Abstract:

The “budborer “, Epinotia aporema, is one of the most important soybean pests in Argentina and Brazil. The objective of this research was to study the within -plant distribution of E. aporema eggs on soybean. In December, January and February, 30, 35, and 40 plants were collected in the field and brought to the laboratory. The number of eggs in different parts (expanded leaves, buds, nodes, inteniodes acid petioles) and strata was registered. The acceptability of different parts and strata to ovipositing females was compared with ANOVA. The higher and the lower number of eggs was registered on nodes and buds, respectively, in Januaty and February. While no significant differences were found in the number of eggs between strata in December and January, the, medium stratum had the higher proportion of eggs in February. Although larvae prefer buds (the most pubescent parts of the plant) as feeding sites, this study shows that these parts were not preferred for oviposition. Taking into account that the higher proportion of eggs were found on nodes, which are the less pubescent parts of the plant, it seems ¡hat pubescence would act as a barrier to the female oviposition behavior.