Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 4, 1996
Publication Date: N/A
Interpretive Summary: The boll weevil is a key pest of cotton in parts of the United States. Catolaccus grandis, a parasitic wasp from southern Mexico, is highly effective as a biological control agent when used in augmentative releases against the boll weevil. However, the practical use of this parasite in augmentative release programs depends on our ability to economically produce it in sufficient numbers. We found that different temperatures, especially low temperatures, influence the survival and mortality of parasite. These findings will be used in the development of highly efficient mass rearing procedures for C. grandis, which will make augmentative releases of the parasite for management of the boll weevil practical.
The low temperature threshold for development of Catolaccus grandis (Burks) was determined to be 12 deg C for eggs, 11.5 deg C for larvae, and 9.5 deg C for pupae. The developmental time for male or female parasitoids increased by 4.6 to 5.3 times and the preovipositional period of females increased from 2.2 to 9.3 days when the temperature was reduced from 30 deg C to 15 deg C. The number of degree-days to complete development was 225.6 for females and 197.2 for males. The length of distribution of emergence of C. grandis was ranged from 3 days at 27-30 deg C to 6 days at 20 deg C. Reduction of the temperature from 25 to 15 deg C increased the death rate of C. grandis 2.4 times and reduced the number of females emerging from parasitized boll weevil larvae by 78.2%. The percentage of emergence of females from pupae stored at temperatures lower than 15 deg C for 10 days or more decreased significantly, compared with females from pupae held at 25 deg C. Storage of pupae at 20 deg C or lower resulted in adult females with reduced fecundity. However, the sex ratio of the progency was not significantly affected.