Companion Plants as Tools for Pest Management of Squash Bug on Summer Squash

Project Overview

Project Type: On-Farm Research
Funds awarded in 2013: $14,792.00
Projected End Date: 12/31/2016
Region: Southern
State: Oklahoma
Principal Investigator:
Dr. Brian Kahn
Oklahoma State University

Annual Reports

Information Products


  • Vegetables: cucurbits


  • Crop Production: cropping systems
  • Pest Management: cultural control


    White yarrow and feverfew were tested as companion plants with summer squash for control of squash bug. Companion planting with white yarrow had few effects.  Companion planting with feverfew tended to reduce squash bug populations, but plot-to-plot variation was high and results often were not statistically significant.  Early-season row covers (without herbs) neither reduced squash bug populations nor increased squash yields.  Herbs reduced marketable squash yields compared to the control only once out of seven experiments.  The tested companion planting strategies inconsistently affected squash bug populations on summer squash.  Therefore, these strategies are not recommended to commercial producers.


    The economic value of the various cucurbit crops produced in the southern United States is very high. Government statistics of the value of these crops, however, are no longer available on a regional basis.  In Oklahoma, the 2007 Census of Agriculture showed a total of over 5,000 acres of cucurbit production.  Using estimated average crop values per acre (Smith and Ancisco, 2005), this production was worth over $11.7 million.

    Vegetable producers in Oklahoma have identified pest control issues as a major concern during Cooperative-Extension-facilitated listening sessions. For cucurbits, the single most important insect pest is the squash bug, Anasa tristis DeGeer.  Squash bug management typically involves multiple applications of chemical insecticides (Bolin and Brandenberger, 2001; Kemble, 2012).  There is considerable qualitative information regarding this insect (e.g., the review of Beard, 1940), but more quantitative data are needed.  In particular, the scientific literature contains very little information about non-insecticidal approaches to squash bug management.

    The concept of companion planting as a potential pest management tool has received some attention recently as interest in sustainable and organic vegetable production has grown. Example studies include:  Issa et al., 2012; Moreau et al., 2006; Finch et al., 2003; Morris and Li, 2000; and Latheef and Ortiz, 1984.  Results have been mixed, and none of these studies has addressed squash bug management.  This project was designed to provide information on the potential of companion plants as tools for pest management of squash bug in commercial production of summer squash.

    There are many possibilities for companion plants, both as resource plants for beneficial insects and as pest insect repellents. To narrow the choices, we began with information in Yepsen Jr. (1976) suggesting that tansy and nasturtium would repel squash bugs.  Next, we examined the one journal article we found on companion planting for insect control in cucurbits (Cline et al., 2008).  They reported that the combined use of three companion plants reduced populations of cucumber beetles in muskmelons in one year.  The plants were radish (Raphanus sativus L.), tansy (Tanacetum vulgare L.), and nasturtium (Tropaeolum majus L.).  However, Cline et al. (2008) did not subsequently study nasturtium due to low rates of survival and vegetative growth.  Radish was deemed unsuitable for our study because it would not thrive during the Oklahoma summer when squash was growing.  Tansy also was removed from consideration, as it can become a large plant and it is considered a noxious weed in four western states (APHIS, 2012).  We then looked for information on alternative species related to tansy.  Yepsen Jr. (1976) had recommended yarrow (Achillea millefolium L.) as being “more manageable than tansy” and as having a generally repellent effect on pest insects.  Yarrow also was reported to help attract and retain predacious and parasitoid arthropods in an apple orchard (Bostanian et al., 2004).  Finally, we found a study where feverfew [Tanacetum parthenium (L.) Sch. Bip.] was found to be a “banker” plant that could attract and maintain high populations of predatory insects (Lopez and Shepard, 2007).  Therefore, we chose yarrow and feverfew as the test species for our study.

    Literature Cited:

    APHIS. 2012.  Federal Noxious Weed List.  Online @ Accessed 18 Oct. 2012.

    Beard, R.L. 1940.  The biology of Anasa tristis DeGeer with particular reference to the tachinid parasite, Trichopoda pennipes Fabr.  Conn. Agr. Exp. Sta. Bul. 440.

    Bolin, P. and L. Brandenberger. 2001.  Cucurbit integrated crop management.  Coop. Ext. Serv., Okla. State Univ., Stillwater.  E-853.

    Bostanian, N.J., H. Goulet, J. O’Hara, L. Masner, and G. Racette. 2004.  Towards insecticide free apple orchards:  Flowering plants to attract beneficial arthropods.  Biocontrol Science and Technology 14:25-37.

    Cline, G.R., J.D. Sedlacek, S.L. Hillman, S.K. Parker, and A.F. Silvernail. 2008.  Organic management of cucumber beetles in watermelon and muskmelon production.  HortTechnology 18:436-444.

    Finch, S., H. Billiald, and R.H. Collier. 2003.  Companion planting – do aromatic plants disrupt host-plant finding by the cabbage root fly and the onion fly more effectively than non-aromatic plants?  Entomol. Exper. Appl. 109:183-195.

    Issa, R.B., L. Gomez, M.H. Sauge, and H. Gautier. 2012.  Effects of companion plants on the behavior of the green peach aphid reared on pepper plants.  IOBC/WPRS Bulletin 75:29-33.

    Kemble, J.M. (ed.). 2012.  Southeastern U.S. 2012 Vegetable Crop Handbook.  Online @  Accessed 5 Nov. 2012.

    Latheef, M.A. and J.H. Ortiz. 1984.  Influence of companion herbs on Phyllotreta cruciferae (Coleoptera: Chrysomelidae) on collard plants.  J. Econ. Entomol. 77:80-82.

    Lopez, R. and B.M. Shepard. 2007.  Arthropods associated with medicinal plants in coastal South Carolina.  Insect Sci. 14:519-524.

    Moreau, T.L., P.R. Warman, and J. Hoyle. 2006.  An evaluation of companion planting and botanical extracts as alternative pest controls for the Colorado potato beetle.  Biol. Agr. Hort. 23:351-370.

    Morris, M.C. and F.Y. Li. 2000.  Coriander (Coriandrum sativum) “companion plants” can attract hoverflies, and may reduce pest infestation in cabbages.  New Zealand J. Crop Hort. Sci. 28:213-217.

    Smith, D.T. and J. L. Ancisco. 2005.  The Crops of Texas.  Dept. Tech. Report SCS-2005-01.  Dept. of Soil and Crop Sciences, Texas A&M Univ.

    Yepsen Jr., R.B. (ed.). 1976.  Organic plant protection.  Rodale Press, Emmaus, PA. 

    Project objectives:

    1. Provide on-farm-research-based information on the potential of companion plants as tools for pest management of squash bug in commercial production of summer squash.
    2. Demonstrate sustainable squash production systems to producers and provide education in the newly-developed pest management systems.
    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.