Making Pest Management More Sustainable in Cucurbit Production

Project Overview

GS14-131
Project Type: Graduate Student
Funds awarded in 2014: $10,922.00
Projected End Date: 12/31/2015
Grant Recipient: Virginia Tech
Region: Southern
State: Virginia
Graduate Student:
Major Professor:
Dr. Thomas Kuhar
Virginia Tech

Annual Reports

Commodities

  • Vegetables: cucurbits

Practices

  • Crop Production: no-till
  • Pest Management: biological control, chemical control, integrated pest management

    Abstract:

    Squash bug is a major pest of squash and pumpkin in the U.S.  Current control tactics involve insecticide applications that are injurious to pollinators and natural enemies.  Based on a 3-year survey in Virginia and surrounding states, we found that >50% of squash bug egg masses were parasitized by the parasitic wasp, Gryon pennsylvanicum.  We also evaluated the toxicity of various reduced risk insecticides to the parasitoid and squash bug and found that neither flupyridafurone, pyrifluquinazon, flonicamid, nor sulfoxaflor controlled squash bug nymphs as well as the pyrethroid, lambda-cyhalothrin, which was also the most toxic to the parasitoid adults.

    Introduction

    The squash bug, Anasa tristis DeGeer (Hemiptera: Coreidae), is an important pest of pumpkin (Cucurbita maxima) and squash (C. pepo) causing wilt in plants with its piercing-sucking mouthparts and by potentially vectoring Cucurbit Yellow Vine Decline (Bruton et al. 2003, Doughty et al. 2016).  Many commercial growers of these crops typically apply broad-spectrum foliar insecticides, commonly pyrethroids (often tank-mixed with fungicides) ( Doughty et al. 2016).  Cucurbits are pollination dependent and many of the registered insecticides recommended for use in commercial cucurbit production are known to be acutely toxic to bees (Agency 2015, Wyenandt et al. 2016).  Beyond pollinators there are other organisms that may be impacted by pest management practices, for instance, natural enemies that could be keeping pests in check in cucurbit systems. 

    Egg parasitoids, in particular, are important natural enemies of heteropteran pests.  Out of the native egg parasitoids of A. tristis, Gryon pennsylvanicum Ashmead (Hymenoptera: Scelionidae), has been found to have the highest fecundity and rate of reproduction than three other encyrtid wasp species that also attack squash bug (Nechols et al. 1989).  Gryon pennsylvanicum also appears to be widespread in North America and was reported to occur in the mid-Atlantic U.S. as early as 1943 (Schell 1943). This scelionid wasp has a host range that is limited to the leaf-footed bugs (family Coreidae), and has been recently introduced as a classical biological control agent for the western conifer seed bug in Italy (Peverieri et al. 2013, Roversi et al. 2014).  Plant hosts can play a potential role in the capacity of A. tristis to lay eggs (Bonjour et al. 1990), overall survival (Bonjour and Fargo 1989), and squash bug reproduction (Bonjour et al. 1993), without effect on the parasitization of G. pennsylvanicum (Vogt and Nechols 1993).  Adult G. pennsylvanicum do not feed on the host eggs (Vogt and Nechols 1993), but rather feed on the exudate from cucurbit leaf trichomes (extra-floral nectaries) that serve as sources of basic sugars and protein (Olson et al. 1996).  The feasibility of augmentative biological control has been explored, but Olson et al. (1996) found that it was not economically feasible compared to chemical control.  Nonetheless, it is important to assess the natural control impact of this parasitoid.  In Kentucky, Decker and Yeargan (2008) observed egg parasitism as high as 31% with G. pennsylvanicum as the predominant egg parasitoid.  More recently, Cornelius et al. (2016) observed high rates of parasitism by this species in Maryland, particulalry later in the season.  To our knowledge a survey of squash bug egg parasitism has not been conducted in Virginia.  Herein, we report the results of a three year survey from 31 counties throughout Virginia and surrounding states to allow us to quantify the potential effects egg parasitism may have on squash bug population dynamics. 

    In addition we evaluated the efficacy of various reduced risk insecticides for control of squash bug and toxicity to the parasitoid. 

    References Cited:

    Abney, M. R., and R. Davila. 2011. Evaluation of Foliar and Soil Applied Insecticides for Control of Squash Bug on Zucchini Squash, 2010. Arthropod Management Tests 36.

    Agency, U. S. E. P. 2015. EPA’s Proposal to Mitigate Exposure to Bees from Acutely Toxic Pesticide Products.

    Authority, E. P. 2015. Addendum to the Evaluation and Review Report APP202145 – Mainman.

    Beard, R. L. 1940. The Biology of Anasa tristis DeGeer with Particular Reference to the Tachinid Parasite, Trichopoda pennipes Fabr., pp. 593-685. In C. A. E. S. N. Haven [ed.].

    Bommireddy, P. L., B. R. Leonard, K. D. Emfinger, and P. Price. 2007. Evaluation of Neonicotinoids and Flonicamid Against Cotton Aphids and Tarnished Plant Bugs in Cotton, 2006. Arthropod Management Tests.

    Bonjour, E. L., and W. S. Fargo. 1989. Host Effects on the Survival and Development of Anasa tristis (Heteroptera: Coreidae). Environmental Entomology 18: 1083-1085.

    Bonjour, E. L., W. S. Fargo, and P. E. Rensner. 1990. Ovipositional Preference of Squash Bugs (Heteroptera: Coreidae) Among Cucurbits in Oklahoma. Journal of Economic Entomology 83: 943-947.

    Bonjour, E. L., W. S. Fargo, A. A. Al-Obaidi, and M. E. Payton. 1993. Host Effects on Repreoduction and Adult Longevity of Squash Bugs (Heteroptera: Coreidae). Environmental Entomology 22: 1344-1348.

    Bruton, B. D., F. Mitchell, J. Fletcher, S. D. Pair, A. Wayadande, U. Melcher, J. Brady, B. Bextine, and T. W. Popham. 2003. Serratia marcescens, a Phloem-Colonizing, Squash Bug -Transmitted Bacterium: Causal Agent of Cucurbit Yellow Vine Disease. Plant Disease 87: 937-944.

    Casida, J.E.; Durkin, K.A. 2013. Neuroactive insecticides: targets, selectivity, resistance, and secondary Effects. Annual Review of Entomology. 58: 99–117.

    Chapman, A., T. Kuhar, P. Schultz, T. Leslie, S. Fleischer, G. Dively & J. Whalen.  2009.  Integrating chemical and biological control of European corn borer in bell pepper.  J. Econ. Entomol.  102: 287 295.

    Cornelius, M. L., M. L. Buffington, E. J. Talamas, and M. W. Gates. 2016. Impact of the Egg Parasitoid, Gryon pennsylvanicum (Hymenoptera: Scelionidae), on Sentinel and Wild Egg Masses of the Squash Bug (Hemiptera: Coreidae) in Maryland. Environmental Entomology 45: 367-375.

    Decker, K. B., and K. V. Yeargan. 2008. Seasonal Phenology and Natural Enemies of the Squash Bug (Hemiptera: Coreidae) in Kentucky. Environmental Entomology 37: 670-678.

    Desneux N, A. Decourtye, and J. M. Delpuech 2007. The sublethal effects of pesticides on beneficial arthropods. Annu. Rev. Entomol. 52: 81–106.

    Doughty, H. B., J. M. Wilson, P. B. Schultz, and T. P. Kuhar. 2016. Squash Bug (Hemiptera: Coreidae): Biology and Management in Cucurbitaceous Crops. Journal of Integrated Pest Management 7: 1.

    Eiben, J., C. Mackey, W. Roberts, and J. V. Edelson. 2004. Foliar Applied Insecticides for Controlling Squash Bug, 2003. Arthropod Management Tests 29.

    EPA, O. o. P. P. 2012. Ecological Risk Summary for the Section 3 New Chemical Registration of Pyrifluquinazon for Indoor Greenhouse Use. In O. o. P. P. EPA [ed.].

    Fargo, W. S., P. E. Rensner, E. L. Bonjour, and T. L. Wagner. 1988. Population Dynamics in the Squash Bug (Heteroptera: Coreidae)-Squash Plant (Cucurbitales: Cucurbitaceae) System in Oklahoma. Journal of Economic Entomology 81: 1073-1079.

    Foster, S. P., G. Devine, and A. L. Devonshire. 2007.  Insecticide resistance, pp. 261–285 in H. F. van Emden and R. Harrington, Aphids as Crop Pests. CABI, U.K.

     Ghidiu, G. M. & T. P. Kuhar.  2012.  Chapter 16: Pepper insects and their control, pp. 216 226.  In V. M. Russo [ed.], Peppers: Botany, Production and Uses.  CAB International, Oxfordshire, United Kingdom., 280 pp.

    IRAC, I. M. W. G. 2016. IRAC Mode of Action Classification Scheme, pp. 1-26.

    Johansen, C. A. 1977. Pesticides and pollinators. Annu. Rev. Entomol. 22: 177-192.

    Kilpatrick, A. L., A. M. Hagerty, S. G. Turnipseed, M. J. Sullivan, and W. C. J. Bridges. 2005. Activity of Selected Neonicotinoids and Dicrotophos on Nontarget Arthropods in Cotton: Implications in Insect Management. Journal of Economic Entomology 98: 814-820.

    Kuhar, T. P., J. Speese, R. J. Cordero and V. M. Barlow. 2005. Evaluation of insecticides in pumpkins, 2004. Arthrop. Manag. Tests 30: E70.

    Kuhar, T. P., C. R. Philips, K. Kamminga, and A. Wallingford.  2011.  Pyrethroid resistance in green peach aphid in Southwestern Virginia (USA) and field efficacy of insecticides in peppers.  Resist. Pest News. 21 (Fall): 8-11. Online. http://whalonlab.msu.edu/newsletter/index.html.

     Kuhar, T. P., H. Doughty, K. Kamminga, A. Wallingford, C. Philips & J. Aigner.  2012.  Evaluation of insecticides for the control of brown marmorated stink bugs in bell peppers in Virginia 2011 Experiment 1.  Arthropod Managt. Tests  38: E37.

     Kuhar, T. P., and H. Doughty. 2016. Evaluation of Foliar and Soil Insecticides for the Control of Foliar Insects in Summer Squash in Virginia, 2015. Arthropod Management Tests 41: tsw023.

    Margolies, D. C., J. R. Nechols, and E. A. Vogt. 1998. Rapid Adaptation of Squash Bug, Anasa tristis, Populations to a Resistant Cucurbit Cultivar. Entomologia Experimentalis et Applicata 89: 65-70.

    McLeod, P., J. Diaz, S. Eaton, and L. Martin. 2003. Evaluation of insecticides for control of squash bug on summer squash, 2002. Arthropod Manag. Tests (2003) 28 (1):    DOI: http://dx.doi.org/10.1093/amt/28.1.E72

    Morita M, Ueda T, Yoneda T, Koyanagi T, Haga T.  2007. Flonicamid, a novel insecticide with a rapid inhibitory effect on aphid feeding. Pest Manag Sci. 2007 Oct;63(10):969-73.

    Natwick, E. T., and M. I. Lopez. 2016. Insecticide Evaluation for Aphid Control in Alfalfa, 2015. Arthropod Management Tests 41: tsw025.

    Nauen, R. Peter Jeschke, Robert Velten, Michael E Beck, Ulrich Ebbinghaus-Kintscher, Wolfgang Thielert, Katharina Wölfel, Matthias Haas, Klaus Kunz, and Georg Raupach. 2015. Flupyradifurone: a brief profile of a new butenolide insecticide. Pest Manag Sci. 2015 Jun; 71(6): 850–862.

    Neal, J. J. 1993. Xylem Transport Interruption by Anasa trsitis Feeding Causes Cucurbita pepo to Wilt. Entomologia Experimentalis et Applicata 69: 195-200.

    Nechols, J. R., J. L. Tracy, and E. A. Vogt. 1989. Comparative Ecological Studies of Indigenous Egg Parasitoids (Hymenoptera: Scelionidae; Encyrtidae) of the Squash Bug, Anasa tristis (Hemiptera: Coreidae). Journal of the Kansas Entomological Society 62: 177-188.

    Olson, D. L., J. R. Nechols, and B. W. Schurle. 1996. Comparative Evaluation of Population Effect and Economic Potential of Biological Suppression Tactics Versus Chemical Control for Squash Bug (Heteroptera: Coreidae) Management on Pumpkins. Journal of economic entomology 89: 631-631.

    Pair, S. D., B. D. Bruton, F. Mitchell, J. Fletcher, A. Wayadande, and U. Melcher. 2004. Overwintering Squash Bugs Harbor and Transmit the Causal Agent of Cucurbit Yellow Vine Disease. Journal of Economic Entomology 97: 74-78.

    Palumbo, J. C. 2006. Evaluation of Flonicamid and Acetamiprid for Aphid Control in Head Lettuce, Spring 2005. Arthropod Management Tests.

    Palumbo, J. C. 2014. Evaluation of Pyrifluquinazon for Control of Sweetpotato Whitefly in Fall Cantaloupes, 2012. Arthropod Management Tests 38.

    Palumbo, J. C. 2016. Control of Sweetpotato Whitefly Adults with Foliar Insecticide Alternatives in Spring Cantaloupes, 2014. Arthropod Management Tests 40: E38.

    Peverieri, G. S., P. Furlan, D. Benassai, S. Caradonna, W. B. Strong, and P. F. Roversi. 2013. Host Egg Age of Leptoglossus occidentalis (Heteroptera, Coreidae) and Parasitism by Gryon pennsylvanicum (Hymenoptera, Platygastridae). Journal of Economic Entomology 106: 633-640.

    Roversi, P. F., G. Sabbatini Peverieri, M. Maltese, P. Furlan, W. B. Strong, and V. Caleca. 2014. Pre-release risk assessment of the egg-parasitoid Gryon pennsylvanicum for classical biological control of Leptoglossus occidentalis. Journal of Applied Entomology 138: 27-35.

    Sappington, K., and M. Ruhman. 2016. 2016 Addendum for the Proposed Section 3 Registration of Transform WG and Closer SC (Sufoxaflor) For Use on Various Crops, Turf, and Ornamentals.

    Schell, S. C. 1943. The Biology of Hadronotus ajax Girault (Hymenoptera – Scelionidae), a Parasite in the Eggs of Squash-bug (Anasa tristis DeGeer). Annals of the Entomological Society of America 36: 625-635.

    Slosser E, Pinchak WE, Rummel DR. 1989. A review of known and potential factors affecting the population dynamics of the cotton aphid. Southwestern Entomologist 14: 302-313.

    Smith, T. M. and G. W. Stratton. 1986. Effects of synthetic pyrethroid insecticides on nontarget organisms. Residue Reviews: Reviews of Environmental Contamination and Toxicology: 93-120.

    Stansly, P. A., and B. C. Kostyk. 2016. Control of Sweetpotato Whitefly With Foliar Insecticides on Staked Tomatoes, Fall 2013. Arthropod Management Tests 40: E61.

    Vogt, E. A., and J. R. Nechols. 1993. The Influence of Host Deprivation and Host Source on the Reproductive Biology and Longevity of the Squash Bug Egg Parasitoid Gryon pennsylvanicum (Ashmead) (Hymenoptera: Scelionidae). Biological Control 3: 148-154.

    Wyenandt, A., T. P. Kuhar, G. C. Hamilton, M. J. VanGessel, E. Sanchez, and D. Dugan. 2016. 2016 Mid-Atlantic Commercial Vegetable Production Recomendations. Virginia Cooperative Extension.

    Project objectives:

    Objective 1: To survey the egg parasitoids of squash bugs throughout Virginia.

    • Collections of squash bug egg masses
    • The specimens collected will be taken to the Virginia Tech Vegetable Entomology Lab and reared in environmental chambers for identification to species where possible. Records of location, host plant, parasitism levels, and squash bug hatch rate will be made.

    Objective 2: To assess the effects of narrow-spectrum insecticides on the eggs and nymphs of squash bug and its egg parasitoid.

    Egg masses collected will be utilized in screening assays to by location. Assays will screen for effects of specific narrow-spectrum insecticides against the controls and a commonly used broad-spectrum insecticide. The controls will provide baseline data on the parasitism levels and squash bug hatch rates for each location. The assay will be structured as follows:

    Bioassay replicated 5 to 6 times.  For each rep per treatment, 1o egg masses will be dipped in treatments. 

    Treatments : water control, Lambda-Cyhalothrin, flupyridafurone, Pyrifluquinazon, Flonicamid, and Sulfoxaflor

    All treatment concentrations will be at maximum label rate

    Assays were replicated as masses became available

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.