Antitermitic Properties Research Articles

Transcriptome analysis of Reticulitermes flaviceps exposed to Mentha spicata essential oil and carvone indicates a potential neurotoxic mechanism of action characterized by intracellular calcium influx mediated by dopamine receptors

Reticulitermes flaviceps is an economically important pest in agriculture, forestry, and construction. Recent studies have shown an increase in research focusing on the anti-termite properties of plant essential oils, however, there remains a lack of information regarding the specific molecular mechanism involved. In this study, RNA-seq analysis was conducted on termites exposed to Mentha spicata essential oil (EO) and carvone, leading to the discovery of various genes that were expressed differentially under different treatment conditions. Numerous genes that exhibited a response to M. spicata EO and carvone found to be associated with stress-related pathways, such as drug metabolism cytochrome P450, glutathione metabolism, fatty acid metabolism, citric acid cycle, neuroactive ligand-receptor interaction, cell apoptosis, the AMPK signalling pathway, the mTOR signalling pathway, the longevity regulation pathway, ubiquitin-mediated protein hydrolysis, and the calcium signalling pathway. The up-regulation of genes (SPHK) associated with calcium channels, such as SPHK, indicates a potential mechanism of neurotoxicity, while the up-regulation of apoptosis-associated genes, including ACTB_G1, PYG, SQSTM1, RNF31, suggests a potential mechanism of cytotoxicity. The metabolism of M. spicata EO induces oxidative stress, elevates free Ca2+ levels in mitochondria, and initiates the generation of reactive oxygen species (ROS), ultimately resulting in programmed cell necrosis and apoptosis, as well as facilitating cellular autophagy. The monoterpenes exhibited neurotoxic and cytotoxic effects on R. flaviceps and could be exploited to advance termiticide development and eco-friendly termite control.

Potential utilization of Indonesian plant extracts for biothermicide to control subterranean termite attack (Coptotermes spp.): a review article

The control of subterranean termite Coptotermes spp. infestation of low-durability wood species still depends on synthetic chemicals and has a negative impact because it is difficult to degrade into the environmental. Mega-biodiversity of Indonesia’s tropical rainforests presents a rich variety of plants with potential utilization, especially plant extracts that have anti-termite properties. The application of plant extracts with potential anti-termite bioactivity can be a more environmentally friendly alternative for natural wood preservation. This research uses the literature review method. The data obtained came from a search of national journal studies published on Google Scholar in the last 10 years. The results showed that the plant extracts used from the preservative formulation at the optimum concentration can produce the largest percentage of mortality and the smallest weight loss. Preserving wood with plant extracts from low durability class wood species used as test wood such as sengon, rubber, bayur, and durian can increase the classification of wood resistance becoming to grade I-II, indicate resistant and strongly resistant for subterranean termite attack. The three major secondary metabolite compounds from extracts plant used as wood preservatives are alkaloids, flavonoids and terpenoids. These components have the potential to provide toxic properties to wood destroying organisms.

Anti-inflammatory, antioxidant, and antitermite valorization of extractable substances from the heartwood of four major species of the Gabonese forest-timber sectors

The aim of this study was to focus on the chemical characterization and the anti-inflammatory, antioxidant, and anti-termite properties of extractable substances from the heartwood of Tieghemella africana, Testulea gabonensis, Staudtia kamerunensis, Entandrophragma utile in Gabon with a view to their valorization. The results of cold maceration extractions revealed that the extractable content varies with wood species and solvent. The high extract contents were obtained with acetone and ethanol, except for S. kamerunensis where the levels of dichloromethane and water extracts were high, respectively, 3.40 and 6.35%. E. useful showed a high content with dichloromethane (4.15%). Phytochemical screening indicated the presence in the acetonic, ethanolic, and water extracts of the wood species several groups of bioactive molecules, such as polyphenols, flavonoids, free quinones, sterols and triterpenes, and saponins. The results of the total phenols assay corroborated those obtained during the phytochemical screening. The results of anti-inflammatory, antioxidant, and anti-termite activities revealed that they vary with wood species, solvent, and concentration in terms of anti-termite activity. The strong anti-inflammatory activities were recorded with the ethanolic, acetonic, and water extracts where the EC50 values of all the essences were the lowest and close to that of our control, diclofenac (555.25 μg/mL). The ethanol extracts of the wood species showed strong activities, particularly those of S. kamerunensis and E. useful where we obtained low EC50 values of 604.13 and 602.38 μg/mL, respectively. The strong antioxidant activities were recorded with the acetonic, ethanolic extracts of S. kamerunensis and E. useful whose respective EC50 values (6.50 and 4.50 μg/mL) for S. kamerunensis and (4.50 and 3.01 μg/mL) for the E. useful. Similarly, the water extract of E. useful whose value is close to that of gallic acid (0.40 μg/mL) our control. The antitermite activity revealed that the acetone and ethanol extracts of the wood species and the water extract of E. useful at 20 mg/mL showed interesting antitermite activities. The strongest activities were recorded with the dichloromethane extracts of the wood species, where the survival rates of the termites were the lowest. Particularly with the dichloromethane extract of E. useful with a survival rate of 30% at 10 mg/mL and 1.70% at 20 mg/mL.

Anti-termite Activities of Extracts from Euphorbia tithymaloides and Euphorbia tithymaloide variegatus

The objective of this work was to investigate the anti-termite properties of solvent extracts of two Euphorbia plant species, Euphorbia tithymaloides and Euphorbia tithymaloides “variegatus”. Termiticidal activity of stem barks and leaf extracts were analysed by using anti-termite activity tests. All crude extracts obtained by petroleum ether and ethyl acetate exhibited 100% repellency activities at a concentration of 36 mg mL-1. Average repellency time decreased as the concentration of crude extracts were increased. Contact bioassay tests revealed that crude extracts from stem barks are more potent than extracts from leaves; and non-polar solvents gave crude extracts which are more effective that those extracted by polar solvents. Crude extracts obtained by petroleum ether from stem barks of both E. tithymaloides and E. tithymaloides “variegatus” plants species gave dissimilar peaks in GC-MS chromatograms, except two peaks, which correspond to the compounds: 1-heptadecene and n-hexadecanoic acid. Crude extract from E. tithymaloides gave a prominent peak corresponding to the compound tetracontane as the principal constituent (73.7%) of the extract. Since this peak is absent in crude extracts from E. tithymaloides “variegatus” stem barks, its presence in crude extracts from E. tithymaloides stem barks can be attributed to its high termite lethality assay results. In general, from the results obtained from this work, it could be concluded that the Euphorbia species are potential sources of botanical pesticides against termites.

Evaluation of Antitermite Properties of Wood Extracts from Pongamia pinnata (L.) Pierre (Leguminosae) against Subterranean Termites.

Termiticide, repellent and antifeedant activities of extracts from Pongamia pinnata wood were evaluated against Coptotermes heimi (Wasmann) at three different concentrations preceded by a preliminary choice and no-choice tests for natural resistance of tested wood. Termites' mortality was determined in each case of extract and solvent treated Whatman filter paper. Finally, wooden blocks of poplar (19×19×19 mm) were treated with extracts and respective solvents and exposed to termites in the field for 28 days. Minimum mean weight loss was observed in dried P. pinnata (6.38%), followed by fresh P. pinnata in choice tests. In no-choice tests, dried P. pinnata was comparatively resistant with a weight loss of 12.37%, followed by fresh P. pinnata and P. deltoides. In toxicity bioassay, ethyl acetate-based wood extracts caused the highest mortality (41.66%), followed by petroleum ether, hexane, and water extracts at 10 mg/ml concentration. Similarly, ethyl acetate-based extracts showed maximum repellency (100%) followed by petroleum ether extracts at 10 mg/ml and ethyl acetate at 5 mg/ml after 60 min of termite exposure. Minimum wood losses were observed in woods treated with ethyl acetate extracts compared to control and other treatments in field experiments.

Anti-Termite Activity of Melia azedarach Extracts

Natural preservatives have been widely considered as non-synthetic materials that can prevent the biodegradation of wood due to subterranean termite attacks, namely Coptotermes curvignathus. Melia azedarach is a fast-growing species that has been widely studied for its antifeedant compounds and shows good potential to be developed as a biopesticide, especially as an anti-termite. This study aimed to identify the termicide and antifeedant properties of the wood, leaves, and bark extracts of Melia azedarach against subterranean termites and identify their bioactive compounds. The acetone extract from the three parts of the tree was fractionated. The most active fractions were selected from each part based on the percentage of termite mortality and antifeedant activity and analyzed for its bioactive compounds by pyrolysis GCMS. The ethyl acetate fraction of Melia azedarach bark exhibited strong toxic properties compared to other fractions. In the leaf section, the diethyl ether fraction showed the best termite repellent (antifeedant) properties. The anti-termite properties influenced phenolic compounds and organic acid that dominated the bark ethyl acetate fraction and leaf diethyl ether fraction. These findings show the great potential of bioactive compounds from biomaterials to be developed as a promising biopesticide. Keywords: anti-termite, bioactive compound, Melia azedarach, natural preservative

Antitermitic and antifungal properties of enantiopure linalool and furanoid linalool oxide confirmed in Lindera umbellata var. membranacea

In this study, antitermitic and antifungal activities of enantiopure linalool and linalool oxide (furanoid) in L. umbellata var. membranacea were evaluated with their racemates. Results of chiral analysis showed that linalool oxide in leaves dominated by (R)-linalool and in twigs dominated by (S)-linalool were (2R,5R)-trans- and (2R,5S)-cis-linalool oxide and (2S,5S)-trans- and (2S,5R)-cis-linalool oxide, respectively. All rac-, (R)-, and (S)-linalool at highest concentration showed termiticidal and antifeedant activities against Reticulitermes speratus. Antitermitic activities of linalool oxides differed depending on their stereostructures, and (2R,5R)-trans-linalool oxide showed the strongest termiticidal activity. (S)-linalool showed significantly stronger antifungal activity than that of rac- and (R)-linalool against Penicillium citrinum and Chaetomium globosum. Racemate of trans- and cis-linalool oxide showed potent activity against P. citrinum, Rhizopus oryzae, and C. globosum; however, the activity decreased in isolated pure enantiomers. These results suggest that linalool and linalool oxide exhibit different antitermitic and antifungal properties.

Anti-Termites Properties of Liquid Smoke from Bintangur Wood

Wood and wood-based products are very vulnerable to termite attacks. One of the methods to control termite attacks is using chemical insecticide. However, the use of chemical insecticide is considered a negative effect on the environment. The aim of this research was to determine the anti-termite properties of liquid smoke against Coptotermes curvignathus Holmgren. The liquid smoke derived from bintangur wood pyrolysis at 370°C, 400°C, and 430°C was assessed as an anti-termite activity. Anti-termite activities against C. curvignathus were conducted by using liquid smoke with the concentration of 2%, 4%, 6%, and 8% (v/v). Simple linear regression was used to measure the effect of liquid smoke concentration against C. curvignathus. The results showed that the liquid smoke concentration of 6% and 8% at the three pyrolysis temperatures effectively controlled the subterranean termite's attack and resulted in 100% termites mortality. The chemical content of bintangur wood vinegar has contained phenol (1.23–1.65%) and acid (4.33–6.68%). Keywords: acid content, antitermitic activity, bintangur wood, phenol content, wood vinegar

Comparative effect of termiticides and plant extracts on mortality and tunnel formation of Odontotermes obesus

Termites play a great role in recycling and decaying of materials but are serious threat to agricultural crops and buildings. There are various practices to control the termites like plant resistance, cultural, biological, physical barriers and synthetic chemicals. Most commonly, synthetic chemicals are used for their control. But the injudicious use of chemicals leads to serious environmental and health problems. Although insecticides of plant origin are safe alternatives to synthetic insecticides but due to their low potential they are not widely used and synthetic chemicals are still playing a great role in insect control. Many plant extracts have been found having anti-termitic properties. The present project was carried out in order to determine the comparative effect of termiticides and plant extracts on mortality and tunnel formation of Odontotermesobesus at Department of plant protection faculty of Agriculture, Ghazi University Dera Ghazi Khan. There were five treatments; two termiticides viz. Bifenthrin and Chlorfenapyr and three plant extracts (Dodonaea viscosa, Rhazya stricta and Citrullus colocynthis). Each treatment consisting of four concentrations i.e., 0% as a control, 1%, 5 % and 10% was tested. The experiment was laid out in Completely Randomized Design and treatments were replicated three times. The data on mortality and tunnel formation was recorded at specific intervals and statistically analyzed by using Kaplan Meier test to determine LT50 values of termiticides and plant extracts. The results showed that Bifenthrin as most effective treatment among chemicals while among plant extracts Dodonaea viscosa was found most effective having lower LT50 values. Keywords: Insecticides; Mortality; Plant extracts; Termites and Tunnel formation http://dx.doi.org/10.19045/bspab.2020.90203

Modification of nanochitosan with NaCl and surfactant for wood preservative

Chitosan is a natural preservative which is really potential termicide to resist attack termites. Chitosan in size nanometers (nanochitosan) is expected to improve the effectiveness of the nature of anti-termite properties. The smaller size of particles has advantage to easily penetrate the wood pores. Nanochitosan was modified with surfactants (polysorbate-20 and polysorbate-80) and NaCl to increase retention and penetration of preservatives and its anti-termite properties. The purpose of this study was to evaluate the effect of surfactant and NaCl on the parameters of preservation tests which included absorption, retention and termite mortality, and particle size data as supporting data. The average value of absorption and retention of preservatives ranged from 105.79-124.43 kg/m3 and 9.18-18.26 kg/m3. The termite mortality was 33.11-46.89 % for 4 weeks of observation. Data were analyzed using variance analysis (ANOVA) to determine the significance of each treatment. It showed that polysorbate had significant effect to the absorption of preservatives and termite mortality while the retention was influenced by the type and concentration of surfactants. The treatments with the various single compounds showed that both surfactants had a significant effect on absorption, whereas polysorbate-20 had a significant effect on all treatment interactions, and NaCl treatment significantly affected the termite mortality. It was thought that he surfactant treatments increased the retention of nanochitosan by hydrophobic interactions whereas the addition of NaCl increased anti-termite properties and made particles smaller and stable which caused in higher retention. In this study, nanochitosan had an average size of 233 - 798 nm.

Anti-termite and anti-fungal bio-sourced wood preservation ingredients from Dacryodes edulis (G. Don) H.J. Lam resin

Abstract Dacryodes edulis (G. Don) H.J. Lam resin was hydro-distilled to recover essential oil (EO), and further purified to produce a heavy fraction constituting less volatile compounds. Chemical composition was investigated by gas chromatography-mass spectrometry (GC-MS), and indicated that different monoterpenes and triterpenes were present depending on the analyzed fraction. Bioassays were performed on the different fractions to evaluate their anti-fungal and anti-termite properties. Results indicated that crude resin, its heavy fraction and its EO all had proved termicidal properties, which decrease on drying for EO and crude resin due to evaporation of monoterpenes. Conversely, no anti-fungal properties were observed for any fraction. Dacryodes edulis resin is therefore a new valuable bioactive ingredient for the formulation of wood protection products with anti-termite properties.

Natural durability of four TunisianEucalyptusspp. and their respective compositions in extractives

AbstractEucalyptustrees have been adapted to the Tunisian climate. Now, they need to be economically valued. TunisianEucalyptushave great technological properties allowing us to use them as wooden material. However, there is large variability in the natural durability between heartwoodEucalyptusspp. The wood sustainability assessment provides reliable parameters to predict the service life of wood-based products. This study aimed to evaluate the wood deterioration of four North Tunisian fast-growingEucalyptusspp. (Eucalyptus maidenii,Eucalyptus saligna,Eucalyptus camaldulensisandEucalyptus gomphocephala) exposed to basidiomycetes (Coniophora puteanaandTrametes versicolor) and termite (Reticulitermes flavipes) attacks. Among the fourEucalyptuswoods,Eucalyptus gomphocephalapresents the highest decay and termite resistance. The fourEucalyptuswood species are classified as very durable against fungal degradation and durable against termite attacks, expect forEucalyptus salignawhich is classified as sensible against termites. The natural durability ofEucalyptusseems to be mainly caused by extractives, and a lot of compounds are involved. Antifungal and anti-termite properties of these compounds were put in perspective with the natural durability of wood. Gas chromatography-mass spectrometry (GC-MS) analyses highlighted thatEucalyptusdurability is mostly governed by gallic acid, fatty acid glycerides, fatty acid esters, phenolic compounds, sitosterol, catechin and ellagic acid.

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.

Profiling of volatile compounds from five interior decoration timbers in Taiwan using TD/GC–MS/FID

Volatile organic compounds (VOCs) released from Chamaecyparis formosensis, Cryptomeria japonica, Cunninghamia lanceolata, Chamaecyparis obtusa var. formosana, and Taiwania cryptomerioides five major building and interior decoration timbers and their essential oil components were analyzed using GC–MS and TD/GC–MS/FID. Results showed that C. obtusa var. formosana had the highest yield of essential oil (3.42%), followed by C. formosensis (3.14%), while C. japonica had the lowest yield (0.95%). Moreover, oxygenated sesquiterpene was the highest relative content in all five essential oils and their main constituents were trans-myrtanol (18.04%), 1-epi-cubenol (15.99%), cedrol (62.26%), α-cadinol (26.42%), and α-cadinol (27.98%), respectively. In terms of emission quantity of top VOC, the results showed the decreasing order of C. formosensis (myrtenal, 74.21 mg/m2) > T. cryptomerioides (thujopsene, 12.00 mg/m2) > C. lanceolata (α-cedrene, 10.27 mg/m2) > C. obtusa var. formosana (α-pinene, 8.05 mg/m2) > C. japonica (α-cedrene, 4.25 mg/m2). C. formosensis had a greater amount of VOCs emitted and hence gave off more fragrance than C. obtusa var. formosana initially. However, after indoor exposure of 24 weeks, the VOC emission quantity of C. obtusa var. formosana exceeded that of C. formosensis. α-Cedrene and thujopsene were the top two major VOCs of both C. lanceolata and T. cryptomerioides. However, they both showed a trend of decrease in emission with prolonged exposure. All five plantation timbers showed good antifungal, antimicrobial, antibacterial, and antitermitic properties, making them ideal materials for interior decoration. Not only do they have strong bioactivities, they can also provide a fragrant and healthy living environment.

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.

In vivo study on analgesic, gastrointestinal tract (GIT) motility, and anti-termite potential of methanolic extract of Sarcococca saligna (D. Don) Muell. fruits

The current paper summarizes the evaluation of the alcoholic extract of Sarcococca saligna (D. Don) Mull. fruits for acute toxicity, analgesic, GIT motility modulation, and anti-termite properties. The extract was evaluated for analgesic activity using acetic acid-induced writhing model while charcoal meal model was adopted for GIT motility estimation in mice. The fruit extract exhibited significant analgesic and GIT motility potential at 700, 1000mg/kg i.p. in comparison to standard drug (Diclofenac sodium). The extract also showed good anti-termite activity. The extract was also evaluated for toxicological effects which showed that the fruit extract is safe for the consumption of mice at 1000mg/kg i.p.

Termiticidal activity of Acorus calamus Linn. rhizomes and its main constituents against Coptotermes curvignathus Holmgren

The termiticidal activity of n-hexane and methanol fractions of Acorus calamus Linn rhizomes against Coptotermes curvignathus Holmgren was investigated. Both fractions have demonstrated strong termiticidal activity. The activity of n-hexane fraction was stronger than that of the methanol fraction. Based on GC-MS data, β-asarone was found to be a major constituent of n-hexane fraction (70.1%) and isolation of β-asarone was carried out on column chromatography to afford as a yellow oil in 59.1% yield. Furthermore, the antitermite properties of β-asarone and α-asarone of the isomer were investigated. Our data suggested that the two asarone isomers have insect control potential. These findings lead to the discovery of more environmentally friendly termiticides against C. curvignathus.

Anti-termitic potential of heartwood and bark extract and chemical compounds isolated from Madhuca utilis Ridl. H. J. Lam and Neobalanocarpus heimii King P. S. Ashton

Abstract The effect of wood extracts as antitermitic agents has been investigated in two Malaysian timber species, namely Madhuca utilis (bitis) and Neobalanocarpus heimii (chengal). The samples taken from Perak State Forest Reserve felled trees with the age of 38 and 45 years old, respectively. The composition of the extracts were analysed by GC-MS. In the toluene/EtOH extracts of M. utilis 19 (bark) and 17 (heartwood, hW) chemical constituents have been identified in total. The dominant compounds in bark were (2Z,6E)-farnesol (44%) and thymol methyl ether (29%) and in hW terpinen-4-ol (38%) and γ-terpinene (16%). The N. heimii essential oils contained 16 chemical constituents (8 in bark and 8 in hW) with benzyl carbinol (62%) and benzyl isoamyl ether (34%) for bark and eicosane (C20) (50%) and cyclopentanone (19%) for hW. Higher concentration of extracts from bark and hW of N. heimii, and from bark of M. utilis) gave 100% mortality of 3rd instars of Coptotermes gestroi Wasmann and 99% for M. utilis hW extract. The extracts of both wood species showed promising antitermitic properties against subterranean termites.

Antitermitic effects of three wood stain treatments

Potential antitermitic properties of some common wood stains were tested against Coptotermes formosanus. Four different wood species treated with 3 different stain chemicals at the 0,1 kg/m2 retention level were exposed to no-choice termite feeding test in laboratory conditions. Mean mass loses, mortality rates and consumption rates were calculated based on weight changes before and after the test. While the hardwood species (beech (Fagus orientalis) and chestnut (Castanea sativa) tested were unaffected by the treatments, the softwood species tested showed drastically reduced mass losses with some stain treatments. Scots pine (Pinus sylvestris) and spruce (Picea orientalis) sapwood exhibited significant reductions in mass losses when treated with the chemical stain.