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Lesser Cornstalk Borer

Article author: Kate Crumley
Most recently reviewed by: Tyler Mays & Danielle Sekula (2021)

Common Name(s): Lesser Cornstalk Borer


The lesser cornstalk borer is a small, yellow to black moth with sexual dimorphism that varies by location. This moth species is a pest on a variety of grain and legume crops, with larvae that feed by tunneling into the stem of the host plant.

Origin and Distribution

The lesser cornstalk borer is native to the United States. It can be found from Maine to California, and has been documented in Hawaii, but is most often found in sandy soils in the southeastern United States. It can also be found in Mexico, Central, and South America.

Habitat & Hosts

The lesser cornstalk borer is a polyphagous pest that feeds on a variety of crops. Vegetable and legume crops are often damaged, and it has a variety of weedy hosts like crabgrass, johnsongrass, wild oats, bermudagrass, wiregrass, goosegrass, and nutsedge.

Life Cycle

Lesser cornstalk borer eggs are oval, and are 0.35mm – 0.43 mm in width, and green when first laid, but turn pink after 8- 24 hours. Eggs turn deeper red as they near hatching, and are a deep iridescent crimson immediately before. Eggs take between 2- 3.5 days to hatch depending on temperature. Larvae that can be found in silk tunnels radiating horizontally from the stems of their host plants immediately below the soil surface. The silk tubes are usually between two or three inches long, depending on the age of the larvae. Larvae normally have 6 instars, but can range from 5- 9, and range from 1.3 mm to 20.8 mm long. The larval stage lasts about 20 days when not overwintering. Pupae can be found in the silk tunnels near base of the plant, or loose in the soil. They are yellow early, and turn dark brown to nearly black before adults eclose. They range from 7.6 mm to 9.6 mm in length. The pupal stage can last from 7- 10 days when not overwintering. Adult moths are 8-9 mm long brown moths with sexual dimorphism, and color patterns that vary based on location. Adults live for about 10 days, and are most active at night.


If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.

Damage from the lesser cornstalk borer is caused by feeding, which tunnels into the stem of the plant or girdles the base of the plant. Wilting is one of the early symptoms of infestation, and can result in a poor crop stand. Insecticides can be used to control this pest, but need to be applied to the root zone, either in the seed furrow or banded over the seed bed. Modified planting practices can be used to minimize damage. Insect populations increase later in the growing season, so early planting can help. Tillage and weed control also help minimize insect populations in the environment, but conservation tillage can also help. Conservation tillage can allow larvae to feed freely on crop residue and organic matter, which can spare seedlings.

Related Publications


All JN, Gallaher RN, Jellum MD. 1979. Influence of planting date, preplanting weed control, irrigation, and conservation tillage practices on efficacy of planting time insecticide applications for control of lesser cornstalk borer in field corn. Journal of Economic Entomology 72: 265-268.

Bessin R. 2004. The common stalk borer in corn. University of Kentucky, Entomology. University of Kentucky, Lexington, KY. (5 September 2008)

Biddle AJ, Hutchins SH, Wightman JA. 1992. Pests living below ground, Elasmopalpus lignosellus: Lesser cornstalk borer, pp. 202-203. In McKinley RG. [editor] Vegetable Crop Pests. CRC press, Boca Raton, FL.

Capinera JL. 2001. Handbook of Vegetable Pests. Academic Press, San Diego. 729 pp.

Chang V, Ota AK. 1987. The lesser cornstalk borer: a new important pest of young sugarcane, pp. 27-30 In Annual Report, 1986. Experiment station. Hawaiian Sugar Planter’s Association, Pahala, HI.

Chapin JW. (1999). Lesser cornstalk borer on peanut. Entomology insect information Series. (20 August 2008).

Funderburk JE, Boucias DG, Herzog DC, Sprenkel RK, Lynch RE. 1984. Parasitoids and pathogens of larval lesser cornstalk borers (Lepidoptera: Pyralidae) in northern Florida. Environmental Entomology 13: 1319-1323.

Funderburk JE, Herzog DC, Mack TP, Lynch RE. 1985. Sampling lesser cornstalk borer (Lepidoptera: Pyralidae) adults in several crops with reference to adult dispersion patterns. Environmental Entomology 14: 452-458.

Gardner WA, All JN. 1982. Chemical control of the lesser cornstalk borer in grain sorghum. Journal of Georgia Entomological Society. 17: 167-171.

Isely D. 1944. The lesser cornstalk borer, a pest of fall beans. Journal of Kansas Entomological Society. 17: 51-57.

Leuck DB. 1966. Biology of the lesser cornstalk borer in south Georgia. Journal of Economic Entomology 59: 797-801.

Luginbill P, Ainslie GG. 1917. The lesser cornstalk borer. U.S. Department of Agriculture Bulletin 539. 27 pp.

Lynch RE, Klun JA, Leonhardt BA, Schwarz M, Garner JW. 1984. Female sex pheromone of the lesser cornstalk borer, Elasmopalpus lignosellus (Lepidoptera: Pyralidae). Environmental Entomology 13: 121-126.

Mack TP, Backman CB. 1984. Effects of temperature and adult age on the oviposition rate of Elasmopalpus lignosellus (Zeller), the lesser cornstalk borer. Environmental Entomology. 13: 966-969.

Mack TP, Davis DP, Backman CB. 1991. Predicting lesser cornstalk borer (Lepidoptera: Pyralidae) larval density from estimates of adult abundance in peanut fields. Journal of Entomological Science 26: 223-230.

Mack TP, Davis DP, Lynch RE. 1993. Development of a system to time scouting for the lesser cornstalk borer (Lepidoptera: Pyralidae) attacking peanuts in the southeastern United States. Journal of Economic Entomology 86: 164-173.

Metcalf CL, Flint WP, Metalf RL. 1962. Lesser cornstalk borer, pp. 497-498. In Destructive and useful insects. McGraw-Hill Book Company, San Francisco, CA.

Nuessly GS, Webb SE. (2007). Insect management for sweet corn. EDIS (7 May 2020).

Riley CV. 1882. The smaller corn stalk-borer. U. S. Department of Agriculture Report 1881: 142-145.

Sanchez, Louis O. 1960. The biology and control of the lesser cornstalk borer, Elasmopalpus lignosellus.

Schaaf AC. 1974. Jumping borer, Elasmopalpus lignosellus, pp. 31-34. In Handbook of pests of sugarcane. Tech Bull 1/75. Sugar Industry Research Institute Mandeville, Jamaica.

Smith JW Jr, Barfield CS. 1982. Management of preharvest insects, pp. 250- 325. In Pattee HE, Young CT (editors), Peanut science and technology. American Peanut Research Education Society, Yoakum, TX.

Smith Jr JW, Johnson SJ, Sams RL. 1981. Spatial distribution of lesser cornstalk borer eggs in peanuts. Environmental Entomology 10: 192-193.

Smith Jr JW, Johnson SJ. 1989. Natural mortality of the lesser cornstalk borer (Lepidoptera: Pyralidae) in a peanut agroecosystem. Environmental Entomology 18: 69-77.).

Tippins HH. 1982. A Review of Information on the Lesser Cornstalk Borer Elasmopalpus lignosellus (Zeller). Georgia Agricultural Experiment Station Special Publication 17. 65 pp.

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Chilli Thrips

Article author: Extension Entomologist at Weslaco (Vacant)
Most recently reviewed by: Pat Porter & Extension Entomologist at Overton (2020)

Common Name(s): Chilli Thrips, Strawberry Thrips, Yellow Tea Thrips


Chilli thrips, Scirtothrips dorsalis, are tiny (> 2mm long), cigar-shaped insects.  The adults are pale in color with black, feathery wings and dark spots forming incomplete stripes on the top of the abdomen.  Immatures, called larvae, look similar to adults but are even smaller and lack wings. Distinguishing chilli thrips from other thrips species is difficult, requires magnification, and some knowledge of insect taxonomy.  Chilli thrips are most often recognized based on their behavior and the type of damage they cause.

Origin and Distribution

Chilli thrips are thought to originally come from Southeast Asia although they are now widely distributed through most of the world including India, Japan, most of Africa, much of the Caribbean and South America, and are quickly becoming established in the United States.  They were first detected in Florida in 1991 and in Southeast Texas in 2005.  They have been intercepted at various ports-of-entry many times on a wide range of host plants and are likely established in many landscapes from Florida to Texas.  This insect has the potential to become a wide-spread pest throughout the Southern and Pacific U.S.

Habitat & Hosts

Chilli thrips are known to infest an impressively wide range of host plants, more than 225 species from at least 40 different plant families, and the list will likely continue to grow as they expand their range.  Their main wild, or native, host plants are in the bean family, Fabaceae.  Among other known plant hosts are numerous important crops and ornamental plants such as citrus, corn, cotton, eggplant, melon, peanut, pepper, rose, strawberry, tobacco, and tomato.

Unlike similar looking species such as the Western flower thrips, which are often found in flowers feeding on pollen, chilli thrips feed on foliage and are typically found on the undersides of leaves near the mid-vein or borders of leaves. However, when population densities are high, some individuals may be found feeding on the upper surface of leaves.


These insects have piercing and sucking mouthparts they use to extract material from individual epidermal plant cells.  Cell death leads to a silvering or bronzing of leaves and may cause them to curl, distort and/or turn brittle and drop from the plant.  Infested plants can become stunted or dwarfed. Chilli thrips tend to favor tender plant tissue, flower buds, and young fruits and vegetables although all above ground parts of plants may be attacked.  Feeding on fruits leads to scarring and, in severe infestations, corky tissues.  Aesthetic damage to ornamental plants can lead to extensive losses in the nursery/horticultural industry.

In addition, chilli thrips are known to vector at least seven viruses to various plants including chilli leaf curl virus, peanut necrosis virus, tobacco streak virus, melon yellow spot virus, watermelon silver mottle virus, and capsicum chlorosis virus, although there are no reports at this time that they have been vectors of any of these viruses in Texas.

Life Cycle

Female thrips insert anywhere from 60 – 200 microscopic, kidney-shaped eggs into plant tissue on or near leaf veins, terminal plant parts and floral structures where they cannot be detected by the naked eye.  Eggs will hatch in 2-7 days.  There are two larval stages that look similar to the adult but are smaller and lack wings.  Larvae feed for 8-10 days before entering a non-feeding pupal stage that lasts 2-3 days.  The length of time it takes to complete their life cycle varies depending on temperature and host plant but ranges from 14 – 20 days.  Their large reproductive capacity and quick generation time means that chilli thrips populations can increase very quickly.


If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.

Early detection of chilli thrips is important.  Monitor for leaf silvering, bronzing or distortion, which can be mistaken for herbicide damage.  To sample for thrips, tap the terminal portion of plants over a white piece of paper and examine with a hand lens or magnifying glass.  In nurseries or greenhouses, yellow or blue sticky traps can be used to monitor for thrips.

Chilli thrips do have some natural enemies including minute pirate bugs (Orius sp.), lacewings, and predatory mites.  While these predators may not always be able to provide adequate control of chilli thrips, it is important to preserve them by avoiding broad-spectrum insecticides such as pyrethroids and organophosphates, both of which also have a limited ability to manage chilli thrips .  Biorational insecticides including horticultural oils, spinosad, and insecticidal soaps will kill larvae and adult thrips but have no residual activity so frequent application will be needed to control larvae as they emerge from eggs and/or new thrips migrate in.  Products containing the conventional insecticide imidacloprid can be used as a soil drench or foliar spray and will provide control for a longer period of time with minimal impact on natural enemies. No matter what product you choose, it is important to rotate between different insecticide modes of action to reduce the risk of developing insecticide resistance.

Contributors: Scott Ludwig and Carlos Bogran

Related Publications

Chilli Thrips Control, Identification, and Management. 2016. Yan Chen, Steven Arthurs and Dennis Ring. LSUAg. Available here

Featured Creatures. Chilli Thrips. UF IFAS University of Florida. Available here

Pest Thrips of the United States: Field Identification Guide. Available here


Ananthakrishnan T. N. 1993. Bionomics of thrips. Annual Review of Entomology 38: 71-92

Chiemsombat, P., O. Gajanandana, N. Warin, R. Hongprayoon, A. Bhunchoth, P. Pongsapich. 2008. Biological and molecular characterization of tospoviruses in Thailand. Archives of Virology 153: 571-577.

Kumar, V., D. R. Seal, G. Kakkar, C. L. McKenzie, and L. S. Osborne. 2012. New tropical fruit hosts of Scirtothrips dorsalis (Thysanoptera: Thripidae) and its relative abundance on them in south Florida. Fla. Entomol. 95: 205 – 207.

Kumar, V., G. Kakkar, D. R. Seal, C. L.  McKenzie, J. Colee, and L. S. Osborne. 2014. Temporal and spatial distribution of an invasive thrips species Scirtothrips dorsalis (Thysanoptera: Thripidae). Crop Protection 55: 80 – 90.

Mound, L. A., and J. M. Palmer. 1981. Identification, distribution and host plants of the pest species of Scirtothrips. (Thysanoptera: Thripidae). Bulletin of Entomological Research 71: 467-479.

Rao, R. D., V. J. Prasada, A. S. Reddy, S. V. Reddy, K. Thirumala-Devi, S. Chander Rao, V.Manoj Kumar, K. Subramaniam, T. Yellamanda Reddy, S. N. Nigam, D. V. R. Reddy. 2003. The host range of tobacco streak virus in India and transmission by thrips. Annals of Applied Biology 142: 365-368.

Reddy, D. N. R., and Puttswamy. 1983. Pest infesting chilli (Capsicum annuum L.) in the nursery. Mysore J. Agric Sci 17: 246 – 251.

Sanap, M. M., R. N. Nawale, 1987. Chemical control of chilli thrips, Scirtothrips dorsalis. Vegetable Science 14: 195 – 199.

Seal, D. R., M. Ciomperlik, M. L. Richards, W. Klassen. 2006. Distribution of the chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae), within pepper plants and within pepper fields on St. Vincent. Florida Entomologist 89: 311-320.

Seal, D. R., W. Klassen, and V. Kumar. 2010. Biological parameters of Scirtothrips dorsalis (Thysanoptera: Thripidae) on selected hosts. Environ. Entomol. 39: 1389 – 1398.

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Sweetpotato whitefly

Article author: Extension Entomologist at Overton
Most recently reviewed by: Pat Porter & David Kerns & Suhas Vyavhare (2018)

Common Name(s): Silverleaf Whitefly, Sweetpotato whitefly


The sweetpotato/silverleaf whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), is a global pest of many economically important host plants (Simmons et al. 2008) such as eggplant, tomato, sweet potato, cucumber, garden bean (Tsai & Wang 1996), cotton, and poinsettias, to name a few. Similar to other sucking insect pests, sweetpotato whiteflies reduce plant vigor, growth, and can even cause mortality by piercing plant tissue and feeding on plant phloem (Bryne & Miller 1990). Whiteflies excrete waste as a sugary solution, known as honeydew. Excessive honeydew can result in inoculation of a complex of fungi, resulting in a black layer or crust forming on the surface, commonly referred to as sooty mold. In addition to causing detrimental damage by feeding, B. tabaci has been recorded to vector more than 100 plant viruses (Jones 2003), which can result in rapid widespread crop loss. Some of these viruses in Texas include Cucurbit leaf curl virus (Brown et al. 2000) and cucurbit yellow stunting disorder virus (Kao et al. 2000).

Adult whiteflies resemble very small (1 mm or 3/64-in) white moths. When disturbed, adult whiteflies will often leap off the plant and fly a short distance before landing on a nearby surface. Whitefly nymphs, especially younger nymphs, can be hard to see with the naked eye. Whitefly nymphs often blend with the leaf due to their color and relatively flat shape. The final nymph instar is often referred to as a pupa, when they become darker yellow color and are more round, making them easier to distinguish on the leaf. Once they emerge as adults, their shed ‘skin’ stays on the leaf, known as an exuvia. The exuviae stay on the leaf and resemble a small empty shell.

Adult sweetpotato whiteflies can be confused for other whiteflies that may occur in Texas, with two other common ones being the bandedwing whitefly (Trialeurodes abutiloneus) and greenhouse whitefly (Trialeurodes vaporariorum).

Origin and Distribution

Sweetpotato whiteflies are considered a global pest, however there are certain biotypes or species that are more prevalent in different parts of the world. Texas has populations of both MEAM1 (B biotype) and MED (Q biotype) whitefly.

Life Cycle

Whiteflies are closely related to mealybugs and scale insects. Female adult whiteflies lay eggs, often in a circular pattern as a result of the female using her feeding proboscis as a pivot while laying eggs. Eggs are pear-shaped and approximately 0.2 mm long (CABI MEAM1). On cotton, eggs take between 5 to 22.5 days to emerge as crawlers when held at 16.7ºC (62F) or 32.5ºC (90.5) (Butler et al. 1983), respectively. After emerging from the eggs, a mobile stage known as “crawlers” find a place nearby to settle. Once settled, whitefly nymphs are considered rather immobile until after metamorphosis. Bemisia tabaci undergo four instar stages before pupation and becoming a winged adult. The total development time from egg to adult varies from 16.6 days at 30ºC (86F) to 65.1 days at 14.9ºC (59F) in cotton (Butler et al. 1983). Adult females lay approximately 72 – 81 eggs and survive an average of 8 to 10.4 days in controlled studies (Butler et al. 1983).


If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.

Sweetpotato whitefly taxonomy is currently under revision, but it is generally agreed upon that there are specific groups of sweetpotato whiteflies that exhibit different host plant preferences, reproductive rates, and resistance to insecticides. Originally, it was thought that sweetpotato whiteflies were composed of several different ‘biotypes’, a couple well-known ones including the “B” (MEAM1) and “Q” (MED) biotypes, but now has been proposed to be made up of at least 34 morphologically indistinguishable species (Tay et al. 2012). The MEAM1 whiteflies have greater reproductive potential than the MED whiteflies, however the MED whiteflies are resistant to several different insecticides, such as pyriproxyfen and imidacloprid. Growers are encouraged to either use biological control to prevent further rise of resistance to insecticides, or rotate between insecticides that are known to be effective against both MEAM1 and MED whiteflies. See “Related Publications” below for more information.

Whitefly populations can be monitored using yellow sticky cards or searching the undersides of leaves for eggs, nymphs, pupae, exuviae, or adults. Look for other signs of infestation, such as honeydew, sooty mold, or chlorosis.

In many regions of Europe and North America, sweetpotato whiteflies in protected culture (i.e. greenhouses) are managed through regular releases of biological control agents. In the USA, commercially available biological control agents that have demonstrated potential management of sweetpotato whiteflies include Eretmocerus eremicus (Hoddle and van Driesche 1999) and Amblyseius swirskii (Calvo et al. 2010).

Insecticidal management of sweetpotato whiteflies are highly dependent on commodity, location, setting, and thresholds. Some active ingredients that have demonstrated efficacy against both MEAM1 and MED sweetpotato whiteflies include:

  • Abamectin
  • Abamectin + Bifenthrin
  • Acetamiprid
  • Beauvaria bassiana
  • Cyantraniliprole
  • Dinotefuran
  • Isaria fumosorosea
  • Horticultural Oil*
  • Insecticidal Soap*
  • Pyridaben
  • Pyrifluquinazon
  • Spiromesifen
  • Spirotetramat
  • Thiamethoxam

(Kumar et al. 2017)
*Beware of application in extreme heat and exposure to sun. Can cause leaf burn/phytotoxicity.

For more information, consult one of our related publications below for whitefly management specific to your situation.

Related Publications

CABI Bemisia tabaci (MEAM1) fact sheet:

CABI Bemisia tabaci (MED) fact sheet:

Byrne, David N. (1991). Whitefly biology. Annual Review of Entomology, 36: 431 – 457.

Suhas et al. (2018). Managing Cotton Insects in Texas. Texas A&M AgriLife Extension.

Kumar et al. (2017). Whitefly (Bemisia tabaci) management program for ornamental plants. UF/IFAS Extension.


Brown et al. (2000). Cucurbit leaf curl virus, a new whitefly transmitted geminivirus in Arizona, Texas, and Mexico. The American Phytopathological Society, 84(7): 809.

Butler et al. (1983). Bemisia tabaci (Homoptera: Aleyrodidae): Development, oviposition, and longevity in relation to temperature. Annals of the Entomological Society of America, 76: 310 – 313.

Byrne & Miller (1990). Carbohydrate and amino acid composition of phloem sap and honeydew produced by Bemisia tabaciJournal of Insect Physiology, 36: 433 – 439.

CABI Bemisia tabaci (MEAM1) fact sheet:

Calvo et al. (2011). Control of Bemisia tabaci and Frankliniella occidentalis in cucumber by Amblyseius swirskii. 56(2): 185 – 192.

Hoddle, M. and van Driesche, R. G. (1999). Evaluation of inundative release of Eretmocerus eremicus and Encarsia formosa Beltsville strain in commercial greenhouses for control of Bemisia argentifolii (Hemiptera: Aleyrodidae) on poinsettia stock plants. Biology and Microbial Control, 92(4): 811 – 824.

Jones D (2003). Plant viruses transmitted by whiteflies. European Journal of Plant Pathology, 109: 197 – 221.

Kao et al. (2000). First report of Cucurbit yellow stunting disorder virus (genus Crinivirus) in North America. The American Phytopathological Society, 84(1): 101.

Kumar et al. (2017). Whitefly (Bemisia tabaci) management program for ornamental plants. UF/IFAS Extension.

Simmons et al. (2008). Forty-nine new host plant species for Bemisia tabaci (Hemiptera: Aleyrodidae). Entomological Science, 11: 385 – 390.

Tay et al. (2012). Will the real Bemisia tabaci please stand up? PLoS ONE, 7(11): 7 – 11.

Tsai & Wang (1996). Development and reproduction of Bemisia argentifolii (Homoptera: Aleyrodidae) on five host plants. Environmental Entomology, 25(4): 810 – 816.

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Soybean Podworm

Article author: David Kerns, Pat Porter
Most recently reviewed by: (1970)

Common Name(s): Corn earworm, Cotton Bollworm, Sorghum headworm, Soybean Podworm, Tomato Fruitworm


The soybean podworm is also known as the corn earworm, cotton bollworm, sorghum headworm and tomato fruitworm and can be found on many garden and farm crops and non-crop vegetation. In most soybean production, soybean podworm is referred to as corn earworm. Adults have buff-colored wings and rather stout bodies. The wingspan is approximately 1½ inches. They are good fliers and can easily move from field to field and often arrive in large numbers on storm fronts. The moths only feed on nectar and are not pests.

However, each female can lay 500 or more eggs. The eggs are laid singly and, when new, are pearly white. The color changes to a yellow/dull white tint over time before hatching. Small caterpillars look much like the small caterpillars of other species, and it is difficult to identify them without a microscope. Soybean podworm caterpillars have many microspines on the back and sides of the body, and these are not found on most other common caterpillar pests. Larvae have a tan head and alternating dark and light stripes running lengthwise down the body, and they have numerous tubercles (dark spots) with long spines. Other pest species have stripes as well, but they do not have the abundance of microspines and tubercles, and a 10x hand lens will allow differentiation. There is no “typical” larval color, and it is common to find larvae that are either light green, dark green to grey green, or pink. Full grown larvae are approximately 1.5 inches long.

A very similar pest that may be found infesting soybean is the tobacco budworm. Eggs and larvae of soybean podworm and tobacco budworm indistinguishable without fine magnification. Tobacco budworm larvae have a tooth-like projection, called a retinaculum, on the inside surface of the mandibles and fine short hairs on the first, second and eighth abdominal projection (tubercle) which bear a single, prominent spine. If the projection and hairs are absent, this indicates a podworm. Damage and management of these two pests are the same in soybean. Soybean podworm may be distinguished from other soybean infesting caterpillars primarily based on the number of pairs of abdominal prolegs.


Origin and Distribution

The soybean podworm is a New World insect (Western Hemisphere) and is present throughout this region. It overwinters only in areas with mild winters, but flies to other areas during the course of the spring, summer and fall.

Habitat & Hosts

Soybean podworm has a very wide host range, and in Texas is usually the caterpillar found in ears of corn. Other cultivated hosts include tomato, sorghum, cotton, sunflower, squash, watermelon, potato, sweet potato, asparagus, artichoke, cowpea, snap pea, green bean, cabbage, cantaloupe, collard, cucumber eggplant, pepper, watermelon and others. The first generation of soybean podworm primarily develops on wild hosts, principally clovers. The second generation develops primarily on corn. Among soybean podworm hosts, corn is the most suitable of all hosts. The third and fourth generations generally occur in other agronomic host crops such as soybean, cotton, and grain sorghum with the fifth generation occurring primarily on volunteer crop plants after harvest and on other non-crop wild hosts.

Host preference of soybean podworm is positively correlated to plant maturity and it strongly prefers plants in the flowering stage. Thus, egg lay in soybean most often occurs during flowering or the R1-R2 stages. Later infestations may occur but are much less common. High infestations of soybean podworm often follow pyrethroid applications during bloom, due to destruction of natural enemies.

Although a less common pest of soybean in Texas, in other parts of the southern U.S. soybean podworm is often the most economically important insect pest of soybean. Soybean podworm causes damage to soybean through defoliation and from consuming pods. Early instars typically feed on blooms and and leaves. Feeding on blooms is not considered economical and defoliation by podworms alone is usually not severe enough to warrant control. Most damage is associated with 3rd-6th instar larvae which will feed upon leaves, but more importantly soybean pods. One larva can consume 15-20 flat pods or 6-10 older pods.


Life Cycle

Adults are quite mobile and can lay eggs on any host that is at a susceptible stage. Eggs are often laid near or on fruiting structures, but they can be laid on leaves and stems as well. Eggs hatch in 3-5 days and there will be five to six larval instars, each separated by a molt to a larger caterpillar. The larval stage lasts from 13 to 31 days depending on temperature. Insects develop faster under higher temperatures. After the last larval stage, the larvae move to the soil and construct a burrow where they will remain while in the pupal stage, which lasts from 10 – 25 days depending on temperature. Adults then emerge and will live for an average of 10 days, some more and some less. Soybean podworm overwinters in south Texas, and often flies north carried on storm fronts. There are several generations per year and the insect can be expected to be present for most of the growing season in the south, but only increases gradually in number in northern parts of the state. However, the growing season starts later in the north, and soybean podworm is usually quite abundant by the time vegetables and other crops reach susceptible stages.

Soybean podworm larvae are cannibalistic but in soybean they are usually not confined to groups in small areas so this behavior is inconsequential.


If you live in the State of Texas, contact your local county agent or entomologist for management information. If you live outside of Texas, contact your local extension for management options.

Most states have well defined action threshold to aid in management decision making. Sampling for soybean podworm usually involves sweep net or drop cloth. In much of the southern U.S., pyrethroid resistance is common in soybean podworm populations so caution should be used if using a pyrethroid for podworm control. Commonly used insecticides for soybean podworm and tobacco budworm include products containing chlorantraniliprole, spinetoram or spinosad. Additionally, the nucleaopolyhedrovirus, i.e. Heligen, has proven to be an effective alternative to chemical insecticides.

Related Publications


Adams, B.P., D.R. Cook, A.L. Catchot, J. Gore, F. Musser, S.D. Stewart, D. L. Kerns, G. M. Lorenz, J.T. Irby and B. Golden. 2016. Evaluation of corn earworm, Helicoverpa zea, (Lepidoptera: Noctuidae), economic injury levels in Mid-South reporductive stage soybean. J. Econ. Entomol. 109: 1161–1166.

Flanders, K. and R. Smith. 2008. Identifying caterpillars in field, forage, and horticultural crops. Alabama Cooperative Extension, ANR-1121.

Hartstack, A. W., J. P. Hollingsworth, R. L. Ridgway, and J. R. Coppedge. 1973. A population dynamics study of the bollworm and the tobacco budworm with light traps. Environ. Entomol. 2: 244–252.

Mueller, A. J., and B. W. Engroff. 1980. Effects of infestation levels of Heliothis zea on soybean. J. Econ. Entomol. 73: 271–275.

Smith, R. H., and M. H. Bass. 1972. Soybean response to various levels of podworm damage. J. Econ. Entomol. 65: 193–195.

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