Termiticidal Activity Research Articles

Exploring termiticidal properties and GC/MS-based chemical profile of Lantana camara (L.)

India accounts for almost 10 % of the worlds' termite species. Odontotermes horni is one of the most important termites, posing significant threats to agricultural and horticultural ecosystems. The persistent nature of synthetic termiticides necessitates the development of alternative control strategies. The present study investigates the phytochemical composition and potential termiticidal and acetylcholinesterase (AChE) inhibitory properties of Lantana camara (L.) leaf against O. horni. Methanolic, ethyl acetate, and aqueous extracts of L. camara (L.) leaves were used to assess their toxicity. The methanolic extract exhibited the highest potency, with an LC50 of 0.98%, followed by ethyl acetate (1.40 %) and water extract (8.81 %). The per cent mortality recorded at 2.5 % concentration for methanol, ethyl acetate, and aqueous extract was 96.20, 78.75 and 21.25, respectively. By fumigant action, the L. camara (L.) leaf extract at a 5% concentration of methanol, ethyl acetate and aqueous extract resulted in 68.75, 42.50 and 26.25 percent mortality, respectively. The methanolic extract showed the highest AChE inhibition (52.39 %), followed by the ethyl acetate (47.00 %) and the aqueous (43.53 %) extracts after 24 hours of exposure. GC-MS analysis of plant volatiles of the L. camara (L.) revealed 196 compounds, including terpenoids, known for termiticidal activity.

Production of chitinase in elicited tomato cell suspensions and its application as a biopesticide and fungicide against soil-borne pests and fungi

Soil-borne fungi and pests present significant challenges to crop production, causing diseases and reducing yields. This study explores the potential of producing chitinase from tomato cell suspension cultures and its application in controlling soil-borne fungi and pests. Tomato cell suspension cultures were established from seeds, and different elicitors—including chitin, fungal debris, and fungal metabolites—were used to optimize chitinase production. The enzyme was purified, and its physicochemical properties were characterized. Its antifungal activity was tested against various soil-borne fungi, while termiticidal activity was evaluated using four bioassay methods. Additionally, the nematicidal activity of chitinase was assessed against different stages of root-knot nematodes. Results indicated that chitin media induced the highest chitinase production and cell growth compared to other elicitors. The purified chitinase had a molecular weight of 34 kDa, with a maximum velocity (Vmax) of 0.940 μg NAG/min and a Michaelis constant of 1.236 mg colloidal chitin/mL. The turnover number (Kcat) was 1.598 μg NAG/min/mol chitinase. The enzyme exhibited a broad range of activity and stability across varying pH levels and temperatures, as well as remarkable stability under different storage times and in the presence of metal ions. Tomato-derived chitinase demonstrated superior antifungal, nematicidal, and termiticidal activities compared to common chemical fungicides and pesticides. Chitinase was successfully produced from tomato cell suspension culture in this study, highlighting its potential as a biocontrol agent for sustainable pest and disease management in agriculture.

Biotermiticidal Activity of Jatropha gossypifolia Linn. plant extract against Odontotermes obesus (Isoptera: Termitidae)

Abstract: Termiticidal potential of methanol and aqueous leaves extract of Jatropha gossypifolia Linn. were studied against Odontotermes obesus. The plant leaves were dried, powdered and extracted with methanol and aqueous solvent in soxhlet apparatus for 24 hrs. The 20 termites were exposed to various concentrations from 9.0 to 14.5 mg/ml) of methanol and of aqueous plant extract of Jatropha gossypifolia and percent mortality were recorded after 24 hrs. The termiticidal activity of leaves extract of Jatropha gossypifolia were (LC10 = 9.8220 mg/ml, LD50 = 10.093, LC90 =12.667 mg/ml) in methanol and (LC10 = 11.984, LC50 = 13.195, LC90 =14.531 mg/ml) in aqueous solvent respectively. Results revealed that the mortality was increased with increasing in concentration of the plant extracts. The methanol solvent extract of Jatropha gossypifolia showed higher termiticidal property against Odontotermes obesus. Statistical variance, 95% confidence limits and regression equations are presented.

The chemical composition of Savannah bamboo (Oxytenanthera abyssinica) vinegar at varying pyrolysis temperatures and its termiticidal activity against wood-feeding termites

Synthetic biocides used in wood preservation present significant environmental and human health risks. An environmentally responsible and efficient substitute for traditional pesticides is bamboo vinegar. However, the chemical component of vinegar, which varies depending on the bamboo species, affects how efficient it is as a preservative. This investigation identified the constituent chemicals and termiticidal properties of vinegar derived from Savannah bamboo (Oxytenanthera abyssinica (A.Rich.) Munro) prepared at various temperatures. Savannah bamboo was pyrolyzed at 350°C, 400°C, and 450°C following established procedures to extract vinegar. Gas Chromatography-Mass Spectrometry (GC-MS) was used to characterize the vinegar's ingredients. The British standard EN 252 was used to assess the vinegar's termiticidal efficacy. The greatest amount of vinegar (0.45 kg) was produced at 450 °C. The vinegar mostly comprised hexadecanoic, pentadecanoic, octadecanoic, and (3,3-dimethyl-1-phenylbut-1-enyl) benzene. The proportions of these primary constituents varied depending on the pyrolyzing temperature. With its highest content of fatty acids, the vinegar generated at 450°C had the strongest termiticidal activity. O. abyssinica vinegar could provide an eco-friendly substitute for artificial biocides. The manufacturing of vinegar from O. abyssinica could open up new markets for industries engaged in the production, processing, and product development of bamboo.

A termiticidal and high denaturation-resistant lectin from Moringa oleifera seed cake

Moringa oleifera seed cake contains a lectin named WSMoLC, which was previously described as an insecticidal agent against the yellow fever mosquito Aedes aegypti. In this study, we evaluated the structural stability of WSMoLC against denaturation by chemical and physical agents, as well as its insecticidal activity against the termite Nasutitermes corniger. Conformational alterations of WSMoLC, when in the presence of urea or whilst subjected to heating or high pressures were monitored by circular dichroism and fluorometric analysis. Termiticidal activity was evaluated by supplying the insects with a diet of varying concentrations of WSMoLC. The effects of WSMoLC on insect digestive enzymes activities were also determined. Treatment with urea at concentrations of 4 M or less led to a conformational rearrangement of WSMoLC, as hydrophobic surfaces had less exposure to water. However, at urea concentrations more than 4 M the hydrophobic pockets of WSMoLC experienced greater exposure to water resulting in a 50 % loss of secondary structure. When subjected to heating of up to 65 °C or pressures up to 2.7 kbar, no conformational changes were detected. WSMoLC was shown to display insecticidal activity for N. corniger workers and soldiers (LC50 of 0.292 and 0.637 mg/mL, respectively). It was shown from gut extracts of these insects that the lectin inhibited exoglucanase and endoglucanase enzymes. In conclusion, WSMoLC can be explored as an alternative for termite control because of its high structural stability and ability to withstand denaturation.

Phenolics Content and DPPH Free Radical Scavenging Activity of Dalbergia latifolia leaf ethanolic extract

Dalbergia latifolia is one of the famous species that naturally grows in Java, Indonesia. The wood of this species is purple in color and the leaf is utilized as forage. The purpose of this study is to determine the bioactivity and phenol contents of D. latifolia leaf ethanolic extract. The antioxidant activity and anti-termite activity were measured through the DPPH method and Neotermes bosei activity. Furthermore, phenol contents were determined through colorimetric method and ethanolic extract constituents were identified by GC-MS. The DPPH inhibition of ethanol extract of D. latifolia leaf exhibited 138.20±2.14 µg/ml. While the measurement of total phenol and total flavonoid content of D. latifolia leaf showed a value of 192.67±9.41 mg GAE/ g and 55.23±5.11 mg QE/ g of dried extract sample. The termiticidal activity of ethanolic extract showed low activity. The GC-MS detection showed fatty acids as dominant compounds. The inhibition of DPPH by D. latifolia leaf ethanol extract in this study suggested this leaf is potent as antioxidant agents.

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.

Preparation and evaluation of panchagavya and a novel natural termiticidal product for termiticidal activity on Jamun and neem trees

Though termites help in soil fertility they cause huge loss to plants and housing. Panchagavya, a bio pesticide is widely used in agriculture as an insecticide but there were no termiticidal studies on the preparation. In the present work, Panchagavya and a novel natural termiticidal product were prepared and investigated against termite infested Jamun and Neem tree stems. When 10ml of Panchagavya was sprayed on these affected trees termites were died within 3-4 minutes. With 10ml of novel termiticidal product spray on the trees all the termites died within 2minutes and 30seconds. Although Panchagavya was found to be effective as termiticidal the prepared novel, natural termiticidal product was found to be more effective as termiticidal compared to the Panchagavya preparation. The inherent mild termiticidal activity of turpentine oil and the fast- acting irritant nature of red Chilli and black Pepper powders may be responsible for more efficacy of this product.

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.

Efficacy of Anti-termite Extracts from Four Saharan Plants against the Harvester Termite, Anacanthotermes ochraceus

This study aimed to examine the anti-termite potential of four Saharan plant extracts, namely, the apple of Sodom or rubber bush, Calotropis procera; pergularia, Pergularia tomentosa; jimsonweed, Datura stramonium, and Egyptian henbane, Hyoscyamus muticus from Bechar (southwest of Algeria) on workers of the harvester termite, Anacanthotermes ochraceus (Isoptera: Hodotermitidae). A direct contact application test was conducted with five fractions from aqueous extracts of each part of plant species (leaves, stems) using hexane, dichloromethane, ethyl acetate, butanol, and exhausted fraction. A repellent test was realized with aqueous extracts (10%) of plant species leaves and stems. According to the direct contact application test, all tested plants fractions showed termiticidal activities with different degrees. Butanolic fractions presented the best effects from leaves of C. procera and P. tomentosa with median lethal time (LT50) = 231.03 and 244.96 min, respectively. In the second test, wood samples were exposed to termite attack for four weeks, and the weight loss percentage was determined. The weight loss ranged from 0.034 to 16.90% at concentrations of 10% of plant extracts. The best repellent effect was obtained from leaves of C. procera (weight loss = 0.034%) and leaves of D. stramonium (weight loss = 1.29%). It was concluded that some Saharan plants are a good source of anti-termite compounds, especially C. procera.

Termiticidal and Nematicidal activities of five extracts from Garlic (Allium sativum)

Garlic (Allium sativum Linn) has been known and used as therapeutic agents to prevent several pathologies diseases. The aim of this study is to evaluate the effects of five garlic extracts, namely, aqueous garlic extract (AGE), methanol garlic extract (MGE), ethyl acetate garlic extract, EAGE), and n-hexane garlic extract (HGE) against root-knot nematode, Meloidogyne sp. and termite, Nasutitermes sp. The nematicidal and termiticidal activities of five garlic extracts were performed at concentration of 10; 25; and 50%. The nematicidal assay revealed that aqueous garlic extract (AGE) and ethyl acetate garlic extract (EAGE) have higher activities against Melodogyne sp at all concentrations tested at 5 h of time incubation with the percentages of viabilities between 4.67%-15.63% and 0%-10.23% respectively. Meanwhile, the termiticidal assay results showed that aqueous garlic extract (AGE), ethyl acetate garlic extract (EAGE), and n-hexane garlic extract (HGE) have stronger activity against Melodogyne sp at all concentrations tested at 8 h of time incubation with the percentages of viabilities of the extracts were 0%. Overall, the results showed that ethyl acetate garlic extract (EAGE) has highest activity against Meloidogyne sp, while the n-hexane garlic extract (HGE) has strongest activity against Nasutitermes sp.

TERMITICIDAL ACTIVITY OF CHITOSAN ON PAPER

Termites are insects that can damage buildings, paper and plants. Termites are controlled by using termiticides (chemicals). Besides polluting the environment, termiticides may have harmful effects to organisms, including humans, and destroy metal. The use of chemicals will be environmentally and economically profitless. A joint effort to utilize biodegradable material will help to reduce the negative impacts of termiticides. One of the materials that can use to control termites is chitosan. The purpose of this study was to determine the termiticidal activity of chitosan on paper against termites. The termiticidal activity test followed method JIS K 1571 2004. The resistance of paper to termite damage was determined by calculating the percentage of weight loss and termite mortality rate. The following concentrations of chitosan in acetic acid were used: 0.5%, 1%, 1.5% and 2%. The test result showed that weight loss percentages were 20.49%, 16.37%, 15.77% and 10.80%, respectively. On the other hand, the weight loss percentage of paper without chitosan was 32.69%, which shows that termites do not favour chitosan used in the paper. The activity of termites was successfully inhibited when the concentration of chitosan was increased, and the percentage of paper weight loss decreased from 10.80% to 20.49%. Paper without chitosan had a termite mortality rate of 18.3%; The addition of chitosan increased termite mortality to 28.2%–30.4%. The percentage of weight loss decreased with increasing termite mortality. The termite mortality rate show that chitosan is nontoxic and potential as biotermiticide for paper.

Correction to: Toxicity and repellent effects of wood extractives of five Malaysian wood species on Asian subterranean termite Coptotermes gestroi Wasmann

Antitermitic potential of heartwood extractives of five Malaysian wood species against the subterranean termite, Coptotermes gestroi was investigated in laboratory experiments. Heartwood extractives of the wood species, Cinnamomum sp., Canarium littorale Blume, Cynometra malaccensis Meeuwen, Eugenia griffithii Duthie and Scorodocarpus borneensis (Baill.) Becc. were removed from wood sawdust using the four solvents, methanol (MeOH), ethanol (EtOH), acetone and toluene:industrial methylated spirit (Tol:IMS). Extraction was done using a Soxhlet extractor. Two different tests, toxicity and repellency, were conducted on filter paper treated with different concentrations (0.5, 1, 2, 3 and 4%) of each wood extract to observe the repellents, feeding response and mortality of termites. No-choice bioassay using Hevea brasiliensis test blocks treated with the same concentrations of each wood extract was also carried out to compare the results with the termiticidal activity of extractives. Termite feeding, repellents, and mortality followed a concentration-dependent response. The highest termite mortality occurred at an extractive concentration of 4% of each wood species. Extractive of each wood species prepared using MeOH showed higher termite mortality, feeding inhibition and lower filter paper consumption when treated with 4% of concentration. Extractive of C. littorale prepared using EtOH as a solvent was least toxic to termite. Acetone extractive of S. borneensis showed significantly higher repellent activity against C. gestroi at 2, 3 and 4% of concentrations compared to the rest of treatments. Further characterization of the extractive content is needed to find out which compounds are responsible for termiticidal and antifeedant activity, either singly or jointly.

Termiticidal Activity and Chemical Components of Bamboo Vinegar against Subterranean Termites under Different Pyrolysis Temperatures

In this study, the chemical components and termiticidal activities of bamboo vinegar against subterranean termite were evaluated. Bamboo vinegar used in this study were produced from Mayan (Gigantochloa robusta Kurz.), Balcoa (Bambusa balcooa Roxb.), and Taiwan (Dendrocalamus latiflorus Munro). It was analyzed by gravimetric methods. Rubberwood (Hevea brasiliensis) was soaked for 24 h and tested against Coptotermes curvignathus Holmgren according to the Indonesian National Standard (SNI 7207-2014). The bamboo vinegar demonstrated antitermite activities against subterranean termite. Vinegar of 400°C recorded higher total phenol and acid than that of 300°C. Results from this study suggest that the phenolic and acidic component of the bamboo vinegar contributed to 100% mortality rate of the termite, some wood weight loss, and a decrease in the termite feeding rate. These results strongly recommend that bamboo vinegar from D. latiflorus Munro is a potential environmentally friendly preservative.

Toxicity and Field Efficiency of Certain Insecticides Against the Subterranean Termite, Psammotermes hypostoma Desneux (Isoptera: Rhinotermitidae)

The subterranean termite, Psammotermes hypostoma Desneux (Isoptera: Rhinotermitidae)is considered one of the most dangerous termites in urban, rural and agricultural areas in the desert belt of Assiut governorate, Egypt. Organophosphate insecticides such as chlorpyrifos have been recommended to control subterranean termites in Egypt. The present research was conducted to evaluate the toxicity, persistency and effectiveness of chlorpyrifos (chlorzan 48% EC), imidacloprid (imidammex 70% WG), chlorantraniliprole (coragen 20% SC), indoxacarb (avaunt 15% EC) and spinosad (tracer 24% SC) against subterranean termites. The toxicity of these insecticides was tested against field strain of the subterranean termites using the cardboard dip-bioassay technique under laboratory conditions. The toxicity index after 12 and 24 hr exposure showed that chlorpyrifos has the highest termiticidal activity, with LC50s 1.19 and 0.13 ppm, followed by imidacloprid with LC50s 3.24 and 0.61 ppm, while spinosad was the least toxic one with LC50s.9.96 and 4.95 ppm. Furthermore, chlorpyrifos, imidacloprid and chlorantraniliprole registered significantly high percent reduction of the infested rural homes by subterranean termite, P. hypostoma, while indoxacarb and spinosad recorded the lowest reduction percentage after 30, 60, 90 and 120 days of treatment. In addition, the efficiency and residual effects of chlorpyrifos persisted up to 120 days followed by imidacloprid and chlorantraniliprole after treatment. Results of this study indicated that, chlorpyrifos exhibited the most powerful pesticide among all the insecticides tested, and imidacloprid and chlorantraniliprole were highly effective and it is given as unique and hopeful trends against subterranean termites under field conditions.

Termiticidal activity of chitinase enzyme of Bacillus licheniformis, a symbiont isolated from the gut of Globitermes sulphureus worker

Abstract Chitinase is a digestive enzyme that breaks down glycosidic bonds in chitin. Chitin is a biopolymer that can be found in the exoskeleton of insects, fungi, yeast, and algae, and in the internal structures of other vertebrates. Bacillus licheniformis strain USMW10IK was isolated from the guts of Globitermes sulphureus workers. The production of chitinase was highest during the stationary phase (72–96 h of incubation) with the enzyme activity was 0.0057 U/mL – 0.0058 U/mL. The crude chitinase extracted after 72 h was used as biotermiticide against termite G. sulphureus. A pathogenic bioassay was done in four methods; no choice, treated sand medium, topical (Petri dish lined with filter paper), and topical (Petri dish lined with sterile sand). Termite mortality was observed for 24–48 h as the crude chitinase stability has decreased by 22.8% after 48 h. As a result, topical (Petri dish lined with filter paper) has caused significant termite mortality after 24 h and topical (Petri dish line with sterile sand) gave significant termite mortality after 48 h while no choice and sand treated medium gave no significant mortality. These findings suggest that chitinase is effective to be used as a biotermiticide when it directly contacts with the termite skin.

Chemical Components, Antitermite and Antifungal Activities of Cinnamomum parthenoxylon Wood Vinegar

Termiticidal and fungicidal activities of wood vinegar from Cinnamomum parthenoxylon (CP) stem wood have been evaluated against Coptotermes curvignathus and wood rotting fungi (Schizophyllum commune and Fomitopsis palustris). The utilized CP wood vinegar was produced in the operating temperature range 250-300°C pyrolysis. A no-choice test was applied for evaluating termiticidal activity with 33 active termites and antifungal activity using the agar media assay. The result showed that an increase in the concentrations of CP wood vinegar significantly raised the mortality of termite. CP wood vinegar showed high termiticidal activity, organic acids (acetic acid 42.91%, 3-butenoic acid 6.89%, butanoic acid, 2-propenyl ester 2.26%), and ketones (1-hydroxy-2-propanone 5.14%, 3-methylcyclopentane-1,2-dione 2.34%) might be largely contributed to termiticidal activity in addition to other minor components. Furthermore, CP wood vinegar exhibited significant inhibition of fungal growth. These data showed that CP wood vinegar was more toxic to white-rot fungi (S. commune) than brown-rot (F. palustris). The results suggested that phenolic compounds from lignin degradation were responsible for good antifungal activity.

Biological Control of Wood Destroying Organism Using Plant Extracts Collected from Mt. Merapi National Park, Indonesia

Due to the climate change and global warming, the biodiversity database has gained the attention of the government. In line with the Indonesian Biodiversity Strategy and Action Plan (IBSAP), we have collected plants with insecticidal activity based on the local wisdom. This program aimed to protect Indonesian biodiversity from deforestation along with the loss of the number of species. This research’s goal was to evaluate termiticidal and antifungal properties from some plant extracts collected from the Turgo forest area, Mt. Merapi National park, Java. Three potential plants were evaluated. Based on specimen identification, the three plant samples were Kina (Cinchona sp.), Kamadoh (Dendrocnide stimulans (L.f.) Chew), and Keremi (Homalanthus populneus (Geiseler) Pax). The phytochemical test showed that Kina contained alkoloid, falvonoid, saponin, and tannin, whereas Kamadoh and Keremi contained saponin and tanin, respectively. Overall, all plant extracts have the termiticidal activities and able to inhibit wood- decay fungi with the inhibition percentage around 60% - 100%. Leaf extracts of Kina (Cinchona sp) and Keremi (Homalanthus populneus (Geiseler) showed the highest activity as wood-decay fungi inhibitor. The disclosure of the potential of bioinsecticides from some plants originating from Mount Merapi is very important before being lost due to deforestation and the Mount Merapi disaster. Thus, the potential bioinsecticide in these plants can increase its economic value as a substitute for synthetic insecticides that are friendly to the environment.

Evaluation of the use of Myracrodruon urundeuva heartwood extracts to protect Moringa oleifera seeds against Nasutitermes corniger attack and improve sanity

Moringa oleifera seeds contain several biotechnologically-relevant molecules but are susceptible to termite attack. On the other hand, Myracrodruon urundeuva is strongly resistant to deterioration and it was previously reported the termiticidal activity of preparations from its heartwood against Nasutitermes corniger. This work evaluated whether methanolic (ME) and saline (SE) extracts from M. urundeuva heartwood would be able to protect M. oleifera seeds against N. corniger and improve seed sanity. Nuclear magnetic resonance (NMR) spectroscopy analysis was used to identify the chemical profile of the extracts. Seeds were sprayed for 5 days with ME (SME), SE (SSE), or positive control 1% (v/v) sodium hypochlorite (SSH) and then infested by workers and soldiers. Controls were also performed using seeds not treated with the extracts and infested (ST control) or not (S control). After death of all termites, the seeds were analyzed for vigor (by measurements of electric conductivity in the exudates) and sanity. The representative 1H NMR spectra showed phenolic compounds among the main components of the extracts. Mortality rate of workers and soldiers after 7 days was 100% in SME, SSE, and SSH while it was 50% in ST control. Perforations made by termites were observed in seeds from ST control and SME treatment but not in seeds treated with SE. Analysis of vigor revealed that seeds from control ST or those treated with ME or sodium hypochlorite were damaged by termites while SE promoted protection against N. corniger. Fusarium spp., Penicillium spp. and Trichoderma harziamum were identified in treatments and controls, revealing that the extracts did not improve seed sanity. In conclusion, SE from M. urundeuva heartwood conferred protection against N. corniger attack when sprayed on M. oleifera seeds and this effect can be related with lectin presence.

Effects of two protease inhibitors from Bauhinia bauhinoides with different specificity towards gut enzymes of Nasutitermes corniger and its survival

Two recombinant protease inhibitors from Bauhinia bauhinioides, rBbKI (kallikrein inhibitor) and rBbCI (cruzipain inhibitor) were evaluated for insecticidal activity against workers and soldiers of Nasutitermes corniger (order: Isoptera; family: Termitidae) through the inhibitors' effect on the insect's gut enzymes. The inhibitor rBbKI was more effective than rBbCI in inhibiting the termite's gut enzymes. The kallikrein inhibitor showed termiticidal activity in workers with an LC50 of 0.9 mg mL−1 after 4 days. Conversely, rBbKI did not affect the survival of soldiers and rBbCI did not show termiticidal activity against N. corniger. The two inhibitors showed different specificity towards the termite's gut enzymes, representing interesting tools to characterize N. corniger enzymes. The different effects of rBbKI and rBbCI on the termite's enzymes and survival may be linked to slight structural differences between these inhibitors.