Location: Insect Behavior and Biocontrol Research
2018 Annual Report
Objectives
Objective 1: Improve the feasibility of using multi-tactic pest control strategies, especially through the improvement of biologically based control methods, for invasive weeds of the southern United States (e.g. tropical soda apple, air potato and Chinese tallow).
Sub-objective 1.A. Develop pre-release techniques that can be used to evaluate the impact of future biological control agents.
Sub-objective 1.B. Determine the role of North American native natural enemies attacking biological control agents on the agents’ population establishment and impact to the targeted weed.
Sub-objective 1.C. Determine release factors that increase successful establishment of weed biological control agents.
Objective 2: Develop biologically based pest control strategies for insect pests of the southern United States.
Sub-objective 2.A. Identify companion plants, commercial products and chemical compounds that i) repel whiteflies and determine their efficacy in limiting pest dispersal into crops (“push” factors), as well as ii) plants and products capable of attracting whiteflies into trap crops to facilitate control (“pull” factors).
Sub-objective 2.B. Evaluate companion or refuge plants that attract or maintain important whitefly predators.
Sub-objective 2.C. Develop an integrated cropping system combining “push-pull” crops or plant products with natural enemy refuges for sustainable biologically-based control of the whitefly.
Sub-objective 2.D. Identify parasitoids with potential as biological control agents for corn silk flies.
Sub-objective 2.E. Determine the Argentine field host range of the potential Argentine cactus moth biological control agent, Apanteles opuntiarum.
Sub-objective 2.F. Determine the effectiveness of a mating disruption technology as a sustainable management option for the cactus moth in commercial cactus production areas.
Sub-objective 2.G. Collect, identify, and distinguish between the complex of Harrisia cactus mealybugs (HCM), their plant hosts, and host specific parasitoids found in Argentina, Puerto Rico, other Caribbean Islands, and Florida.
Sub-Objective 2.H.Identify volatile chemicals from plants or oils repellent to whiteflies as basis for develop for area-wide release of repellents to protect vegetable crops.
Approach
Invasive insect pests and weeds are among the most serious problems facing agricultural and natural ecosystems throughout the United States. This project plan describes research to improve implementation of biologically based tactics for non-pesticide management of insect pests and weeds. The goals will be achieved through acquiring a better understanding of the pest species biology along with the interactions between host plants and natural enemies to support the development of optimized approaches, technologies and strategies for control of a variety of targets. One area of research will address improvement of techniques to enhance release success and increased efficiency of establishment and impact of biological control insect species against invasive weed species, specifically targeting the air potato and Chinese tallow. A second area of research focuses on the development of an integrated vegetable cropping system for control of whiteflies using a “push/pull” pest management approach. A vegetable crop system will be assessed using ‘push’ components consisting of naturally repellent plants or plant compounds, in conjunction with ‘pull’ components that consist of trap crops and refuge plants that naturally harbor whitefly predators. The potential use of parasitoids for reduction of the impact of corn silk flies on sweet corn will also be examined. A third area of emphasis is on the protection of U.S. native cacti from the invasive Argentine cactus moth and the Harissia cactus mealybug complex. Control of the Argentine cactus moth will be assessed through the use of a mating disrupting pheromone along with a potential exotic parasitoid. Control of the Harissia cactus mealybug complex will be based on developing an understanding of the species complex composition, alternative host plant reservoirs and potential parasitoids.Identification of volatile repellent chemicals to whiteflies will be determined as the basis for development of area-wide release of repellents to protect vegetable crops. The outcomes of this research project will improve the sustainability of agricultural production, reduce reliance on pesticides and reduce the environmental degradation caused by invasive pest insect and weed species.
Progress Report
The research efforts by the Insect Behavior and Biocontrol Research Unit – Tallahassee, Florida, resulted in significant progress towards the two objectives and subobjectives for this project. Significant progress was made under Objective 1 on developing a biological control program against the Harrisia cactus mealybug (HCM), a pest devastating the columnar cactus in the protected dry forest of Puerto Rico. Surveys, collections, and identifications were made of parasitoids attacking HCM in Argentina, Brazil, Puerto Rico, and Florida. Two Argentine species of parasitoids were delivered to the Puerto Rico quarantine to begin impact studies on the Puerto Rican HCM and to initiate host range tests on non-target mealybugs occurring in Puerto Rico. Under Objective 2 significant progress was made on assessing the predatory insects associated with cover crops. An abundance of different species and in large numbers of carabid ground-dwelling predators were found associated in sunn hemp cover crops which demonstrates that planting of beneficial cover crops can enhance the use of biological control in managing insect pests.
Accomplishments
1. Hurricanes increased the dispersal of Harrisia cactus mealybug in Puerto Rico. The Harrisia cactus mealybug (HCM), is devastating cactus in the dry forest systems of Puerto Rico. Following the hurricanes of September, 2017, ARS researchers at Tallahassee, Florida, conducted a rapid assessment of this non-native insect pest in Puerto Rico. Generally, sites where HCM was known not to occur from 2016 surveys remained free of HCM in 2018. However, 3 plants at 3 new sites showed damage indicative of HCM infestations, but no HCM life-stages were found. The putative HCM infestations at the 3 sites suggests that the HCM has indeed expanded its range onto smaller islands of Puerto Rico, Culebra, and Vieques. If the insect is being spread by hurricanes, then native and endangered cactus throughout the Caribbean basin are at additional risk from this insect pest.
2. Beetles in cover crops serve as predators of insect pests. Ground-dwelling carabid beetles are common and important predators of major insect pests. Additionally, they are excellent bioindicators of soil fertility. ARS researchers at Gainesville and Tallahassee, Florida, studied the population dynamics of ground beetles using pitfall traps in two varieties of sunn hemp cover crops (var. Auburn Golden and Tillage Sunn) planted at three different times in Tallahassee, Florida. Six different species of carabid beetles were identified in these plots over several growing seasons. These studies suggest that the good abundance of species and numbers of carabid ground-dwelling predators in sunn hemp cover crops can enhance the use of biological control in managing insect pests in beneficial cover crops.
Review Publications
Tavares, W.S., Da Silva, I.M., Legaspi, J.C., Serrao, J.E., Zanuncio, J.C., Serrao, J.E. 2017. Podisus distinctus (Heteroptera: Pentatomidae) females are lighter feeding on Tenebrio molitor (Coleoptera: Tenebrionidae) pupae subjected to ventral nerve cord transection. Entomologica Americana. 123(1-4):35-41.
Gordon, T.L., Haseeb, M., Kanga, L.H., Legaspi, J.C. 2017. Potential of three trap crops in managing Nezara viridula (Hemiptera: Pentatomidae) on tomatoes in Florida. Journal of Economic Entomology. 110(6):2478-2482. https://doi.org/10.1093/jee/tox267.
Wheeler, G.S., Hight, S.D., Wright, S.A. 2017. Impact of field densities of the naturalized defoliator Caloptilia triadicae on the invasive weed Chinese tallowtree. Environmental Entomology. 46(6):1305–1312.
Haseeb, M., Gordon, T., Kanga, L.H., Legaspi, J.C. 2018. Abundance of natural enemies of Nezara viridula (Hemipteera:Pentatomidae)on three cultivars of sweeet alyssum. Journal of Applied Entomology. 142:847-853. https://doi.org/10.1111/jen.12552.
Smith, M., Overholt, W.C., Lake, E.C., Diaz, R., Manrique, V., Hight, S.D., Rohrig, E., Minteer, C., Wheeler, G.S., Rayamajhi, M.B., Bowers, K.E., Kerr, C. 2018. Changes in latitude: overwintering survival of two Lilioceris cheni(Coleoptera: Chrysomelidae) biotypes in Florida. Biocontrol Science and Technology. 28(3):293-306. https://doi.org/10.1080/09583157.2018.1441371.
