Submitted to: Entomological Society of America Annual Meeting North Central Branch
Publication Type: Proceedings
Publication Acceptance Date: April 18, 1997
Publication Date: N/A
Technical Abstract: The western corn rootworm is among the most important insect pests in the United States, causing an estimated $1 billion in yield losses and treatment costs each year. Host-plant phenology in relation to egg hatch time and host-plant genotype are two aspects that affect suitability of corn to western corn rootworm larvae. Interactions of planting date, corn maturity class, corn genotype, soil temperatures, infestation time, and infestation strain all can significantly impact larval establishment and subsequent damage to corn. We have been conducting field, greenhouse, and laboratory screening of exotic corn and corn relatives in an effort to identify germplasm resistant (antibiosis/nonpreference) to this major pest. In addition, we have evaluated different infestation times, egg strains, and infestation levels in the field. Results from our studies, as well as the results of research from other workers, will be discussed in terms our current state of knowledge of the effects of corn phenology and genotype o western corn rootworm establishment and damage. In addition, I will discuss the results of previous work where maize silk volatiles, which are attractive to western corn rootworm adults, were evaluated using an electroantennogram (EAG) technique to determine the morphology and phenology of silk that is most EAG active. Senescing portions (the brown portion that protrudes from the tip of the ear) of silks 7 to 24 d after silk emergence elicited strong EAG responses from adults, and these were significantly stronger than EAG responses to the green portion of silks (under the husks).