For over 20 years CMAVE has been providing employment and learning opportunities for students interested in working at one of the top entomological research centers in the world.  In the summer of 2004, CMAVE sponsored two college and one high school student internships with ARS funds.  In addition, we welcomed one student from the Student Science Training Program (S.S.T.P.), a summer program run through U.F. to provide research experience to high school students from around the state.

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Summer SSTP
(click on the pictures for more information)

Daniel Ortner

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Summer Interns
(click on the pictures for more information)

Isaiah Branton

Jennifer Dark

Melissa Oliver

 

Weak Microwave Signals Increase Activity Levels and Acoustic Detectability of Indian Meal Moth Larvae

Mentor: Richard Mankin

Abstract:   Hidden infestations of stored product insect larvae are detected most rapidly by acoustic techniques when the larvae are highly active.  A microwave radar tracking system was used in an attempt to stimulate Plodia interpunctella larvae into increased activity that could be more easily detected by an acoustic sensor.  Dog biscuits were artificially infested with 3rd or 4th instar larvae, placed on a piezoelectric microphone, and exposed to three minutes of weak (100 milliwatt) microwave stimulation in a reflective container.  Acoustic recordings were taken before and after stimulation as well as after ten additional minutes.  There was a significant increase in the average sound rate immediately after stimulation which continued up through the ten-minute wait period.  A possible explanation for these results is that the microwaves increase the biscuits temperature and therefore increase larval activity levels.

Daniel is putting an insect into a shielded container to begin the process of stimulating it with microwaves and acoustically recording the activity.

 

Trapping Female Medflies with Male Medflies, Sound, Pheromone, and Combinations in a Wind Tunnel

Mentor: Richard Mankin

Abstract:   Medflies are important pests of citrus, coffee, and other crops in tropical and subtropical regions.  Efficient traps are needed to detect these pests in the mainland US and other areas where they have not yet spread.  Male medflies attract females by emitting sex pheromone from abdominal glands.  Sex pheromone lures have been developed to capture female medflies, but they have not yet proven to be efficient baits in trapping systems.  One possible way to improve the efficiency of these lures is to broadcast the wing-fanning sounds that males produce while they are emitting sex pheromone.

To test this hypothesis, I conducted a series of bioassays in a wind tunnel.  I placed an adhesive-covered yellow ball at the upwind end and released groups of 30 females at the downwind end.  In different tests, I compared the numbers of females trapped by 1) the ball alone, 2) the ball with a nearby sex pheromone lure, 3) the ball with a nearby speaker broadcasting wing-buzzing sounds, 4) the ball with a nearby mesh ball holding 10 calling males, and several different combinations of 1-4.  We have not gathered enough data for statistical significance, but the balls near the 10 calling males, the broadcasting speaker, and the pheromone, with or without the speaker, all caught more females than the sticky ball alone.

Isaiah is preparing the wind tunnel for a female medfly trapping experiment.

Closeup of yellow sticky ball, speaker, and pheromone/male medfly container used as stimuli in trapping experiments.

 

Lasioderma serricorne: Effect of Dead Beetles on Efficiency of Pitfall Traps

Mentor: Terry Arbogast

Abstract:   The cigarette beetle Lasioderma serricorne (Fabricius) is a widely distributed stored-product insect found in tropical and subtropical climates worldwide, as well as in warm buildings in temperate climates.  The cigarette beetle, so named because it causes a great deal of damage to stored and processed tobacco, is highly adaptable and infests a wide variety of foodstuffs ranging from regular household products to products stored in warehouses.

Because of its highly destructive potential, it is important to understand the life history and behavior of cigarette beetles so that infestations can be located, eliminated, and prevented.  This experiment was designed to determine if traps with dead beetles are more attractive than empty traps, which would raise the possibility that trapped beetles give off pheromones.  To test this hypothesis, 14 traps were laid out in 3 semi-circles, 7 traps with 50 dead beetles each and 7 without beetles, to determine if there is a bias towards traps with beetles.  Using trap catch data collected for each of the 5 replicates, contour maps were created using Surfer to show concentrations of beetles in the experiment shed.  The results of this experiment show a statistically significant bias in favor of the traps with dead beetles.

Jennifer counting cigarette beetles caught in traps.

 

Delayed Toxicity of Fast Acting Fire Ant Baits

Mentor: David Oi

Abstract:   The objective of this study was to determine the delayed toxicity of active ingredients in fire ant baits.  Delayed toxicity was defined as an active ingredient that produced less than 15% mortality by 24h and greater than 89% mortality at the conclusion of a 14-day study.  Delayed toxicity is an important factor in fire ant baits because the delay in death enables the active ingredient to be spread throughout a fire ant colony.  Hydramethylnon has been the standard active ingredient in fire ant baits for many years.  Spinosad is a newer active ingredient that claims to be faster acting than hydramethylnon.  Indoxacarb is an active ingredient that is currently unregistered but is reportedly fast-acting.  To assess delayed toxicity, red imported fire ants, Solenopsis invicta, were exposed to each of these active ingredients for 24h, and mortality readings were taken at set intervals within a 14-day test period.  Hydramethylnon was the only bait that approached the criteria for delayed toxicity, showing less than 15% mortality by 20h and 89% mortality by Day 8.  Spinosad and indoxacarb acted too quickly, with 90% and 57% mortality by 24h, respectively.  However, research conducted previously showed that indoxacarb produced 100% mortality of large laboratory colonies in 3 days.  These data suggest that the criteria for delayed toxicity may have to be altered to accommodate the new, faster-acting fire ant baits.

Melissa making friends with fire ants.