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.  This year CMAVE served as host for 4 students from South Carolina, 2 in the South Carolina Alliance for Minority Participation (SCAMP) and 2 in the Minority Biomedical Research Support (MBRS) programs, and 3 students from the University of Florida.  In addition, we welcomed two high school students from the Youth Employment Start (YES) program and five high school summer students.

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Summer Interns
(click on the pictures for more information)

Danna Ancrum

Jeff Browning

Tredina Davis

Melissa Oliver

Whitney Roberson

Amanda Tovey

Deonna Young

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Summer YES

Hannah Esty

Bryon Hu

 

Voorhees College, Denmark, South Carolina, Junior, major: Biology

Mentor: Baldwyn Torto and Peter E.A. Teal

Composition and attractiveness of Bee-collected and Bee-processed pollen to the Small Hive Beetle

Abstract:  The Small Hive Beetle (SHB), Aethina tumida, is a new invasive parasitic pest of European honeybee colonies in the United States. The beetle originated from South Africa, however, its first appearance in the US was in Florida in 1998. The Small Hive Beetle locates the honeybee hive by cueing in on alarm pheromones of worker bees.  A fungus isolated from the Small Hive Beetle was grown on bee-collected and bee-processed pollen to monitor the efficacy of these substrates to produce these same alarm pheromones.  The volatiles released were also compared for their attractiveness to the Small Hive Beetle in wind tunnel bioassays.  Preliminary results showed significant differences in the amounts of alarm pheromone released and attractiveness to the volatiles produced by the different pollen sources.  The volatiles of bee-collected pollen released higher amounts of alarm pheromone than those of the bee-processed pollen.  Furthermore, the volatiles from bee- collected pollen were relatively more attractive to the beetle in the wind tunnel bioassay.  Detailed experiments are in progress to confirm these results.

Danna preparing bee pollen for inoculation with a yeast isolated from the small hive bee, Aethina tumida.

 

University of Florida, Gainesville, Florida, senior, major: biology with a special interest in molecular biology.

Mentor: Prem Chourey

Seed Development in Zea mays

Abstract:  All flowering plants including Zea mays undergo double fertilization that initiates independent pathways for the endosperm and embryo in seed development.  The mechanisms by which the endosperm and embryo communicate, or diverge without communicating, are not fully understood.  This experiment searches for a correlation between maize embryo and endosperm masses and sugar and starch levels to determine the amount of cross-talk that takes place between the embryo and endosperm, and determine if this cross-talk may be responsible for hybrid vigor.  It is predicted that the development of the endosperm and embryo are interdependent.  The masses of starch-deficient mutant kernels were compared to the wild-type kernels to determine if less massive endosperms correlated to less massive embryos, which may indicate that deficient endosperms translated the deficiency to the embryo.  Although the assays are not yet complete, sugar and starch levels in the mutant embryos and endosperms and those of hybrid kernels will be determined.  The corresponding sugar and starch levels in the embryos will reveal whether or not the starch deficiency in the endosperm affects the sugar levels in the embryos.  In conclusion, preliminary results show that development is dependent on endosperm, and that hybrid vigor is apparent in kernel size.

Jeff Browning dissects developing corn kernels to better understand cross-talk between nourishing part, endosperm, and the germ, embryo.

 

Voorhees College, Denmark, South Carolina, Sophomore, major: Biology

Mentor: Robert L. Meagher and Rodney Nagoshi

Differentiating Fall Armyworms through Genetic Markers

Abstract:  Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a migratory polyphagous pest of many agricultural habitats such as corn, sorghum, forage grasses for livestock, turf grasses, rice, cotton, and peanuts in eastern and central North America and in South America.  FAW consists of two host strains; rice and corn, which are distinguished using genetic markers.  Growers, consultants, and researchers monitor for FAW male moths using sex pheromone-baited traps.  As with many traps, nontarget species can also be collected.  Identifying FAW moths from other similar species can be difficult, especially when moths have been in traps for an extended period of time.  One similar species found in the northeast is Leucania phragmatidicola Guenée (LP).  My research project was to first separate FAW and LP moths collected in pheromone traps in Pennsylvania (Penn State).  I isolated DNA and separated the FAW host strains using PCR and genomic markers.  My experimental hypothesis was that DNA patterns found with FAW host strains would be different when analyzing LP moths.

Tredina weighing fall armyworm larvae in the feeding study.

Tredina collecting Florana stargrass for the fall armyworm feeding study.

 

University of Florida, Gainesville, Florida, senior, major: Entomology

Mentor: David Oi

Transovarial Transmission, Queen Weight, and Brood Development in Vairimorpha invictae infected Fire Ant Colonies

Abstract:  Vairimorpha invictae is an entomopathogen of the red imported fire ant, Solenopsis invicta and is currently being researched as a potential biological control agent. Five queens from an uninfected polygyne S. invicta colony and five queens from V. invictae positive colonies were isolated for 48 hrs with = 20 uninfected callow workers. The uninfected queens weighed 0.0118 grams and laid approximately 500 eggs per queen. Queens from V. invictae infected colonies weighed 0.0079 grams and produced approximately 75 eggs per queen. At the conclusion of the 24 day study, eggs from only one V. invictae infected colony queen developed into larvae. A second study added uninfected 4th instar larvae along with the queens and callows. Uninfected queens weighed 0.0153 grams and laid approximately 700 eggs per queen while queens from V. invictae colonies weighed 0.0096 grams and laid approximately 50-75 eggs per queen. After 15 days, 60 and 30% of the uninfected and V. invictae replicates contained brood, respectively. V. invictae was not detected by PCR in any of the surviving brood, thus transovarial transmission was not evident in this study.

"Say cheese!" Melissa Oliver at dissecting scope.

Melissa counting fire ant larvae.

Melissa meticulously separating larval instars of fire ants.

 

South Carolina State University, Orangeburg, South Carolina, Sophomore, major: Biology

Mentor: Robert Vander Meer

Species Specificity of Fire Ant Alarm Pheromone

Abstract:  Fire ants have many behavioral responses which are meditated by chemicals they produce. These specific chemicals are called pheromones. One pheromone system is called the alarm pheromone, which is known to be responsible for elevating workers to a heighten state of awareness, rapid movement, and attraction to the source. Due to the heighten awareness and attraction of fire ants, the alarm pheromone has the potential to be used in baits, resulting in quicker location of bait particles. In additional, the alarm pheromone has been shown to disrupt normal colony functions and to attract parasitic decapitating phorid flies.

In this study we conducted bioassays to determine the species specificity of alarm pheromones between three related species of ants; Solenopsis invicta, Solenopsis geminata, and Solenopsis xyloni.  The behavioral response of fire ants to alarm pheromones was measured on a scale from 1 to 5, 1 being no reaction and 3 being the first sign of alarm. The results from the bioassay showed that Solenopsis invicta responded to all species. The Solenopsis geminata only responded to Solenopsis xyloni and its own alarm pheromone. The Solenopsis xyloni responded to only itself and Solenopsis geminata. Bioassays were followed with dissection of the heads and mandibular glands for GC, and Mass Spectrometry analysis to determine the chemical make up of the alarm pheromone in all three species of fire ants. The GC separated the complex compounds found in the head and mandibular glands. The results from the different compounds were identified by the Mass Spectrometry. The compound, pyrazine was identified in all species alarm pheromone. In both Solenopsis geminata and Solenopsis xyloni, Propanal, 3-(methyitho) and 2-furanmethanol were found; they may be use in the alarm pheromone.

Whitney is dissecting fire ant mandibular glands.

Whitney is preparing a dry ice acetone bath for freezing ants prior to dissection.

 

Univ. of Florida College of Veterinary Medicine, Gainesville, Florida. Class of 2008.

Mentor: Richard Mankin

Acoustic and Visual Monitoring of Female Mediterranean Fruit Fly (Ceratitis capitata) Capture Events in a Bioassay Tunnel

Abstract:  The medfly is a worldwide pest to citrus and some deciduous fruits. Quarantine officials have successfully kept medfly infestation under control in the mainland U.S. by deploying early warning traps to target accidental introductions. However, the traps that are currently used in medfly surveillance programs require considerable time and labor to monitor and maintain, and medfly populations can build up rapidly between scheduled inspections. Researchers are attempting to develop automated trapping systems that would employ microphones to identify the medfly by its wingbeat frequency. Such devices would decrease labor costs and provide immediate notification of medfly detection. While these devices work well in a laboratory setting where interfering background noise can be eliminated, it is uncertain how these detection devices will perform under “real world” environmental conditions. In this project, female medflies were observed and recorded while being captured at a male-baited trap in a bioassay tunnel. The acoustic environment of the tunnel was similar to the outside, in that the microphone was exposed to street, wind, and thunderstorm noise. It is expected that the results of analysis of these recordings will help improve the capability of an automated system to detect medfly wingbeats under non-ideal conditions.

Amanda Tovey is recording a video of female medflies that have flown in a wind tunnel to a lure baited with male medflies and are being captured on a yellow sticky ball nearby.  Wingbeats of  flying females and females attempting to takeoff after capture are being recorded simultaneously for subsequent signal analysis of flight sound characteristics.

Amanda Tovey is conducting an analysis of female medfly wingbeat signals that will be used to help identify features that distinguish among different insect species.  Ultimately, the goal is to automate the process of identifying insects that are captured by a trap.

 

Allen University, Columbia, South Carolina, Junior, major: Biology

Mentor: Terry Arbogast

Efficiency of Baited and Non-baited Pitfall Traps in Capturing Lasioderma serricorne

Abstract:  The cigarette beetle, (Lasioderma serricorne) is a major pest of stored products.  It feeds on a variety of products including spices, flour, cereal, dry mixes, and almost anything stored in homes, stores, and warehouses. These pests are so hard to control because of the large number of eggs that they produce and the vast number of items that they attack.  In an attempt to use control methods to minimize the use of pesticides, and also determine and compare the trap efficiency of baited and nonbaited traps, pitfall traps were set up at the CMAVE shed.  The experiment consisted of releasing 2000 beetles into the shed and recording the number of beetles captured.  In addition to recording the number of beetles, temperature was also measured at each trap position and release position.  Each treatment was replicated three times.  The data collected were then entered and analyzed in an Excel spreadsheet.  The information developed from this experiment, will help us in estimating how many beetles were captured, thus making it better for us to minimize the number of pests found in homes, stores and warehouses.  This will also help limit the use of pesticides.

Deonna Young counts cigarette beetles captured in a pitfall trap.

Deonna is analyzing trap catch and temperature data using spreadsheet and statistical programs.