The constructive comments of Kevin Steffey, Eileen Cullen, and two anonymous reviewers are acknowledged and greatly appreciated. The following are possible options for fields with a confirmed history of stalk borer problems: Cornfields planted with a Bt hybrid expressing the lepidopteran-active protein Cry1Ab for European corn borer may attain sufficient suppression of stalk borers that no further management is necessary. Photograph by James F. Price, University of Florida. ME Eggs: The eggs are oval, measuring about 0.6 mm in length and 0.4 mm in width. Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Horticulture and Home Pest News, and Iowa State University Extension and Outreach. Bailey The lesser cornstalk borer, a pest of fall beans. Lynch RE, Klun JA, Leonhardt BA, Schwarz M, Garner JW. 5). Levine (1986) later used higher minimum thresholds, accumulated after January 1, and recalculated the average first hatch and 50% hatch to occur at 297.7FDD/147.6CDD (base 47.3F/8.5C) and 309.6FDD/154.2CDD (base 48.0F/8.9C), respectively. 1982. LP Liquid formulations can also be applied, but it is important that they be directed to the root zone. For fields not planted to a lepidopteran-active Bt (Cry1Ab) corn hybrid and with historical problems only in the border rows: Kill stalk borer eggs in terraces, ditches, and waterways by burning the grass during the early spring before it emerges from winter dormancy. Meyer Leuck DB. Chemical control of the lesser cornstalk borer in grain sorghum. Pedigo Adults are attracted to light traps, but are difficult to monitor with this technique because lesser cornstalk borer moths are difficult to distinguish from many other species.
Female sex pheromone of the lesser cornstalk borer, Mack TP, Backman CB. Stalk tunneling results in upper leaves being cut off within the center of the plant, which then wilt and die. The tip of the abdomen is marked by a row of six hooked spines. Lesser cornstalk borer on peanut. Larger third- and fourth-stage larvae were unaffected by the transgenic corn and there was no differences in the mortality between the transgenic and nontransgenic hybrids, but surviving larvae on transgenic Cry1Ab weighed less, which would lengthen the developmental time to pupation and increase their exposure to pathogens, predators, and parasitoids (Binning and Rice 2002). RKD However, herbicides applied to weeds, especially those scattered throughout a field, can force stalk borers from their weedy host and into adjacent corn, thereby aggravating stalk borer damage (Rubink and McCartney 1982, Levine 1983) and possibly destroying a significant number of plants.
Corn is attacked when early stage larvae occur nearby or when partially grown larvae crawl from grassy areas to adjacent corn rows in search of larger hosts. Larvae live in the soil, constructing tunnels from soil and excrement tightly woven together with silk. First instar larva of the lesser cornstalk borer, Elasmopalpus lignosellus (Zeller).
A common misconception is that rows are stunted because of competition for moisture from the neighboring grass or weeds. In general, the forewing of the male moth is yellowish centrally, bordered by a broad dark band bearing purplish scales. There is no single solution to effectively managing stalk borers in corn. During the early instars, larvae are yellowish green, with reddish pigmentation dorsally, tending to form transverse bands. Pheromone traps have been used successfully to monitor adult populations, and adults can be flushed from fields by beating the vegetation. ; wirestem muhly, Muhlenbergia frondosa (Poiret); woolly cupgrass; smartweed, Polygonum spp. However, crop culture that uses conservation tillage (i.e., retention of crop residue at the soil surface) experiences less injury from lesser cornstalk borer feeding because the larvae feed freely on crop residue and other organic matter, sparing the young crop plants (All et al. Lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), damage to soybean. Isely D, Miner FD. The damage can be severe enough to kill the plant, especially if the borer has tunneled into the stalk of the plant at the soil-level. 1981. Photograph by University of Florida. Populations tend to increase over the course of a season, so some damage can be avoided by early planting. The stalk borer moth lays eggs in the fall on grasses and weeds. Nearly all eggs are laid on dead vegetation inside curled leaves or between the leaf sheath and stem, or in cracks of stems (Decker 1931, Levine 1985). Parasitoids accounted for <5% of stalk borer mortality. Arthropods and other invertebrates in conservation-tillage agriculture. ; and yarrow, Achillea spp.
Larvae have been found tunneling in soybean shortly after plant emergence (Fig. PM Pupal development time averages about nine to 10 days, with a range of seven to13 days. Infested plants usually have wilted terminals. The smaller corn stalk-borer. CD Photograph by Hardev Sandhu, University of Florida. A calendar date to predict movement out of grass is less reliable because temperature influences the hatch by as much as two weeks. We do not have an effective control for borers that are inside of the stem. Metcalf CL, Flint WP, Metalf RL. Bailey (1987) evaluated European corn borer, Ostrinia nubilalis Hbner, resistant corn inbred lines for resistance to stalk borers. . Pilcher
Figure 2. In its larval stage it is called a borer because of the way it chews holes into the stalks of plants and bores intoand tunnels throughthem. 1882. Highland Smith Jr JW, Johnson SJ, Sams RL. (1987) examined potential biological and environmental influences on stalk borer populations. Journal of Georgia Entomological Society. . The Common Stalk Borer (Papaipema nebris) [family: Noctuidae], is a type of moth (in the adult stage) which is native to North America. Total larval development time varies widely, but normally averages about 20 days. When first deposited, they are greenish, soon turning pinkish, and eventually reddish. One bushel per acre = 0.6277 quintal per hectare. It was first discovered outside the continental U.S. in July 1986 infesting sugarcane in Kauai (Hawaii) (Chang and Ota 1987). Vegetables and field crops injured by lesser cornstalk borer are shown in Table 1. The younger a plant is injured, the more likely it is to not produce a harvestable ear (Levine et al. Photo credit Adam Sisson. If the grass is not controlled, the problem can repeat itself the following year. Figure 6. Soil tubes formed by the lesser cornstalk borer, Elasmopalpus lignosellus (Zeller). Long-term management of field-wide infestations requires grass control so that eggs will not be laid across the field during late summer. Later, when 4th through 6th-stage larvae migrated in search of larger-diameter hosts, predators such as ants, ground beetles, and spiders were significant mortality factors. Tillage and destruction of weeds are recommended prior to planting because this helps to destroy larvae that may be present in the soil and might damage seedlings, the stage most susceptible to destruction. Pedigo On rare occasions, field-wide stand losses have been reported in corn where grass or giant ragweed, Ambrosia trifida L., problems occur. In females, however, the entire forewing is dark, sometimes almost black, but also bearing reddish or purplish scales. . . R This species is also found in Mexico, Central America, and South America (Luginbill and Ainslie 1917). E Journal of Economic Entomology 59: 797-801. 1966. Marlin E. Rice, Paula Davis, Stalk Borer (Lepidoptera: Noctuidae) Ecology and Integrated Pest Management in Corn, Journal of Integrated Pest Management, Volume 1, Issue 1, 1 October 2010, Pages C1C6, https://doi.org/10.1603/IPM10006. Activity extends from June to November, with the generations overlapping considerably and little evidence of breaks between generations. Decker The best suggestion is to keep weeds and tall grasses controlled and mowed around gardens and flowers, especially in the fall. Evaluation of two management strategies for stalk borer, Economic injury levels for management of stalk borer (Lepidoptera: Noctuidae) in corn, Injury profiles and yield responses of seedling corn attacked by stalk borer (Lepidoptera: Noctuidae), Iowa State College of Agriculture and Mechanical Arts, Research Bulletin No. Please see our website for current forms,fees,and instructions on preserving and mailing insects. Our recent observations suggest that mulching may reduce incidence of lesser cornstalk borer attack. Adult pheromone trap catches and flush counts are correlated (Funderburk et al. All of these factors contribute to larval mortality, but they cannot be relied upon to prevent yield losses. There is one generation per year. Davis and Pedigo (1990) compared the accuracy of the 41.2 or 48.0F threshold for predicting 50% egg hatch and found that both gave reasonable estimates of hatch as measured by occurrence of first instars in the field. LP Contact information for each state's diagnostic laboratory forU.S. residents. Decker (1931) maintains that the elimination of giant ragweed and similar hosts is the most important step in reducing stalk borer damage. Using fire to destroy eggs in grass and weeds in egg-laying sites (Fig. The metathoracic segment (third segment behind the head) and first four abdominal segments are dark purple or brown, except for the light dorsal stripe. Pathogens are commonly present in lesser cornstalk borer populations. If an insecticide is needed, spray between 1,4001,700 FDD (760930 CDD). The wingspan is 11.6 inch (2540 mm; Fig. Natural mortality of the lesser cornstalk borer This article was originally published on . The information contained within may not be the most current and accurate depending on when it is accessed. Wilted plants should be considered as a source of additional borer problems and these should be removed and destroyed. 27-30. They found that inbred line BS9(CB)C5 had less feeding than other lines and may be useful for future programs breeding resistance into seedling corn. Chang V, Ota AK. When stalk borer larvae were fed transgenic Cry1Ab corn tissue for 72 hours, or leaf tissue was incorporated into a meridic diet, there was no affect on larval survival, pupal weight, or days to adult emergence, but less leaf injury was recorded on the transgenic hybrid compared with the nontransgenic hybrid (Pilcher et al. 1917. ; alfalfa, Medicago sativa L.; sweet clover, Melilotus spp. While more often observed in the southeastern United States, this pest species is sporadic in nature and distributed from Maine to southern California. This stripe remains through all stages and is a distinctive characteristic used to distinguish stalk borers from all other caterpillars that feed on corn in the Midwest. Mack TP, Davis DP, Lynch RE. Published by Oxford University Press on behalf of Entomological Society of America. WC Plants that are attacked at earlier developmental stages tend to produce fewer and smaller ears than do plants attacked at later developmental stages (Davis and Pedigo 1991). Lasack Smith HA, Ota AK. In late-stage larvae, the darker colors fade and the larva assumes a dirty-white color (Fig. Early planted fields may escape some stalk borer damage, but this varies from year to year, depending on when the eggs begin to hatch. BR Legume and grass crops are most often damaged. Larvae also may tunnel into the corn cob (Decker 1931), but this injury is very rare. Academic Press, San Diego. Overwintering apparently occurs in the larval and pupal stage, and diapause is not present. If live larvae and pupae are found in 10% of plants, then treatment is recommended (Chapin 1999). Buntin Pope 1985. Densities of 0.2 and 0.5 larva per feet2 in grass are sufficient to injure 10 and 34%, respectively, of plants adjacent to grassy areas (Lasack and Pedigo 1987).When the first or second corn rows are shorter than the inside rows, stalk borers are usually the cause of this stunting. . 1997). Stalk tunneling may cause deformation of the upper plant and tassel (Decker 1931). An insecticide applied to grass terraces and timed at 570750 FDD, 41F base (300400 CDD, 5.1C base), reduced stalk borer populations by 5485%, resulting in a 5075% reduction in damaged corn plants (Davis and Pedigo 1990). Targeting hatching eggs works best in fields that have a history of field-wide infestations. Oxford University Press is a department of the University of Oxford. 1992, Chapin 1999). (2007). Despite its wide distribution, damage is limited principally to crops in sandy soil (Metcalf et al. Larvae: Larvae are strong and active when disturbed and wiggle violently so that in some countries it is called the jumping borer (Schaaf 1974). Adult longevity under field conditions is estimated at about 10 days. A second approach is to target the insecticide to coincide with migration of the larvae from the grass to the adjacent corn. Here we present an overview of stalk borer ecology and discuss IPM for this insect in corn. This is especially true of the females, which are less distinctive than the males. Lesser cornstalk borer has a number of weed hosts, such as: nutsedges (Cyperus rotundus), watergrass (Hydrochloa caroliniensis), Johnsongrass (Sorghum halepense), crabgrass (Digitaria sanguinalis), wild oats (Avena fatua), Bermudagrass (Cynodon dactylon), wiregrass (Aristida stricta), and goosegrass (Eleusine indica) (Isely and Miner 1994, Gardner and All 1982). LP Grass is best burned in the spring just as it begins to break winter dormancy. Nineteen species of Papaipema occur in Iowa and P. nebris represented 95.3% of adult specimens collected, but it is the only species known to injure corn (Peterson et al. Roberts
12) can reduce crop damage from stalk borers. There are three to four generations annually in the southeast, but in the southwest there are only three generations annually. 1992). The common stalk borer is a slender, purple and white striped caterpillar found tunneling inside the stems of a wide variety of plants. The lesser cornstalk borer: a new important pest of young sugarcane, pp. Hutchins ; lambsquarters, Chenopodium album L.; pigweed, Amaranthus spp. 1982. Figure 8. Duration of the egg stage is two to three days. Or apply the insecticide 710 days after application of a slow-acting herbicide. Photograph by James L. Castner, University of Florida. During mid to late June, the larvae grow to be too large for the grass stems and they move to larger plant stems in the vicinity. Younger plants are more susceptible to yield losses from stalk borers, so the insecticide should be sprayed during the early phase of movement. 27 pp. LC Soybean are planted at rates of 100,000 seeds or more per acre and stalk borers are unlikely to reduce the plant stand to levels that show a yield reduction. Parasitoids and pathogens of larval lesser cornstalk borers (Lepidoptera: Pyralidae) in northern Florida.
1979. Larvae rarely may occur in other crops such as soybean, Glycines max (L.) (Rice and Pedigo 1997), oat, Avena sativa L.; wheat, Triticum sativum Lamarck; and sunflower, Helianthus annnus L. (Decker 1931). 2150 Beardshear Hall 1994. Lesser cornstalk borer, Elasmopalpus lignosellus (Zeller), damage. Once the plant reaches the 6-leaf stage, the plant's ability to tolerate stalk borer injury greatly increases. 1979). Peterson et al. Use the economic injury level (EIL) table to determine if an insecticide application is justified based on larval counts in the young corn. Pupae are about 8 mm long and 2 mm wide. . Peak occurrence is usually during the first two weeks of September with 50% trap capture of flying adults during September 814 (Bailey et al. The outer leaves remain green and apparently healthy. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, providedthe original work is properly cited. In Iowaa major corn producing stateit is a widespread pest and has been recorded in all 99 counties (Decker 1931). Pedigo instructions on preserving and mailing insects. Journal of Kansas Entomological Society. Gardner WA, All JN. Smith and Johnson (1989) constructed life tables for populations in Texas, and identified survival of large lesser cornstalk borer larvae as the key element in generation survival, but the causative factor remains unidentified. In cultivated fields where grassy weeds are kept under control, most stalk borer damage is confined to the first several rows adjacent to grass ditches, terraces, fence lines, and waterways. All JN, Gallaher RN, Jellum MD. Spatial distribution of lesser cornstalk borer eggs in peanuts. Adult and larval counts are often highly correlated, indicating that flush counts can be used to predict the abundance of larvae in subsequent weeks. Figure 1. As the larvae mature, whitish longitudinal stripes develop, so that by the fifth instar they are pronounced. The herbicide kills the grass, forcing the larvae out of the plant to search for another host and is then killed by the residual insecticide. Variability in color of wings and wing patterns were reported both in male and female moths, depending on climatic and regional conditions (Biddle et al. Its range is from southern Canada, throughout the eastern U.S. (east of the Rockies), and south to the Gulf of Mexico; but, it is absent from Florida. If borer days equals 5 to 9, then damage is possible and fields should be scouted. E However, when larvae were fed seedling transgenic corn plants and the feeding period was extended to 28 days, different results were obtained. The female deposits nearly all her eggs below the soil surface adjacent to plants. Pedigo The head is orange except for an oblique, lateral black stripe extending through the ocelli.
The thorax is light in males, but dark in females. It is based on the concept of borer-days. Copyright 2022ISU Extension and Outreach Adult male lesser cornstalk borer, Elasmopalpus lignosellus (Zeller). 1993. In addition, healthy neighboring plants adjacent to infested plants will likely compensate for insect damage. Using fire in grass to kill stalk borer eggs. Davis Stalk borers do not migrate very far from grassy areas, so treat only the first four corn rows next to terraces, fence lines or waterways. 2). Plants can sometimes be saved by slicing open the stem and removing the borers by hand. 1985), but some adults fly as late as October 20 in Illinois (Levine 1983). . 143, Product safety assessment (PSA): Herculex I Insect Protection. Insecticide sprays or dusts used in the garden are not effective against this pest. The pupa is reddish brown. Dead hearts symptoms are caused by the larva boring into the stalk at the soil level and tunneling upward. Figure 5. Figure 4. It frequently damages corn, especially in conservation-tillage systems, and occasionally soybean, in the Midwestern United States. Tippins HH. . Larvae are cannibalistic and small diameter hosts seldom contain more than one larva per plant, but large multi-branched hosts, such as giant ragweed, may contain up to 30 larvae (Decker 1931).