Parasitismo de Ceratitis capitata por Diachasmimorpha longicaudata e sua dispersão em cultivos de fruteiras no semiárido

Abstract

Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) is one of the most important biological agents in the control of fruit flies in several countries. In Brazil, there is little information about their behavior in the field, especially in extreme environments, as is the case in the hot and dry regions of Northeast Brazil. This study aimed to evaluate the ability to search and parasitize in Ceratitis capitata (Wied.) (Diptera: Tephritidae) larvae by D. longicaudata in barbados cherry and mango fruits, in addition to studying the pattern of dispersion and survival of the parasitoid after being released into the orchards of these fruits under the conditions of the semiarid region. D. longicaudata releases were carried out in barbados cherry and mango orchards, in the fruiting stage, located in Petrolina, PE. Initially, 800 parasitoids were released in three orchards in each of these fruit trees. Twenty-four and 48 hours later, the fruits were collected, weighed and stored in the laboratory. The insects emerged from the fruits were counted and the parasitoids were identified. To assess the dispersion and survival of the parasitoid after release, two orchards, one of barbados cherry and one of mango, were selected, each with about 5.5 hectares. In each orchard, concentric radii ranging from 14m to 135m away from the release point in the barbados cherry orchard and 10m to 150m in mango were demarcated. There were eight rays and 61 points in barbados cherry orchard and nine rays and 51 points in mango orchard. At each monitoring point, third instar larvae of C. capitata (Wied.) were offered as hosts by means of sentinel traps that were hung from the trees and remained for 24 h in the field, being replaced by new ones that also remained for another 24 h. Assessments were performed on the 1st, 2nd, 3rd, 8th and 15th day after release. The number of parasitoids recovered from the barbados cherry and mango fruits, the percentage of parasitism in the different rays and in time, the effects of abiotic factors on the dispersion of the parasitoid, the direction it took from the dispersion, the average distance of dispersion (DM) were evaluated. covered and the area it has dispersed (S2). The females of D. longicaudata parasitized the larvae of C. capitata in barbados cherry and mango fruits at 24 and 48 hours after release. The released females survived and parasitized the larvae of C. capitata in the sentinel traps for up to eight days after the releases carried out in the mango orchard and for 15 days in the barbados cherry orchard. In both orchards, greater parasitism was found in the first three days after the releases. In sentinel traps, parasitism in mango was greater than in barbados cherry in the first radius, about 10 meters from the point of release, but females parasitized over greater distances in barbados cherry orchard. In barbados cherry, the females had already covered a dispersion area of almost 10,000 m2, on the second day after release. In the mango orchard, the females reached a maximum distance of 70 m and covered an area of dispersion of almost 0.5 ha, on the eighth day after release. The parasitoids dispersed to the southeast direction in the barbados cherry orchard and, randomly, in five directions, in the mango orchard. Parasitoids parasitized more with increasing thermal amplitude and when the wind was at a lower speed. Diachasmimorpha longicaudata is able to parasitize fruit fly larvae, C. capitata, which are infesting barbados cherry and mango fruits, survive for more than eight days and disperse after being released into orchards of these fruit trees grown in the semiarid region of Pernambuco, Brazil.