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 2003, CMAVE sponsored four high school student apprentices, selected from high schools in Alachua county, and five college student interns, chosen from colleges around the country, with ARS funds.  We also hosted one students from an area high school through the Youth Employment Start (YES) program, a federally funded work-training program administered by Santa Fe Community College.  In addition, we welcomed four students 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 Apprentices
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Crystal Amber Kelts

Arikia Millikan

Alyce Nejame

LaShaun Smith

 

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Summer Interns
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Elizabeth Aninakwa	Isaiah Branton	Christine Harrison
Mathew Phipps	Tracey Tam

 

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Summer YES
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Korin Scott

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Summer SSTP
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Kaylin Gong

Jennifer Jackson

Kathleen Towers

Christina White

 

 

Mentor: Baldwyn Torto

Objective:   Crystal Kelts spent the summer carrying out research on two sap beetles, the small hive beetle, a serious pest of honeybee hives, and the picnic beetle, a pest of strawberries in Florida.  For the small hive beetle, she studied oviposition behavior focusing on the effect of beetle population density on egg laying.  For the picnic beetle, she was involved in pheromone identification which included collection of volatiles from different sexes of the beetle and analysis by coupled gas chromatography-electroantennographic detection and gas chromatography-mass spectrometry.

Sexing small hive beetles before collecting volatiles for pheromone analysis.  The apparatus behind the microscope is the volatile collection system.

Feeding small hive beetles with pollen-honey diet in oviposition assays.  Eggs are then transferred into moist sand contained in the chamber located near the cage.

 

 

Evaluation of Compounds from Blood as Mosquito Attractants

Mentor: Sandra Allan

Project:   The purpose of this project was to devise a bioassay method and determine which compounds identified from beef blood serve as attractants for mosquitoes.  Arikia conducted still air bioassays to compare the landing and feeding responses of three species of mosquitoes (Aedes aegypti, Culex quinquefasciatus and Culex nigripalpus) to beef blood and water controls warmed to 40°C.   She optimized light, temperature and sugar-deprivation conditions for examining mosquito responses in the bioassay protocol.  Then, she evaluated responses to a range of compounds identified from blood over a range of concentrations.  Responses of mosquitoes to blood and water controls in a two-choice olfactometer confirmed that mosquitoes were responding to volatiles from the blood.  In bioassays, Aedes aegypti responded readily to the beef blood and several of the compounds; Cx. quinquefasciatus responded moderately and responses of Cx. nigripalpus were very low.  Levels of responses of the different species to beef blood appeared to reflect the published host preference of mammalian over avian hosts for each species.  None of the compounds examined were as effective as the blood controls in eliciting landing or feeding in any of the three species tested.  These studies serve the basis for future studies that will test additional compounds and mixtures of compounds.

Removing mosquitoes from a cage with a battery-operated aspirator.

Sorting and counting mosquitoes on a chill table to make sure that an equal number of female mosquitoes are added to each of the biassay cages.

 

Weather and Storage Effects on Insecticide-Impregnated Cloth for Use Against Stable Flies (Diptera: Muscidae)

Mentor: Jerry Hogsette

Objective:   The justification of this project stems from the need to know how well the product will resist the degrading effects of the Florida weather and how well it will withstand long-term storage.  Treated cloth targets were hung outside at the U.F. Horse Teaching Unit and hung inside a storage barn at the same location.  Samples (ca. 4 x 4 in) were taken from each cloth and tested with an application of ~15 stable flies at the USDA-ARS lab.  Results as of right now are not complete because samples must be taken again in August and in September to show long-term effects.  However, in all treatments but one, all flies died within 30 minutes of exposure to the treated cloth.

This is Alyce’s second year as a Summer Apprentice and she has been working on a project to check the longevity of pesticide-treated cloth to be used as toxic targets for management of the stable fly, Stomoxys calcitrans L.  Alyce has also been working on a project to find non-toxic substances that can be applied to a surface and will prevent house flies from landing.  She is also assisting Tracey Tam with work on the Sonic Web traps.

Alyce hanging treated targets at the outside location on the U.F. Horse Teaching Unit.

Alyce lables treated targets at the inside location.

 

Identification of Bacterial Strains, and Their Effects against Red Imported Fire Ants (Solenopsis invicta)

Mentors: David Williams and Roberto Pereira

Objective: The purpose of the bioassays experiments conducted was to test the effectiveness of unknown bacteria against fire ants (Solenopsis invicta).  The fire ants in the experiment were each fed 1 g of egg yolk each with a different unknown bacterium for three weeks.  At the end of the three-week period the mortality of the ants were calculated.  The mortality percents proved that the seven different types of bacteria were not effective in killing fire ants (Solenopsis invicta).  The bacterium that was used to feed the ants was also tested for identification in the Biolog® system.  A pure culture of bacteria was taken and grown for a period of 24 hours.  Once the bacteria had been grown it was then tested through the Biolog® system for identification.  All seven of the bacteria tested in this experiment were found to be matches with some form of bacteria in the Biolog® system.

LaShaun entering data into the computer program "Biolog" (a bacterial identification system).

LaShaun is working at a biological safety hood, inoculating agar plates with bacterial isolates she used in her research.

 

Testing presence of oviposition deterrence by Chrysoperla rufilabris (Neuroptera Chrysopidae) against the silverleaf whitefly Bemisia argentifolii (Homoptera: Aleyrodidae)

Mentor: Dr. Jesusa C. Legaspi

Project:  The silverleaf whitefly (SLWF), Bemisia argentifolii is known to cause severe damage on crops.  The green lacewing, Chrysoperla rufilabris is known to feed on the silverleaf whitefly, which helps prevent the damage to crops.  Previous studies indicated a possible repellant effect or oviposition deterrence by C. rufilabris against the silverleaf whitefly.  The objective of the study is to determine repellant effect on oviposition of SLWF on plants exposed to green lacewing at different durations.  We exposed lima bean plants with C. rufilabris on each plant for 10, 6, and 4 days.  The control consisted of plants that were not exposed to the green lacewing.  After the Chrysoperla each exposure time, we removed the Chrysoperla.  The plants were then exposed to the SLWF for 3 days.  SLWF eggs were counted from each leaf.  Results indicate that plants exposed to green lacewing for 6 days had a significantly higher number of eggs compared to the 4 and 10 day treatments and the control.  Thus, no oviposition deterrence by green lacewing was observed in this experiment.
Elizabeth Aninakwa labeling potted lima bean plants Elizabeth Aninakwa labeling potted
lima bean plants.

Elizabeth Aninakwa labeling potted lima bean plants.	Elizabeth Aninakwa counting eggs of the silverleaf whitefly, Bemisia argentifolii, on lima beans.
Elizabeth Aninakwa releasing larva of green lacewing, Chrysoperla rufilibris, on lima bean plants.	Elizabeth Aninakwa releasing adults of the silverleaf whitefly, Bemisia argentifolii, into cages.

 

New Technology for Detection of Hidden Insect Infestations in Packaged Goods

Mentor: Richard Mankin

Objective:   My goal this summer was to determine whether the Termatrac, a termite detection device, could detect stored product pests.  I observed that the Termatrac successfully detects small numbers of sawtoothed grain beetles in boxes if the boxes are tested in multiple positions so that the instrument is able to catch activity wherever it occurs.

Abstract:   One of the greatest needs in the field of Postharvest and Bioregulation is to be able to detect stored product pest without destroying the manufacturer’s product and ensuring a quality product for the consumer.  In my experiment, I infested boxes of Jiffy Mix and Bisquick with the sawtoothed grain beetle.  I put 0, 5, 10, 15, 20, 50, or 100 beetles in each box.  The boxes with zero beetles were used as a control.  I then monitored the boxes with the Termatrac and recorded activity five times each day for ten days.  The Termatrac operates by sending out a microwave radar signal and detecting reflections from objects in a narrow field of view, essentially a plane about 10-cm thick, extending about 50 cm in front of the instrument, depending on how rapidly the material attenuates the radar.  The boxes were turned in many different positions, testing different planes through each box, to catch insect movement.  Activity was noted on a 4-category scale as no activity, low, medium, and high activity.  On average, boxes with sawtoothed grain beetle had medium or high activity.  The boxes with zero beetles all had no activity.

ARS Summer Intern Isaiah Branton hangs a sticky ball trap next to a UV light in a test where the attractiveness of UV light to female medflies is being studied. Isaiah is participating in a project to create a trap that combines acoustic and olfactory cues to selectively attract female medflies.

ARS Summer Intern Isaiah Branton examines a box of Bisquick that has been artificially infested with sawtoothed grain beetles.  He is detecting hidden infestations of insects in packaged goods using the Termatrac (yellow instrument at lower right), a device that uses microwave technology to detect movement.

 

Mentor: David Oi

Project Description:   Christine Harrison compared the filtration capabilities of queens of several species of pest ants.  The ants were fed fluorescent microspheres of known diameters and then dissected.  The presence or absence of microspheres in the abdomen of an ant indicated its filtration capability.  The results will be used to evaluate potential chemical and biological control methods for these ants.

Fluorescent microscopy was used to examine ants for microspheres.

Christine Harrison compared the filtration capabilities of queens of several species of pest ants.  The ants were fed fluorescent microspheres of known diameters and then dissected.  The presence or absence of microspheres in the abdomen of an ant indicated its filtration capability.  The results will be used to evaluate potential chemical and biological control methods for these ants.

 

Armyworm table manners: quantification of caterpillar elicitors transferred to the plant leaf surface during herbivory.

Mentor: Eric Schmelz

Abstract:   The fatty acid-amino acid conjugate N-(17-hydroxylinenoyl)-L-glutamine, termed volicitin, is a potent elicitor of plant volatile emission and present in the regurgitate of the beet armyworm larvae (Spodoptera exigua).  These caterpillar-induced plant volatiles serve as important ecological signals used by parasitoids and predators in the location of suitable hosts and prey.  The mechanistic interaction between volicitin, stimulation of the plant defense hormones (i.e. jasmonic acid) and initiation of volatile emission has been well described.  What has not been made clear is the amount of volicitin, if any, that comes in contact with the leaf surface during actual beet armyworm herbivory.  Volicitin levels in caterpillar regurgitate are routinely measured using HPLC and UV detection; however, to quantify trace levels of volicitin that may exist on the leaf surface following caterpillar attack more sensitive detection method is needed.  We explore the use of chemical ionization-gas chromatography-mass spectroscopy (CI-GC-MS) using cool-on-column sample introduction and selected ion monitoring.  Due to the high molecular weight of volicitin (MW 421) and poor chromatographic properties, a method was explored to cleave the glutamine from the 17-hydroxy-linolenic acid.  In theory, the unique 17-hydroxy-fatty acid should be available as a marker of herbivory and demonstrate the presence of insect elicitors on the leaf surface after attack.

Setting up samples for cool-on-column gas chromatographic analyses.

Preparation of fatty acid methyl esters for vapor phase extraction based purification.

Anallysis of flame ionization detection response of hydroxy-fatty acid methyl esters separated by gas chromatography.

Construction of summarized figure detailing the use of chemical ionization GC/MS in metabolic profiling.

Collection of volatile metabolites and fatty acid methyl esters using vapor phase extraction.

 

Relative Attractiveness of the Sonic Web and the Horse to Stomoxys calcitrans

Mentor: Jerry Hogsette

Objective:   The objective of this study was to see if a fly trap could be used to protect horses from stable flies by trapping the flies before they could take a blood meal from the horses.  The Sonic Web trap (Applica Consumer Products, Inc., Miami Lakes, Fla.) was used to trap the flies.  Horses were dusted with a colored fluorescent dust and either tethered to a post or released in a paddock.  Sonic Web traps were placed around the horses 12, 24, 48, or 94 feet away in four separate experiments.  If the flies caught on the traps were colored with fluorescent dust, this indicated that they had visited the horse before becoming trapped. Flies that were not marked with dust were captured before they contacted the horse.

The Sonic Web traps proved to be effective for trapping the stable flies during the experiments.  Only 10% of the total stable flies captured were marked, indicating that 90% of the stable flies were captured on the traps before they could feed on the horses.  Thus the traps provided a high degree of protection against stable flies without the use of pesticides.

Tracey worked primarily on her project to determine the ability of a trap to provide significant protection for horses against the biting stable fly, Stomoxys calcitrans L.  However, she also worked with Alyce Nejame on her project to evaluate the toxicity of pesticide-treated blue cloth against stable flies.

Tracey and the Sonic Web Trap with the superstructure in the open position.

Tracey applying colored fluorescent dust to a horse prior to starting a trial.

 

Isolation and Colonization of Parasitoids from Crop Collected Noctuid Pest

Mentor: Rob Meagher

Project:  Korin assisted with the isolation and colonization of field collected parasitoids.  This required her to rear the host (both on artificial diet and the crops they infest), parasitize with Cotesia, Euplectrus, and Meteorus spp. in order to establish parasitoid colonies for future study.   This required that she be able to sex the host pupae and adult parasitoids.   Then there was the unglamorous support tasks that goes with rearing insects such as dishes, diet, staging, etc.

Korin harvesting Bermuda grass to be used for the tropical sod webworms colony which is reared on cultivated plants.

Colony maintenance of parasitoids which attack the crop pest Spodoptera frugiperda.

Isolating the crop pest (Spodoptera frugiperda) relative to their sex during their pupal stage.

 

Mentor: Dave Carlson

Project:   SSTP students Christina White and Kaylin Gong studied the suspected West Nile virus vector, Culex quinquefaciatus.  These mosquitoes prefer to bite birds over people.  There are no good chemical attractants known for these mosquitoes.  Their project was to prepare solvent extracts of materials known to be attractive to other species of mosquitoes.  Then they used the olfactometer to identify the most attractive class of chemicals for these mosquitoes.

SSTP Students Christina White and Kaylin Gong are comparing attractiveness of their human skin odors to the suspected West Nile virus vector, Culex quinquefaciatus.

Christina is collecting mosquitoes for a bioassay from a rearing cage.

 

Isolation of Queen Pheromone Components in Solenopsis invicta

Mentor: Robert K. Vander Meer

Project:   In the red imported fire ant, Solenopsis invicta, the queen releases a pheromone that functions in attracting worker ants.  This pheromone could be a potentially valuable tool to control the red imported fire ant, such as using it to enhance baits.  Previous studies have determined that this pheromone is stored in the queen’s poison sac (QPS).  To identify the active components within the poison that are responsible for this attraction, we used bioassay-driven fractionation.   We first modified a surrogate queen bioassay, where we added solvent extracts of QPSs to queen-size pieces of filter paper, allowed the solvent to evaporate and placed it into a petri dish arena with worker ants.  We monitored the number of ants visiting the treated filter paper as well as those visiting the control (solvent only) filter paper.  If there was attraction, the solvent extract of QPSs was fractionated via liquid chromatography.  The extract was applied to a silica gel column, which was then rinsed with solvents of different polarities in order to separate the components within the QPSs.  These fractions were tested using the modified surrogate queen bioassay to determine which fraction contained the active components.  This project will continue to use the surrogate queen bioassay, fractionation and evaluation by GC-MS to identify the queen pheromone.

Jennifer carrying out fire ant attraction bioassay.

Jennifer dissecting fire ant queen poison glands.

 

Snap, Crackle, Pop--Eavesdropping on Insects in Stored Products

Mentor: Richard Mankin

Abstract:   Kathleen participated in a project to examine the detectability of sounds made by Indian meal moth, rice weevil, and other insects in birdseed, grain, and other stored products, and to compare the qualities and patterns of sounds made by different insects in different stored products.

SSTP Student Kathleen Towers use a computer program to analyze insect acoustical signals.

SSTP Student Kathleen Towers listens to individual kernels of wheat to find ones infested with rice weevil larvae.  A highly sensitive piezoelectric sensor is being used to detect the vibrations made by the larva while it moves and feeds inside the kernel.

SSTP Student Kathleen Towers listens to sounds being made by Indian meal moth larvae in a jar of birdseed.  She is using the AED-2000 acoustic probe inside an anechoic chamber that shields the probe from background noise.  The AED-2000 was developed two years ago in a cooperative research project with an acoustic instrumentation manufacturer.