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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #87074
Title: CUMULATIVE EFFECTS OF ANTIBIOSIS ON FIVE BIOLOGICAL PARAMETERS OF THE FALL ARMYWORM

Author
item Wiseman, Billy

Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: The fall armyworm is an economically important pest of many crops in Nort and South America. Corn plants with a natural resistance to the fall armyworm due to chemicals in the silks have been identified. Results of a laboratory study showed that even low levels of resistant corn silks reduced fall armyworm growth, extended the life cycle, but did not consistently reduce the number of eggs that the moths produced. An intermediate level of resistance reduced growth, extended the life cycle by an average of ca. 4 d and significantly reduced egg production in each of the five generations. A high level of resistant silks reduced growth significantly, extended the life cycle on an average of ca. 10 d per generation and reduced egg production by almost 50% over that for the laboratory control in generations four and five. Thus, fall armyworm larvae fed on different levels of resistant silk-diets did not appear to adjust to the resistance in any of the five parameters measured during five generations.

Technical Abstract: Results of a laboratory study showed that even low levels of resistant maize, Zea mays L., silks reduced fall armyworm, Spodoptera frugiperda (J. E. Smith) growth, extended the life cycle, and reduced fecundity in four of five generations. An intermediate level of resistance reduced growth, extended the life cycle by an average of ca. 4 d and significantly reduced d fecundity in each of the five generations. A high level of resistant silks reduced growth significantly, extended the life cycle on an average of ca. 10 d per generation and reduced fecundity by almost 50% over that for the laboratory control in generations four and five. Though the estimated fecundity was not greatly reduced in all generations, there were no apparent adjustments to the stress of various levels of resistance after five generations. Thus, fall armyworm fed on various levels of resistant silk-diets did not appear to adjust to the resistance in any of the five parameters measured after five generations.