Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2016
Publication Date: 9/1/2016
Citation: Foley, J.R., Minteer, C., Tipping, P.W. 2016. Differences in seasonal variation between two biotypes of Megamelus scutellaris (Hemiptera: Delphacidae), a biological control agent for Eichhornia crassipes in Florida. Florida Entomologist. 99:569-571.

Interpretive Summary: Climate matching between the native and adventive ranges of insects used for biological control is a generally accepted strategy for both increasing the likelihood of establishing an agent, as well as improving its overall performance, thereby maximizing the potential success. The purpose of this study was to compare the seasonal performances in southern Florida of two putative biotypes (Argentine vs. Paraguay) of Megamelus scutellaris, a biological control agent for waterhyacinth. Plants infested with M. scutellaris were placed into environmental chambers that were programmed to change temperatures hourly to mirror monthly southern Florida averages from 2011-2012. The number of adult offspring that developed at each temperature regime were counted and weighed. Significant differences in mean adult weight between populations and among seasons were found. Adults from the Paraguay biotype weighed more than those from the Argentine biotype during the summer season. This difference could lead to an increase in the number of offspring produced in subsequent generations. This information has been used to guide decisions on the deployment of the two biotypes in Florida.

Technical Abstract: Climate matching between the native and adventive ranges of insects used for biological control is a generally accepted strategy for both increasing the likelihood of establishing an agent, as well as improving its overall performance, thereby maximizing the potential utility of an agent across the widest area. The purpose of this study was to compare the seasonal performances in southern Florida of two putative biotypes (Argentine vs. Paraguay) of Megamelus scutellaris, a biological control agent for waterhyacinth. Plants infested with M. scutellaris were placed into environmental chambers that were programmed to change temperatures hourly to mirror monthly southern Florida averages from 2011-2012. The number of F1 adults that developed at each seasonal temperature regime were tallied and weighed. Multiple analysis of variance (manova) found significant differences in mean adult biomass between populations and among seasons namely, F1 adults from the Paraguay biotype weighed more than those from the Argentine biotype during the summer season. This information has been used to guide decisions on the deployment of the two biotypes in Florida.