Thermal requirements and development of Bracon 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: 2007
• Subjects: adaptation; ambient temperature; Anthonomus grandis; biological control agents; Bracon; Bracon vulgaris; Braconidae; Coleoptera; Curculionidae; desiccants; eclosion; females; gender differences; heat sums; Hymenoptera; insect development; insect pests; instars; lower development threshold; males; ova; parasitoids; phenology; photoperiod; plant pests; thermal constants; threshold temperatures
• ISSN: 0334-2123; 1876-7184
• DOI: 10.1007/BF02980696

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