Beauveria bassiana fungi utilization on the biological control of cotton ball weevil in Pernambuco

Abstract

The cotton crop in the Northeast of Brazil suffers from low productivity owing to lack of any potent production technology. The most important cause for this low production is the attack of ball weevil for which there is no effective control. In the present paper the use of fungo Beauveria bassiana for the control of ball weevil (Anthonomus grandis) has been described. ln the first method the fungi was tested in the laboratory and was found to be very effective for the control of weevil. This was then directly contaminated on the insects. The studies were carried out at "Três Lagoas" farm, Limoeiro county, PE, Brazil, where cotton crop always suffers from high infection with this pest. In the second method modified feromonio traps (Hardee) were used to capture sufficient number of ball weevils. These were then transfered to capture chamber, where one rice substrate sample of 5 g fungi was kept in order to contaminate the captured insects. The observations were taken for a period of 30 days. Half of captured ball weevil were released again in the field for dissemination of pathogen further on other. The other half were kept in the laboratory to confirm pathogenicity. The results indicated 87.83% infection index and average period of infection around six days. The present work is the first of its kind of work done on this crop in Brazil more particularly in Northeast region and attempts to establish a rational control of this pest in the integrated management of pests.