Diabrotica undecimpunctata tenella LeConte

Species name

Diabrotica undecimpunctata tenella LeConte 1858: 88

Common name

Western cucumber beetle

Type locality

California, Fort Yuma

Type depository

MCZ, lectotype, male, verified

Diagnosis

Body length 4.8-7.1 mm. Body width 2.7-3.8 mm. Head basic color black. Antennae filiformfiliform:
slender antennae with antennomeres of similar shape
, bi- or tricolored, antennomeres 1-3 sulphur yellow, antennomeres 4-11 yellow ocher. Maxillary palpi yellow or yellow ocher, labrumlabrum:
the "upper lip" of beetles, a movable sclerite joined under clypeus
black or chestnut. Pronotumpronotum:
the notum of the prothorax with highly sclerotized pronotal disc
yellow or sulphur yellow, subquadrate, bifoveate, with small round foveae, shagreened with minute wrinkles. Scutellumscutellum:
small, usually triangular shield between the bases of elytra
black or amber brown. Elytra green, yellow or rufous, with 12 round black maculae. Elytral epipleura completely yellow, sutural anglesutural angle:
the posterior angle or apex of the elytron near the suture
of elytra round, punctation scattered, fine. Abdomen yellow. Tarsi black or amber brown, tibiae bicolored yellow, outer edge with piceous or testaceous line, or extensively darkened. Femora bicolored, yellow, darkened with black or brown from 1/2 to 2/3. Aedeagusaedeagus:
the main sclerotized part of the male genitalia; "aedeagus" is used here instead of "median lobe of aedeagus"
symmetric, with four internal sac scleritessclerites:
(here) the sclerotized hooks, spines or plates in the internal sac
.

Known distribution

USA: AZ, CA, NV, UT

Host plants

Dahlia Cav., Ericameria nauseosa (Pall. ex Pursh) G.L. Nesom & Baird., lettuce, beet, Citrullus vulgaris Schrad. ex Eckl. & Zeyh., Cucumis melo L., C. sativus L., Cucurbita L., Medicago sativa L., bean, pea, cotton, Hordeum sativum Jess., Sorghum L., corn (Zea mays L.), apricot, peach, Solanum elaeagnifolium Cav., S. tuberosum L., Agave shawii Engelm., Cucurbita mixta Pang., Prosopis L. (Clark et al., 2004)

Potential problems with identification

Diabrotica undecimpunctata tenella LeConte can be separated from other subspecies by the following features: abdomen is yellow in D. undecimpunctata tenella, entirely black in D. undecimpunctata undecimpunctata and black in the middle in D. undecimpunctata duodecimnotata; legs, usually only femora, partly pale in D. undecimpunctata tenella, but entirely black in D. undecimpunctata undecimpunctata; spots on elytra in D. undecimpunctata tenella are smaller than in D. undecimpunctata undecimpunctata and D. undecimpunctata howardi. Diabrotica undecimpunctata tenella is smaller and slender than Diabrotica undecimpunctata howardi.