A Preliminary Analysis of Quantifying Endemic Beauveria bassiana (Balsamo) Vuillemin in Kudzu Patch Soils Where Megacopta cribraria Populations Reside
Beauveria bassiana (Balsamo) Vuillemin is an entomopathogen endemic to soils in the United States that cause natural epizootics in insect populations. The GHA strain of this fungus has been commercially formulated to control insect pest populations. One such insect pest that this fungus could potentially control is the kudzu bug, Megacopta cribraria (Fabricius). M. cribraria is an invasive insect of kudzu and agronomic crops with no known natural enemies. However, one report indicated that a kudzu bug was naturally infected with B. bassiana in Georgia. This suggests a natural epizootic could be occurring in kudzu patches in North Carolina. Thus, this study aims to quantify B. bassiana in soil samples of M. cribraria infested kudzu.
1 Dept of Biology, Wingate University, Wingate, NC; 2Dept of Entomology, University of Georgia, Griffin, GA
P99 • Brittany D. Harry1, Flor Acevedo2, Michelle Peiffer2, Shan Jin2, Ketia Shumaker, Dr.1, Dawn S. Luthe, Dr.2, Gary Felton, Dr.2
Corn Earworm Saliva Induces Herbivore Defense Gene Expression in Corn
Corn is one of the most important crops worldwide. Corn earworm (Helicoverpa zea) herbivory on corn is costly in terms of the lack of crop yield that occurs and the damage it does. Caterpillar saliva is known to elicit plant defense response in several plants, but surprisingly the effect of H. zea saliva on corn defenses has not been reported. A series of experiments were conducted to determine the expression of several defense-related genes in Z. mays corn plant hybrid MC 4050 after herbivory by H. zea. We tested the saliva of the H. zea to determine if this factor is an elicitor of Z. mays defense gene expression in corn. Corn plants in the V3 stage were challenged with ablated (cauterized spinnerets) and non-ablated (intact spinnerets) H. zea caterpillars for 24 hours. Control plants were not exposed to H. zea caterpillars. The expression of plant defense genes (MPI, LOX3, RIP2) were analyzed by quantitative real-time PCR (qRT-PCR), using Actin as the endogenous control. We found significant differences (α=0.05) among treatments. The greatest gene expression was observed with non-ablated (intact) caterpillars. These results suggest that H. zea saliva is triggering defenses in corn. This information is important because corn is an important food crop worldwide and understanding the components of H. zea saliva that triggers corn defenses against this herbivore will help scientists develop novel insect control strategies. Future experiments will be aimed at identifying the components of H. zea saliva that induces defense gene expression in corn.
1 University of West Alabama; 2 Pennsylvania State University
P100 • Deep Sangani, Bradley Vaughn, Dr. John Moeller, Dr. Caleb Arrington
Dasymutilla occidentalis, a velvet ant, lays its eggs in the brood chambers in bumblebee hives. Once the D. occidentalis larvae hatch they feed on the larvae of these hosts, thus establishing its parasitoid nature. During excavation of their nest, the bumblebees likely impregnate the soil with the hydrocarbons from the hairs and outer layer of the cuticle. It is theorized that D. occidentalis use chemosensation of these cuticular hydrocarbons in the soil to discover the location of the hives. A behavioral assay suggested that D. occidentalis prefer dried, crushed cuticle from bumblebee hosts compared to honey bees, a non-host hymenopteran. The purpose of this experiment is to determine the cuticle hydrocarbon involved in the chemosensory preference of D. occidentalis. The composition of the bumblebee cuticle was determined by extracting the hydrocarbons with hexane. This hydrocarbon-hexane solution was separated into its individual components by gas chromatograph/mass spectrometry. Comparison of the chromatogram retention times to the retention times of known hydrocarbons allowed for compound identification. From this analysis it was determined that the cuticular hydrocarbons of the bumblebee are composed primarily of long unsaturated hydrocarbons with a few alkene derivatives. A comparison to the cuticular hydrocarbon of the honey bees identified four potential hydrocarbons present in the bumblebee cuticle that are not present in the non-host honey bee. These compounds (7-tricosene, 9-tricosene, 7-pentacosene, and 9-pentacosene) are the best candidates for the chemosensory signal used to locate host nests.
The Relationship Between Achilles Tendon Dimensions and Ankle Joint Range of Motion in Humans
The purpose of this study was to determine the relationship between Achilles tendon dimensions and ankle range of motion. Ankle range of motion (ROM) was measured in forty participants that were 18 to 25 years of age and did not have any known Achilles tendon pathologies or current lower limb injuries. First, the participants warmed up by performing a 30 second hamstring, quadriceps, and calf stretch for each leg. Then, they sat on a ledge so that their feet did not touch the ground. The base and head of the fifth metatarsal, fibular head, and apex of the lateral malleolus were palpated and marked on each leg. A goniometer was used to measure the angles of dorsiflexion and plantarflexion of each ankle. Each measurement was performed three times, and then the mean dorsiflexion and plantarflexion angles were calculated. The mean ROM was calculated by subtracting the mean dorsiflexion angle from the mean plantarflexion angle. Additionally, the length, width, thickness, and moment arm of the Achilles tendon were measured using ultrasonography. Relative measurements were calculated for each tendon dimension. Length and moment arm measurements were divided by hip height, and width and thickness measurements were divided by weight. Finally, the mean dorsiflexion, plantarflexion, and ROM angles will be regressed against the relative tendon dimensions. It is expected that there will be a relationship between the relative dimensions of the Achilles tendon and the movement of the ankle joint.
