Location: Insect Behavior and Biocontrol Research
2019 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. Genetic markers were used to determine that the “Harrisia cactus mealybug” (HCM), is a complex of at least three mealybug species. The species of HCM found on non-cactus host plants is a different species than the HCM found on cactus. This established that there is little risk of the non-cactus HCM species present in Florida moving onto susceptible cactus host plants. Under Objective 2 significant progress was made on demonstrating that cultural control through companion planting may aid in mitigating damage by the sweetpotato whitefly and aphids, invasive insects on organic vegetable crops in protected structures. In addition, three species of corn silk flies but no parasitoids were obtained from sweet corn fields at Belle Glade and Citra at a location of high fly populations and established in laboratory culture.
Accomplishments
1. Untangling the Harrisia cactus mealybug complex of species. The Harrisia cactus mealybug (HCM), is a destructive pest of columnar cactus in Puerto Rico. ARS researchers in Tallahassee, Florida, collaborated with international scientists to determine at least three mealybug species using genetic markers. The phylogenetic relationships among HCM populations collected in Argentina, Australia and Puerto Rico that were feeding on plants in the cactus family or the amaranth family were examined. The finds demonstrated that the species of HCM found on non-cactus host plants is a different species than the HCM found on cactus. Consequently, there is little risk of the non-cactus HCM species present in Florida moving onto susceptible cactus host plants.
2. Parasitoids for corn silk flies. Over 25% of the U.S. production of fresh market sweet corn production occurs in southern Florida. One of the major pests of this crop are several species of corn silk flies whose larvae can render the cob unmarketable and result in discarding an entire crop. Control of these flies relies on timing pesticide sprays to control flies but not leaving residues on mature cobs ready for harvest. ARS researchers in Gainesville, Florida, have evaluated different commercially available parasitoid wasps for their potential for control of the flies. Several wasp species effectively killed fly pupae and this approach provides both a potentially organic approach to fly control and a new tool for corn silk fly control.
3. Plant-mediated management of insect pests in vegetables. Cultural control through companion planting may aid in mitigating damage by the sweetpotato whitefly and aphids, invasive insects on organic vegetable crops in protected structures. An ARS scientist in Gainesville, Florida, in collaboration with university scientists demonstrated that planting of attractive flowering refuge plants such as marigold, basil, dill and sweet alyssum on the border of heat-tolerant greens such as mustard, pak choi and swiss attracted insect natural enemies and pollinators. Preliminary results indicate that sweetpotato whiteflies, aphids and thrips were the common insect pests in mustard plants. The results from the study show the potential use of companion planting of flowering plants and cover crops to enhance biological control in an organic vegetable crop system.
Review Publications
Palen, D.I., Almarinez, B.J., Amalin, D.M., Legaspi, J.C., David, G. 2018. A host-parasitoid model for Aspidiotus rigidus (Hemiptera: Diaspididae) and Comperiella calauanica (Hymenoptera: Encyrtidae). Environmental Entomology. 48(1):134-140. https://doi.org/10.1093/ee/nvy150.
Eason, J., Kanga, L.H., Haseeb, M., Qureshi, J., Legaspi, J.C. 2018. Mechanisms of resistance to organophosphorus and pyrethroid insecticides in Asian citrus psyllid populations in Florida. Current Investigations in Agriculture and Current Research(CIACR). 1(3):111.
Triapitsyn, S.V., Aguirre, M.B., Logarzo, G.A., Hight, S.D., Ciomperlik, M.A., Rugman, J.P., Verle Rodrigues, J.C. 2018. Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeoccoccus spp. mealybugs (Hemiptera: Pseudococcidae) in the New World. Florida Entomologist. 101(3):411:434. https://doi.org/10.1653/024.101.0320.
Awad, J., Hodges, A., Hight, S.D., Srivastava, M., Howe, A., Rohig, E. 2019. Laboratory rearing and sex ratio of Apanteles opuntiarum (Hymenoptera: Braconidae), a potential biocontrol agent of Cactoblastis cactorum (Lepidoptera: Pyralidae). Florida Entomologist. 102(1):216-221. https://doi.org/10.1653/024.102.0135.
Varone, L., Aguirre, M.B., Lobos, E., Ruiz, D., Hight, S.D., Palotini, F., Guala, M., Logarzo, G.A. 2019. Causes of mortality at different stages of Cactoblastis cactorum in the native range. Biocontrol. 64(3):249-261. https://doi.org/10.1007/s10526-019-09938-0.
Meagher Jr, R.L., Watrous, K., Fleischer, S., Nagoshi, R.N., Brown, J.T., Bowers, K.E., Miller, N.W., Hight, S.D., Legaspi, J.C., Westbrook, J.K. 2019. Documenting potential sunn hemp (Crotallaria juncea L.) (Fabaceae) pollinators in Florida. Environmental Entomology. 48(2):343-350. https://doi.org/10.1093/ee/nvy190.
Tavares, W., Legaspi, J.C., De Castro, A., Haseeb, M., Meagher Jr, R.L., Kanga, L.H., Zanuncio, J.C. 2019. Turmeric powder and its derivatives of Curcuma longa and black mustard oil of Brassica nigra affecting interactions among Spodoptera exigua and its natural Cotesia flavipes and Podisus maculiventris. Dose Response. https://doi.org/10.1177/1559325819827454.
De Castro, A.A., Legaspi, J.C., Tavares, W.S., Meagher Jr, R.L., Miller, N.W., Kanga, L., Haseeb, M., Serrao, J.E., Wilckep, C.F., Zanuncio, J.C. 2018. Lethal and behavioral effects of synthetic and organic insecticides Spodoptera exigua and its predator Podisus maculiventris. PLoS One. 13(11):e0206789. https://doi.org/10.1371/journal.pone.0206789.
Srivastava, M., Srivastava, P., Karna, R., Jeyaprakash, A., Whilby, L., Rohrig, E., Howe, A.C., Hight, S.D., Varone, L. 2019. Molecular detection method developed to track the koinobiont larval parasitoid Apanteles opuntiarum (Hymenoptera: Braconidae) imported from Argentina to control Cactoblastis cactorum (Lepidoptera: Pyralidae). Florida Entomologist. 102(2):329-335. https://doi.org/10.1653/024.102.0207.
