Field and Laboratory Selection for Resistance in Soybeans to the Mexican Bean Beetle 13

Abstract

More than 350 soybean lines were screened for host plant resistance to Epilachna varivestis Mulsant in field and laboratory experiments conducted in 1971 and 1972. Entries with low feeding damage scores in the field were screened in the laboratory in a larval antibiosis test and an adult seedling-preference test. Those entries which performed well in both the field and laboratory studies were retested and run through a 3rd laboratory test, the larval leaf disk test. Laboratory studies confirmed moderate levels of resistance found in the field in the following soybean lines: P.I. 90481, P.I. 96089, P.I. 157413, V–21, and V–156. Antibiosis and nonpreference were 2 mechanisms responsible. The performance of several selected lines in both field and laboratory screening studies indicated that the laboratory methods were effective for selecting lines with resistance and identifying in some instances the mechanism of resistance.