Neotropical Entomology | 2019
Biology and host selection stage of Symmetrischema dulce Povolny (Lepidoptera: Gelechiidae) in chili pepper
Abstract
The pepper-fruit-borer Symmetrischema dulce Povolny (Lepidoptera: Gelechiidae) is an important chili pepper pest causing significant yield losses. However, chili pepper has insufficient crop protection support and primary information about S. dulce is scarce. In the present study, we aimed to study the biology and ecology of S. dulce in pepper plants (Capsicum frutescens L.) focusing to support integrated pest management programs. In the field, we sampled ripe and unripe chili pepper fruits in three different plant strata. In the laboratory, we established colonies of the S. dulce and we recorded the duration, viability, morphology of each life stage, and number of larval instars. We conducted experiments to evaluate insect reproduction, whereby we registered the pre-oviposition and oviposition period, daily oviposition rate, and sex ratio. From these results, we estimated the reproductive success of S. dulce through the intrinsic population growth rate. The higher occurrence of S. dulce was in unripe fruits with no difference between plant strata. Egg stage lasted 4\xa0days with 94% viability, and larval phase lasted on average 10.72\xa0days and presented four instars with viability of 66.6%. Pupal stage lasted 9.61\xa0days with viability of 94.73%. The adult stage lasted 24.14\xa0days with a pre-oviposition period of 3\xa0days and oviposition period of 13.85\xa0days. The intrinsic growth rate (rm) recorded was 0.0035. Our results suggest that the biology of S. dulce has similarities with other Lepidoptera, but its peculiarities in reproductive parameters are essential for future programs of pest management.