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Sting nematode | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Nematoda |
Class: | Secernentea |
Order: | Tylenchida |
Family: | Belonolaimidae |
Genus: | Belonolaimus |
Species: | B. longicaudatus |
Binomial name | |
Belonolaimus longicaudatus Rau, (1958 ) | |
Belonolaimus longicaudatus (Sting nematode) is a common parasite of grasses and other plant crops and products. It is the most destructive nematode pest of turf grass, and it also attacks a wide range of fruit, vegetable, and fiber crops such as citrus, cotton, ornamentals, and forage. The sting nematode is a migratory ectoparasite of roots. It is well established in many golf courses and presents a problem in turf management. The sting nematode is only present in very sandy soils. It cannot reproduce in heavier or clay soils.
The genus was originally described by Steiner in 1942 but because of WWII the work was not published until 1949 (B. gracilis, Steiner 1949). Rau (1958) further refined the anatomical description and clarified the genus to note that there were several species, most common of which is B. longicaudatus.
A long nematode compared to other plant parasitic nematodes at 2–3 mm for both the male and female. Description: The lip region is hemispherical, divided bilateral, dorsal, and ventral with grooves into four main lobes (two subdorsal and two subventral) each bearing six or more horizontal striations; two smaller lobes (lateral) with amphid apertures. The lip region is generally set off from the body by deep constriction, but this may be less marked in some populations. The lateral field is marked by a single incisure extending from the base of the lip region to near the tail terminus. The stylet is 100-140 micrometers long; it is very thin and flexible with rounded knobs. The excretory pore is posterior to median bulb. The esophageal gland is lobe-like and extends anteriorly over the intestine. The tail is 115-189 micrometers long with a rounded terminus.
Males: Outline of lip region is more flattened at the sides than in females but arrangement of lobes is similar. The testis is outstretched. Spicules are arcuate with ventral flanges and the distal ends pointed with small apical notches. The gubernaculum is well developed and there is a bursa enveloping the tail.
Female: The vulva is a transverse slit and the vulval lips do not protrude into the vagina which generally has an opposing pair of sclerotized pieces in the lateral view. There are two ovaries which are amphidelphic and outstretched. There is also a spermatheca present. [1]
Sting nematodes are endemic to the southeastern United States and are only capable of reproducing in sandy soils. This fact is the primary limiting factor in this nematodes distribution. The nematode has been reported in all the southeastern gulf states and additionally in Kansas, Oklahoma, New Jersey, Connecticut and Arkansas (Robbins and Barker, 1974). More recently it has been reported as a pest in Californian golf courses due to the transport of infested root stock. It is a major pest of golf courses (Luc et al. 2010) strawberries (Noling 2012) cotton (Crow et al. 2005), corn (Perry and Rhodes, 1982) and citrus (Duncan et al. 1996). The large size of the nematode paired with its ability to repeatedly feed from site to site on the root system of many crops makes this a formidable pest. Reduction of yield and substantial reduction in plant size have been reported for multiple crops.
The life cycle is around 24–28 days with optimum temperature being 25–30 °C (77–86 °F) (Huang and Becker, 1999; Robbins and Barker, 1974). The nematode survives extremes in temperature or drought by moving deeper into the soil (Robbins and Barker, 1974). All vermiform life stages feed on roots and feeding is required to mate and reproduce. Females must be fertilized by a male for viable eggs to be produced (Huang and Becker, 1999).
The nematode feeds as an ectoparasite, most often at the site of cell division and elongation of the root (Huang and Becker, 1997). The long stylet allows the nematode to feed on the inner cortex and endodermis. The feeding at root tips causes root abbreviation and stunting (Crow and Han, 2005). In corn roots swelling at root tips may occur due to repeated attempts by the plant to produce new root branches. In cotton the feeding may cause lesions which eventually cause root girdling.
Historically, methyl bromide has been the chemical most often used to control sting nematodes however its scheduled removal from the market on January 1, 2015 (Rosskoph et al. 2005) has led to testing of new chemicals and biopesticides. Endospores of Pasteuria sp. have been tested on turf grass with mixed success (Luc et al. 2010). The extensive use of various chemicals in the strawberry and turf grass industries offers insight into the future of chemical control of nematodes which will surely involve a multifaceted approach. The leading candidate for most control is Telone (Noling 2012). Crop rotation is generally viewed as economically prohibitive due to the pests' wide host range.
Host list from: Noling, J.W. (2012) "Nematode management in strawberries". Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida.
* indicates a variable host response to geographic/physiologic races of sting nematode.
Bluegrass, bentgrass, centipedegrass, St. Augustine grass, bahiagrass, Bermuda grass, pangola grass, fescue, corn, oats, millet, rye, wheat, peanut*, clovers, cotton, soybean, barley, Lespedeza.
Beans, carrots, celery, sweet corn, cowpea, eggplant, onion*, pea, citrus*, strawberry*, cabbage*, cantaloupe, cauliflower, endive, lettuce, tomato, turnip, okra*, cucumber*, snap bean, squash, pepper, sweet potato*, potato.
Sesbania, sorghum/Sudan grass, iron clay pea, mung bean, pigeon pea, hairy vetch, joint vetch.
Use of poor or non-host cover crops within the rotation sequence may in some cases offer an effective approach to nematode control. Four leguminous cover crops adaptable for managing soil populations of sting or root-knot nematode include Iron Clay cowpea ( Vigna unguiculata cv. 'Iron Clay'), sunn hemp ( Crotalaria juncea ), hairy indigo ( Indigofena hirsuta ) and American joint vetch ( Aeschynomene americana ). Sorghum is also a popular cover crop restoring large amounts of soil organic matter, but is a good host for sting nematode but not root-knot. Most of the small grains commonly used as winter cover crops in central and north Florida, such as rye, barley, wheat, or oats, can support limited reproduction of root-knot nematodes. [2]
Crabgrass, Bermuda grass, fescues, lambsquarter*, cudweed, dog fennel, Johnson grass, beggarweed, ragweed, wild carrot, Spanish needle.
Tobacco, watermelon*, asparagus, hot pepper, sunn hemp, hairy indigo, Crotalaria , velvet bean*, Bidens , horseweed, buckhorn plantain, pokeweed, sandbur, cocklebur*, jimson weed, sorrel, wild garlic, Jerusalem oak.
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Root-knot nematodes are plant-parasitic nematodes from the genus Meloidogyne. They exist in soil in areas with hot climates or short winters. About 2000 plants worldwide are susceptible to infection by root-knot nematodes and they cause approximately 5% of global crop loss. Root-knot nematode larvae infect plant roots, causing the development of root-knot galls that drain the plant's photosynthate and nutrients. Infection of young plants may be lethal, while infection of mature plants causes decreased yield.
Radopholus similis is a species of nematode known commonly as the burrowing nematode. It is a parasite of plants, and it is a pest of many agricultural crops. It is an especially important pest of bananas, and it can be found on coconut, avocado, coffee, sugarcane, other grasses, and ornamentals. It is a migratory endoparasite of roots, causing lesions that form cankers. Infected plants experience malnutrition.
Rotylenchulus reniformis, the reniform nematode, is a species of parasitic nematode of plants with a worldwide distribution in the tropical and subtropical regions.
Paratrichodorus minor is a species of nematode in the family Trichodoridae, the stubby-root nematodes. It occurs in tropical and subtropical regions of the world. It damages plants by feeding on the roots and it is a vector of plant viruses. It is a pest of some agricultural crops.
Pratylenchus brachyurus is a plant parasitic nematode.
Pratylenchus zeae is a plant-pathogenic nematode found on potatoes, maize, cereal, tobacco, coffee, blackberry, and found most often on sugarcane.
Meloidogyne acronea, the African cotton root-knot nematode or African cotton root nematode, is a plant pathogenic nematode affecting pigeonpeas. It is also an invasive species. The roots and surrounding soils of cereals, grasses, and Gossypium spp. provide habitat for this organism. M. acronea was confirmed as a potentially problematic pest of cotton, Gossypium hirsutum cv. Makoka, which was proven through pot experiments.
Xiphinema americanum, the American dagger nematode, is a species of plant pathogenic nematodes. It is one of many species that belongs to the genus Xiphinema. It was first described by N. A. Cobb in 1913, who found it on both sides of the United States on the roots of grass, corn, and citrus trees. Not only is Xiphinema americanum known to vector plant viruses, but also X. americanum has been referred to as "the most destructive plant parasitic nematode in America", and one of the four major nematode pests in the Southeastern United States.
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Heterodera sacchari, the sugarcane cyst nematode, mitotic parthenogenic sedentary endoparasitic nematode. This plant-parasitic nematode infects the roots of sugarcane, and the female nematode eventually becomes a thick-walled cyst filled with eggs. Aboveground symptoms are species specific and are similar to those caused by other Heterodera species. Symptoms include: stunted and chlorotic plants, and reduced root growth. Seedlings may be killed in heavily infested soils.
Belonolaimus is a genus of nematodes. They are known commonly as sting nematodes. They are ectoparasites that feed on plant roots, sometimes becoming agricultural pests. They are found in the United States, Mexico, and Puerto Rico.
Pratylenchus is a genus of nematodes known commonly as lesion nematodes. They are parasitic on plants and are responsible for root lesion disease on many taxa of host plants in temperate regions around the world. Lesion nematodes are migratory endoparasites that feed and reproduce in the root and move around, unlike the cyst or root-knot nematodes, which may stay in one place. They usually only feed on the cortex of the root. Species are distinguished primarily by the morphology of the stylets.
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Helicotylenchus is a genus of nematodes in the family Hoplolaimidae. They are known generally as spiral nematodes. They are found worldwide because they can live and survive in a wide range of habitats. They are among the most common parasitic nematodes of plants; found in corn, bananas, grass, soybeans.
Hoplolaimus galeatus is a plant pathogenic nematode.
Heterodera zeae, the corn cyst nematode (CCN), is a plant parasitic nematode that feeds on Zea mays (maize/corn). The CCN has a limited economic impact worldwide due to its high soil temperature requirements.
Dolichodorus is a genus of nematodes known commonly as awl nematodes. They are distributed worldwide. They are ectoparasites of plant roots, and some are pests of agricultural crops.
Trichodorus is a genus of terrestrial root feeding (stubby-root) nematodes in the Trichodoridae family (trichorids), being one of five genera. They are economically important plant parasites and virus vectors.