The pathogenicity of known and locally discovered strains of bacterial and fungal pathogens was studied. It was found that various concentrations of commercial preparation of B. thuringiensis (Bifiditermes beesoni and Heterotermes indicola. Other B. and Bectospeine ) initiated mortality of odeontotermes obesus in the mounds. Histopathological studies showed that B. thuringiensis eroded epithelial cells of various portion of the guts in all the three species of termites.
Various strains of B. thuringiensis such as HD-201, 11 â€“ toumanoffi; HD-224, 5a, c-Canadensis and HD-109, 6-subtoxious were highly pathogenic to the nymphs of B. beesoni and workers of M. championi and H. indicola, respectively.
A survey of pathogens, parasites and predators of termites was carried out in different ecological zones of Pakistan. the search for possible pathogens yielded seven bacteria (serratia marcescens, pseudomonas fluorescence, staphylococous aureus, citrobacter frundii, Ecterobacter aero genes, bacillus cereus, Bacillus thuringiensis); two fungi (A. flavus and aspergillus sp.) a probable cytoplasmic polyedrosis virus, a possible pathogenic nematode, microsporidia and a probable predatory mite. All these bacteria were pathogenic to M. championi, B. beesoni H. indicola. However, termites showed various degrees of susceptibility to each bacterial pathogen. The locally discovered Aspergillus and Aspergillus sp. Were highly pathogenic to m.chamioni, H. indicola and B. beesoni. Higher mortality of termites occurred when they were crawled on fungal culture for a longer period. Histopathological studies and B. beesoni was through integuments, their mycelia branched into the body cavity and attacked all the organs including the gangilion of the nierve cord. when the conidia entered the termites through oral rounded, they were seen trapped by cytoplasmic masses and atranda developing in the gizzards and guts of the termites concerned.
Studies were conducted on the enhancement of pathogenicity of H. thuringiensis, serratia marcescens and pseudomonas fluorescens by gamma rays. The results showed that 72 hrs old and 60 or 70 irradiated cultures of B. thuringiensis, and 72 hrs old and 30 kr irradiated S. marcescens were more pathogenic than non-irradiated ones.
Boric acid (1%) when mixed with B. thuringiensis and 1% potassium chloride or sodium citrate when with S. marcescens also enhanced the pathogenicity of the bacteria concerned.
The synergistic action of pathogena on termites was studied. The results showed that A. flavus or aspergillus sp. , when combined with b. thuringiensis , p. fluorescens or S. marcescesn, caused mortality of m. championi, H. indicola and B. beesioni more rapidly than when used alone. Histopathological studies of H. indicola infected by a combination of A. flavus and B. thuringiensis showed that both the pathogens attacked epithelial cells of the gut and fat body tissues of the host.
Cannibalism and prophylaxis help in the spread of pathogens from one individual to another. The role of trophallaxis in the transfer and localization of 1131 in B. beesoni infected by various bacterial pathogens was studied. The results showed that there was more flow of radioactivity from the guts towards the exoskeletons of B. thuringiensis, p. fluorescens and s.marcens infected termites as compared to the non- infected ones.