Termite Mortality Research Articles

KUALITAS PAPAN PARTIKEL DARI KULIT BATANG SAGU (Metroxylon spp) DENGAN PEREKAT ALAMI ASAM SITRAT: SIFAT FISIK, SIFAT MEKANIK, DAN KEAWETAN TERHADAP RAYAP TANAH Coptotermes curvignathus Holmgren

The study aimed to analyze the quality of particle boards from bark fiber of sago (Metroxylon spp) with citric acid as natural adhesives based on physical properties, mechanical properties, and durability from subterranean termites Coptotermes curvignathus Holmgren. Particle boards are made with a size of 30 cm x 30 cm x 1 cm. The experimental factors used in the study included densities (0.7 gr/cm3 and 0.8 gr/cm3) and concentrations of citric acid adhesives (20% and 30%). The material then flow into hotpress with 1800C for 15 minutes and pressure at 25 kg/cm2. Testing of the physical and mechanical properties of particle boards refers to the JIS A 5908-2003 standard and durability against subterranean termites Coptotermes curvignathus Holmgren was conducted based on SNI 01. 7207-2006. The results showed that the densities factor had a significant effect on density, thickness swelling, MOE, MOR, internal bond, screw holding strength, and weight loss of the particle board against termites. Meanwhile concentration of citric acid adhesive significantly affected the density, moisture content, water absorption, thickness swelling, MOR, internal bond, and screw holding strength. The interaction between the densities factor and concentration of citric acid has a significant effect on thickness swelling and density. The physical and mechanical properties of particle boards which fulfill the JIS A 5908 2003 standard were density, moisture content, MOR, and screw holding strength. The durability of particleboard againts termites has a very strong level. The average values of termites mortality were 94% ~ 100%. The average of wood weight loss values were 9.61%~ 18.51%. The particle board made with a density 0.8 gr/cm3 and concentration of citric acid adhesive 30% achieved the highest values on physical properties, mechanical properties and durability to the termites Coptotermes curvignathus. Keywords : citric acid, Coptotermes curvignathus, Metroxylon spp, particle board, sago

PERBANDINGAN TINGKAT KEAWETAN KAYU SENGON (Falcataria moluccana L. Nielsen) DAN KAYU SUGI (Cryptomeria japonica D. Don) DENGAN EKSTRAK LIMBAH KULIT KAYU JATI (Tectona grandis L.F.) TERHADAP SERANGAN RAYAP TANAH Coptotermes curvignathus Holmgren

The aim of the study was to obtain a comparison of the durability of sengon (Falcataria moluccana) and sugi wood (Cryptomeria japonica) after preservation with Jati (Tectona grandis) tree bark waste to subterranean termites Coptotermes curvignathus Holmgren attack and to determine the best concentration of wood preservation from Jati extract. Evaluation the durability of wood used the JIS K 1571 2004 standar method. Test parameters in the study were preservative retention, termite mortality and weight loss of the wood test sample. The results showed the highest retention was achieved in Sengon wood of 0.466 kg /m3 and the followed by Sugi wood which was 0.740 kg /m3. The lowest termites mortality value was in non-teated wood of Sengon wood with value 13.091%, and in other sengon wood which treated by extract of Jati bark with concentration of 2%, 4%, 5%, the termites mortality was 100%. Meanwhile in Sugi wood the termites mortality in non-treated wood was 12.576% and other Sugi wood which treated by extract of Jati bark with concentration of 1%, 2%, 3%, 4%, 5% the mortality value reached 100%. The average percentage values of the highest weight loss was 15.483% in non-treated sugi wood, while the lowest weight loss was in sengon wood which was given 5% extract of teak bark with a concentration of only 2.099%. The optimal concentration of Jati tree bark for wood preservation to Sengon wood was on concentration 25, meanwhile in Sugi wood was on concentration 1%.Keywords: Cryptomeria japonica, ekstrak kulit kayu, Falcataria moluccana, preservation, Tectona grandis

Evaluation of Selected Botanical Extracts against Mendi Termite Macrotermes subhyalinus (Isoptera: Termitidae), under Laboratory Condition

Termites are most pestiferous insects causing damage to crop and buildings. Their control still relies mainly on harmful chemical pesticides to the detriment of eco-friendly pesticides. The main objective of the study was evaluate seed extracts of Brassica nigra and leaves extracts of Acokantra schimperi, Croton macrostachyus and Rhamnus prinoides against Macrotermes subhyalinus, known to cause damage to crops, vegetation and buildings in Ethiopia. Treatments were consisted of three concentrations levels (5, 10 and 15 weight of botanical powder (g) per 100 ml volume of water) by three replications. Mortality of termite was counted after 24, 48 and 72 hours exposure for both conditions. The results of all botanical extracts at all concentration levels showed that caused mortality of M. subhyalinus workers. Complete mortality (100%) of M. subhyalinus was observed after treatment with 15 w/v B. nigra extract at three time intervals. Moreover, A. schimperi at 15 w/v concentration also resulted 100% mortality after 48-72 hours of exposure. Brassica nigra extract showed least LC50 (5.63g/100ml) value than other botanical extracts after 24 hours exposure. Based on their toxicity status extracts of B. nigra > A. schmperi > R. prinoides > C. macrostachyus leaf extracts.

Toxicity potential of heartwood extractives from two mulberry species against Heterotermes indicola

Choice and no-choice tests were run to evaluate natural resistance of the woods of two Morus species (Morus alba and Morus nigra) against the subterranean, Heterotermes indicola, under field conditions. Toxicity, antifeedant and repellency potential of the heartwood extractives was also investigated under laboratory conditions. Heartwood extractives were removed from wood shavings by using methanol or an ethanol: toluene (2:1) mixture. Results of choice and no-choice tests with sap and heartwood blocks exposed to termites, showed that both mulberry species were resistant to termites but in comparison, Morus alba wood was more resistant than Morus nigra to termite feeding as it showed <5 % weight loss after 90 days. Termites exhibited a concentration dependent mortality after exposure to either mulberry species’ heartwood extractives. The highest termite mortality occurred after termites were exposed to filter paper treated with Morus alba extractives at a concentration of 5 %. At this concentration, antifeedancy and repellency were calculated to be 91,67 and 84 % respectively. . Our results also showed that extractives from either mulberry species imparted resistance to vacuum-pressure treated non-durable Populus deltoides wood. Termite mortality was greater than 75 % after feeding on Populus deltoides wood treated with extractives from Morus alba. Solvent only (methanol) treated Populus deltoides controls, showed a minimum weight loss of 2,69 % after 28 days. These results suggest that Morus alba extractives have antitermitic properties and may be potentially useful in the development of environment friendly termiticides.

Prevalence of Pathogenic Fungi of Endemic Termites in the Environment of Saladin Governorate in Iraq

Six fungal isolates were isolated from termite insects affecting citrus and palm trees in Samarra district-Salah Al-Din governorate-Iraq, during October 2017. A. flavus was significantly superior in the percentage of termite mortality than the rest of the fungal isolates for all treatments after 24, 48, 72 and 96 hours in the percentage of termite mortality were 16.67, 78.00, 100.00 and 100.00, followed by M. anisopliae that recorded 10.33, 39.33, 80, 91%, respectively. The results showed that all fungal filtrate superior in the percentage of termite mortality than the control. The highest percentages of termite mortality recorded by A. flavus which were13.67, 73.33, 88.67 and 94.67% for the periods 24, 48, 72 and 96 hours, respectively, while M. anisopliae filtrate was the second highest in percentages of termite mortality reached to 9.67, 41.33, 80.00 and 91.33% for these periods. The results showed that all isolated fungi on the termite insect had the ability to secrete the chitinase, protease and lipase the highest specific activity of chitinase and protease reached to (4.87 and 3.93), (4.27 and 3.81) and (3.81 and 3.08) unit/mg protein by M.anisopliae, A. flavus and T. harzianum, respectively.

Efficiency of Vegetable Oils in Wood Resistance to Cryptotermes brevis Termites

ABSTRACT Natural products have been studied in order to ensure environmental sustainability, human health, and diminish the use of traditional products. The objective of this study was to evaluate the efficiency of pure andiroba (Carapa guianensis), copaiba (Copaifera langsdorffii) and jatropha (Jatropha curcas) oils and enriched with iodine (I2) on the biological resistance of Pinus elliottii wood to dry-wood termites (Cryptotermes brevis). The oils were enriched with 1%, 3%, and 5% of I2 and impregnated into the wood by cold immersion. The treated samples were subjected to volatilization and leaching. Volatilization and leaching did not affect the loss of mass caused by termites, except for treatments with pure and enriched with 1% iodine copaiba oil. Leached samples were more damaged. The addition of iodine to the oils resulted in a greater efficiency against termites. Andiroba (3% and 5% I2) and jatropha oils (5%) were the most efficient, providing total termite mortality.

Persistency of Chlorpyrifos and Termiban (Imidacloprid) in soil against subterranean termites

Subterranean termites are considered to be one of the most destructive termites in urban areas in Pakistan. Different types of insecticides have been used to control subterranean termites. The present studies were conducted to evaluate the comparative persistency and effectiveness of Termiban (imidacloprid 5 SC) and Chlorpyrifos (40 EC) against subterranean termites in the three type of soils (sand, silt and clay) at different time interval. Two different concentrations (100 and 200 ppm) of selected insecticides were prepared and applied to soil in petri plates and termite were released at different time interval to record mortality. Results showed that at each time interval and concentration, mortality of termite was non-significantly different for both insecticides. When persistency of insecticides was tested under closed condition, results showed that lowest weight loss (8.60%) of wood was observed in Termiban treated soil at 200 ppm which was significant different from rest of the treatments. Similarly, under open conditions, at each time interval, there was significant more mortality of termites in soil treated with Termiban compared to Chlorpyrifos.

Feeding rate of subterranean termites in wood treated with smoke wood and borax

This study aimed to analyze the feeding preference of subterranean termites (Coptotermes curvignathus) against 3 Indonesian native woods such as Jabon (Anthocephalus cadamba), Jati (Tectona grandis) and Ulin (Eusideroxylon zwageri) treated with borax and bamboo smoke wood. The method was conducted and evaluated according to Japanese Industrial Standards (JIS 2004) and Indoneisan National Standard (SNI 2014) with Pinus mercusii as the control. The results showed that Jabon (A. cadamba), Jati (T. grandis) and Ulin (E. zwageri) woods treated using smoke and borax were not significantly different. All treatments have effectively increased the resistance to subterranean termite attacks. The treated wood samples have less weight loss, higher termite mortality, and lower termite feeding rate compared to the untreated wood. Daily termite feeding rate of untreated P. mercusii was 1.63 mg/termite/day, smoke wood treated was 1.5 mg/termite/day and borax treated wood was 1.4 mg/termite/day. In conclusion, the smoke wood treatments effectively decreased the daily feeding rate of the termites.

Biocidal potential of the extractives of four Malaysian timbers against subterranean termites and wood decay fungi

Wood extracts of four selected Malaysian timbers, Neobalanocarpus heimii, Cotylelobium lanceolatum, Madhuca utilis and Shorea curtisii, were tested at various concentrations against the subterranean termites, Coptotermes curvignathus and C. gestroi, and the fungi, Trametes versicolor (white-rot), Lentinus sajor-caju (white-rot), and Coniophera puteana (brown-rot). Paper discs were treated with 0.5, 1, and 2% w/v extracts and exposed to termites using a no-choice test. For the wood decay test, blocks of a non-durable species, Hevea brasiliensis, were treated with 2, 4, 6, and 8% of each extractive concentration and exposed to termites for a 12-week period. The results showed that 2% w/v of N. heimii extract was highly effective against both the termite species, C. curvignathus and C. gestroi after 10 days of exposure, leading to complete mortality with slight attack of the filter paper (mass loss = 1.10% and 0.69%, respectively). The 0.5% w/v extract resulted in 50% termite mortality with 2.53% and 1.42% filter paper consumption. Maximum weight losses were observed with 2% of each wood extractive against each fungus tested. Higher concentrations were needed when it comes to controlling fungi. The results from this study indicate that Malaysian wood extracts show some promise as alternative termiticides or fungicides.

Effect of biofertilizers and diatomaceous earth on life and movement of subterranean termites under laboratory conditions

AbstractThe presence of biofertilizers can affect the life and movement of subterranean organisms in the soil. In the current study, the effect of three biofertilizers (Unigrow, Rhizogold and Rhizogold Plus) alone and in combination with diatomaceous earth (DE) and insecticides on mortality and movement of subterranean termites, Coptotermes heimi (Wasmann), was investigated under laboratory conditions. The mortality of termites in soil mixed with biofertilizers was low as compared to the control treatment, which led to significant mortality. Length of galleries formed by termites with the addition of Unigrow in the soil was significantly higher as compared to the other two biofertilizers and control treatments. Mortality increased in the presence of insecticides and DE in the soil substrate. Unigrow mixed soil having chlorfenapyr had maximum mortality and minimum gallery length followed by Rhizogold and Rhizogold Plus. The addition of DE and insecticide further enhances mortality, and we recommend that some toxic elements should be incorporated in biofertilizers to control subterranean termites.

KARAKTERISTIK PAPAN PARTIKEL DARI LIMBAH KULIT KACANG TANAH DENGAN PEREKAT ALAMI ASAM SITRAT DENGAN PELARUT ASAP CAIR

Binderlessboard is one of the potential eco friendly products that can be developed. Utiliation of natural adhesives for non-wood composite is still very limited. Therefore, this research is focused on effects of citric acid content and pressing time on characteristics of particleboard made from peanut shell including its durability to dry wood termite attacks. Peanut shell particles were used as raw materials. Citric acid dissolved in liquid smoke which functioned as a water substitute solvent under a certain ratio and the concentration of the solution was adjusted to 60%. The use of liquid smoke is expected to increase the durability of the particleboard. Factors used in this research were citric acid content (10-30% based on dry weight particles) and pressing time (10 minutes and 15 minutes). Properties of particleboard were analyed based on Japanese Industrial Standard (JIS) A 5908 for particleboard. The dry wood termite resistance was then analyzed for its weight loss and mortality after 4 weeks. The results showed that the best particleboard was obtained from the treatment of 30% citric acid content with 15 minutes of pressing time where only the modulus of rupture and modulus of elasticity did not met the requirement of JIS A 5908 type 8 with the thickness swelling were 3.276%, water absorption were 44,991%, internal bonding were 4.679 kgf / cm², modulus of rupture were 26.822 kgf / cm², and modulus of elasticity were 8,986,058 kgf / cm². The best value of weight loss and mortality of dry wood termites on particleboard was obtained in a combination of 30% citric acid content with 10 minutes pressing time were 1.083% and 38.67% respectively.

Bioactivity of diatomaceous earth against the subterranean termite Reticulitermes chinensis Snyder (Isoptera: Rhinotermitidae).

The effects of diatomaceous earth (DE) on the penetrating behavior, tunneling behavior, mortality, and body surface characteristics of the subterranean termite Reticulitermes chinensis were investigated in this study. Our results show that the workers of R. chinensis were able to penetrate 1- and 2-mm layers of dry DE but not 3-mm layers. After treatment with dry DE for 6h, the mortality of termites reached 100%, which was significantly higher than in the treatment with DE with a 10 and 25% moisture content and treatment with sand of three different moisture contents. The tunneling distances of workers in DE with 10, 25, and 50% moisture contents were all significantly shorter than those in sand with the same moisture contents (10, 25, and 50%), indicating that DE has a good suppressing effect on the tunneling behavior of workers. After treatment with dry DE for different times (1, 3, and 6h), many DE particles adhered to the bodies of workers, whereas no particles adhered to the body of workers in the case of treatment with dry sand. The treatment with dry DE for 6h resulted in the death of all workers, which presented conspicuous abdominal shrinkage, whereas workers treated with sand had no significant mortality and no obvious abdominal shrinkage. In summary, we suggest that dry DE has ideal insecticidal activity against the subterranean termite R. chinensis and can be further exploited for controlling termites inside houses.

Utilization of Bark Condensed Tannin as Natural Preservatives Against Subterranean Termite

Extractive-based preservative has been isolated from many parts of plant to protect wood from fungi or pest. This is due to the presence of bioactive chemical as a natural preservative. Present study, the condensed tannin was isolated from bark-waste of Acacia crassicarpa and Acacia mearnsii. The yield of the extracts obtained from A. crassicarpa using a 70% acetone aqueous solution (7% based on bark weight) is less than that obtained from A. mearnsii (34%). To evaluate the termiticidal activity of condensed tannin from both extracts, no-choice tests were conducted using Reticulitermes speratus. After 14 days, mass loss of the dimmer condensed tannin treated was less than 50%, significantly different with control. In addition, a monomer condensed tannin, catechin was presented the similar result. Meanwhile, the termite mortality of catechin is slightly higher than the dimmer. According to both parameter, the medium level of mass loss and termite mortality, the dimmer suggested as antifeedant in mechanism of termiticidal. The feeding activity is decreased after contact with the treated paper disc. In polymer condensed tannin, the result seems similar to dimmer condensed tannin. Condensed tannin and hydrolyzable tannin which were contained in the bark effected termite consumption because it caused inactivation of enzyme in termite digestion system. In fact, many factors effect termite activity from natural extractives such as compound type, quantity and also extract retention activity. The finding of this study should contribute to the developing of natural wood preservative from extractive-based. Especially, the study of structure-active relationship (SAR) of condensed tannin from A. crassicarpa, which can improve the utilization of bark-waste from pulp industry.

Isolation of secondary metabolites from Stenochlaena palustris stems and structure-activity relationships of 20-hydroxyecdysone derivatives on antitermite activity

AbstractStenochlaena palustrisis an edible fern, belonging to the Blechnaceae family and is called kelakai in South Kalimantan, Indonesia. The effects of fractions ofS. palustrisstems and isolated constituents on termite mortality and paper disc consumption byCoptotermes curvignathushave been studied. Treatment of the ethyl acetate (EtOAc) fraction on paper discs greatly induced death ofC. curvignathuswithin 6 days. Our phytochemical investigation ofS. palustrisstems led to the isolation of major constituents and 20-hydroxyecdysone exerted the highest termiticidal activity, followed by stenopalustroside A and ajugasterone C. Moreover, the structure-activity relationships (SAR) of synthetic derivatives from 20-hydroxyecdysone and ajugasterone C suggested that a 2,3-diol has considerable effect on their antitermite properties againstC. curvignathus.

Effects of White Mulberry (Morus alba) Heartwood Extract Against Reticulitermes flavipes (Blattodea: Rhinotermitidae).

Heartwood extract from white mulberry (Morus alba L.) (Rosales: Moraceae) were investigated for antitermitic activity against Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae) in laboratory experiments. An ethanol:toluene (2:1) solvent system was used to remove extract from heartwood shavings. A concentration-dependent feeding response and mortality were observed for termites exposed to a concentration series range of 1.25 to 10 mg/ml of extract based on their dry weight. Results showed that maximum termite mortality occurred at 10 mg/ml. Based on the concentration series data, LC50 was calculated at 1.71 mg/ml. In filter paper feeding and repellency assays, extract significantly decreased the total number of gut protozoa compared with untreated and solvent controls. After feeding on filter paper treated at 10 mg/ml for 2 wk, protozoan populations were reduced by >55%. In choice and no-choice tests with mulberry heartwood, greater wood loss from termite feeding was found on solvent extracted blocks compared with nonextracted. Complete (100%) mortality was observed after feeding on nonextracted blocks compared with extracted blocks. Heartwood extract from white mulberry imparted resistance to vacuum pressure treated, nondurable southern pine and cottonwood. At every concentration tested, 100% mortality was observed after feeding on extract-treated southern pine or cottonwood. GC-MS analysis of extract showed high levels of the phenol compound, resorcinol. Results indicated that heartwood extract from white mulberry have antitermitic properties and might be potentially valuable in the development of environmentally benign termiticides.

Mealworm Powder as Culture Media of Local Isolate Semarang Entomopathogenic Nematodes

Many researchers confirmed that entomopathogenic nematodes (EPNs) of the genera Heterorhabditis and Steinernema can be cultivated in vitro using artificial media that containing animal nutrition. However, artificial media with insect component hasn’t been widely studied. This research aims to analyze the population of EPNs isolate of Semarang cultivated in mealworm powder media. Five doses of mealworm powder (Tenebrio molitor) were tested in this research, i.e: 0.5; 1.0; 1.5; 2.0 g. Culture media using 1 g of mealworm larvae was used as control. The best treatment was further tested for its pathogenicity on Macrotermes sp. at seven levels of invective juveniles (IJs) : 0; 50; 100; 150; 200; 250; 300 IJs/mL. Each treatment was repeated five times. The EPNs population and termites mortality were analyzed using ANAVA, whereas pathogenic value was calculated using Probit analysis. The result showed EPNs population were significantly (LSD test; α&gt; 0.05), likewise on termites mortality. The EPNs isolate of Semarang optimally at 0.5 g mealworm powder and pathogenicity against termites based on LD50 and LD90 values at 220 JI/mL and 410 JI/mL doses, respectively. In conclusion, this result can be an alternative to mass cultivation of EPNs, in effort of development of local bioinsecticides. The findings of this study also inform farmers that EPNs can be easily cultivated using the simple and available materials.

The effect of clay nanoparticleon the retention and attack of drywood termite (Cryptotermes cynocephalus Light).

The aplication of clay nanoparticles as wood preservative was intended to examine its resistant to infestation of drywood termite (C. cynocephalusLight). Loam was crushed into small pieces as clay nanoparticles, which was used as wood preservative that was soluble in water. The material was dissolved with water in a given concentration and put it into anggerung (Trema orientalis), white meranti (Shorea bracteolata) and sengon (Paraseriehthes falcataria) by full cell method or impregnation. The tested samples were preserved by clay nanoparticles at the air pressure 60 psi for 2 hours and then furnace-dried, and tested by infestation of drywood termites. Results of the research showed that mortality of the drywood termites on those three preserved woods with clay nanoparticles by concentration of 2.5% and 5%, which reached 96.4% and 100% on average, respectively, in comparison without preservation by average mortality value was 27.4%. The highest retention of clay nanoparticle was 24.89 kg.m3 was obtained by concentration of 5% for white merantiand the lowest was 9.32 kg.m3 by concentration of 2.5% for anggerung. The application of clay nanoparticle as effective wood preservative against the infestation of drywood termite by concentration of 5% has been proven by mortality 100%.

Efects of Usnic, Barbatic and Fumarprotocetraric acids on Survival of Nasutitermes corniger (Isoptera: Termitidae: Nasutitermitinae)

Lichens (Algal-Fungal association) synthesize unique chemical substances with different biological activities. Three pure lichen compounds were assayed to evaluate their potential insecticidal activity against the termite Nasutitermes corniger on Petri dishes. Usnic, fumarprotocetraric and barbatic acids were isolated and purified from the lichens Cladonia substellata, C. verticillaris and Cladia aggregata, respectively, using thin-layer and high-performance liquid chromatography for attesting their purity. Nuclear proton magnetic resonance and infrared spectrophotometry was used for their chemical characterization. After exposure, mortality of termites (workers and soldiers) was determined during 11 days period. The termiticidal effect was influenced by the exposure time and the type of member colony. The results showed that lichen substances, tested at 5, 7 and 10 mg mL-1, have a termiticidal activity (~100%) on worker termites after 8th days of treatment, in comparison with controls. However, no significant effect on soldiers was found. These findings indicate that usnic, fumarprotocetraric and barbatic acids are potential compounds for use in the control of this urban pest.

Termiticidal activity of chitosan against the subterranean termites Reticulitermes flavipes and Reticulitermes virginicus.

Chitosan is a derivative form of chitin, which is the major component of exoskeletons of arthropods and the cell walls of fungi. The antimicrobial activity of chitosan against lepidopterans, aphids, fungi and bacteria has been extensively investigated, but only one report on the termiticidal effect of chitosan on termites has been published. In this study, we examined the termiticidal activity of chitosan by exposing single colonies of Reticulitermes flavipes (Kollar) and Reticulitermes virginicus Banks to wood treated with six different concentrations of chitosan solutions. Termite mortality and percent mass loss of wood samples after exposure to termites for 4 weeks were calculated. High termite mortality (≥ 94%) occurred during exposure of R. flavipes termites to chitosan-treated wood with ≥38 mg g-1 treatment concentrations (≥ 2% chitosan), while <50% termite mortality was observed at lower treatment concentrations (11-15 mg g-1 ; 0.5% and 1% chitosan). For R. virginicus, 100% mortality was observed at all levels of treatment concentrations. A decrease in the percent mass loss of the wood sample was apparent in samples treated with solutions with an increasing chitosan concentration, with a significant difference (P < 0.05) between lower and higher treatment concentrations. Treatment retention in wood samples upon leaching was also determined and showed retention levels of between 0 and 30 mg g-1 chitosan retention. This study investigated the exposure of subterranean termites to chitosan as a wood preservative. The results show that chitosan treatments at sufficiently high loadings could protect wood against termites, preferably under non-leaching conditions. © 2018 Society of Chemical Industry.

Fipronil enhanced natural occurrence of Fusarium solani (Hypocreales: Nectriaceae) on building infesting termite Heterotermes indicola Wasmann (Blattodea: Rhinotermitidae)

Abstract The Southeast Asian subterranean termite, Heterotermes indicola Wasmann (Blattodea; Rhinotermitidae), is recognized as a building infesting lower termite species in urban environment. The extensive use of chemical termiticides against aerial mud tubes and underground nests of H. indicola beneath the buildings could not suppress its infestation; however, it enhanced the environmental contamination and insecticide resistance. In the present study, we tried to control termites using naturally occurring entomopathogenic fungi Fusarium solani (Mart.) Sacc., along with sublethal concentrations of termiticide fipronil in no-choice feeding pathogenecity bioassay for 20 days. Termite mortality after 20 days of continuous exposure to highest fungal treatment 1 × 109 conidia/mL was 10% exclusively, whereas 100% mortality was calculated just after 16 days of concurrently exposure to 5 ppm of fipronil and highest rate of fungus 1 × 109 conidia/mL. These results indicated that insecticidal stress declined the immune response of termites and reduced the repellency of termites against fungal conidia by breaching the primary defense mechanism (allogrooming). This co-application of F. solani at suitable sublethal concentrations of fipronil showed the promising potential against termites that may reduce the selection pressure of pesticides and resistance risk by targeted pests, but further investigations are necessary for developing field trials.