Fatores da biologia reprodutiva que influenciam o manejo comportamental de Tuta absoluta (Meyrick) (Lepidoptera : Gelechiidae)

Abstract

The tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the major tomato pest in Brazil. Mass trapping technique was tested as an alternative control of this pest, and although it provided a reduction of male population, no control below the economic injury level was attained. Therefore, this work tested the potential effect of reproductive and behavior factors on the low performance of T. absoluta mass trapping. A decrease in the fecundity and fertility, as well as an increment in the female longevity was observed after female mating delays. Calling activities changed with mating delays depending on the weight and feeding. Upon feeding, light females showed an increase in the calling intensity. Unlike these, heavy females showed a higher intensity and maintenance of calling. Apparently, females are still able of keeping the population growth, despite of the reproductive potential reduction. Males of tomato leafminer are polygynic and can mate up to 12 consecutive times, but they mated 6.5 times intheir lifespan on average. Males that mates consecutively and many times cause not only a reduction in the fecundity and fertility but also an increase of longevity of their females. Females of T. absoluta are, on minor scale, polyandric and this contributed only to increase the females longevity. In general, there is an asymmetry of multiple mating potential between males and females of T. absoluta, and males are more promiscuous than females. Males that escape the masstrapping may compensate part of the trapped male population and upon waiting; the females may mate with these males with almost no loss of reproductive potential. In conclusion, success of pheromone use depends on the capacity of competition among traps to eliminate as many males as possible, hence reducing the mating chance of this species in the field.