Research Article

Development and Evaluation of a Maize Cob Based Bait Formulation against Subterranean Termites (Odontotermes spp.)

Hassan Raza1, Muhammad Zeeshan Majeed1*, Muhammad Irfan Majeed2, Mujeeb-Ur-Rehman1 and Muhammad Asam Riaz1

1Department of Entomology, College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan; 2Department of Chemistry, University of Agriculture, Faisalabad, 38040, Pakistan.

Received | January 01, 2022; Accepted | February 25, 2022; Published | September 15, 2022

*Correspondence | Muhammad Zeeshan Majeed, Department of Entomology, College of Agriculture, University of Sargodha, Sargodha 40100, Pakistan; Email: zeeshan.majeed@uos.edu.pk

Citation | Raza, H., M.Z. Majeed, M.I. Majeed, M.U. Rehman and M.A. Riaz. 2022. Development and evaluation of a maize cob based bait formulation against subterranean termites (Odontotermes spp.). Sarhad Journal of Agriculture, 38(4): 1172-1183.

DOI | https://dx.doi.org/10.17582/journal.sja/2022/38.4.1172.1183

Keywords | Subterranean termites, Slow-release formulation, Fipronil bait, Termite monitoring station, Field evaluation

Copyright: 2022 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

Introduction

With more than 3,000 described species, termites (Insecta: Isoptera) constitute an important eusocial fauna in the tropical and subtropical ecosystems. These invertebrates feed upon decaying plant material including damp and dry wood, grasses and leaf litter. They are key components of plant decomposition and nutrients cycling and render many ecosystem services in terrestrial biomes (Abe et al., 2000; Schuurman, 2005; Majeed, 2012; Constantino, 2021).

Apart from their great ecological significance, many termite species (about 10% of known termite species) are economically important pests of agricultural and urban sectors (Mitchell, 2002; Govorushko, 2019). Subterranean termite species particularly are very damaging agricultural pests and cause substantial injury to wooden infrastructures, agricultural and horticultural crops and forest plantations all over the world including Pakistan (Rouland-Lefèvre, 2011; Manzoor et al., 2011; Rust and Su, 2012; Paul et al., 2018; Hussain et al., 2021).

In Pakistan, around 53 species of termites have been recorded in various biogeographical areas (Manzoor et al., 2009; Manzoor and Mir, 2010). In Punjab province, most damaging and economically important subterranean termite species belong to genera Microtermes and Odontotermes such as M. mycophagus, M. obesi, O. obesus and O. guptai. These species infest many agricultural crops including sugarcane, maize, sorghum, cotton, sesame, gram, wheat etc. and agro-forestry and tree plantations (Ahmed et al., 2008; Manzoor et al., 2011; Hussain et al., 2021).

Farmers rely primarily on the direct and extensive applications of synthetic insecticides such as imidacloprid, chlorpyrifos, bifenthrin, deltamethrin, lambda-cyhalothrin, hexaflumuron, indoxacarb and fipronil etc. to combat subterranean termite infestations (Su and Scheffrahn, 1996; 1998; Ahmed and Farhan, 2006; Iqbal and Saeed, 2013). These insecticides are mostly applied as liquid formulations and often get off the target site through leaching, evaporation and rapid decomposition by weather extremes resulting in unsatisfactory and short-term termite eradication and also pose ecological consequences such environmental contaminations and human health hazards (Fernández-Pérez, 2007; Huang et al., 2018; Meftaul et al., 2020).

This situation necessitates looking for more target-oriented and ecologically safer strategies such as slow-release formulations in which a non-repellent toxicant is baited with some pest attractant material and is formulated in such a way that it can persist and remains effective against pests for longer period of time than the direct application of toxicant itself (Grace and Su, 2001; Davies et al., 2021). Termite baits are being effectively used to eliminate the pest termites for last few decades and usually toxicant-laced cellulosic foodstuff such as cardboard or wood are often employed in commercial termite baiting systems (Grace and Su, 2001; Tracy, 2003; Glenn et al., 2008; Zhang et al., 2009; Hamm et al., 2013; Su et al., 2016; Davies et al., 2021).

Here we developed and evaluated a maize cob based bait formulation of fipronil against subterranean termites (Odontotermes spp.) under the laboratory and field conditions. Fipronil is a non-repellent phenylpyrazole insecticide acting as GABA-gated chloride channel blocker (Grant et al., 1998), and has been widely used as an active ingredient in different baits against many insect pests including termites (Collins and Callcott, 1998; Shelton and Grace, 2003; Huang et al., 2006; Mao et al., 2011; Iqbal and Evans, 2018; Peters et al., 2019).

Materials and Methods

This research work was carried out in the Laboratory of Entomology, College of Agriculture, University of Sargodha and in a sugarcane (Saccharum officinarum L.) field situated in surroundings of College of Agriculture (72°41’35” E; 32°07’54” N).

Procurement of experimental material

Fipronil ((5-amino-1-[2,6-dichloro-4-(trifluoromethyl) -phenyl]-4-[(trifluoromethyl)-sulfinyl]-1H- pyrazole-3-carbonitrile) is an effective synthetic termiticide and belongs to phenylpyrazole group of insecticides. Technical grade fipronil (purity: 95%) was procured from Ruina International Co., Beijing, China through Ali Akbar Group Pvt. Ltd, Pakistan. Sodium silicate and sodium alginate (97.9%; Sigma- Aldrich, MO, USA) were imported and provided by Chemical House Pvt. Ltd., Lahore, Pakistan. Starch and Urea (99.9%; Merck-Schuchardt, Germany) were purchased from local scientific store. Cobs of a full season white grain variety (Gohar-19) of maize (Zea mays L.) were acquired from a local farmer. PVC pipes and corrugated cardboard sheets for termite monitoring stations were procured locally from the market.

Preparation of bait matrix

Three kilogram maize cobs were cut into small pieces and were air-dried under sunlight for three days. These dried cobs were further crushed into fine powder through a heavy duty electric blender and then were sieved to get fine powder. Maize cob based bead formulation was prepared following a slightly modified previously described method (Singh et al., 2009). In brief, a 500 mL glass beaker was filled with 100

 

 

mL of warm distilled water and 5 g fipronil, 6 g sodium alginate, 4 g sodium silicate were added in it and were mixed thoroughly with the help of a stirrer. Then, 2 g urea, 18 g starch and 350 mL semi-hot water was further added and stirred for two to three min. In the third step, 65 g grinded maize cob was added in it and the matrix was thoroughly mixed for 5 min. Composition of bait matrix ingredients is detailed in Table 1.

 

Table 1: List of ingredients used for the preparation of maize-cob based matrix of fipronil bait formulation.

Bait ingredients	Composition (%)
Technical grade fipronil (96% pure)	5
Maize-cob powder	65
Sodium alginate	6
Sodium silicate	4
Urea	2
Starch	18

All these ingredients were mixed in a sequence in 450 mL semi-hot distilled water to prepare the stock bait matrix.

 

Preparation of formulation beads

Prepared bait matrix was formulated in the form of small beads (Figure 1). For this purpose, bait matrix was first lined as a 1.5 mm layer in a Petri-plate and was allowed to be dried for thirty min. Then, small quantity of bait matrix was collected from the Petri-plate by using a plastic straw and was blown on another Petri-plate set on an orbital shaker running at a speed of 270 rpm. The purpose of this shaking was to make the beads round. The size of bead was measured with the help of a screw gauge. The average bead size was 3.5 mm.

Stability test of formulation beads

This preliminary test was conducted in order to determine the integrity of prepared formulation beads that whether they get distorted or not after the irrigation/rain episode under the field conditions. It was checked in two ways. One was evaluation on a Whatman No. 1 filter paper disc and second was on sieved agricultural soil to simulate field conditions (Figure 2). Three replications were set for each method. For this test, nine beads were arranged in each Petri-plate (150 mm Ø) and plates were moistened regularly at 24 h time intervals for 5 consecutive days. Observations on texture and integrity of the bait beads were recorded on daily basis.

Termite attraction test for formulated beads

In this experiment, potential attraction of 15 work

 

er individuals of subterranean termite (Odontotermes spp.; Termitidae) was evaluated by placing 10 formulation beads per Petri-plate (150 mm Ø). One of the Petri-plates was having moist Whatman No. 1 filter paper disc and the second had moistened sieved agricultural field soil as test media (Figure 3). The variation in media was kept in order to observe if termites feed on the filter paper or get attracted and feed on the maize cob based formulation beads.

Preparation of termite monitoring stations

Eleven PVC pipes, each with 3 inches diameter and 1.5 feet length, were taken and twenty holes (8 mm Ø) were made randomly on all sides of each pipe with a drill machine (Figure 4). Then, a moistened corrugated cardboard roll was inserted into each pipe. One side of each pipe was wrapped up with a plastic sheet in order to hold the cardboard roll intact inside the pipe.

Field assessment of bait formulation of fipronil against subterranean termite colonies

Alive and active 11 termite mounds were searched and selected in a sugarcane field and it was ensured that all mounds had active termite colonies and activ

 

ities. Each monitoring stations were installed 6 inches away from the mound, after digging up the soil with a metallic soil corer (90 mm Ø). These termitemonitoring stations were inspected regularly for the infestation of subterranean termites at every third day and cardboards were changed on every sixth day. After observing the activity of termites, 10 highly infested monitoring stations were selected for bait application and evaluation. Five stations were treated with fipronil-loaded formulation beads while five were exposed to beads without fipronil as control. Within each termite-infested monitoring station, 15 pre-moistened bait beads (weighing approximately 0.5 g) were placed (Figure 4) and observations regarding the termites’ activity inside each station were observed at 15 and 30 days post-treatment. For ensuring termite infestation, the cardboards present inside the monitoring stations were pulled out and the termite individuals were counted on them and the condition of formulation beads were also inspected carefully.

Results and Discussion

Stability test of formulated maize cob based beads

Whatman No. 1 filter paper discs were used in the 1st treatment and sieved soil collected from agricultural field was used in the 2nd treatment. Water was applied to simulate field irrigation in each Petri-plate and then was allowed to dry. There was no evidence of disintegration of beads after five simulated field irrigation in five consecutive days. The formulated beads were stable after irrigated five times with the interval of 24 h and no beads were found broken or disintegrated till the end of experiment (Figure 2).

Termite attraction test

Termites (Odontotermes spp.) were collected from the adjacent sugarcane field and were placed in the dark for 24 h, then randomly collected active and healthy termite workers were exposed to formulated beads in Petri-plates. First Petri-plate had moistened Whatman No. 1 filter paper discs and the second Petri-plate had moistened sieved agricultural field soil with 10 beads placed in each treatment. After 6 h, almost 50% of the released termite individuals moved towards the formulated beads. Some termite individuals were attached on the beads and fed on it. In other treatment, some termites fed on the edges of the filter paper discs, while about 50% individuals were attracted towards the formulated maize cob based beads (Figure 3).

Field evaluation of fipronil bait bead formulation against foraging subterranean termites

Maximum termites’ feeding and foraging activities were observed inside the control termite infested monitoring stations (Figure 5). Whole stations were filled up with the excavating soil when viewed from top or down side of the station. Cardboard sheets were completely infested by the termites throughout the height of station with a lot of foraging termite individuals found in the entire cardboard material. Moreover, when installed monitoring stations were removed out, we found some intact portions of termite fungal garden (termitarium) along with the eggs and immatures of the termites (Figure 5) ensuring that infesting termite species was Odontotermes spp.

On the other hand, when termite monitoring stations,

 

 

treated with fipronil-containing formulation beads, were dug out, no activity or population of termites was observed inside or at bottom of the monitoring sheet as shown in Figure 6. Formulation beads seemed to be semi-exploited by the termite individuals. Cardboard sheets were thoroughly inspected but there were no live termite foragers inside the cardboard sheets.

Subterranean termites pose a serious threat to agricultural and urban sectors all over the world. In semi-arid subtropical regions such as Sargodha and other rain-fed areas of Pakistan, subterranean termites is emerging as a challenging pest attacking a number of agricultural crops including wheat, gram, maize, sorghum, sugarcane and sesame etc. (Manzoor et al., 2011; Buczkowski and Bertelsmeier, 2017; Hussain et al., 2021). Currently available termiticides being used by the indigenous farmers are mostly in liquid form (Hu, 2011; Akbar et al., 2019) and exhibit unsatisfactory and short-term control of termite infestations most probably due to off-target movement (Wiltz, 2012; Rashid et al., 2018) and quick degradation of these applied insecticides (Huang et al., 2018).

More target-oriented and persistent formulations such as controlled-release termiticide baits present a promising strategy to alleviate this problem. Many such bait formulations have been demonstrated effective against various insect pests including subterranean termites and other soil inhabiting pests such as cockroaches, ants, wasps, fleas and turf insects (Collins and Callcot, 1998; Shelton and Grace, 2003; Overmyer et al., 2005; Zhang et al., 2009; Durier and Rivault, 2000; Mao et al., 2011; Rashid et al., 2012; Hamm et al., 2013; Su et al., 2016; Davies et al., 2021).

In laboratory tests, it was recorded that formulated bead baits remained intact and did not disintegrate even after several wetting and drying episodes demonstrating the binding properties of polymers sodium silicate, sodium alginate and starch. All these polymers are used in most of slow- or controlled-release pesticide formulation matrices (Fernandez-Perez, 2007; Glenn et al., 2008; Singh et al., 2009; Osbrink et al., 2011; Chen et al., 2017; Ashitha and Mathew, 2020). Similarly, other additives such as urea are known to influence the release dynamics and physico-chemical properties of such pesticide formulations (Wang and Wu, 2003; Cao et al., 2005).

It was observed that formulated bait beads attracted more than 50% termite workers in 6 h exposure. This finding corroborates the fact that maize cob constitute a cost-effective source of natural cellulose with dual advantage that it can keep the pesticidal compounds for longer time and can attract termites more efficiently than other natural cellulose sources (Lenz and Evans, 2002; Varvel and Wilhelm, 2008; Wang and Henderson, 2012).

Current investigations report significant suppression of termites’ feeding and foraging activities inside the monitoring stations treated with fipronil baited beads. This might be possible due to the elimination of complete or partial disruption of foraging individuals approaching baited stations and nearby subterranean termite colonies. It was further verified by the presence of foraging ants observed in the termite stations treated with fipronil-loaded beads at 1st and 2nd week inspection as ants are efficient predators of subterranean termites (Tuma et al., 2020). Many previous studies have concluded that entire colony of subterranean termites can be eliminated by termite baits and controlled-release formulations (Grace et al., 1996; Tsunoda et al., 1998; Peters and Fitzgerald, 1999; Prabhakaran, 2001; Fernández-Pérez, 2007; Evans, 2010; Neoh et al., 2011; Eger et al., 2012; Webb, 2017).

Our results are also in line with those of Iqbal and Evans (2018) who showed under laboratory and field conditions that 5-7% fipronil treated toilet paper baits were more effective than imidacloprid as bait ingredient and eliminated all five colonies as compared to control and imidacloprid treatments. Moreover, our research findings are in line with Huang et al. (2006) revealing that fipronil bait was very efficient in eliminating O. formosanus colonies in the field. Similarly, findings of this study corroborate the results of Sarmad et al. (2020), where they demonstrated that macrocosm soils, treated with 5% technical grade fipronil formulated as maize cob based pellets, were toxic against subterranean termite O. obesus worker individuals till 15–21 days post-treatment and caused 70–85% termite mortality in 48 h bioassays.

Conclusions and Recommendations

Results of these laboratory and field trials indicate that formulated fipronil beads remained intact and did not disintegrate by consecutive episodes of wetting and drying of five days and were able to attract more than 50% termite individuals exposed in 90 mm diameter Petri-plates. Moreover, these beads seem suppressing the foraging activities of subterranean termite workers in the field for few weeks post-treatment. These study results overall corroborate the effectiveness of fipronil and formulated beads to be further tested and potential incorporation in environment-friendly and target-specific management of subterranean termites in agricultural crops. However, further more detailed investigations are needed to get more empirical data regarding this formulation and to determine the insecticide release kinetics (Cao et al., 2005) and potential biological and physico-chemical and environmental factors influencing the efficiency (Glenn et al., 2008) of these formulated beads under laboratory and field conditions.

Novelty Statement

This study describes an attempt to develop and evaluate a 5% technical grade fipronil against subterranean termites (Odontotermes spp.) under field conditions. Results demonstrated a considerable suppression of active termite colonies in the sugarcane field by the application of formulated beads of fipronil bait.

Authors’ Contribution

Muhammad Zeeshan Majeed and Muhammad Asam Riaz: Conceived the idea and designed the experimental protocols.

Hassan Raza: Conducted the experiments and recorded data.

Muhammad Irfan Majeed: Provided the technical support during research work.

Hassan Raza and Muhammad Zeeshan Majeed: Prepared the manuscript.

Muhammad Zeeshan Majeed and Muhammad Asam Riaz: Provided financial assistance and technically proofread the manuscript.

Conflict of Interest

The authors declare no conflict of interest regarding the publication of this research work.

References

Abe, T., D.E. Bignell and Higashi, M. 2000. Termites: Evolution, Sociality, Symbioses, Ecology. Springer, Dordrecht, 466. https://doi.org/10.1007/978-94-017-3223-9

Ahmed, S. and M. Farhan. 2006. Laboratory evaluation of chlorpyrifos, bifenthrin, imidacloprid, thiamethoxam and flufenoxuron against Microtermes obesi (Isoptera: Termitidae). Pak. Entomol., 28: 45–49.

Ahmed, S., M.R. Ashraf, M.A. Hussain and M.A. Riaz. 2008. Pathogenicity of isolates of Metarhizium anisopliae from Murree (Pakistan) against Coptotermes heimi (Wasmann) (Isoptera: Rhinotermitidae) in the laboratory. Pak. Entomol., 30: 119–125.

Akbar, M.S., M. Aslam, M.R. Khalid, S. Iqbal, M. Luqman and M.Z. Majeed. 2019. Comparative toxicity of methanolic extracts of some indigenous and exotic flowers against subterranean termites Odontotermes obesus (Isoptera: Termitidae). Pak. J. Agric. Res., 32: 636–641. https://doi.org/10.17582/journal.pjar/2019/32.4.636.641

Ashitha, A. and J. Mathew. 2020. Characteristics and types of slow/controlled release of pesticides. In: Controlled Release of Pesticides for Sustainable Agriculture (eds. Rakhimol, K.R., S. Thomas, T. Volova and K. Jayachandran), Springer-Verlag, Berlin, Germany, pp. 141–153. https://doi.org/10.1007/978-3-030-23396-9_6

Buczkowski, G. and C. Bertelsmeier. 2017. Invasive termites in a changing climate: A global perspective. Ecol. Evol., 7: 974–985. https://doi.org/10.1002/ece3.2674

Cao, Y., L. Huang, J. Chen, J. Liang, S. Long and Y. Lu. 2005. Development of a controlled release formulation based on a starch matrix system. Int. J. Pharm., 298: 108–116. https://doi.org/10.1016/j.ijpharm.2005.04.005

Chen, K., G. Yu, F. He, Q. Zhou, D. Xiao, J. Li and Y. Feng. 2017. A pH-responsive emulsion stabilized by alginate-grafted anisotropic silica and its application in the controlled release of λ-cyhalothrin. Carbohyd. Polym., 176: 203–213. https://doi.org/10.1016/j.carbpol.2017.07.046

Collins, H.L. and A.M.A. Callcott. 1998. Fipronil: an ultra-low-dose bait toxicant for control of red imported fire ants (Hymenoptera: Formicidae). Fla. Entomol., 81: 407–415. https://doi.org/10.2307/3495930

Constantino, R. 2021. Termite taxonomy from 2001–2021: The contribution of Zootaxa. Zootaxa, 4979: 222–223. https://doi.org/10.11646/zootaxa.4979.1.22

Davies, A.B., C.L. Parr and P. Eggleton. 2021. A global review of termite sampling methods. Insect. Soc., 68: 1–12. https://doi.org/10.1007/s00040-020-00797-y

Durier, V. and Rivault, C. 2000. Secondary transmission of toxic baits in German cockroach (Dictyoptera: Blattellidae). J. Econ. Entomol., 93: 434–440. https://doi.org/10.1603/0022-0493-93.2.434

Eger Jr, J.E., M.D. Lees, P.A. Neese, T.H. Atkinson, E.M. Thoms, M.T. Messenger and M.P. Tolley. 2012. Elimination of subterranean termite (Isoptera: Rhinotermitidae) colonies using a refined cellulose bait matrix containing noviflumuron when monitored and replenished quarterly. J. Econ. Entomol., 105: 533–539. https://doi.org/10.1603/EC11027

Evans, T.A. 2010. Rapid elimination of field colonies of subterranean termites (Isoptera: Rhinotermitidae) using bistrifluron solid bait pellets. J. Econ. Entomol., 103: 423–432. https://doi.org/10.1603/EC09067

Fernández-Pérez, M. 2007. Controlled release systems to prevent the agro-environmental pollution derived from pesticide use. J. Environ. Sci. Heal., 42: 857–862. https://doi.org/10.1080/03601230701555138

Grant, D.B., A.E. Chalmers, M.A. Wolff, H.B. Hoffman and D.F. Bushey. 1998. Fipronil: action at the GABA receptor. In: Pesticides and the future: minimizing chronic exposure of humans and the environment (eds. Kuhr, R.J. and N. Motoyama), IOS Press, Amsterdam, pp. 147–156.

Glenn, G.J., J.W. Austin and R.E. Gold. 2008. Efficacy of commercial termite baiting systems for management of subterranean termites (Isoptera: Rhinotermitidae) in Texas. Sociobiol., 51: 333–362.

Govorushko, S. 2019. Economic and ecological importance of termites: A global review. Entomol. Sci., 22: 21–35. https://doi.org/10.1111/ens.12328

Grace, J.K. and N.Y. Su. 2001. Evidence supporting the use of termite baiting systems for long-term structural protection (Isoptera). Sociobiol., 37: 301–310.

Grace, J.K., C.H.M. Tome, T.G. Shelton, R.J. Oshiro and J.R. Yates. 1996. Baiting studies and consideration with Coptotermes formosanus (Isoptera: Rhinotermitidae) in Hawaii. Sociobiol., 28: 511–520.

Hamm, R.L., J.J. DeMark, E. Chin-Heady and M.P. Tolley. 2013. Consumption of a durable termite bait matrix by subterranean termites (Isoptera: Rhinotermitidae) and resulting insecticidal activity. Pest Manage. Sci., 69: 507–511. https://doi.org/10.1002/ps.3401

Hu, X.P. 2011. Liquid termiticides: their role in subterranean termite management, In: Urban Pest Management: an Environmental Perspective (ed. Dhang D.), CABI, Wallingford, Oxon, UK, pp. 114–132. https://doi.org/10.1079/9781845938031.0114

Huang, Q.Y., C.L. Lei and D. Xue. 2006. Field evaluation of a fipronil bait against subterranean termite Odontotermes formosanus (Isoptera: Termitidae). J. Econ. Entomol., 99: 455–461. https://doi.org/10.1093/jee/99.2.455

Huang, Y., L. Xiao, F. Li, M. Xiao, D. Lin, X. Long and Z. Wu. 2018. Microbial degradation of pesticide residues and an emphasis on the degradation of cypermethrin and 3-phenoxy benzoic acid: a review. Molecules, 23: 2313. https://doi.org/10.3390/molecules23092313

Hussain, D., M. Asrar, B. Khalid, F. Hafeez, M. Saleem, M. Akhter, M. Ahmed, I. Ali and K. Hanif. 2021. Insect pests of economic importance attacking wheat crop (Triticum aestivum L.) in Punjab, Pakistan. Int. J. Trop. Insect Sci., 1–12. https://doi.org/10.1007/s42690-021-00574-9

Iqbal, N. and T.A. Evans. 2018. Evaluation of fipronil and imidacloprid as bait active ingredients against fungus-growing termites (Blattodea: Termitidae: Macrotermitinae). Bull. Entomol. Res., 108: 14–22. https://doi.org/10.1017/S000748531700044X

Iqbal, N. and S. Saeed. 2013. Toxicity of six new chemical insecticides against the termite, Microtermes mycophagus D. (Isoptera: Termitidae: Macrotermitinae). Pak. J. Zool., 45: 709–713.

Lenz, M. and T.A. Evans. 2002. Termite bait technology: Perspectives from Australia. In: Proceedings of the 4th International Conference on Urban Pests, pp. 7–10.

Majeed, M.Z. 2012. Emissions of nitrous oxide by tropical soil macrofauna: Impact of feeding guilds and microbial communities involved. Doctoral dissertation, University of Montpellier II, France.

Manzoor, F. and N. Mir. 2010. Survey of termite infested houses, indigenous building materials and construction techniques in Pakistan. Pak. J. Zool., 42: 693–696.

Manzoor, F., M. Chaudhary, N. Sheikh, I.A. Khan and T. Khan. 2011. Diversity and proportion of termite species in garden trees and wheat crop in District Bhakkar, Pakistan. Pak. J. Zool., 43: 537–541.

Manzoor, F., K. Zameer, S.A. Malik, K.J. Cheema and A. Rahmin. 2009. Comparative studies on two Pakistani subterranean termites (Isoptera: Rhinotermitidae, Termitidae) for natural resistance and feeding preferences in laboratory and field trials. Sociobiol., 53: 259–274.

Mao, L., G. Henderson and C.W. Scherer. 2011. Toxicity of seven termiticides on the Formosan and eastern subterranean termites. J. Econ. Entomol., 104: 1002–1008. https://doi.org/10.1603/EC11005

Meftaul, I.M., K. Venkateswarlu, R. Dharmarajan, P. Annamalai and M. Megharaj. 2020. Pesticides in the urban environment: A potential threat that knocks at the door. Sci. Total Environ., 711, 134612. https://doi.org/10.1016/j.scitotenv.2019.134612

Mitchell, J.D. 2002. Termites as pests of crops, forestry, rangeland and structures in southern Africa and their control. Sociobiol., 40: 47–69.

Neoh, K.B., N.A. Jalaludin and C.Y. Lee. 2011. Elimination of field colonies of a mound-building termite Globitermes sulphureus (Isoptera: Termitidae) by bistrifluron bait. J. Econ. Entomol., 104: 607–613. https://doi.org/10.1603/EC10161

Osbrink, W.L., M.L. Cornelius and A.R. Lax. 2011. Areawide field study on effect of three chitin synthesis inhibitor baits on populations of Coptotermes formosanus and Reticulitermes flavipes (Isoptera: Rhinotermitidae). J. Econ. Entomol., 104: 1009–1017. https://doi.org/10.1603/EC10217

Overmyer, J.P., B.N. Mason and K.L. Armbrust. 2005. Acute toxicity of imidacloprid and fipronil to a nontarget aquatic insect, Simulium vittatum Zetterstedt cytospecies IS-7. Bull. Environ. Contam. Toxicol., 74: 872–879. https://doi.org/10.1007/s00128-005-0662-7

Paul, B., M.A. Khan, S. Paul, K. Shankarganesh and S. Chakravorty. 2018. Termites and Indian agriculture. In: Termites and sustainable management: sustainability in plant and crop protection (eds. Khan, M.A. and W. Ahmad), Springer International Publishing AG. pp. 51–96. https://doi.org/10.1007/978-3-319-68726-1_3

Peters, B. and C. Fitzgerald. 1999. Field evaluation of the effectiveness of three timber species as bait stakes and the bait toxicant hexaflumuron in eradicating Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermidae). Sociobiol., 33: 227–238.

Peters, B.C., D. Wibowo, G.Z. Yang, Y. Hui, A.P. Middelberg and C.X. Zhao. 2019. Evaluation of baiting fipronil-loaded silica nanocapsules against termite colonies in fields. Heliyon, 5: e02277, 2019. https://doi.org/10.1016/j.heliyon.2019.e02277

Prabhakaran, S.K. 2001. Eastern subterranean termite management using baits containing hexaflumuron in affected University of Iowa structures (Isoptera: Rhinotermitidae). Sociobiol., 37: 221–233.

Rashid, M.F.M., S.M. Ramli and A.H. Ab Majid. 2018. Leaching of termiticides containing bifenthrin, fipronil and imidacloprid in different types of soils under laboratory conditions. Malay. J. Soil Sci., 22: 77–92.

Rashid, M., A.S. Garjan, B. Naseri and F. Saberfar. 2012. Comparative toxicity of five insecticides against subterranean termite, Amitermes vilis (Isoptera: Termitidae) under laboratory conditions. Mun. Entomol. Zool., 7: 1044–1050.

Rouland-Lefèvre, C. 2011. Termites as pests of agriculture. In: Biology of termites: a modern synthesis. (eds. Bignell, D.E., Y. Roisin and N. Lo), Springer, Dordrecht, Netherlands. pp. 499–517. https://doi.org/10.1007/978-90-481-3977-4_18

Rust, M.K. and N.Y. Su. 2012. Managing social insects of urban importance. Ann. Rev. Entomol., 57: 355–375. https://doi.org/10.1146/annurev-ento-120710-100634

Sarmad, S.A., M.Z. Majeed, M. Luqman, M.A. Riaz, S. Ahmed and S.N. Ouédraogo. 2020. Development and laboratory evaluation of a slow release formulation of fipronil against subterranean termites (Odontotermes obesus Rambur). Sarh. J. Agric., 36: 1279–1288. https://doi.org/10.17582/journal.sja/2020/36.4.1279.1288

Schuurman, G. 2005. Decomposition rates and termite assemblage composition in semiarid Afr. Ecol., 86: 1236–1249. https://doi.org/10.1890/03-0570

Shelton, T.G. and Grace, J.K. 2003. Effects of exposure duration on transfer of nonrepellent termiticides among workers of Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae). J. Econ. Entomol., 96: 456–460. https://doi.org/10.1093/jee/96.2.456

Singh, B., D. Sharma and A. Gupta. 2009. A study towards release dynamics of thiram fungicide from starch–alginate beads to control environmental and health hazards. J. Hazard. Mat., 161: 208–216. https://doi.org/10.1016/j.jhazmat.2008.03.074

Su, N.Y. and R.H. Scheffrahn. 1996. Comparative effects of two chitin synthesis inhibitors, hexaflumuron and lufenuron, in a bait matrix against subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol., 89: 1156–1160. https://doi.org/10.1093/jee/89.5.1156

Su, N.Y. and R.H. Scheffrahn. 1998. A review of subterranean termite control practices and prospects for integrated pest management programmes. Integ. Pest Manage. Rev., 3: 1–13. https://doi.org/10.1023/A:1009684821954

Su, N.Y., E. Guidry and C. Cottone. 2016. Sustainable management of subterranean termite populations (Isoptera: Rhinotermitidae) in Armstrong Park, New Orleans, with durable baits. J. Econ. Entomol., 109: 1326–1332. https://doi.org/10.1093/jee/tow051

Tracy, Z.D.G. 2003. Sampling subterranean termite species diversity and activity in tropical savannas: an assessment of different bait choices. Ecol. Entomol., 28: 397–404. https://doi.org/10.1046/j.1365-2311.2003.00525.x

Tsunoda, K., H. Matsuoka and T. Yoshimura. 1998. Colony elimination of Reticulitermes speratus (Isoptera: Rhinotermitidae) by bait application and the effect on foraging territory. J. Econ. Entomol., 91: 1383–1386. https://doi.org/10.1093/jee/91.6.1383

Tuma, J., P. Eggleton and T.M. Fayle. 2020. Ant-termite interactions: An important but under-explored ecological linkage. Biol. Rev., 95: 555–572. https://doi.org/10.1111/brv.12577

Varvel, G.E. and W.W. Wilhelm. 2008. Cob biomass production in the western corn belt. Bioenerg. Res., 1: 223–228. https://doi.org/10.1007/s12155-008-9026-6

Wang, C. and G. Henderson. 2012. Evaluation of three bait materials and their food transfer efficiency in Formosan subterranean termites (Isoptera: Rhinotermitidae). J. Econ. Entomol., 105: 1758–1765. https://doi.org/10.1603/EC12201

Wang, X. and Y. Wu. 2003. Preparation of urea–dialdehyde starch glue. Technol. Develop., 13: 18–20.

Webb, G. 2017. Elimination of Coptotermes lacteus (Froggatt) (Blattodea: Rhinotemitidae) colonies using bistrifluron bait applied through in-ground bait stations surrounding mounds. Insects, 8: 98. https://doi.org/10.3390/insects8030098

Wiltz, B.A. 2012. Factors affecting performance of soil termiticides. In: Insecticides-Basic and Other Applications, InTech, pp. 153–170.

Zhang, J.H., Z.L. Liu and L. Huang. 2009. A review on the termite bait monitoring system. J. Hunan Univ. Art. Sci., 21: 78–80.