Thermal requirements and annual number of generations of Diachasmimorpha longicaudata (Hymenoptera: Braconidae) reared in the South American fruit fly and the Mediterranean fruit fly (Diptera: Tephritidae)
Keywords:
Anastrepha fraterculus, Ceratitis capitata, degree days, lower development threshold, parasitoid, thermal constantAbstract
Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) is the most widely used parasitoid in biological control of Tephritidae programs around the world. Nevertheless, we have little information about the use of these parasitoids against Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae). This study was conducted to evaluate the thermal requirements for the development of D. longicaudata in 2 of its hosts, A. fraterculus and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Third instars of each fly species were exposed for 1 h to 50 couples of the parasitoid. Subsequently, the larvae were placed individually in glass jars maintained in chambers at temperatures of 15, 18, 21, 25, 28, and 31 °C, at 60 ± 10% RH and a photoperiod of 14:10 h L:D until the emergence of D. longicaudata. The rate of development of D. longicaudata, in both hosts, increased as temperature increased. The development period of egg-to-adult phases was used to estimate, by the hyperbola method, the lower development threshold (Dt) and the thermal constant (K) of D. longicaudata. Dt and K were, respectively, 7.83 °C and 322.58 degree days for individuals that developed in C. capitata, and 12.5 °C and 227.27 degree days for those that developed in A. fraterculus. Adult longevity was inversely proportional to temperature. The results indicated that D. longicaudata may not develop in Rio Grande do Sul in the winter, because it is very common that minimum temperatures in the months of Jun and Jul fall below the Dt. In the 4 fruit-producing regions of the state of Rio Grande do Sul, the average numbers of generations of D. longicaudata per year were estimated in A. fraterculus and C. capitata, respectively, as follows: Porto Alegre (11.16 and 13.12), Pelotas (7.97 and 10.89), Bento Gonçalves (6.99 and 10.05), and Vacaria (4.84 and 8.28).
Resumo
Diachasmimorpha longicaudata (Ashmead) (Hymenoptera: Braconidae) é o parasitoide mais utilizado em programas de controle biológico de tefritídeos no mundo. Existem poucas informações sobre o seu desenvolvimento em Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae). Este estudo foi realizado para avaliar as exigências térmicas de D. longicaudata tendo como hospedeiros A. fraterculus e Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) em diferentes temperaturas. Larvas de terceiro ínstar de cada espécie de mosca foram expostas, por uma hora, para 50 casais do parasitoide. Em seguida, as larvas foram individualizadas em frascos de vidro e mantidas em câmaras nas temperaturas de 15, 18, 21, 25, 28 e 31 °C (60 ± 10% UR e 14 horas de fotofase) até a emergência dos parasitoides. A duração das fases de ovo-adulto foi usada para avaliar, por meio do método de hipérbole, a temperatura basal (Tb) e da constante térmica (K). A longevidade foi comparada entre as temperaturas. A taxa de desenvolvimento de D. longicaudata, nos dois hospedeiros, aumentou com a elevação da temperatura. Tb e K foram, respectivamente, 7,83 °C e 322,58 graus-dias para os indivíduos que se desenvolveram na C. capitata, e 12,5 °C e 227,27 graus-dias em A. fraterculus. A longevidade foi inversamente proporcional à elevação da temperatura. Os resultados indicaram que D. longicaudata pode não conseguir se manter no Rio Grande do Sul no inverno, quando são comuns temperaturas mínimas abaixo das Tbs registradas. O número médio de gerações por ano foi estimado para as cidades de Bento Gonçalves, Pelotas, Porto Alegre e Vacaria; Porto Alegre teve o maior número, enquanto Vacaria teve o menor.
Downloads
Published
Issue
Section
License
Copyright for any article published in Florida Entomologist is held by the author(s) of the article. Florida Entomologist is an open access journal. Florida Entomologist follows terms of the Creative Commons, Attribution Non-Commercial License (cc by-nc). By submitting and publishing articles in Florida Entomologist, authors grant the FOJ and Florida Entomologist's host institutions permission to make the article available through Internet posting and electronic dissemination, and to otherwise archive the information contained both electronically and in a hard printed version. When used, information and images obtained from articles must be referenced and cited appropriately. Articles may be reproduced for personal, educational, or archival purposes, or any non-commercial use. Permission should be sought from the author(s) for multiple, non-commercial reproduction. Written permission from the author(s) is required for any commercial reproduction.