Fungos patogênicos a insetos-praga Monalonium annulipes do cacaueiro e Hypothenemus hampei do cafeeiro, no Território da Transamazônica e Xingu, PA, e seu potencial biotecnológico

Abstract

Interest in the use of entomopathogenic microorganisms in agriculture have increased significantly in recent years, faced with problems of inadequate use of pesticides, the accumulation of waste on the environment and ecological imbalances. Currently, the research institutions are concerned to identify a greater number of microorganisms with potential use in biological control of pests that are adapted to the local ecosystem. On economic issues, has increased the demand for technologies that contribute to sustainable agriculture and in response, microbial control, more precisely with entomopathogenic fungi is a promising alternative. Cacao is the main crop of the Trans Territory and Xingu, Pará, and the municipality of Medicilândia the largest Brazilian producer. The coffee is a crop that had great expression in the region, especially Coffea canephora cv. Conilon, and has the potential to become important culture due to availability of culturable areas. In this context, the study aimed to identify naturally occurring entomopathogenic fungi that could be used in biocontrol of insect pests of cultivated plants, seeking the lowest imbalance to the environment. The specific objectives aimed to: i) collect, isolate, identify and characterize the occurrence of entomopathogenic fungi in insect pest of coffee and cocoa, ii) evaluate the effectiveness of microbial agents identified as the pathogenicity and virulence under controlled conditions and iii) testing the production of chitinase enzymes, pectinases, amylases, cellulases and lipases in the isolates obtained and identify them by molecular and classical methods. The work began with several hits on pastures, barns and crops of cocoa and coffee in the municipalities of Altamira, Brazil and New Medicilândia. The parasitized insects were coffee borers (H. hampei) one insect of the order Hemiptera, unidentified, and M. annulipes (monalônio) in cocoa, all colonized by fungi. Where were found parasitized insects, soil was collected for possible identification of entomopathogenic isolates, except where it was found monalônio. We found 14 isolates of fungi colonizing insects, being the main species Verticillium spp., Penicillium citrinum, Hiphopichia burtonii and Fusarium sp. and soil Rhinocladiella sp., Cladosporium sphaerospermum, Verticillium sp. and Pseudallescheria boydii. The analysis of enzymatic activity observed that soil isolates showed the largest degradation of substrates. In bioassay performed against coffee berry borer, with 7 isolates, which have shown highest mortality two H. burtonii, and Icaf 5 were the most pathogenic. Monalônio against the isolated Fusarium sp, colonized 96% of the insects in the ten-day trial. Thus, it is considered that the strains showed significant potential to be introduced in biocontrol programs, with prospects promising results for microbial control of insect pests and enzyme activity.