ABSTRACT Diachasmimorpha longicaudata is an Old World parasitoid of tephritid fruit flies that was widely introduced in the Americas to control pest species such as the Mediterranean fruit fly Ceratitis capitata. Augmentative releases in irrigated coffee plantations in semiarid regions of Brazil are under consideration and dispersal capacity of D. longicaudata in this habitat are important to develop release strategies. Approximately 2,000 individuals of D. longicaudata (5 to 7 days old) were released in the center of a fruiting coffee plantation every two weeks from Dec. 2009 to Apr. 2010. Dispersal from the central release point was monitored to the north, south, east, west, northeast, northwest, southeast and southwest at 11 distances, beginning at 4.6 m and ending at 90 m from the release point. At each point, a parasitism unit (approximately 120 larvae of C. capitata in the 3rd instar wrapped in voile fabric) and 10 coffee beans were collected. The average dispersion distance and dispersion area were estimated by the model proposed by Dobzhansky and Wright (1943). The average dispersion distances were 27.06 m (as estimated by fruit collection) and 33.11 m (as estimated by oviposition traps). The average dispersion areas were 1,315.25 m2 and 1,752.45 m2 originating from the collection of beans and parasitism units, respectively. Cohorts of 2,000 adult D. longicaudata released at six points ha−1 are estimated to result in sufficient colonization to exert significant control of Ceratitis capitata.

Objetivou-se avaliar a influência da idade (tamanho) das larvas de Ceratitis capitata utilizadas na criação de Diachasmimorpha longicaudata sobre o parasitismo, a razão sexual e a longevidade das fêmeas da progênie, quando as fêmeas mães foram mantidas sozinhas ou competindo pelo mesmo hospedeiro. Para isso, foram oferecidas larvas de cinco, seis, sete e oito dias de idade às fêmeas do parasitoide em "unidades de parasitismo", no interior de gaiolas adaptadas, contendo uma ou duas fêmeas do parasitoide de sete dias de idade. O número de fêmeas do parasitoide dividindo a mesma "unidade de parasitismo" não afetou nenhum aspecto da qualidade do parasitoide. O tamanho do hospedeiro influenciou significativamente no número de parasitoides emergidos. Larvas hospedeiras menores (cinco dias) provocaram uma redução no parasitismo em relação às larvas de seis, sete e oito dias de idade. Houve maior emergência de parasitoides machos de hospedeiros com cinco e seis dias de idade, enquanto mais fêmeas emergiram de larvas com sete e oito dias de idade. As fêmeas de D. longicaudata provenientes de larvas com seis, sete e oito dias viveram mais do que as fêmeas obtidas de larvas com cinco dias de idade. Larvas hospedeiras maiores, quando utilizadas na criação de parasitoides de moscas-das-frutas, aumentam a porcentagem de parasitismo, o número de fêmeas na progênie e a longevidade das fêmeas da progênie, podendo proporcionar vantagens econômicas quando utilizadas para liberação aumentativa no campo.

This work was carried out in order to evaluate the influence of age (size) of larvae Ceratitis capitata used in the rearing of the Diachasmimorpha longicaudataon parasitism, sex ratio of the progeny and the longevity of progeny's females, when the mothers were maintained alone or sharing the same host. Larvae at different ages (five, six, seven and eight days old), in "units of parasitism" were offered to female parasitoids, inside adapted cages, containing one or two seven days old female parasitoids. The number of females of the parasitoid sharing the same "unit of parasitism" in the same cage did not affect any aspect of parasitoid quality. However, the size of the host had significant influence on the number of emerged parasitoids. The youngest host larvae (five days old) reduced parasitism more than larvae at six, seven and eight days old. There was higher emergence of male parasitoids of five and six days old hosts, while more females emerged from seven and eight days old larvae. The females of D. longicaudata from larvae with six, seven and eight days old lived more than those obtained from females of five days old larvae. When larger host larvae are used in the rearing of parasitoids of fruit flies, it increases parasitism, the number of female progeny and the longevity of female progeny; it can provide economic advantages when used for augmentative liberation on the field.