Title: Biology and population dynamics of the cactus moth, Cactoblastis cactorum Author
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 20, 2011
Publication Date: N/A
Technical Abstract: The cactus moth, Cactoblastis cactorum, was a successful biological control agent against prickly pear cacti in Australia in the 1920’s. Since then, it was introduced to other countries including the Carribean islands. In 1989, the cactus moth was reported in Florida and has continued to spread north to South Carolina and towards the desert southwest. Cactus moth is a threat to commercial and rare cactus from Florida to Texas in the United States, and to the cactus industry in Mexico. Computer models such as the bioclimatic model can aid in guiding the research to control the cactus moth. Our studies using Climex analysis predict that cactus moth can survive throughout the Big Bend Coast into Mexico, where cactus is an important economic and cultural plant species. The cactus moth is now considered a serious insect pest. Detailed biological and ecological studies are needed to develop management strategies against this pest. Field surveys in Florida indicated three distinct generations per year (two reported in colder climates). Laboratory studies of its life history showed that the duration of immature stages was generally longest at 18, declining significantly at 22 and shortest at 26, 30 and 34 oC. Total immature development time from eggs to pupae was about 180 days at 18, 116 at 22 and ranged from 65 to 72 days at 26 to 34 oC. Estimated lower developmental threshold was 13.3 oC. The highest reproductive values were found at 30 oC, which indicates an approximate optimal temperature. Our field and laboratory studies indicate that the most vulnerable lifestage appears to be the egg stage, both because it is exposed, and also because of the relatively long duration time in this stage. Biological and insecticidal control may need to target the vulnerable egg stage. Biological control agents studied include parasites, entomopathogens and predators. There is a need for further studies of the cactus moth migration and biology. Data from the latter studies will aid in developing area-wide management strategies to prevent the spread of the cactus moth and economic loss to the cactus industries in the US and Mexico.