Flea beetles (FB), (Coleoptera: Chrysomelidae), are common pests of cabbage and eggplant, but little is known about the FB populations in Virginia, their impact on yield, or the most effective control methods. This research investigates the FB populations and impact of their feeding injury on cabbage and eggplant in Southwest Virginia, and determines the most efficacious control methods.
In Whitethorne, VA, cabbage and eggplant crops were vacuum sampled weekly throughout two summers. Crucifer flea beetle, Phyllotreta cruciferae (Goeze), and striped flea beetle, Phyllotreta striolata Fabr. were found on cabbage; whereas, eggplant flea beetle, Epitrix fucula (Crotch), and the tobacco flea beetle, Epitrix hirtipennis (Melsheimer) were found on eggplant. To evaluate the impact of FB feeding on these plants, insecticides were used to create a range of pest pressure. Flea beetle densities and defoliation was visually assessed weekly and individual plant as well as whole plot yields assessed at harvest. In both crops, as little as 20% defoliation significantly reduced yield, with higher defoliation resulting in lower yield. The efficacy of various insecticides was also evaluated; soil application of the systemic neonicotinoid dinotefuran had the fewest beetles, the least amount of leaf defoliation, and the highest yield in cabbage and eggplant. Lastly, deltamethrin-incorporated mesh row covers were evaluated and shown to provide excellent control of FB compared to an untreated row cover or a control; and comparable to the standard insecticide, dinotefuran. This research helps vegetable growers to better understand the severity of these pests and how to effectively combat them. / MSLFS / Flea beetles are tiny leaf-chewing pests of vegetables, particularly cabbage and eggplant. High populations of FB chewing on leaves can kill plants in early stages of development, and insecticides are the most common defense. Little is known about which FBs are in Virginia, their effect on vegetables grown in the state, or what the best way of controlling these pests. This research investigates FBs to determine the how they affected yield of cabbage and eggplant in Southwest Virginia, as well as determine the best methods for controlling these pests.
Cabbage and eggplant were sampled weekly throughout two seasons, and two species were found on cabbage, the crucifer flea beetle and the striped flea beetle, whereas the eggplant flea beetle and the tobacco flea beetle were found on eggplant. To evaluate FB damage on these plants, defoliation of leaves was evaluated then yield was assessed. In both crops as little as 20% defoliation reduced yield, with higher defoliation resulting in lower yield of surviving plants. Various insecticides were evaluated to determine which treatment and application method were the most effective for controlling FB. A soil-applied systemic insecticide, dinotefuran, had the lowest density of beetles, the least amount of leaf defoliation, and the highest yield in cabbage and eggplant. Lastly, insecticide treated mesh row covers were evaluated and shown to be an effective method for controlling flea beetles on these crops. Treated row covers reduced FB numbers and feeding damage on these crops when compared to an untreated row cover. This research can benefit vegetable growers by helping them understand the severity of these pests and by providing effective management strategies to combat them.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/95956 |
| Date | 15 June 2018 |
| Creators | Mason, James Allen Cole |
| Contributors | Entomology, Kuhar, Thomas P., Walgenbach, James F., Brewster, Carlyle C. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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