Center for Medical, Agricultural and Veterinary Entomology : 2002 Summer Employment Program Participants

Jerry Hogsette, Mentor

Alyce NeJame examining one of many screen fly cages located in a row on the floor
Inspecting the cages, each one containing 25 female house flies, and an experimental poison bait made from boric acid and sugar.

This summer Alyce NeJame worked on three projects involving house flies. One examined the effectiveness of poison baits made from various ratios of boric acid to sugar, and the effect of freeze drying, and later reconstituting the baits. Another involved the use of bait strips made from Kimwipes, boric acid, and sugar, and the third involved testing of the GT200 fly trap, a device employed by supermarkets to eliminate house flies that have entered the stores.

Alyce NeJame peering into the glowing trap, consisting of a metal frame enclosing two fluorescent tubes, and an inside lining of sticky paper.
Inspecting the kill from an experiment using the GT200 fly trap with Sylvania Quantum bulbs.

A view of the trap, showing two horizontal fluorescent lamps, in front of flies stuck to the paper at the back of the trap.
The GT200 fly trap with dead house flies stuck to the light colored paper behind the Sylvania Quantum (UVA emitting) lamps. Experiments show that the flies are far more likely to become trapped on the light colored sticky paper than dark sticky paper. (Food stores would prefer to use darker paper to mitigate the gross appearance of the flies.)

Alyce's Abstract:

Reconstituting Freeze Dried Boric Acid Sugar Baits for Musca domestica

The objective of this project was to see if freeze-drying and then reconstituting boric acid baits in sugar solutions would affect the repellency observed in the initial liquid form. Based on a previous study with liquid bait solutions, Musca domestica (L.), the house fly, became repelled by a 2.5% boric acid sugar solution. Upon retesting, we found that the LC50 for the initial liquid solutions was ~3.6%. The LC50 was ~83.4%. After reconstituting the freeze-dried baits, the LC50 was found to be ~4.1%. Because of the overlapping confidence intervals, there is no difference between the LC50s of the initial solutions and the reconstituted solutions. There seems to be a difference in how fast the boric acid works upon the flies based on the form it is ingested. The liquids seem to work faster than the freeze-dried solid and the LT50 of the reconstituted liquid is decreased by several more hours than the LT50 of the original solutions. The LT50s of the negative controls indicate no repellency even at the highest doses tested.