Metarhizium anisopliae (Metchnikoff) Sorokin, a pathogenic fungus to insects, infects the subterranean termite, Coptotermes curvignathus Holmgren, a devastating pest of plantation trees in the tropics. Electron microscopy and proteomics were used to investigate the infection and developmental process of M. anisopliae in C. curvignathus. Fungal infection was initiated by germ tube penetration through the host’s cuticle as observed at 6 h post-inoculation (PI), after which it elongated into the host’s integumental tissue. The colonization process continued as seen from dissemination of blastospores in the hemocoel at 96 h PI. At this time point, the emergent mycelia had mummified the host and forty-eight hours later, new conidia were dispersed on the termites’ body surface. Meanwhile, hyphal bodies were observed in abundance in the intercellular space in the host’s body. The proteomes of the pathogen and host were isolated separately using inoculated termite samples withdrawn at each PI-time point and analyzed in two-dimensional electrophoresis (2-DE) gels. Proteins expressed in termites showed evidence of being related to cell regulation and the immune response, while those expressed in M. anisopliae, to transportation and fungal virulence. This study provides new information on the interaction between termites and its entomopathogen, with potential utilization for developing future biopesticide to control the termite population.

Nine aerobic cellulolytic bacterial cultures were obtained from the Leibniz Institute DSMZ‐German Collection of Microorganisms and Cell Culture (DSMZ) and the American Type Culture Collection (ATCC). The objectives of this study were to characterize the cellulolytic bacteria and to determine the optimum moisture ratio required for solid state fermentation (SSF) of palm kernel cake (PKC). The bacteria cultures were grown on reconstituted nutrient broth, incubated at 30^∘C and agitated at 200 rpm. Carboxymethyl cellulase, xylanase, and mannanase activities were determined using different substrates and after SSF of PKC. The SSF was conducted for 4 and 7 days with inoculum size of 10% (v/w) on different PKC concentration‐to‐moisture ratios: 1 : 0.2, 1 : 0.3, 1 : 0.4, and 1 : 0.5. Results showed that Bacillus amyloliquefaciens 1067 DSMZ, Bacillus megaterium 9885 ATCC, Paenibacillus curdlanolyticus 10248 DSMZ, and Paenibacillus polymyxa 842 ATCC produced higher enzyme activities as compared to other bacterial cultures grown on different substrates. The cultures mentioned above also produced higher enzyme activities when they were incubated under SSF using PKC as a substrate in different PKC‐to‐moisture ratios after 4 days of incubation, indicating that these cellulolytic bacteria can be used to degrade and improve the nutrient quality of PKC.

Heat shock proteins (hsps) protect proteins in eukaryotic cells from damage. Expression of hsps in insects subject to different environmental stimuli is poorly characterized. Here, levels of expression of the hsps genes (hsp40, hsp70, and hsp90) were recorded in Apis mellifera Linnaeus (Hymenoptera: Apidae) workers after exposure to sublethal concentrations of thymol, eucalyptol, α-pinene, trans-anethole, diallyl disulfide and infestation with Varroa mites. Our results show a dose-dependent up-regulation in the levels of all the hsps tested after the bees were treated with thymol, eucalyptol and α-pinene. Although these up-regulated expressions were statistically significant for hsp70 and hsp90 when the bees were treated with thymol and eucalyptol, they were not significant when treated with α-pinene. In addition, significant down-regulated expressions of the hsp genes were recorded in the diallyl disulfide treatment. The transcriptions of all the hsps tested were significantly down-regulated when pupae were infested with different numbers (0-5) of Varroa mites. Thus, it is likely that hsps can be used as biomarkers of survival when honey bees are under toxic and pathogenic stress, but this needs to be confirmed.

Background: Coptotermes curvignathus Holmgren (Isoptera: Rhinotermitidae) is a subterranean termite that poses serious damage to oil palm and rubber trees. Chemical pesticides could cause negative effect to human and the environment in long-term usage. The use of entomopathogenic fungi (EPF) to suppress the population of subterranean termites is in favour when compared to chemical pesticides because they do not harm to the environment and non-target organisms. The study aimed to isolate and identify the EPF from the soil using yellow mealworm larvae of Tenebrio molitor Linnaeus in the baiting method and assessed their efficacy against subterranean termite, C. curvignathus. Result: Eleven EPF isolates were successfully isolated from the oil palm plantation in Universiti Putra Malaysia, namely: Aspergillus auricomus (UPM-A1C-1), A. caelatus (UPM-A1C-2), Metarhizium anisopliae var anisopliae (UPM-A2C-1, UPM-A3C-1, UPM-A3C-2, UPM-A5C-1 and UPM-A10C-1), Purpureocillium lilacinum (UPM-A2C-3 and UPM-A7C-1), Cordyceps javanica (UPM-A2C-5), and M. pinghaense (UPM-A13C-2). The identity of these EPF were confirmed by morphological and molecular characteristics. All EPF yielded 100% mortality in C. curvignathus in 10 days after inoculation (DAI), except UPM-A1C-1 and UPM-A1C-2 after exposure to 1 × 10⁷ conidia ml⁻¹. UPM-A2C-5 Cordyceps javanica yielded the highest mycelia formation (69%) after 6 DAI. The LT₅₀ values varied from 3.90 to 7.75 days. UPM A2C-1 M. anisopliae var anisopliae showed the lowest LT₅₀ (3.90 days), while UPM-A1C-1 Aspergillus auricomus showed the highest LT₅₀ (7.75 days). The lowest LC₅₀ value (1.49 × 10⁵ conidia ml⁻¹) was recorded in UPM A2C-1 M. anisopliae var anisopliae. Conclusions: The present study confirmed the soilborne EPF with potential insecticidal activity against C. curvignathus. UPM-A2C-1 M. anisopliae var anisopliae was a potential biological control agent against Subterranean termite, C. curvignathus due to its virulence score and high percentage of mycelia formation after 6 DAI. The data reported in the present study, particularly using P. lilacinum, M. pinghaense, Aspergillus auricomus, A. caelatus and C. javanica with potential insecticidal activity against C. curvignathus, are new records.

The CRB (coconut rhinoceros beetle) haplotype was classified into CRB-S and CRB-G, based on the presence of single nucleotide polymorphisms (SNPs) in the mitochondrial cox1 gene. Mitochondrial genomes (mitogenomes) are the most widely used genetic resources for molecular evolution, phylogenetics, and population genetics in relation to insects. This study presents the mitogenome CRB-G and CRB-S which were collected in Johor, Malaysia. The mitogenome of CRB-G collected from oil palm plantations in 2020 and 2021, and wild coconut palms in 2021 was 15,315 bp, 15,475 bp, and 17,275 bp, respectively. The CRB-S was discovered in coconut and oil palms in 2021, and its mitogenome was 15,484 bp and 17,142 bp, respectively. All the mitogenomes have 37 genes with more than 99% nucleotide sequence homology, except the CRB-G haplotype collected from oil palm in 2021 with 89.24% nucleotide sequence homology. The mitogenome of Johor CRBs was variable in the natural population due to its elevated mutation rate. Substitutions and indels in cox1, cox2, nad2 and atp6 genes were able to distinguish the Johor CRBs into two haplotypes. The mitogenome data generated in the present study may provide baseline information to study the infection and relationship between the two haplotypes of Johor CRB and OrNV in the field. This study is the first report on the mitogenomes of mixed haplotypes of CRB in the field.