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Species name

Diabrotica longicornis Say 1823: 460 as Galleruca

 

Type locality

Arkansa, near the Rocky Mountains.
Colorado, Avondale, Pueblo County [neotype]

 

Type depository

Type has been lost.
MCZ, neotype, male, verified.

 

Diagnosis

Body length 4.6-5.2 mm. Body width 2.0-2.3 mm. Head basic color black. Antennae filiform, bi- or tricolored, antennomeres 1-3 yellow, upper sides darkened, antennomeres 4-11 brussels brown. Maxillary palpi black or amber brown, labrum black or chestnut. Pronotum yellow or sulphur yellow, quadrate, deeply bifoveate, not shagreened. Scutellum piceous or black. Elytra green, yellow or rufous, vittate, with one sutural and one humeral chestnut vittae (sometimes reduced to a variable extent). Elytral epipleura completely yellow, elytra surface with four distinct sinuate sulci, strongest behind the humeral callus and extending beyond the middle. Sutural angle of elytra round, punctation scattered, coarse. Abdomen yellow. Tarsi black or amber brown, tibiae black or piceous. Femora uniformly yellow. Aedeagus symmetric, with four internal sac sclerites.

 

Known distribution

Mexico, USA: AZ, CO, KS, NE, NM, OK, TX, WY (Krysan & Smith, 1987a)

 

Host plants

Cucurbitacea, Cucurbita foetidissima Kunth in H.B.K. (Krysan & Smith, 1987a). Zea mays (L.), perennial grasses (Poaceae), Gutierrezia sarothrae (Pursh) N.L. Britt.&Rusby (Clark et al., 2004)

 

Remarks

Smith and Lawrence (1967) indicated that Say's type series has been lost. In the discussion on this problem they noted that Say's type series of D. longicornis was probably a mixture at least two species: D. virgifera and D. longicornis. Smith and Lawrence indicated that Say's original description is not definitive to separate these two species. In order to preserve two names in the interest of nomenclatorial stability, they proposed the neotype which conforms to Smith and Lawrence's restricted concept of D. longicornis.

 

Potential problems with identification

Diabrotica longicornis (Say) is similar to D. barberi Smith & Lawrence and D. virgifera LeConte. They can be separated by the following features: in D. barberi the head, tibia and tarsi are paler than in D. longicornis; in D. longicornis femora are uniformly yellow or green, femora of D. virgifera as a rule are bicolored with dark, chestnut or piceous outer edge. The shape of the internal sac sclerites (especially sclerite 4B) differentiates all three species very well.