Biologia e comportamento reprodutivo de Palpita forficifera (Lepidoptera: Crambidae)

Abstract

Palpita forficifera Munroe, 1959 (Lepidoptera: Crambidae) is one of the main species of economic importance to the olive groves in Brazil and in Uruguay. From the neotropical region, this species occurs in various countries from South America. Since olive groves are recent in Brazil, little is known about its bioecology, behavior and consequentially its control. Thus, the objective of this work was studying the biology in different hosts and the mating and oviposition behavior of P. forficifera. To the biology study, we evaluated the development of the species in the olive cultivars Arbequina, Arbosana and Koroneiki and in the alternative host privet (Ligustrum lucidum Ait., Oleaceae). The biological parameters evaluated were duration and viability of the developmental phases, the number and duration of instars, sexual ratio, fecundity, longevity and the duration of the periods of pre-oviposition, oviposition and post-oviposition. Based on this information, the fertility life table for P. forficifera was elaborated. To the study of mating and oviposition behavior, the sex responsible for releasing the sexual pheromone was determined in field and in laboratory were registered the emergence rhythm of males and females, the age, timetable and duration of the mating, number of mating, presence of spermatophore and oviposition timetable. Caterpillars fed on privet presented the longest duration of larval phase and, consequentially, of egg-pupae. The larval viability was smaller in cv. Arbosana, which reflected in the smaller viability in egg-pupae period. Caterpillars fed on cv. Koroneiki originated females with higher fecundity. From the joint evaluation of the biological parameters and the fertility life table, cv. Koroneiki propitiated the highest population increase. The results in field showed that males are attracted to the females for mating, being possible to capture up to five males per trap in only one night. The emergence rhythm occurs in a synchronized way, not occurring protandry (male emerging before female) or protogyny (females emerging before males). The mating occurs between the seventh and the twenty-third day of life, being more often between the third and the sixth hour of scotophase. The average duration of the first mating was 174 minutes, and 35% of the couples remated, occurring up to five mating. The mating was confirmed through the presence of spermatophore in the bursa copulatrix. The oviposition time was concentrated in the first six hours of scotophase. The results obtained with the studies of biology and reproductive behavior enable to advance in the knowledge of this species and thus, subsidize studies aiming the management of this pest, which has been caused considerable damage to olives.