INCORPORATION OF BODY COMPONENTS OF DIVERSE MICROORGANISMS BY LARVAL MOSQUITOS

A pulse-purge schedule of exposure to labeled microorganisms was used to compare their digestibility by larval mosquitoes. Larvae were place d for an hour in suspensions of diverse axenically grown microorganism s that had been labeled with radioactive carbon (in the form of glucos e or glycine). The guts of these mosquitoes were then purged with nonl abeled Sephadex(TM) particles for 30 min, and retained radioactivity w as measured. Larvae imbibed no dissolved material. Larval mosquitoes d iffer in their capacity to derive label from algae (sensu lato), and c ertain algae contribute more label to these mosquitoes than do others. The nature of any algal food, as well as the feeding habits and devel opmental stage of the larva, influence its capacity to derive label fr om algae. This pulse-purge method of analysis can assist in the select ion of algal ''vectors'' suitable as vehicles for transgenic larvicide . Although larval mosquitoes fail to assimilate the contents of Palmel lacoccus cells with which they are confined, as much as 1/3 of the bod y contents of a Euglena gracilis cells become incorporated into their bodies. Because larval mosquitoes internalize more material from Eugle na than they do from various other algae, these microorganisms provide a promising candidate vehicle for transgenic Bacillus thuringiensis i sraelensis.