Diabrotica

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Diabrotica
Western corn rootworm.jpg
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Chrysomelidae
Subfamily: Galerucinae
Tribe: Luperini
Genus: Diabrotica
Chevrolat in Dejean, 1836 [1]
Species

Diabrotica balteata
Diabrotica barberi
Diabrotica beniensis
Diabrotica cristata
Diabrotica curvipustulata
Diabrotica dissimilis
Diabrotica elegantula
Diabrotica emorsitans
Diabrotica graminea
Diabrotica hispanolae
Diabrotica lemniscata
Diabrotica linsleyi
Diabrotica longicornis
Diabrotica milleri
Diabrotica nummularis
Diabrotica occlusa
Diabrotica porracea
Diabrotica scutellata
Diabrotica speciosa
Diabrotica tibialis
Diabrotica trifasciata
Diabrotica undecimpunctata
Diabrotica virgifera
Diabrotica viridula

Diabrotica is a widespread genus of beetles, sometimes referred to as cucumber beetles or corn rootworms, in the family Chrysomelidae. Members of this genus include several destructive agricultural pest species.

Range[edit]

Corn rootworms are one of the most economically destructive predators of maize in the United States.[2] The western corn rootworm, D. virgifera virgifera, and the northern corn rootworm, D. barberi, are the most devastating rootworm species in Iowa, a major corn-growing area. A third species, the southern corn rootworm, D. undecimpunctata howardi, causes much economic damage in other regions.[3] Corn rootworm larvae can destroy significant acreage of corn if left untreated. In the United States, current estimates show 30 million acres (12×10^6 ha) of corn, out of 80 million total are infested with corn rootworm. Estimates of economic damage to corn growers from the pest are about $1 billion.[4]

Diabrotica was unknown in Europe until the late 1990s and was forbidden even in laboratories because of the difficulty in eliminating it with insecticides. It appears to have entered Europe from the US in large numbers during the Yugoslav wars and is especially widespread around US military airports, whose planes were likely to have transported the pest. It has since spread primarily in Italy, France and Germany.[5]

Species[edit]

Several species of Diabrotica are significant pests in North America, including:

D. undecimpunctata[edit]

Adults of D. undecimpunctata are greenish-yellow with six large black spots on each elytron. They are about .2 inches (5.1 mm) long. The larvae are yellowish and wormlike.

D. virgifera[edit]

Main article: Diabrotica virgifera

Adult rootworms are about .25 inches (6.4 mm) long. Western corn rootworm adults are yellowish with a black stripe on each wing cover. Northern corn rootworm beetles are solid in color and vary from light tan to pale green.[6] The eggs are deposited in the soil during the summer, and are football-shaped, white, and less than 0.004 inches (0.10 mm) long. Larvae hatch in late May or early June and begin to feed on corn roots. Newly hatched larvae are small, less than .125 inches (3.2 mm) long, white worms. They go through three larval instars, pupate in the soil and emerge as adults in July and August, with one generation per year. Larvae have brown heads and a brown marking on the top of the last abdominal segment, giving them a double-headed appearance. Larvae have three pairs of legs, but these are not usually visible without magnification. After feeding for several weeks, the larvae dig a cell in the soil and molt into the pupal stage. The pupal stage is white and has the basic shape of the adult.

References[edit]

  1. ^ "Diabrotica". Integrated Taxonomic Information System. 
  2. ^ Wright, R.; Meinke, L.; Jarvi, K. (July 1999). "Corn Rootworm Management". University of Nebraska. Retrieved 2007-02-03. 
  3. ^ Staff, Purdue University Extension Service. Corn Rootworms
  4. ^ Marra, M.C., Piggott, N.E., & Goodwin, B.K. (2012). The impact of corn rootworm protected biotechnology traits in the United States. AgBioForum, 15(2), 217-230
    Erin W. Hodgson, Utah State University Extension and Utah Plant Pest Diagnostic Laboratory. Western corn rootworm
  5. ^ Miller N et al. Multiple Transatlantic Introductions of the Western Corn Rootworm Miller, N.; Estoup, A; Toepfer, S; Bourguet, D; Lapchin, L; Derridj, S; Kim, K. S.; Reynaud, P; Furlan, L; Guillemaud, T (2005). "Multiple Transatlantic Introductions of the Western Corn Rootworm". Science 310 (5750): 992. doi:10.1126/science.1115871. PMID 16284172.  edit
    Kiss, J. Edwards et al. (2005). "Monitoring of western corn rootworm (Diabrotica virgifera virgifera LeConte) in Europe 1992-2003.". In Vidal, Stefan; Kuhlmann, Ulrich; Edwards, C. Richard. Western Corn Rootworm: Ecology and Management (CABI). ISBN 978-0-85199-070-5. 
  6. ^ Wright, Meinke & Jarvi 1999.

External links[edit]