The cowpea bruchid (Callosobruchus maculatus) is the most important storage pest of grain legumes and comprises geographically distinct strains. Storage under a modified atmosphere with decreased O2 content represents an alternative to chemical fumigants for pest control of stored grains. In this study, we compared reproduction, development and survival, as well as genome size of bruchid strains from South India (SI), Burkina Faso (BF), Niger (CmNnC) and the United States (OH), reared on mung bean (Vigna radiata). Fecundity and egg-to-adult duration varied significantly among these strains. Notably, strain BF had the highest fecundity, and strain SI displayed the fastest development whereas strain OH was the slowest. Differences in adult lifespan among strains were only detected in unmated but not in the mated group. Genome size of SI females was significantly larger than that of OH females, and for all four strains, the female genomes were larger than those of their corresponding males. Furthermore, we studied effects of exposure to 1% O2+99% N2 on strains SI and BF. Mortality caused by hypoxia was influenced by not only developmental stage but also by insect strain. Eggs were most sensitive, particularly at the early stage, whereas the 3rd and 4th instar larvae were most tolerant and could survive up to 15days of low O2. Strain SI was slightly more resistant than BF in egg and larval stages. Proteolytic activity prior to, during and after hypoxia treatment revealed remarkable metabolic plasticity of cowpea bruchids in response to modified atmosphere.
|Number of pages||7|
|Journal||Journal of Insect Physiology|
|State||Published - Apr 1 2015|
Bibliographical noteFunding Information:
We would like to thank Drs. Ron Salzman and Aaron Tarone for their critical review and thoughtful comments on the manuscript. We appreciate Carl Hjelmen and Shawn Hanrahan for their assistance in genome size measurement. This project was supported by the USDA – AFRI grant #2014-67013-21781 .
© 2015 Elsevier Ltd.
- Callosobruchus maculatus
- Genome size
- Modified atmosphere
- Vigna radiata
ASJC Scopus subject areas
- Insect Science