Location: Fruit and Tree Nut Research
2016 Annual Report
Accomplishments
1. Fire-gel protects beneficial nematodes in a single spray. Beneficial nematodes can control a wide variety of soil-dwelling insect pests. However, the nematodes are sensitive to UV radiation and desiccation and therefore have difficulty controlling insects that attack plants aboveground. ARS researchers from Byron, Georgia, used a fire-gel to protect the nematodes from harmful environmental conditions. The gel is usually used to protect houses or other structures from fire. In this new research, the ARS researchers discovered that the nematodes can be used as a single spray in combination with the gel to kill harmful insect pests. The researchers used the gel and nematode combination to control the lesser peachtree borer, a major pest of peaches, plums and other stone fruit trees. The lesser peachtree borer attacks the tree’s trunk and scaffold limbs causing severe reductions in productivity. The nematode-gel combination enhances natural pest control and may be applicable in various other cropping systems.
2. Cheaters reduce virulence in beneficial nematodes. Beneficial nematodes are environmentally friendly bio-insecticides that are used to control a wide variety of economically important insect pests. However, when the nematodes are cultured repeatedly, they can lose their virulence (killing-power); this is called attenuation. ARS researchers from Byron, Georgia, discovered one of the causes for attenuation. Some nematodes let the others do the work of the killing the insect while the lazy nematodes (called cheaters) sit back and take a rest. If a lot of cheaters develop, then the whole nematode population will be less able to kill insect pests. Fortunately, the researchers also discovered that the number of cheaters can be reduced by controlling the number of nematodes that invade the insect. Overcrowding inside the dead insect, where the nematodes reproduce, causes more cheaters to develop. This research contributes significantly to fundamental understanding of host-pathogen relationships, and provides methodology to improve the quality of nematodes as effective biological control agents.
3. Ladybird, ladybird fly away home. Another reason for the successful establishment of the invasive multicolored Asian lady beetle may include the beetle’s exploitation of pests wherever they occur on a plant. An ARS researcher from Byron, Georgia, discovered that in tall pecan orchards, this invasive predator is found feeding on pecan aphids at all heights in the pecan canopy and also on aphids on plants in the orchard understory. Most other lady beetle species either occur low (on plants in the pecan orchard understory) or high (in the pecan tree canopy) but not at all vertical strata of the orchard as does the invasive multicolored Asian lady beetle. Utilizing prey at all vertical strata is not a strategy employed by many other lady beetle species and may give this invasive predator an advantage.
4. Barriers keep stink bugs away from peaches. Stink bugs are notorious, season-long pests of peach that are difficult to control. ARS researchers at Byron and Tifton, Georgia, erected fabric fencing around peach trees to stop stink bugs. The fencing prevented stink bugs from reaching peach trees and damaging fruit. Apparently, the stink bugs were not inclined to fly up and over the barrier. This research proves that barriers, and likely dense plant barriers, can affect stink bug movement and even direct movement around and away from host plants.
Review Publications
Hazir, S., Shapiro-Ilan, D.I., Hazir, C., Leite, L., Cakmak, I., Olson, D.M. 2016. Multifaceted effects of host plants on entomopathogenic nematodes. Journal of Invertebrate Pathology. 135:53-59.
Shapiro-Ilan, D.I., Raymond, B. 2016. Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes. Evolutionary Applications. 9(3):462-470.
Gumus, A., Karagoz, M., Shapiro-Ilan, D.I., Hazir, S. 2015. A novel approach to biocontrol: release of live insect hosts pre-infected with entomopathogenic nematodes. Journal of Invertebrate Pathology. 130:56-60.
Lacey, L., Grzywacz, D., Shapiro-Ilan, D.I., Frutos, R., Brownbridge, M., Goettel, M. 2015. Insect pathogens as biological control agents: back to the future. Journal of Invertebrate Pathology. 132:1-41.
Shapiro-Ilan, D.I., Hazir, S., Leite, L. 2015. Viability and virulence of entomopathogenic nematodes exposed to ultraviolet radiation. Journal of Nematology. 47(3):184–189.
Blackburn, D., Crawford, B., Shapiro-Ilan, D.I., Adams, B. 2016. Environmental drivers of trait changes in Photorhabdus luminescens. Biological Control. 92:145-152.
Shapiro-Ilan, D.I., Cottrell, T.E., Mizell, R.F., Horton, D.L. 2016. Efficacy of Steinernema carpocapsae plus fire gel applied as a single spray for control of the lesser peachtree borer, Synanthedon pictipes. Biological Control. 94:33-36.
Dito, D.F., Shapiro-Ilan, D.I., Dunlap, C.A., Behle, R.W., Lewis, E.E. 2016. Enhanced biological control potential of the entomopathogenic nematode, Steinernema carpocapsae, applied with a protective gel formulation. Biocontrol Science and Technology. 26(6):835–848.
Blackburn, D., Shapiro-Ilan, D.I., Adams, B. 2106. Biological control and nutrition: food for thought. Biological Control. 97:131-138.
Sun, Y., Bai, G., Wang, Y., Zhang, Y., Pan, J., Cheng, W., Feng, X., Li, H., Ma, C., Ruan, W., Shapiro-Ilan, D.I. 2016. The impact of Cu, Zn and Cr salts on the relationship between insect and plant parasitic nematodes: a reduction in biocontrol efficacy. Environmental Science and Technology. 107(11):108-115.
Shapiro-Ilan, D.I., Dolinski, C. 2015. Entomopathogenic nematode application technology. In: Campos-Herrera, R., editor. Nematode pathogenesis of insects and other pests - ecology and applied technologies for sustainable plant and crop protection. Springer International Publishing. p. 231-534.
Dolinski, C., Shapiro-Ilan, D.I., Lewis, E.E. 2015. Insect cadaver applications: pros and cons. In: Campos-Herrera, R., editor. Nematode pathogenesis of insects and other pests - ecology and applied technologies for sustainable plant and crop protection. Springer International Publishing. p. 207-229.
Tillman, P.G., Khrimian, A., Cottrell, T.E., Mizell, R.F., Johnson, W.C. 2015. Trap cropping systems and a physical barrier for suppression of stink bugs (Heteroptera: Pentatomidae) in Cotton. Journal of Economic Entomology. doi:10.1093/jee/tov217.
Bock, C.H., Hotchkiss, M.W., Cottrell, T.E., Wood, B.W. 2015. The effect of sample height on spray coverage in mature pecan trees. Plant Disease. 99(7):916-925. https://doi.org/10.1094/PDIS-11-14-1154-RE.
Tillman, P.G., Cottrell, T.E. 2015. Spatial distribution of Chinavia hilaris (Hemiptera:Pentatomidae) in peanut-cotton farmscapes. Journal of Insect Science. 15(1):iev081.
Chen, C., Bock, C.H., Hotchkiss, M.W., Garbelotto, M.M., Cottrell, T.E. 2015. Observation and identification of wood decay fungi from the heartwood of peach tree limbs in central Georgia, USA. European Journal of Plant Pathology. 143(1):11-23.
Kemp, E.A., Cottrell, T.E. 2015. Effect of lures and colors on capture of lady beetles (coleoptera: coccinellidae) in tedders pyramidal traps. Environmental Entomology. 44(5):1395-1406.
