Characterization of fungal flora associated with sternorrhyncha insects of cotton plants

In this study, 22 different fungal isolates associated with naturally dead insects of order Hemiptera including Bemisia tabaci, Aphis gossypii and Phenacoccus solenopsis were isolated from three different agroecological zones namely hot arid, cotton and central mixed zone. Fungal species were characterized morphologically on the basis of colony color, shape and spore structures through using different dichotomous keys. As a result fungi belonging to different species of Aspergillus, Acremonium, Beauveria, Cladosporium, Alternaria, Clonostachys, Penicillium, Trichoderma, Fusarium, Metarhizium and Verticillium were identified. All isolates of individual species were identical with respect to morphological differentiation. Principal component analysis (PCA) indicates strong correlation between Verticillium lecanii and Aspergillus fumigatus with respect to their isolation source (insect host). However, based on PCA, an uneven distribution of entomopathogenic fungi in different insect hosts is evident. Phylogenetic analysis revealed that Aspergillus fumigatus and A. nidulans are more closely related to different species of Penicillium, while Aspergillus oryzae and A. flavus formed separate clades, whereas different species of Alternaria, Cladosporium and Fusarium formed separate clades. Thus, the information generated will add to our understanding of the insect associated fungal communities for future development of potential biocontrol agents and their application as a vital component of sustainable agriculture.