Related Experiment Video
Updated: Jul 27, 2026
Fat Body Organ Culture System in Aedes Aegypti, a Vector of Zika Virus
Published on: August 19, 2017
Incorporation of body components of diverse microorganisms by larval mosquitoes
Y J Avissar1, J Margalit, A Spielman
1Department of Tropical Public Health, Harvard School of Public Health, Boston, MA 02115.
Abstract:
A pulse-purge schedule of exposure to labeled microorganisms was used to compare their digestibility by larval mosquitoes. Larvae were placed for an hour in suspensions of diverse axenically grown microorganisms that had been labeled with radioactive carbon (in the form of glucose or glycine). The guts of these mosquitoes were then purged with nonlabeled Sephadex particles for 30 min, and retained radioactivity was measured. Larvae imbibed no dissolved material. Larval mosquitoes differ in their capacity to derive label from algae (sensu lato), and certain algae contribute more label to these mosquitoes than do others. The nature of any algal food, as well as the feeding habits and developmental stage of the larva, influence its capacity to derive label from algae. This pulse-purge method of analysis can assist in the selection of algal "vectors" suitable as vehicles for transgenic larvicide. Although larval mosquitoes fail to assimilate the contents of Palmellacoccus cells with which they are confined, as much as 1/3 of the body contents of a Euglena gracilis cells become incorporated into their bodies. Because larval mosquitoes internalize more material from Euglena than they do from various other algae, these microorganisms provide a promising candidate vehicle for transgenic Bacillus thuringiensis israelensis.
Insights
Larval mosquitoes digest various algae differently, with Euglena gracilis being a promising candidate for delivering transgenic larvicides. This research aids in selecting effective algal vectors for mosquito control.
Area of Science:
- Mosquito biology
- Microbiology
- Vector control
Background:
- Larval mosquitoes consume microorganisms as a primary food source.
- Understanding differential digestibility is crucial for developing novel control strategies.
- Algal species vary in their suitability as food for mosquito larvae.
Purpose of the Study:
- To compare the digestibility of various axenically grown microorganisms by larval mosquitoes.
- To identify specific algal species that are efficiently assimilated by mosquito larvae.
- To evaluate the potential of algae as delivery vehicles for transgenic larvicides, such as Bacillus thuringiensis israelensis.
Main Methods:
- A pulse-purge technique was employed using radioactively labeled microorganisms (carbon-14).
- Larval mosquitoes were exposed to labeled microbial suspensions, followed by a purge with non-labeled Sephadex particles.
- Retained radioactivity in mosquito guts was measured to quantify assimilation.
Main Results:
- Larval mosquitoes exhibited differential capacity to derive labeled material from various algae.
- Euglena gracilis showed significantly higher assimilation by mosquito larvae compared to other tested algae.
- Palmellacoccus cells were not assimilated, while up to one-third of Euglena gracilis cell contents were incorporated.
Conclusions:
- Algal food source, feeding behavior, and larval developmental stage influence assimilation efficiency.
- Euglena gracilis is a promising candidate for developing transgenic larvicide delivery systems.
- The pulse-purge method is effective for selecting suitable algal vectors for biocontrol applications.
