Influence of Vineyard Vegetational Borders on Western Grape Leafhopper (Erythroneura elegantula Osborn), its Egg Parasitoids (Anagrus spp.) and Generalist Insect Predators

  • Michael J. Costello California Polytechnic State University
  • Ann Thrupp Fetzer VineyardsHopland, California
  • Glenn McGourty University of California, Cooperative Extension


Studies have shown that vegetational diversity in or around cropping systems can enhance natural
enemy abundance, although the impact on herbivores is less certain. We studied the influence of vineyard
vegetational borders on density of the western grape leafhopper, Erythroneura elegantula, its major
parasitoids, Anagrus spp., and two generalist predators, Orius spp. and Leptothrips mali. Two study
vineyards had planted, perennial flowering hedgerows, one bordered a natural riparian zone, and one
had a sparse border of native trees. From April to September 2007, we counted leafhopper nymphs and
adults of Anagrus spp., Orius spp. and L. mali within 10 m of the border, and at additional 20 m intervals
up to 90 m. At two sites with a diverse border, leafhopper density was stable nearest the border; at other
distances leafhopper density decreased between the first and second generations. This effect was not
seen at the sparse border site. Anagrus spp. density was enhanced at one site with a diverse border, but
only late season. There was no border effect on the generalist insect predators, by site or early vs. late
season. Regression analysis showed a positive relationship between leafhopper and Anagrus spp. density,
suggesting that the parasitoids were responding to higher leafhopper density. We conclude that, depending
on the nature of the border vegetation, there can be an effect on leafhopper nymphal density, but in this
study there is no evidence that it was due to natural enemies.

Author Biographies

Michael J. Costello, California Polytechnic State University

Horticulture and Crop Science Department, California Polytechnic State University, San Luis Obispo

Ann Thrupp, Fetzer VineyardsHopland, California

Fetzer Vineyards, Hopland, CA

Glenn McGourty, University of California, Cooperative Extension

University of California, Cooperative Extension, Ukiah, CA


Andow D., 1991. Vegetational diversity and arthropod population response. Annu. Rev. Entomol. 36, 561–586.

Bianchi, F.J.J.A. & Wäckers, F., 2008. Effects of flower attractiveness and nectar availability in field margins on biological control by parasitoids. Biol. Control 46, 400-408.

Corbett, A. & Rosenheim, J.A., 1996. Impact of a natural enemy overwintering refuge and its interaction with the surrounding landscape. Ecol. Entomol. 21, 155-164.

Costello, M.J. & Daane, K.M., 1999. Abundance of spiders and insect predators on grapes in central California. J. Arachnology 27, 531-538.

Costello, M.J., 2008. Regulated deficit irrigation and density of Erythroneura spp. (Hemiptera: Cicadellidae) on grape. J. Econ. Entomol. 101, 1287-1294.

Daane, K.M. & Williams, L.E., 2003. Manipulating vineyard irrigation amounts to reduce insect pest damage. Ecol. Appl. 13, 1650-1666.

Daane, K.M., Rosenheim, J.A., Smith, R.J. & Coviello, R.L., 2013. Western Grape Leafhopper. In: Bettiga, L.J. (ed.), Grape Pest Management, 3rd edition. University of California, Agriculture and Natural Resources Publication 3343, Richmond, CA, USA, pp. 202-219.

Doutt, R.L. & Nakata, J., 1965. Overwintering refuge of Anagrus epos (Hymenoptera: Mymaridae). J. Econ. Entomol. 58, 586.

Gaigher, R., Pryke, J.S. & Samways, M.J., 2015. High parasitoid diversity in remnant natural vegetation, but limited spillover into the agricultural matrix in South African vineyard agroecosystems. Biol. Conserv. 186, 69-74.

Griffiths, G.J.K., Holland, J.M., Bailey, A. & Thomas, M.B., 2008. Efficacy and economics of shelter habitats for conservation biological control. Biol. Control 45, 200-209.

Gurr, G.M., Wratten, S.D., Tylianakis, J., Kean, J. & Keller, M., 2005. Providing plant foods for natural enemies in farming systems: balancing practicalities and theory. In: Wäckers, F.L., van Rijn, P.C.J. & Bruin, J. (eds.), Plant-provided Food for Carnivorous Insects: A Protective Mutualism and its Applications. Cambridge University Press, Cambridge, UK, pp. 326-347.

Haddad, N.M., Crutsinger, G.M., Gross, K., Haarstad, J. & Tilman, D., 2011. Plant diversity and the stability of foodwebs. Ecol. Lett. 14, 42-46.

Jonsson, M., Wratten, S.D., Landis, D.A. & Gurr G.M., 2008. Recent advances in conservation biological control of arthropods by arthropods. Biol. Control 45, 172-175.

Judt, C.C., Guzmán, G., Gómez, J.A., Cabezas, J.M., Entrenas, J.A., Winter, S., Zaller, J.G. & Paredes, D., 2019. Diverging effects of landscape factors and inter-row management on the abundance of beneficial and herbivorous arthropods in Andalusian vineyards (Spain). Insects 10. doi:10.3390/insects10100320.

Kido, H., Flaherty, D., Bosch, D. & Valero, K., 1984. French prune trees as overwintering sites for the grape leafhopper egg parasite. Am. J. Enol. Vit. 35, 156–160.

Landis, D.A., Wratten, S.D. & Gurr, G.M., 2000. Habitat management to conserve natural enemies of arthropod pests in agriculture. Annu. Rev. Entomol. 45, 175–201.

Letourneau, D.K., Armbrecht, I., Rivera, B.S., Lerma, J.M., Carmona, E.J., Daza, M.C., Escobar, S., Galindo, V., Gutiérrez C., López, S.D., Mejía, J.L., Rangel, A.M.A., Rangel, J.H., Rivera, L., Saavedra, C.A., Torres, A.M. & Trujillo, A.R., 2011. Does plant diversity benefit agroecosystems? A synthetic review. Ecol. Appl. 21, 9-21.

Murphy, B.C., Rosenheim, J.A. & Granett, J., 1996. Habitat diversification for improving biological control: abundance of Anagrus epos (Hymenoptera: Mymaridae) in grape vineyards. Environ. Entomol. 25, 495–504.

Murphy, B.C., Rosenheim, J.A., Dowell, R.V. & Granett, J., 1998. Habitat diversification tactic for improving biological control: parasitism of the western grape leafhopper. Entomol. Exp. Appl. 87, 225–235.

Nicholls, C.I., Parella, M. & Altieri, M.A., 2001. The effects of a vegetational corridor on the abundance and dispersal of insect biodiversity within a northern California organic vineyard. Landsc. Ecol. 16, 133-146.

Prischmann, D., James, D., Storm, C., Wright, L. & Snyder, W., 2007. Identity, abundance, and phenology of Anagrus spp. (Hymenoptera: Mymaridae) and leafhoppers (Homoptera: Cicadellidae) associated with grape, blackberry, and wild rose in Washington State. Ann. Entomol. Soc. Am. 100, 41–52.

Ratnadass, A., Fernandes, P., Avelino, J. & Habib, R., 2012. Plant species diversity for sustainable management of crop pests and diseases in agroecosystems: a review. Agron. Sustain. Develop. 32, 273-303.

Root, R.B., 1973. Organization of a plant-arthropod association in simple and diverse habitats: the fauna of collards (Brassica oleracea). Ecol. Monogr. 43, 95-124.

Russell, E., 1989. Enemies hypothesis: A review of the effect of vegetational diversity on predatory insects and parasitoids. Environ. Entomol. 18, 590-599.

Shapira, I., Gavish-Regev, E., Sharon, R., Harari, A.R., Kishinevsky, M. & Keasar, T., 2018. Habitat use by crop pests and natural enemies in a Mediterranean vineyard agroecosystem. Agric. Ecosyst. Environ. 267, 109-118.

SAS Institute Inc., 2012. SAS for Windows Release 9.4. Cary, NC, USA.

Thomson, L.J. & Hoffmann, A.A., 2009. Vegetation increases the abundance of natural enemies in vineyards. Biol. Control 49, 259-269.

Thomson, L.J. & Hoffmann, A.A., 2013. Spatial scale of benefits from adjacent woody vegetation on natural enemies within vineyards. Biol. Control 64, 57–65.

Thomson, L.J., McKenzie, J., Sharley, D.J., Nash, M.A., Tsitsilas, A. & Hoffmann, A.A., 2010. Effect of woody vegetation at the landscape scale on the abundance

of natural enemies in Australian vineyards Biol. Control 54: 248–254.

Wäckers, F.L., Romeis, J. & van Rijn, P., 2007. Nectar and pollen feeding by insect herbivores and implications for multitrophic interactions. Annu. Rev. Entomol. 52, 301–323.

Wilson, H., Miles, A.F., Daane, K.M. & Altieri, M.A., 2015a. Vineyard proximity to riparian habitat influences Western grape leafhopper (Erythroneura elegantula Osborn) populations. Agric. Ecosyst. Environ. 211, 43-50.

Wilson, H., Miles, A.F., Daane, K.M. & Altieri, M.A., 2015b. Landscape diversity and crop vigor influence biological control of the western grape leafhopper (E. elegantula Osborn) in Vineyards. PLoS ONE 10, e0141752. doi:10.1371/journal.pone.0141752.

Wilson, H., Miles, A.F., Daane, K.M. & Altieri, M.A., 2016. Host plant associations of Anagrus spp. (Hymenoptera: Mymaridae) and Erythroneura elegantula (Hemiptera: Cicadellidae) in Northern California. Environ. Entomol. 45, 602–615.

Wilson, H., Miles, A.F., Daane, K.M. & Altieri, M.A., 2017. Landscape diversity and crop vigor outweigh influence of local diversification on biological control of a vineyard pest. Ecosphere 8, e01736. doi:10.1002/ecs2.1736.

Wright, L.C. & James, D.G., 2007. Anagrus spp. (Hymenoptera: Mymaridae) reared from plants collected during winter in south central Washington and north central Oregon. J. Entomol. Soc. B.C. 100, 41–52.