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Squash Bug and Squash Vine Borer: Organic Controls
 

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Squash Bug and Squash Vine Borer: Organic Controls

Squash Bug and Squash Vine Borer: Organic Controls

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    Squash Bug and Squash Vine Borer: Organic Controls Squash Bug and Squash Vine Borer: Organic Controls Document Transcript

    • Squash Bug and Squash Vine ATTRA Borer: Organic Controls A Publication of ATTRA - National Sustainable Agriculture Information Service • 1-800-346-9140 • www.attra.ncat.orgBy Katherine L. Adam Squash bug and squash vine borer are major pests among cucurbits. This publication addresses organicNCAT Agriculture control methods for these pests. The life cycles and characteristics of each pest are presented. VariousSpecialist levels and types of organically sanctioned controls are discussed. Row covers, cultural methods, and©2006 NCAT physical practices are also covered. Experimental controls, biological controls, and alternative insecti- cides are also discussed and a case study is presented. A list of references follows the narrative.ContentsIntroduction ..................... 1Life Cycle andCharacteristics:Squash Bug....................... 2Life Cycle andCharacteristics: SquashVine Borer ......................... 2Planning for Control ..... 2Levels of Control inCertified OrganicProduction ........................ 3Systems-basedpractices (level 1)............ 3Mechanical and physical Squash bug. Squash vine borer.practices (level 2) ........... 3 ©Bruce Marlin 2003 ©Bruce Marlin 2004.Material (level 3) ............. 4 http://cirrusimage.com http://cirrusimage.comRow Covers ...................... 5Host Preference andGenetic Resistance ....... 5 Introduction and die back. Certain species and variet- SOther Cultural andPhysical Controls ............ 7 quash bug and squash vine borer are ies of pumpkins, watermelons, and squashExperimental, creative among a trio of serious cucurbit pests. are more susceptible than others. Plantsapproaches .................... 8 Striped cucumber beetle is another. are most susceptible to damage when theyRecommended For control measures for striped cucumberstrategies ........................... 8 are small. beetle on squashes in organic production, seeBiological Control ......... 9 the ATTRA publication Cucumber Beetles: Squash vine borer (Melittia satyriniformisKaolin Clay ...................... 10 Organic and Biorational IPM. Lepidoptera: Ageiriidae) is a pest in theAlternative eastern half of the United States. SquashInsecticides .................... 10 Squash bug (Anasa tristis Hemiptera: Core- vine borer is native to a large area fromReferences ...................... 10 idae) is the most serious pest of squash east of the Rocky Mountains to the Atlantic and pumpkins in the U.S. and is a poten-ATTRA—National Sustainable Coast and from Canada to South America.Agriculture Information Service tial problem for all cucurbits. Squash bugsis managed by the National Cen- (found only in the Western Hemisphere) (2) In the U.S. it can cause significant cropter for Appropriate Technology(NCAT) and is funded under a range widely from the east to west coasts losses east of a line that roughly parallelsgrant from the United States and north to south from Canada to South Interstate 35. (3) The larvae of squash vineDepartment of Agriculture’sRural Business-Cooperative Ser- America. (1) Adults and nymphs of squash borer damage plants by destroying tissuevice. Visit the NCAT Web site(www.ncat.org/agri. bugs damage plants by sucking plant juices in the stem and causing anything beyondhtml) for more informa- from the leaves. Further, they inject a toxin that point to die—either the whole plant ortion on our sustainableagriculture projects. ���� that causes the plants to wilt, blacken, a runner.
    • Some of the same controls have recently Life Cycle and Characteristics: been found to work well for both pests in commercial-scale organic production, even Squash Vine Borer though the two pests come from different Squash vine borers overwinter as larvae orders/families of insects, and their dif- or pupae in the soil. Adult moths emerge ferent developmental stages do damage in the spring and deposit eggs on a host to different parts of the squash plants. (4, plant. Disk-shaped, dark-reddish-brown 5) Preventive management practices con- eggs are laid singly on the plant near the base. (7) After hatching, the larvae pen- sist of destroying crop residues and debris etrate the plant stem and burrow toward that provide shelter for overwintering adults the base. An individual adult can lay from and excluding entry using a row cover- 150 to 250 eggs, and (theoretically at least) ing strategy between the time of planting as few as 10 moths can cause 100 percent and flowering. infestation on a single acre of squash-fam- ily plants. (8) Occasionally, small borers Life Cycle and Characteristics: may also enter leaf stems. The burrowing Squash Bug larvae destroy the internal vascular tissue and cause the whole plant or the invadedRelated ATTRA Adult squash bugs pass the winter under runner to wilt and die. Feeding may con-Publications whatever shelter is available—including tinue for four to six weeks. A sticky gob leaves, boards, stones, and other debris. of excrement ( frass)—which resembles wetOrganic Pumpkin andWinter Squash The adult bugs re-emerge as soon as the sawdust—typically marks the entrance site.Production weather warms, and mate soon thereafter. (9, 10) If a vine dies before the borer has Squash bugs lay eggs in masses of a dozen completed its larval cycle, the larva canFarmscaping to or more on the underside of leaves, usually migrate to a neighboring plant and resumeEnhance BiologicalControl in the vein axils. Eggs hatch in 10 to 14 feeding there. (8) days. The nymphs pass through five instarsSeason Extension over a period of four to six weeks to reach The squash vine borer larvae are whitish,Techniques for wrinkled, brown-headed worms that canMarket Gardeners maturity. Since the overwintering adults lay eggs well into midsummer, all stages of the grow to about 1 inch in length. The adult[hoophouses and row pest’s lifecycle can be observed in the field moth, a member of the clear-winged mothcovers] throughout most of the season. (6) Two gen- family, has translucent wings (wing expanseNCAT’s Organic Crops erations may occur in the South. of about 1.5 inches) with metallic green-Workbook black and orange colors on the body andCucumber Beetles: Squash bug adults are easy to identify. wing fringes. The moth is a day flier, oftenOrganic and They are approximately 5/8-inch long, dark mistaken for a wasp.Biorational IPM brown or mottled, and hard-shelled. Being Generally, only one generation per year isOverview of Cover true bugs, they have a long, shield-like produced in northern states, two genera-Crops and Green shape and membranous-looking wing tips. tions in many southern states.Manures They give off a disagreeable odor in large numbers or when crushed. Nymphs are delicate, with bright orangish-red heads, Planning for Control legs, and antennae; the abdomen is green. Planning for control of squash bug in As the nymphs age, they become grayish- organic production must begin before a white with dark legs. (6) They range in size single seed or seedling is planted. Recent from 1/10 to 2/5 of an inch. research has identified squash bug as a vector for the newly named Cucurbit Yel- Squash bug eggs are easy to identify. The low Vine Disease (CYVD). Once squash orange-yellow eggs are each about 1/16-inch plants start to yellow from infection with in length. Eggs appear in neatly ordered this virus, there is very little that can be rows on the underside of host-plant leaves. done. The viral disease, which shows up They gradually change to a bronze color as soon after transplanting, has been reported hatch nears. (1) in Kentucky, Oklahoma, and Texas, and isPage 2 ATTRA Squash Bug and Squash Vine Borer: Organic Controls
    • suspected in Ohio. The organism has been squash vine borer and the squash bug.identified as Serratia marcescens. (11) However, producers should be aware that the squash vine borer adults are strong fli-Planning for squash vine borer control is ers and have been known to find squashlikewise very important, since a very small fields as far as one-half mile from theirpopulation of borers can be highly destruc- emergence site in another field. (8)tive. Feeding within the plant stem, a sin-gle borer can kill a whole plant or a large Field sanitation procedures are recom-runner vine. mended as a measure of control of the squash vine borer, as well. Vine residuesLevels of Control in Certified should be destroyed as soon as possible after harvest to prevent late larvae fromOrganic Production completing their lifecycle. (9, 10) Fall till-The National Organic Program, adminis- age exposes cocoons (pupae) to predationtered by the U.S. Department of Agricul- and deep incorporation in early spring fur-ture (USDA), has set standards for pest ther helps to keep populations suppressed.management. The Crop Pest, Weed, and (10) On the other hand, fall sanitationDisease Management Practice Standard A procedures that leave the ground bare for(Section 205.206) requires that produc- very small extended periods are contrary to gooders use a three-level hierarchical approach organic agriculture practice. Consider populationin deciding how to deal with pest planting cover crops or other measures that of squashmanagement problems. minimize the risks of erosion or compaction vine borers can beManagement levels 1, 2, and 3 in the fol- of bare soil. highly destructive.lowing discussion describe three tiers ofpest management. See also the interpre- Mechanical and physicaltation of the National Organic Standards practices (level 2)found in NCAT’s Organic Crops Workbook: After cultural practices, mechanical andA Guide to Sustainable and Allowed physical practices provide a second linePractices, p. 22. of defense against pests. Such practices include the use of barriers and nonsyn-Systems-based practices (level 1) thetic lures, traps, and repellents such asCultural practices such as timing of plant- kaolin clay products. Level 2 practices alsoings, choice of cultivars, and field sanitation include developing habitat for beneficialpractices are examples of first-line, systemic predators and parasites.strategies for pest management. Mulches Iowa State University Organics Researchare known to harbor squash bugs. Help- Program conducted trials of various con-ful sanitation measures include removal of trol methods for squash bug and squashplant debris, soil incorporation of cucurbit vine borer. Researchers found that mulch-crop residue, and removal of old boards and ing with newspaper and hay, combinedother overwintering sites. These practices with tightly secured row covers on the plotscan prevent squash bug infestations. (a level 2 control), provided very effectiveField sanitation techniques have both posi- control of both weeds and squash bugs intive and negative consequences in organic pumpkin (C. pepo)—especially in the wetproduction. Some types of mulches used season of 2002. (4, 5) The row coversfor weed control appear to attract more apparently excluded squash bugs, prevent-squash bugs than other types of mulches. ing them from entering to lay eggs.(12) Removal of plant residues can be con- Gauze row covers (e.g., Reemay™, Agri-trary to good organic practice, unless a win- force™, Agribon™, Tuf bell™) [Sectionter cover crop replaces the organic matter. 205.206(b)(1),(2),(3)] physically excludeAnnual rotation to non-curcubit crops is pests and prevent them from reachinga primary step toward cultural control of the plants in large numbers. Preventivewww.attra.ncat.org ATTRA Page 3
    • strategies have become more important with Some products acceptable in organic veg- recognition of A. tristis as a probable etable production that are effective against disease vector. squash bugs include diatomaceous earth, Hand picking and trapping of A. tristis, or sabodilla, and neem oil. Growers that slitting each vine to remove the larva, in the anticipate using materials to control heavy case of M. satyriniformis, represent attempts pest infestations must list these materi- to control pests after they have begun rear- als and the circumstances for their use in ing another generation in numbers sufficient their organic systems plan. This plan must to cause economic damage and pest build- be submitted to and approved by the up. Such labor-intensive controls may be organic certifier before the producer uses uneconomical for large plantings. any material. Botanicals and biorationals are discussed Material (level 3) below in Alternative Insecticides. Level 3 strategies include the wider use of Organic advisors strongly encourage early biologicals and botanicals to control pests. cultural and other controls, rather than rely- Organic producers also have the option ing on product applications after popula- to use materials included on the National tions have been allowed to reach economic List under Section 205.206(e)—“Synthetic threshold levels. www.ipm.ucdavis.edu/ substances allowed for use in organic PMG/r116301111.html According to Cor- crop production.” nell University Extension, “application of National Organic Standards Rule Section 205.206 Crop pest, weed, and disease management practice standard. a. The producer must use management practices to prevent crop pests, weeds, and diseases including but not limited to: 1. Crop rotation and soil and crop nutrient management practices, as provided for in sections 205.203 and 205.205; 2. Sanitation measures to remove disease vectors, weed seeds, and habitat for pest organisms; and 3. Cultural practices that enhance crop health, including selection of plant species and varieties with regard to suitability to site-specific conditions and resistance to prevalent pests, weeds, and diseases. b. Pest problems may be controlled through mechanical or physical methods including but not limited to: 1. Augmentation or introduction of predators or parasites of the pest species; 2. Development of habitat for natural enemies of pests; 3. Nonsynthetic controls such as lures, traps, and repellents. c. Weed problems may be controlled through: 1. Mulching with fully biodegradable materials; 2. Mowing; 3. Livestock grazing; 4. Hand weeding and mechanical cultivation; 5. Flame, heat, or electrical means; or 6. Plastic or other synthetic mulches: Provided, That, they are removed from the field at the end of the growing or harvest season. d. Disease problems may be controlled through: 1. Management practices which suppress the spread of disease organisms; or 2. Application of nonsynthetic biological, botanical, or mineral inputs. e. When the practices provided for in paragraphs (a) through (d) of this section are insufficient to prevent or control crop pests, weeds, and diseases, a biological or botanical substance or a substance included on the National List of synthetic substances allowed for use in organic crop production may be applied to prevent, suppress, or control pests, weeds, or diseases: Provided, That the conditions for using the substance are documented in the organic system plan.Page 4 ATTRA Squash Bug and Squash Vine Borer: Organic Controls
    • approved products is not currently a viable the ground. Row covers are removed justmanagement option” for squash vine borer. before female blossoms appear, to facili-www.nysaes.cornell.edu/pp/resourceguide tate pollination. For more information on use of row covers, Iowa State Organic Research (Gerber trials) see ATTRA’s Season Extension Techniques In 2002 Kathleen Delate, Organic Crops Specialist at Iowa State University, for Market Gardeners. began comparative field trials on methods of insect control in organic pro- duction of winter squash, four zucchinis (representing summer squash, usually sold as fresh produce, rather than processed), and pumpkins. This Host first trial included specific squash and pumpkin cultivars—many of them bush, rather than vining types. It is unclear why the specific cultivars Preference listed in the Abbe Farm profiles (below) were selected for the initial trial; and Genetic according to Ashworth, the named cultivars represent three distinct squash species—C. moschata, C. maxima, and C. pepo. Production was destined Resistance for the organic baby food market. With two cooperating farmers, Delate It is important to use established sites to evaluate how three methods of pest management scientific nomencla- affected plant health and crop yields. Subsequent trials in 2002 and 2003 ture when discuss- R narrowed the cultivar range to C. moschata varieties for which squash bug ing cucurbit crops, and squash vine borer show inverse preferences. ow cov- in order to identify In the first year, the three methods consisted of: species and subspe- ers must cies correctly. The be tightly • A kaolin clay product applied bi-weekly from plant emergence until a month before harvest terms squash and secured to be effec- pumpkin are used in tive in excluding • Interplanting of buckwheat to supply food for a fly parasite the produce industry (tachnid fly) of the squash bug, and insects. and among home gar- • Reemay™ row cover, a gauze-like fabric used to prevent coloniza- deners to refer to a tion by the pests. confusing variety of After the second year, project results indicate a slight preference for row cucurbits. Scientifi- covers as the most effective method to control both squash bug and squash cally, there are either vine borer. Varieties of C. moschata were the only cultivars trialed after five or six recognized the first year. (4) species: C. pepo, C. moschata, C. mixta, C. maxima (the four types commonly found in U.S. markets)—Row Covers plus C. ficifolia (known as chilacayote inA two-year organic squash and pumpkin Mexico and commonly used in candies)variety trial from West Virginia found ben- and C. foetidissima (the foul-smelling wildefits for row covers comparable to the Iowa “Buffalo Gourd,” sometimes employed asState work. (13) Row covers must be tightly a source of seeds pressed for oil). Thesesecured to be effective in excluding insects. species were established and defined byEspecially in areas with high winds, row the fact that members do not cross whencovers have to be securely anchored to planted near each other. However, evidence Regionality The results of the Iowa and West Virginia pest management trials are preliminary and regional. For instance, squash vine borer is not a significant problem in the West (west of Interstate 35). In general, organic growers need to be guided primarily by research done in their own regions. The University of California IPM Web site, however, presents very similar recommenda- tions to what these research studies suggest: field sanitation and crop rotation to break pest cycles in the field, and use of row covers to prevent infestation from nearby pest hatching sites. www.ipm.ucdavis.edu/PMG/r116301111.html Research remains to be done—region by region and under weather conditions that may differ markedly from year to year—on the best organic methods to control insect pests on all varieties and market types of Cucurbita.www.attra.ncat.org ATTRA Page 5
    • suggests that C. mixta may cross with C. moschata under certain conditions. (14) Cultivar Preference of Squash Vine Borer C. pepo includes all the “summer squash”— Scientific i.e., preferred culinary use is before matu- Variety or Type Rating name rity—most “pumpkins,” and hard-shell Blue Hubbard C. maxima keepers like acorn, as well as novelties such 5 (Hubbard type) as spaghetti squash. However, “Cushaw Boston Marrow 4 C. maxima pumpkins” are C. moschata, and some (Hubbard type) “white pumpkins” are C. maxima. Some- Golden Delicious 4 C. maxima times giant orange varieties, such as C. (Hubbard type) maxima, are marketed as pumpkins. Connecticut Field 4 C. pepo A 1990 study at Oklahoma State Univer- pumpkin (ornam.) sity of ovipositional preference by squash Small Sugar 4 C. pepo bugs found a decided preference for yel- pumpkin low straightneck and crookneck (C. pepo), (ornamental) as compared with zucchini, acorn, spaghetti Zucchini 4 C. pepoT he bottom (all C. pepo), and butternut (C. moschata). White Bush 3 C. pepo (15) Other studies have found a squash Scallop line is that bug preference for C. maxima and C. mixta any organic Acorn 3 C. pepo over some types of C. pepo. Acorn squashgrower who wishes and all the C. moschatas are quite tolerant Summer 2 C. pepo crookneckto raise squashes of squash bug damage. (16, 17) Cocoz- elle (C. pepo) has been identified as an Dickenson 2 C. moschataand pumpkins must extremely susceptible sub-type of zucchini. pumpkingrow varieties pre- A research study in Texas found C. foetidis- Green striped 1 C. mixtaferred by the cus- sima extremely distasteful to squash bugs, cushawtomers, and cannot as well as to humans. (18) Butternut 1 C. moschatarely on “host pref- The University of Illinois rated the suscep- elsewhere and could account for some of theerence and genetic tibility of twelve varieties (types) of squash Iowa State results as a “missing variable.”resistance” to deter on degree of resistance to squash vine borer Feeding preferences have been studied pri-squash bugs. attack. The list corresponds almost exactly marily in the context of cultural manage- to the four sub-types of squashes cultivated ment of cucumber beetle through the use in the U.S. A rating of 1 indicates most of trap crops. (20, 21) (See the ATTRA resistant to vine publication Cucumber Beetles: Organic and borer; a rating of 5, Biorational IPM.) least resistant. (19) When applied to squash bug and squash A l so, see the vine borer control, research on feeding ATTRA publication preferences does not address market prefer- Organic Pumpkin ences. The bottom line is that any organic and Winter Squash grower who wishes to raise squashes and Production. pumpkins must grow varieties preferred Investigation into by the customers, and cannot rely on “host host preferences preference and genetic resistance” to deter of squash bug and squash bugs. Squash bug control in pump- squash vine borer kins cannot be achieved by simply sub- and inferred genetic stituting ‘Cushaw’ for the jack-o-lantern, resistance, while not nor can patty pan be considered a substi- an objective of the tute for the ‘Prolific straightneck’ or the Iowa State trials, highly desirable fresh market ‘Cocozelle.’Pumpkin. has been carried on (16) A winter squash producer having aPage 6 ATTRA Squash Bug and Squash Vine Borer: Organic Controls
    • Farm Profile: Abbe Hills Farm, Mt. Vernon, IowaAbbe Hills Farm, managed by ISU farmer cooperator Laura Krause, was one of two farmsparticipating in a two-year trial of pest control methods in certified organic squash pro-duction intended for Gerber Products, Inc. The project evaluated methods of pest man-agement in terms of pest suppression and crop yields, in addition to the productivity(plant performance and health) of organically raised squash. Other heirloom vegetableswere raised as part of the trial, as well, and processed at the Iowa State University Food Sci-ence Department according to Gerber specifications for baby food.Heirloom squashes raised in 2001 in the trial plots at Abbe Hills included the following. Noother cucurbits were grown.Winter squashTable Queen (C. pepo)Early Butternut (C. moschata) hybridBurgess Buttercup (C. maxima)Heart of Gold (C. pepo) hybrid D [sweet dumpling acorn type] elayedSweet Dumpling (C. pepo) planting [sweet dumpling acorn type] has some-Cream of the Crop (C. pepo) hybrid times been sug-(semi-bush) gested as a means toTable Ace (C. pepo) hybrid(semi-bush) control both squashSummer squash bug and squash vine borer.Zucchinis (C. pepo)Costata Romanesco, Nimba,Aristocrat (hybrid), Cocozelle(hybrid), BlackPumpkinsGhost Rider (C. pepo)Howden (C. pepo)Orange Smoothie (C. pepo) hybridRacer (C. pepo) hybridFindings reported after two years clearly showed row covers to be a superior method ofpest management, based on yields, plant health, and absence of squash bugs in all stagesof development.problem with vine borers will undoubtedly find insect and disease management commentsit easier and more cost-effective to take on “possible organic controls that lack effi-different measures to control the pest cacy.” (22) Some are discussed below.than to convince the marketplace to acceptbutternut as a substitute for Giant Blue Delayed planting has sometimes beenHubbard. suggested as a means to control both squash bug and squash vine borer. Con- ditions for success seem to limit its useOther Cultural and Physical rather narrowly.ControlsResearch can be useful to show what is • A moderately long growing seasonnot effective, as well as what does work. A • No neighbors growing any of the2005 Cornell University guide for organic cucurbitswww.attra.ncat.org ATTRA Page 7
    • • No wild cucurbits to serve as hosts Recommended strategies A method in use to control squash vine Among the successful strategies to suppress borer is syringe injection of the bacterial squash bugs on a larger scale are field sani- insecticide Bt (Bacillus thuringiensis) into tation techniques. The use of postharvest each vine by hand. In home gardens or tillage—routinely recommended to destroy small market gardens, growers often try overwintering sites and to bury the adults— to control squash bugs by hand picking has worked well to control both squash bug or placing wooden boards near the plants, and squash vine borer. where squash bugs will congregate for hand collection and disposal. For squash vine Sanitation procedures that remove crop res- borer, small growers are advised to slit idues by burning or high-temperature com- each vine showing frass (the insect excre- posting are also successful. (1, 11, 15) It ment) and extract the larva before the vine is helpful to clear adjacent areas of litter, is irreparably damaged. Such methods leaf piles, and (especially) cucurbitaceous are not suitable for commercial production weeds, as well. Burning crop residues is of three or four acres because of the hand permitted as an exception to Organic Stand- ard Section 205.203c(3) for the expressA labor involved. mong the purpose of disease suppression. High-tem- successful perature composting would be preferable. Experimental, creative These strategies, when approved by a cer- strategiesto suppress squash approaches tifying agent, should be viewed as stopgap Eero Ruuttila, an organic farmer from New measures and not be employed as part of abugs on a larger long-term crop management plan. Hampshire, has observed that squash bugscale are field sani- oviposition on vines tends to take place dis- Fall tillage and cover cropping is the normtation techniques. proportionately on the growing ends of mid- in organic squash production. Research season offshoots. He harvests one-third of from Oklahoma State found that plastic the young vines in July and August, before mulch provided squash bugs with more the eggs hatch, and sells the harvested off- shelter from sprayed insecticides than did shoots in ethnic markets. (23) Harvesting other types of mulch. (20) Mulch used in a marketable alternative crop for a specialty the Iowa State study (first year) consisted of market is a creative way to avoid—rather newspaper and hay, which provided good than solve—pest problems. weed control. (4) An experimental technique for squash bug control is companion planting with repellant National Organic Standards Rule plants—catnip, tansy, (16) radishes, nastur- Section 205.203 Soil fertility and crop nutrient tiums, or marigolds, (6) beebalm, (24) or management practice standard. mints. (25) For more information on such strategies, ask for ATTRA’s Companion e. The producer must not use (3) burn- ing as a means of disposal for crop Planting publication. residues produced on the operation: Except, that burning may be used to suppress the spread of disease or to stimulate seed germination.Marigold. Crop rotation is a recommended production practice that reduces squash pests within a field. Rotation can contribute to pest sup- pression by delaying population build-up early in the season. Rotation does not, how- ever, provide complete, reliable control of either pest because adults can move easilyPage 8 ATTRA Squash Bug and Squash Vine Borer: Organic Controls
    • between fields. Sustaining vigorous plantgrowth is a very important part of a borer Table 1. Squash harvest parameters. Pratt Farm, 2001 (5)control strategy. Supplemental fertilization Treatment Yield (lbs)/acre ± SE Fruit/acre ± SEmay be necessary to promote the vigorously Control 2,472.9 ± 663.3 1,375.0 ± 291.7growing plants that can tolerate one or twoborers and still produce a crop through Surround™ [kaolin clay] 3,580.8 ± 2246.1 1,708.3 ± 718.1additional rooting along the stem. (10) Buckwheat intercrop 1,901.7 ± 986.9 1,000.0 ± 343.6 LSDO.05 nsd nsdBiological ControlBiological control was part of the Iowa Table 2. Squash harvest parameters. Abbe Hills Farm,State Study. Buckwheat was interplanted to 2001 (5)attract the tachinid fly parasitoid, Trichop- Treatment Yield (lbs)/acre ± SE Fruit/acre ± SEoda pennipes, of A. tristis. T. pennipes depos- Control 13,812.5 ± 1,226.4 6,437.5 ± 437.5its eggs on large nymph and adult squashbugs. After hatching, tachinid fly larvae Surround™ 12,750.0 ± 4,165.8 5,625.0 ± 1,419.7feed on the squash bug, eventually killing Buckwheat intercrop 2,000.0 ± 639.4 1,062.5 ± 213.5it. Unfortunately, the victim may continue Row cover 13,937.5 ± 2,303.5 6,562.5 ± 868.3to feed and lay eggs for a while after it has LSDO.05 7,637.2 2,671.4been parasitized. Therefore, even parasit- (5)ism levels as high as 80 percent may notprevent measurable economic damage. (26) Populations of squash bug can also beThe Iowa State study found that planting a suppressed by the presence of other natu-buckwheat intercrop to enhance tachinid fly ral predators. Limiting pesticide use is aparasitism consistently outperformed appli- most important step in protecting these ben-cations of kaolin clay in reducing squash eficials in agricultural systems. They canbug infestations. However, squash yields in be further encouraged through the use ofthe buckwheat intercrop plots were reduced beneficial habitats, or refugia, in the formby a factor of at least six at Abbe Hills Farm of cover crops, strip plantings of diverseand a factor of three at Pratt Farm, when crops, and maintenance of desirable non-compared with the row-cover trial plots. crop border areas. For more information on creating habitat for beneficials (refugia), see the ATTRA publication Farmscaping to Enhance Biological Control, www.attra.org/ attra-pubs/farmscape.html, also available in print upon request. For squash bugs, gen- eralist predators include spiders, predatory mites, disease organisms, and a number of beneficial insect species—especially ground beetles and robber flies. At least one egg parasitoid of squash vine borer has been identified that helps to keep its numbers under control (8, 9, 23). Parasitic nema- todes can be effective predators. Cornell Extension points out that soil treatmentsTachinid fly (Trichopoda pennipes). will not reliably control squash vine borer, as adults are strong flyers.The “Results and Discussion” section of thereport noted: “The number of squash per Because a single borer can be so highlyplot and yields were significantly less in the destructive, biological controls have notsquash plots intercropped with buckwheat.” been considered a key strategy in man-(4) (See Table 2.) aging the squash vine borer. (9)www.attra.ncat.org ATTRA Page 9
    • Kaolin Clay All pesticides pose known and potential risks.Comparison of Kaolin Clay (Surround™) treatment with When applying any pesticide, be certain to fol-other physical and mechanical pest control methods low label instructions and use appropriate protec-in the second-year Iowa State study showed “no sig- tive gear. Some natural substances used in organicnificant difference” in populations of squash bug and production as pesticides can have significant toxicsquash vine borer or in populations of beneficials effects. The decision to use any pesticide should beamong the three pest management treatments. It should made only when other approaches to pest manage-be noted that this trial involved only C. moschata— ment fail to provide adequate protection, and afternext to C. foetidissima, the type least preferred by plans for application have been included in thesquash bugs. (4, 5) organic system plan that has been approved by the organic certifier.In 2003 and 2004, further trials were held at IowaState, comparing two different Kaolin Clay formula-tions—Surround-WP and Surround-XP—on Waltham ReferencesButternut Squash (C. moschata) at the Nerely-Kinyon 1. McKinlay, Roderick G. 1992. Vegetable CropResearch Farm, Greenfield, Iowa. Nine rows were Pests. CRC Press, Boston, MA. p. 143.treated with Surround-WP, applied on a bi-weekly basis 2. Sorensen, Kenneth A. 1994. The squash vinefrom plant establishment until plant leaf senescence; borer. Cooperative Extension, North Carolinanine rows, with Surround-XP, applied the same. A con- State University, Raleigh, NC.trol plot received no treatment. There was no signifi- www.ces.ncsu.edu/depts/ent/notes/Vegetables/cant difference found among the three plots in yields veg20.html(measured by count and individual squash weights) orpresence of insects. (27) 3. Anon. No date. Squash vine borer. Lane Agri- cultural Experiment Station, Oklahoma State Uni- versity, Lane, OK. www.lane-ag.org/Alternative InsecticidesOrganic growers have traditionally used botanical insec- 4. Delate, Kathleen. 2002. Progress Report to Ger-ticides such as sabadilla, ryania, rotenone, or various ber Products, Inc.: Organic Squash Pest Manage-blends of these to control squash bug. However, most ment Trials and Heirloom Vegetables. January 9.botanicals have generally proven to be a bit expensive Iowa State University, Ames, IA. 6 p.and only marginally effective. For information on what http://extension.agron.iastate.edu/organicag/to use, see “What can I use in organic production?” researchreports/gerber.pdfon page 20 and Chapter VIII, Pest and Disease 5. Delate, Kathleen. 2003. Progress Report toManagement, pages 25–29, in NCAT’s Organic Gerber Products, Inc.: Organic Squash Trials.Crops Workbook. Also consult the Organic Materi- February 12. Iowa State University, Ames, IA.als Review Institute (OMRI) for more information on http://extension.agron.iastate.edu/insecticides permitted in organic squash production organicag/(www.omri.org). 6. Bessin, Ric. 2004. Squash Vine Borer andIn all cases where pesticides—natural or synthetic—are Squash Bug. www.uky.edu/Ag/Entomology/used, timing is critical. Application should coincide entfacts/veg/ef314.htmwith maximum egg hatch, because the nymph stage ismost vulnerable. Timing can be judged by frequent 7. Friend, R.B. 1931. The Squash Vine Borer.and careful field scouting. In organic farming, there Bulletin 328. Connecticut Agricultural Experi-is no substitute for the eye of the farmer. Monitoring ment Station, University of Connecticut, Newsquash bug emergence is not difficult, as the egg clus- Haven, CT. 25 p.ters are easy to find and identify. Egg placement and 8. Worthley, Harlan N. 1923. The Control of thehatch occur on the undersides of leaves, and the nymphs Squash Vine Borer in Massachusetts, Bulletin No.tend to remain there. Therefore, to be effective, pesti- 218. Massachusetts Agricultural Experiment Sta-cide sprays or dusts must reach these areas and blan- tion, Amherst, MA. 80 p.ket them thoroughly. Since hatching occurs continuallythroughout the season, subsequent treatments will be 9. Sorensen, Kenneth A., and James R. Baker.required to assure sufficient control. (28) 1983. Insect and Related Pests of Vegetables:Page 10 ATTRA Squash Bug and Squash Vine Borer: Organic Controls
    • Some Important, Common, and Potential Pests in University of Illinois, Urbana, IL. the Southeastern United States. Pub. AG-295. www.urbanext.uiuc.edu/bugreview/ North Carolina State University, Raleigh, NC. squashvineborer.html 173 p. 20. Palumbo, John C. 1988. Innovative methods of10. Metcalf, Robert L. and Robert A. Metcalf. 1993. coping with squash bugs on cucurbits. Proceed- Destructive and Useful Insects: Their Habits and ings of the 7th Annual Oklahoma Horticulture Control. McGraw-Hill, Inc., New York, NY. p. Industries Show. p. 152–155. 14.38–14.39. 21. Naegely, Stella K. 1997. Faking out bugs.11. Bruton, B.D., et al. 2003. Serratia marcescens, a American Vegetable Grower. August. Phloem-Colonizing, Squash Bug-Transmitted Bac- p. 38–39. terium: Causal Agent of Cucurbit Yellow Vine Dis- 22. Cornell University. 2005. Resource Guide for ease. Plant Dis. 87:937-944. Organic Insect and Disease Management. www.apsnet.org/pd/abstracts/2003/ www.nysaes.cornell.edu/pp/resourceguide/cmp/ dau03ab.htm cucurbit.php12. Staff. 1990. Mulch attracts squash bugs. 23. Stoner, Kimberly A. (ed.) 1998. Proceed- HortIdeas. November. p. 126. ings: Alternatives to Insecticides Conference.13. Van Tine, Melissa, and Sven Verlinden. 2003. Abstracts: Cucurbit crops. Connecticut Managing Insects and Disease Damage under an Agricultural Experiment Station (CAES), New Organic System. West Virginia Extension, Mor- Haven. 2 p. www.caes.state.ct.us/ gantown, WV. 3 p. AlternativestoInsecticides/Abstracts/ www.wvu.edu/%7Eagexten/farmman2/organic/ abstractcucurbit.htm insects.pdf 24. Garrett, J.H. 1993. J. Howard Garrett’s Organic14. Ashworth, Suzanne. 2002. Seed to Seed. Manual. The Summit Group. Fort Worth, TX. Seed Saver Publications, Decorah, IA. p. 114, 121.15. Bonjour, E.L., W.S. Fargo, and P.E. Rensner. 25. Patterson, Peg. 2000. Peppermint defeats those 1990. Ovipositional preference of squash bugs nasty squash bugs. Organic Gardening. Vol. 48, (Heteroptera: Coreidae) among cucurbits in Okla- No. 2. p. 70–71. homa. Journal of the Entomological Society of 26. Hoffman, Michael P., and Anne C. Frodsham. America. Vol. 83, No. 3. p. 943–947. 1993. Natural Enemies of Vegetable Insect Pests.16. Ellis, Barbara W., and Fern Marshall Bradley. Cornell University Cooperative Extension. Ithaca, 1992. The Organic Gardener’s Handbook of Nat- NY. 63 p. ural Insect and Disease Control. Rodale Press. 27. Delate, Kathleen, and A. McKern. 2004. An Emmaus, PA. 534 p. examination of Kaolin Particle Film for Insect17. Davidson, Ralph H., and William F. Lyon. 1987. Pest Management in Organic Winter Squash. Insect Pests of Farm, Garden and Orchard, 8th www.organicaginfo/upload/ ed. John Wiley & Sons. New York, NY. Gerber_2004_squash_report.doc p. 302–303. 28. Bishop, Beth A. 2000. The Vegetable Growers18. Paige, J. et al. 1989. Ovipositional host associa- News. Vol. 34, No. 7. p. 6–7. tion of Anasa Tristis (DeGeer) and various Cucur- bita cultivars on the Texas High Plains. Journal of Agricultural Entomology. Vol. 6, No. 1. p. 5–8. Note: For an assessment of C. foetidissema poten- tial in biodiesel production, see the ATTRA publica- tion Biodiesel: The Sustainability Dimensions.19. Grupp, Susan M. No date. The bug review: Squash vine borer. Cooperative Extension,www.attra.ncat.org ATTRA Page 11
    • Squash Bug and Squash Vine Borer: Organic Controls By Katherine L. Adam NCAT Agriculture Specialist ©2006 NCAT Paul Driscoll, Editor Cynthia Arnold, Production This publication is available on the Web at: www.attra.ncat.org/attra-pub/squash_pest.html and www.attra.ncat.org/attra-pub/PDF/squash_pest.pdf IP298 Slot 117 Version 022808Page 12 ATTRA