Skip to main content
ARS Home » Midwest Area » Ames, Iowa » Corn Insects and Crop Genetics Research » Research » Publications at this Location » Publication #121946
Title: WHORL AND POLLEN-SHED STAGE APPLICATION OF BEAUVERIA BASSIANA FOR SUPPRESSION OF ADULT WESTERN CORN ROOTWORM

Author
item BRUCK, DENNY
item LEWIS, LESLIE

Submitted to: Entomologia Experimentalis et Applicata
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/4/2002
Publication Date: N/A
Citation: N/A

Interpretive Summary: The corn rootworm complex is the most damaging insect pest of corn. This study was conducted to determine if a granular formulation of the insect-killing fungus Beauveria bassiana could be used to control adult western corn rootworm. This fungus does not harm humans or other animals. The effects of application time (plant growth stage: whorl-stage, pollen-shed) and the plant surface to which beetles were exposed [(leaves and leaf collars)(silks)(leaves, leaf collars and silks)] on levels of beetle infection with the fungus were investigated. In the 3 years (1998-2000) of the study, application of B. bassiana to corn when it was 1-2 feet tall did not significantly increase the level of beetle infection. Beauveria bassiana applied at pollen-shed in 1998 resulted in 43% beetle infection in treated plants, whereas only 6.0% of the beetles on control plants were infected. Similar applications at pollen-shed in 1999 and 2000 0did not result in increased levels of infection. These data show that in given year an application of the fungus B. bassiana kills adult corn rootworm, thus preventing them from laying eggs. This fungus is a potential alternative to chemical insecticides in reducing populations of this pest in corn.

Technical Abstract: The corn rootworm complex is the most damaging insect pest of corn (Zea mays L.). This study was conducted to determine the efficacy of whorl and pollen-shed stage applications of a granular formulation of Beauveria bassiana (Balsamo) Vuillemin (Hyphomycetes: Moniliaceae) for control of adult western corn rootworm (Diabrotica virgifera virgifera Le Conte(Coleoptera: Chrysomelidae)). The effects of application time (whorl-stage, pollen-shed) and plant surface exposed [(leaves and leaf collars)(silks)(leaves, leaf collars and silks)] on levels of beetle infection were investigated. In addition, the amount of B. bassiana present in leaf collars was quantified. In the 3 years (1998-2000) of the study, application of B. bassiana during whorl-stage did not significantly increase the level of beetle infection. Beauveria bassiana applied at pollen-shed in 1998 resulted in 43% beetle infection in treated plants, whereas only 6.0% of the beetles on control plants were infected. Similar applications at pollen-shed in 1999 and 2000 did not result in increased levels of infection. The level of beetle infection did not differ consistently between plant surfaces to which beetles were exposed in whorl or pollen-shed stage applications. Fungal application at whorl or pollen-shed stage significantly increased the number of colony forming units per leaf collar. Increased fungal load in leaf collars did not translate into increased levels of adult infection.