Effect of susceptible and resistant genotypes on the biology of the velvetbean caterpillar (Anticarsia gemmatalis Hübner)

Abstract

With the purpose of studying the effect of soybean cultivars; and lines on the biology of the velvetbean caterpillar Anticarsia genimatalis Hübner, a laboratory trial was set up at the Centro Nacional de Pesquisa de Soja (Soybean National Research Center), Embrapa, Londrina, PR, Brazil, during the year of 1993. The genotypes tested were BRT92-10868, BRT92-10644, IAC-100, IAC-17, Crockett, Lamar (resistant) and Paraná (susceptible). Just after hatching, larvae were fed with each genotype up to the end of larval stage, reared on growing chamber set at 26ºC ± 1ºC, relative humidity of 75% ± 5% and photophase of 14 hours. Evaluation was made through measurement of larval consumption, dry weight of faeces, dry weight of larvae, weight of pupac, duration of each stage and insect mortality. Larvae feeding on Crockett: showed lower larval and pupal weight and lower gain of weight; however, it was not statistically different from other genotypes. 'Crockett' also showed the highest rates of relative consumption and relative metabolic, while 'Paraná' obtained the highest rates of conversion of both ingested and digested food. Results indicated that 'Crockett' proved not to be an adequated food to the velvetbean caterpillar.