Diabrotica virgifera virgifera LeConte

Species name

Diabrotica virgifera virgifera LeConte 1868: 59

Common name

Western corn rootworm

Type locality

"Fort Wallace"

Type depository

MCZ, lectotype, female, verified

Synonyms

filicornis Horn, 1893: 94 (type locality: New Mexico; type depository: ANSP, holotype, male) (Smith and Lawrence, 1967).

Diagnosis

Body length 4.6-5.9. Body width 2.1-2.7. Head basic coloration from chestnut brown to black, fronsfrons:
the outer part of the head capsule of beetle occupied the space between clypeus and antennal calli
yellow ocher, vertexvertex:
the upper part of the head capsule behind the eyes
chestnut, clypeusclypeus:
the part of the frontal surface of the head capsule between frons and labrum
black or chestnut, labrumlabrum:
the "upper lip" of beetles, a movable sclerite joined under clypeus
black or chestnut. Antennae filiformfiliform:
slender antennae with antennomeres of similar shape
, uniformly brussels brown. Pronotumpronotum:
the notum of the prothorax with highly sclerotized pronotal disc
yellow or sulphur yellow, deeply bifoveate. Scutellumscutellum:
small, usually triangular shield between the bases of elytra
black or amber brown. Elytra green, vittatevittate:
(here) marked by longitudinally extended maculae different from the basic color of elytron
, with one sutural and one humeral vittae (often expanding to cover most of elytra), vittae black, humeral calli black, elytral epipleura completely green. Elytral surface with four distinct sinuatesinuate:
curved in some way
sulci, deepest behind humeral callushumeral callus:
<em>(pl. calli)</em> more or less marked tubercle or knob on the anterobasal angle of elytron
and extending beyond middle, humeral plicae distinct, sutural anglesutural angle:
the posterior angle or apex of the elytron near the suture
of elytra rounded, elytral punctation dense and coarse. Tarsi yellow or yellow ocher. Protibia bicolored, yellow, outer edge with piceous or testaceous line, or almost entirely darkened. Meso- and metatibia uniform black or chestnut. Femora bicolored, yellow or green, outer edge chestnut or piceous. Internal sac of aedeagusaedeagus:
the main sclerotized part of the male genitalia; "aedeagus" is used here instead of "median lobe of aedeagus"
with four scleritessclerites:
(here) the sclerotized hooks, spines or plates in the internal sac
.

Known distribution

Canada, Southwestern USA (AZ, UT) Northwestern USA (ID, MT) Northeastern USA (DE, IN, KY, MI, NJ, NY, OH, PA) Central USA (CO, IL, IA, KS, MN, MO, NE, NM, ND, OK, SD, TX, WV, WI, WY), Northern Mexico (Krysan et al., 1980; Krysan & Smith 1987a)

Host plants

Zea mays L., Setaria P.Beauv, Cucurbitaceae, was observed associated with flowers of Asteraceae, Brassicaceae, apple, tomato and others (Clark et al., 2004).

Potential problems with identification

Diabrotica virgifera virgifera LeConte is most similar to another D. virgifera subspecies, D. v. zeae. The only feature that allows for distinguishing D. v. virgifera from D. v. zeae is distinct black humeral vittae on elytra of D. v. virgifera. In Texas and Northern Mexico, a transitional zone between two subspecies, it is impossible to separate them reliably. The internal sacs of the aedeagusaedeagus:
the main sclerotized part of the male genitalia; "aedeagus" is used here instead of "median lobe of aedeagus"
of both subspecies are essentially the same. Diabrotica v. virgifera is also similar to D. longicornis (Say) and D. barberi Smith & Lawrence. They can be separated by the following features: femora of D. virgifera as a rule bicolored with dark, chestnut or piceous, outer edge, while in D. longicornis and D. barberi femora unicolorous green or flavous; distance from apexapex:
<em>(pl. apices)</em> the far distal end of a structure; opposite of base
to ventral flange of aedeagusaedeagus:
the main sclerotized part of the male genitalia; "aedeagus" is used here instead of "median lobe of aedeagus"
in D. v. virgifera is 1.5 - 2.0 times that of D. longicornis and D. barberi. The shape of the internal sac scleritessclerites:
(here) the sclerotized hooks, spines or plates in the internal sac
(especially sclerite 4B) differentiates all three species well.