Thermal requirements and development ofBracon vulgaris, a parasitoid of the cotton boll weevil

• Published in: Phytoparasitica Vol. 35; no. 4; pp. 336 - 345
• Main Authors: Wanderley, P. A., Ramalho, F. S., Zanuncio, J. C., Leite, G. L. D.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Nature B.V 01-08-2007
• Subjects: Braconidae; Coleoptera; Cotton; Curculionidae; Hymenoptera
• ISSN: 0334-2123; 1876-7184
• DOI: 10.1007/BF02980696

The development ofBracon vulgaris Ashmead (Hymenoptera: Braconidae), parasitoid of the cotton boll weevilAnthonomus grandis Boheman (Coleoptera: Curculionidae), was studied at constant temperatures of 18, 20, 23, 25, 28, 30, 33, 35 and 38°C, 70±10% r.h. and 14:10 L:D period. The period from egg to adult ofB. vulgaris varied from 8.6 (35°C) to 32.9 days (18°C). The eggs of this parasitoid became desiccated and did not hatch at 38°C. The lower development threshold (LDT) and thermal constants for development varied withB. vulgaris instar, but they were similar for males and females. The duration of the 1st, 2nd, 3rd and 4thB. vulgaris instars required, respectively, 9.36 degree-days above one LDT=12.27°C, 13.48 degree-days above one LDT=6.83°C, 11.65 degree-days above one LDT=9.41°C, and 12.82 degree-days above one LDT=10.78°C.B. vulgaris has physiological adaptations to different threshold temperatures and it shows high potential to be used againstA. grandis in cotton crops.[PUBLICATION ABSTRACT]