Remarkable changes in the cellular response and oxygen uptake in the wax moth Galleria mellonella were observed when larvae were infected with the entomopathogenic fungus Metarhizium anisopliae. The number of haemocytes increased 48, 72 and 96 h after infection with fungal conidiospores. Extensive blebbing of the cell membrane in the haemocytes and large numbers of vacuoles were noticed as a result of fungal infection. The study showed a significant difference in oxygen uptake between healthy and infected larvae and the greatest uptake was recorded 72 h after fungal infection. The results suggested that the rate of cellular reaction and oxygen uptake were associated with the development of fungal infection.

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The pathogenicity of the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae against the tick fowl Argas persicargas persicus was studied. Bioassays revealed significant differences between the two fungi and the A. persicargas persicus stages exposed. The first nymphal instar was more highly susceptible to both fungi than the second nymphal instar. The unfed female of A. persicargas persicus was significantly less susceptible to both fungi than the engorged female. Application of M. anisopliae to sackcloth naturally infested with the tick fowl A. persicargas persicus induced mortality which reached 100 % three weeks after treatment under field conditions. The present study suggests that entomopathogenic fungi have good potential for tick fowl, A. persicargas persicus, control.

The invasive red palm weevil, Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae), is considered one of the world's most devastating insect pests to palm trees. It was observed that larvae of this pest are able to inhibit microbial growth on the rearing media when they start feeding and this observation has led us to study the effect of red palm weevils on various microbial species. The antimicrobial effect of extracts from different parts of the alimentary canal on Gram positive bacteria (Enterococcus faecalis and Staphylococcus aureus), Gram negative bacteria (Escherichia coli and Klebsiella spp.), Candida albicans, and Penicillium sp. was tested using the agar well diffusion method. All extracts inhibited the tested microbial species. Foregut extracts had the greatest zones of growth inhibition. Enterococcus faecalis, Staphylococcus aureus, and Penicillium sp. were significantly sensitive to the extracts and had the largest growth inhibition zones. It is concluded that the gut extracts contain potent antimicrobial activity and may provide a new source of antimicrobial peptides.