Jerry Hogsette, Mentor
Alyce NeJame was involved in two projects this summer. The first involved testing of solid baits used to combat house flies. The tests were conducted in aluminum screen cages (above) with baits composed of varying ratios of boric acid and sugar.
The solid bait containers.
Alyce's second project examined the effectiveness of a new trap for flies and mosquitos, called the BugJammer. This device produces the sound of a beating heart (dog or human), and may emit carbon dioxide, heat, or light, depending on the model.
The BugJammer unit with stable flies and house flies stuck to the adhesive cap insert.
Efficacy of Boric Acid Granular Baits on Musca domestica
The efficacy of boric acid granular baits was tested in this experiment. Concentrations ranging from 3% to 33% were tested. The hypothesis was that the 9% concentration would be the most effective to produce 50% mortality in the least amount of time. This assumption was made based on last year's experimentation where the 8% concentration of boric acid bait worked the best. Probit analysis showed that the LD50 (lethal dose to kill 50 percent of the population) was essentially 9%, based on the data collected.
The baits were mixed in a liquid form and then freeze dried. The experiment was set up with 7 standard (35 x 45 x 35 cm high) fly cages with 25 female house flies (Musca domestica L.), 5 to 6 days old and starved for 4 hours, in each. A 150 ml beaker containing 140 ml of water was placed in the front left corner of each cage. The bait was weighed out at approximately 1 g per concentration, placed in aluminum weigh boats, and placed in the rear right corner of the cages. The flies were released and mortality was recorded at 24, 48, 72 and 96 hours after release time.
The results were not as predicted in the hypothesis. After analysis by probit analysis (SAS), the LD50 was shown to be ~14 percent boric acid. The concentration tested that was closest to the LD50 was 17 percent. Therefore, this was the concentration used to calculate the LT50, which was ~53 hours.
Continuing research is being planned with several tests to determine if color or scent has a positive effect on the efficacy of the baits. Also, is there a level at which the boric acid concentration becomes repellent to the flies? Currently, data are being collected on how long the flies have to be exposed to the bait.