User:FlyingToaster/sandbox6
| Army worm Fall army worm | |
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| Army worm larvae | |
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| Army worm larvae feeding on host plant | |
| Scientific classification | |
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| Species: | S. frugiperda
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| Binomial name | |
| Spodoptera frugiperda | |
Cite error: The <ref> tag has too many names (see the help page). Army worms are considered some of the most destructive pests in the world. If allowed to breed, the worms can lay waste to entire crops within days, only moving on to the next when their food source is wiped out (hence "army"). Their presence is difficult to detect before the worms begin their devastation, as they move to new areas during the cooler temperatures of night.[1]
- not used:When the caterpillars near maturity, approximately 1-1/2" to 2" inches in length,
Distribution
[edit]The fall armyworm is native to the tropical regions of the western hemisphere from the United States to Argentina. It normally hibernates in the United States only in southern Florida and southern Texas. The fall armyworm is a strong flier, and disperses long distances annually during the summer months. It is recorded from virtually all states east of the Rocky Mountains. However, as a regular and serious pest, its range tends to be mostly the southeastern states. [2]
Life cycle
[edit]The life cycle is completed in about 30 days during the summer, but 60 days in the spring and autumn, and 80 to 90 days during the winter. The number of generations occurring in an area varies with the appearance of the dispersing adults. In Minnesota and New York, where fall army worm moths do not appear until August, there may be but a single generation. The number of generations is reported to be one to two in Kansas, three in South Carolina, and four in Louisiana. In coastal areas of north Florida, moths are abundant from April to December, but some are found even during the winter months. [3]
The army worm's eggs are dome shaped, with a flat base and upward curves that point to an apex. It measure about 0.4 mm in diameter and 0.3 mm in height. The number of eggs per mass varies considerably but is often 100 to 200. Total egg production per female averages about 1500, with a maximum of over 2000. The eggs are sometimes deposited in layers, but most eggs are spread over a single layer attached to foliage. The female also deposits a layer of grayish scales between the eggs and over the egg mass, imparting a furry or moldy appearance. Duration of the egg stage is only two to three days during the summer months. [4]
Larvae
[edit]Pupation normally takes place in the soil at a depth 2 to 8 cm. The larva constructs a loose cocoon, oval in shape and 20 to 30 mm in length, by tying together particles of soil with silk. If the soil at this point is too hard, the larvae may web together natural debris such as leaves to form a cocoon on the surface of the soil. The pupa is reddish brown, and measures 14 to 18 mm in length and about 4.5 mm in width. The pupal stage of fall armyworm cannot withstand protracted periods of cold weather. For example, Pitre and Hogg (1983) studied winter survival of the pupal stage in Florida, and found 51 percent survival in southern Florida, but only 27.5 percent survival in central Florida, and 11.6 percent survival in northern Florida.[4]
The moths have a wingspan of 32 to 40 mm. The forewings of males are shaded grey and brown, with a triangular white spot at the tip, near the center of the wing. Females' forewings are uniform grey or brown. Army moth hind wings are iridescent silver-white in both sexes. After a preoviposition period of three to four days, the female normally deposits most of her eggs during the first four to five days of life. However, some oviposition occurs for up to three weeks. Duration of adult life is estimated to average about 10 days, with a range of about seven to 21 days.
Host plants
[edit]Army worms display a very wide host range, with over 80 plants recorded, but clearly prefer grasses. The most frequently consumed plants are field corn and sweet corn, sorghum, Bermudagrass, and grass weeds such as crabgrass. Once the larvae are numerous, they defoliate the host plant and disperse, consuming all other plants in their path. Field crops at risk include alfalfa, barley, Bermuda grass, buckwheat, cotton, clover, corn, oat, millet, peanut, rice, ryegrass, sorghum, sugarbeet, sudangrass, soybean, sugarcane, timothy, tobacco, and wheat. Among vegetable crops, only sweet corn is regularly damaged, but others are attacked occasionally. Other crops sometimes injured are apple, grape, orange, papaya, peach, strawberry and a number of flowers. [5]
2009 infestation in West Africa
[edit]STAR radio in Liberia reported in January 2009 that Zota District in Bong County had been invaded by army worms, which had consumed vegetation and polluted creeks and running water.[6][7]
As of 27 January 2009, they are moving to Guinea and Sierra Leone.[7]
As of 2 February 2009, the plague is indeed thought to be of an entirely unknown species, not the army worm.[7]
References
[edit]- ^ [www.sel.barc.usda.gov/lep/spodoptera/spodoptera.html "Lepidoptera: Noctuidae"]. US Department of Agriculture. Retrieved 2008-10-19.
{{cite web}}: Check|url=value (help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ "common name: fall armyworm". University of Florida. Retrieved 2008-10-19.
- ^ Vickery, RA (1929). "Studies of the fall armyworm in the Gulf coast region of Texas". USDA Technical Bulletin (138): 63.
- ^ a b Pitre, HN (1983). "Development of the fall armyworm on cotton, soybean and corn". Ournal of the Georgia Entomological Society (18): 187–194.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Foster, RE (1989). "Strategies for protecting sweet corn ears from damage by fall armyworms (Lepidoptera: Noctuidae) in southern Florida". Florida Entomologist. 72: 146–151. doi:10.2307/3494981. JSTOR 3494981.
{{cite journal}}: CS1 maint: location (link) - ^ STAR radio Liberia: Caterpillar invasion: Government declares Zota District emergency zone
- ^ a b c "Liberia worms trigger emergency". BBC. Retrieved 2009-01-27. Cite error: The named reference "BBC" was defined multiple times with different content (see the help page).