Taiwan native cereal plant, Chenopodium formosanum, have been observed to have an
insecticidal activity against the red flour beetle, Tribolium castaneum [30]; and, flavonoid glycosides
such as kaempferol, quercetin, and isorhamnetin derivatives, the major phenolic compounds of
the Agave americana leaf extract were observed to have insecticidal activities against the rice
weevil, Sitophilus oryzae [31]. In fact, phenolic compounds such as flavonoids, polyphenols and
diterpenes showed potent termicidal and antifeedant activities [32, 33]. Thus, due to the high content of
phenolics and flavonoids observed in the present study, they may play a role in the termiticidal activity
of propolis as discussed below.
A 30% (w/v) propolis exhibits a more than 70% repellency activity against the termites (Figure 1).
This value is significantly 47% higher than when a 10% (w/v) propolis was used. Preference index of
the three concentrations of propolis analysed was -0.27, -0.40 and -0.73 for 10%, 20% and 30% (w/v)
propolis, respectively. These values fall between -1.0 and -0.1 indicating that the propolis extracts are
repellent towards the termites [25]. Insects rely on chemical senses to adapt and survive. Insects possess
olfactory receptor neurons which play an important role in an insect’s behavioural ecology [34].
Chemicals inside the repellents may disrupt the olfactory orientation of insects to oviposition and food
substrate [35] or affect the different types of antennal olfactory sensilla in insects [36]. The evading
behaviour of termites toward the propolis-treated filter papers in our study was probably due to the
presence of strong toxic substances in the ethanolic propolis extract. This similar effect was also
observed in a study by [14] on two tropical termites, Globitermes sulphureus and Coptotermes gestroi
against the methanolic extracts of four tropical plants. Plants with repellent properties deter the pests by
stimulating their sensory organs before invading the plants, thus, lessen the negative impact on the
environment [37].

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
5
Figure 1. Repellency activity of different concentrations of H.
itama propolis against C. curvignathus. Different letters above
bars indicate significant difference between treatments at
p<0.05 (n=3).
It was observed that as high as 5 termites were found dead after 1h treatment with 30% (w/v) propolis.
After 3h, all 10 termites died (Figure 2). On average, 3 termites died per hour after treatment with 20%
(w/v) propolis compared to 2 died per hour after treatment with 10% (w/v) propolis. Probit analysis
showed that it took 1.5 h (i.e. LT50) and 15.9% (w/v) of propolis (i.e. LC50) to kill 50% of the termite’s
population.
Figure 2. Mortality of C. curvignathus after treatment with
different concentrations of H. itama propolis. Different letters
above bars indicate significant difference between treatments at
p<0.05 (n=3).
Our findings are comparable to previous studies on Coptotermes sp. For instances, essential oil from
Dipterocarpus sp. was reported to be more effective in killing C. curvignathus than essential oils from
Cinnamomum camphora, Cymbopogon nardus and Melaleuca cajuputi with LC50 of 1.62% at 24 h [38],
while, C. curvignathus was observed to be more susceptible compared to C. gestroi when coming into

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
6
contact with essential oil from Alpinia galanga with 50% lethal dose (LD50) of about 945 mg/kg [39].
In addition, [40] reported that among the three timber species tested, wood extract from Madhuca utilis
was found to be the most toxic against C. curvignathus with all termites dead within 15 days after
treatment. Even though there is not much studies done on the ability of propolis acting as termiticides,
several studies have reported the ability of propolis as insecticides. Ethanolic extract of propolis, for
example, has shown to cause mortality to the lesser wax moth Achroia grisella larvae [41] as well as the
greater wax moth Galleria mellonella L. larvae [42]. It took 5-7 days of treatment for propolis extract
to exhibit toxicity effects on the cotton leafworm Spodoptera littoralis [43].
In addition, plant essential oils from Lippia sidoides and Pogostemon cablin caused mortality of
the termite Nasutitermes corniger after 48 h of exposure with 50% lethal dose of 0.27 and 0.37 μg of
oil/mg of N. corniger, respectively [44] while an essential oil from Citrus grandis showed the highest
contact toxicity against the termite Odontotermes feae with 50% lethal concentration of 272 ppm at 6 h
[45]. According to [46], close contact to toxic plant’s extract would cause the termites to become
perplexed and eventually die.
The propolis also exhibits the capacity to inhibit the cellulase activity of C. curvignathus. This is
shown by the reduction of the clearing zone’s diameter on the CMC agar of extracts containing both
termites and propolis compared to that of only termites (Table 1). The propolis extract did not contain
cellulase since there is no clearing zone detected. As more propolis was added to a constant volume of
termite’s protein extract, the diameter of the clearing zone became significantly decreased, ranging from
5% to 22% reduction (Table 1).
Figure 3. CMC agar of termite’s extract (A), propolis extract (B) and mixture of termites and propolis
extracts (C) showing the clearing zone. Clearing zone indicates the presence of cellulase. (a indicates
the diameter of the clearing zone measured in cm).
Table 1. Diameter of clear zones on the CMC agar of termites, propolis and mixture of termites
and propolis at different ratios. Different letters after the values indicate significant differences
between extracts (p<0.05, n=5).
Extracts
Diameter of Clear Zones (Mean±SE cm)
Termites
3.04±0.03a
Propolis
-
Termites:propolis
1:1
2.88±0.02b
1:2
2.76±0.03c
1:3
2.56±0.03d
1:4
2.38±0.02e
Cellulase is an enzyme that is required by phytophagous insects including termites to digest the
wood. The ability to digest lignocellulose not only depends on their digestive tract physiology, but also
on the symbiotic relationship between termites and the microbiota present in their intestines

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
7
[47]. Enzyme assays and RNAi experiments indicate that endogenous cellulases play an important role
in termite metabolism [48]. Thus, one of the strategies that can be used to stop the feeding activity of
termites, and, potential termite treatment avenue, is by inhibiting the enzyme cellulase. Studies done on
the effectiveness of phenolics and flavonoids compounds as cellulase inhibitors were also reported.
Among others are the phenolic compounds, coumaric acid and ferulic acid which inhibited cellulase
production by Trichoderma reesei [49], and, two glycosylated flavonoids extracted from Mango leaves
which not only inhibit cellulase activity but retard the growth of a bacterium, Aulacophora foveicollis
[50].
Furthermore, other secondary metabolites in plants can also possess the ability to inhibit cellulose
degrading enzymes like cellulase. These include saponins and azadirachtin extracted from Neem plant
which can be a potential cellulase inhibitor for the red flour beetle, rice grasshopper and red pumpkin
beetle [19]. In a study by [51], three carbohydrate-based cellulase inhibitors, namely, cellobiose
imidazole (CBI), fluoromethyl cellobiose (FMCB) and fluoromethyl glucose (FMG), were observed to
be effective against the eastern subterranean termite, Reticulitermes flavipes. In addition, some toxic
proteins in plant’s essential oil are termiticidal by disrupting enzyme’s activity inside the termite’s gut
[52]. Therefore, in conclusion, propolis from the stingless bee, H. itama exhibits prospect to be used as
natural insecticide and replacement of chemical termiticides to minimise the infestation of the
subterranean termite, C. curvignathus. The propolis can act as repellent, is toxic upon contact as well as
able to starve the termite by inhibiting its cellulase function.
4. Conclusion
In conclusion, from the results obtained, propolis from Heterotrigona itama has high potential to be used
as an environmentally safe alternative to chemical termiticide. It was observed that the propolis is a
termite’s repellent with a preference index of -0.73. Upon contact, it can kill 50% of the termite's
population within 1.5 hours with lethal concentration of about 16% (w/v). It’s extract also can inhibit
cellulase activity of termites. Diameter of the clear zone on the CMC agar was found to be significantly
reduced from 3.1 cm to 2.4 cm when 30% (w/v) propolis’s extract was added into the termite extract at
the ratio of 1 to 4 (termite: propolis extract)
Acknowledgement
The authors acknowledged the School of Fundamental Science (now known as Faculty of Science and
Marine Environment), UMT for their support.
References
[1] Verma M, Sharma S and Prasad R 2009 Int. Biodeterior. Biodegradation 63 959-72.
[2] Baker P B and Bellamy D E 2006 J. Econ. Entomol. 99 1345-53.
[3] Hidayat M R, Endris W M and Dwiyanti Y 2018 Agric. Nat. Resour. 52 439-44.
[4] Loong C Y, Prastyo K C, Keong S E and Hoak O L 2017 Planter 93 357-62.
[5] Mahapatro G K and Kumar S 2015 Indian J. Entomol. 77 152-59.
[6] Mao L, Henderson G and Scherer C W 2011 J. Econ. Entomol. 104 1002-8.
[7] Sapkota R, Stout M J and Henderson G 2020 J. Econ. Entomol. 113 367-74.
[8] Azmi W, Sulaiman Z, Ishak I, Kin P, Lin G and Addis S 2016 Malays J. Microbiol. 12 492-97.
[9] Verma P, Yadav A N, Kumar V, Khan M A and Saxena A K 2018 Termites and Sustainable
Management: Sustainability in Plant and Crop Protection ed M Khan and W Ahmad
(Switzerland: Springer Nature) pp 197-217.
[10] Subekti N, Widiyaningrum P, Nurvaizah I and Mar’ah, R 2019 Sys. Rev. Pharm. 19 31-3.
[11] Sudrajat S, Kustiawan W, Mardji D and Kusuma I W 2018 J. Adv. Sci. Res. 9 24-30.
[12] Adfa M, Sanusi S, Manaf S, Gustian I and Banon C 2017 Orient. J. Chem. 33 3063-68.
[13] Campos E V R, Proença P L F, Oliveira J L, Bakshi M, Abhilash P C and Fraceto L F 2019 Ecol.
Indic. 105 483-95.

The 10th AIC-ELS 2020
IOP Conf. Series: Earth and Environmental Science 711 (2021) 012018
IOP Publishing
doi:10.1088/1755-1315/711/1/012018
8
[14] Bakaruddin N H, Deing H, Sulaiman S F and Ab Majid A H 2018 Inf. Process. Agric. 5 298-307.
[15] Wang Y, Zhang L-T, Feng Y-X, Guo S-S, Pang X, Zhang D, Geng Z-F and Du S-S 2019 Environ.
Sci. Pollut. Res. 26 24988-97.
[16] Oladipo-nee Ajayi O E, Oyeniyi E A and Elijah O A 2020 J. Basic Appl. Zool. 81 17.
[17] Afzal M, Farman M, Rasib K Z and Qureshi N A 2019 Int. Biodeterior. Biodegradation 139 1-10.
[18] Mukai A, Takahashi K, Kofujita H and Ashitani T 2019 Eur. J. Wood Prod. 77 311–17.
[19] Sami A J and Shakoori A R 2014 Biotechnol. J. Int. 4 904-17.
[20] Huang Y, Liu J, Pang T and Li L 2017 Biomass Bioenerg. 99 31-7.
[21] Tsetkov V O and Yarullina L G 2019 Appl. Biochem. Microbiol. 55 460-69.
[22] Garedew A, Lamprecht I, Schmolz E and Schricker B 2002 Apidologie 33 41-50.
[23] Ibrahim N, Zakaria A J, Ismail Z and Mohd K S 2016 Int. J. Pharmacogn. Phytochem. Res. 8 156-
61.
[24] Ojianwuna C, Olisedeme P and Ossai S L 2015 J. Entomol. Zool. Stud. 4 406-18.
[25] Chaubey, M K 2016 Entomol. Appl. Sci. Lett. 3 43-8.
[26] Ko K, Juntarajumnong W and Chandrapatya A 2009 Thai J. Agric. Sci. 42 27-33.
[27] Sami A J and Shakoori A R 2007 Proc. Pak. Congr. Zool. 27 105-18.
[28] Ibrahim N, Niza N S F M, Rodi M, Zakaria A J, Ismail Z and Mohd K S 2016 Malays J. Anal. Sci.
20 413-22.
[29] Wang Z, Zhao Z, Cheng X, Liu S, Wei Q and Scott I M 2016 Pestic. Biochem. Physiol. 127 1-7.
[30] Chuang K-J, Chen Z-J, Cheng C-L and Hong G-B 2018 Int. J. Mol. Sci. 19 2726-37.
[31] Maazoun A M, Hamdi S H, Belhadj F, Jemâa J M B, Messaoud C and Marzouki M N
2019 Environ. Sci. Pollut. Res. 26 19468-80.
[32] Boué S M and Raina A K 2003 J. Chem. Ecol. 29 2575-84.
[33] Kusumoto N, Ashitani T, Hayasaka Y, Murayama T, Ogiyama K and Takahashi K 2009 J. Chem.
Ecol. 35 635-42.
[34] de Bruyne M and Baker T C 2008 J. Chem. Ecol. 34 882-97.
[35] Germinara G S, Cristofaro A D and Rotundo G 2015 J. Pest Sci. 88 675-84.
[36] Liu F, Haynes K F, Appel A G and Liu N 2014 J. Chem. Ecol. 40 522-33.
[37] Addisu, S., Mohamed, D. and Waktole, S. 2013. Int. J. Agric. Res. 9 60-73.
[38] Roszaini K, Nor Azah M A, Mailina J M, Zaini S and Faridz Z M 2013 Wood Sci. Technol. 47
1273-84.
[39] Abdullah F, Subramanian P, Ibrahim H, Abdul Malek S N, Lee G S, Hong S L 2015 J. Insect Sci.
15 7.
[40] Kadir R 2017 Maderas-Cienc. Technol. 19 417-32.
[41] Ararso, Z. and Legesse, G, 2016. Agric. Biol. J. North Am. 7 302-6.
[42] Fawzy A, Al-Ahmadi S, Al-Hazmi H 2017 J. Plant Protect. Pathol. 8 407-13.
[43] Amer, R.A.M. and Nafea, E.A. 2011 J. Plant Protect. Pathol. 2 347-59.
[44] Lima J K A, Albuquerque E L D, Santos A C C, Oliveira A P, Araújo A P A, Blank A F, Arrigoni-
Blank M F, Alves P B, Santos D A and Bacci L 2013 Indust. Crop Prod. 47 246-51.
[45] Khanikor B, Barman J, Sarma R, Mahanta S, and Adhikari K 2018 J. Environ. Pollut. Human
Health 8 68-76.
[46] Osipitan A and Oseyemi A E 2012 J. Entomol. 9 257-65.
[47] Hassan B, Mankowski M E, Kirker G and Ahmed S 2017 Int. Biodeterior. Biodegradation 123 27-
36.
[48] Lo N, Tokuda G and Watanabe H 2010 Biology of Termites: a Modern Synthesis, ed D
Bignell, Y Roisin and N Lo (Dordrecht:Springer) p. 51-67.
[49] Zheng W, Zheng Q, Xue Y, Hu J and Gao M T 2017 J. Biosci. Bioeng. 123 731-38.
[50] Sami A J and Shakoori A R 2011 J. Med. Plant. Res. 5 184-90.
[51] Zhou X, Wheeler M M, Oi F M and Scharf M E 2008 Pestic. Biochem. Physiol. 90 31-41.
[52] Lima V L S, Bailez O E, Viana-Bailez A M 2013 Rev. Bras. Entomol. 57 309–12.