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Species name

Diabrotica chontalensis Jacoby 1887: 515

 

Type locality

Nicaragua, Chontales

 

Type depository

BMNH, holotype, male, verified

 

Diagnosis

Body length 5.5-6.3 mm, width 2.7-3.0 mm. Head basic color black. Antennae filiform, uniformly yellow or bi- or tricolored, antennomeres 1-3 yellow, antennomeres 4-8 uniformly yellow or gradually infuscated, antennomeres 9-10 light cadmium, antennomere 11 completely light (light cadmium) or dark apically. Antennomere 3 length subequal to length of antennomere 2, 2nd and 3d together equal to half or to less than a half length of 4th antennomere. Male antennal length exceed two thirds of elytron length. Maxillary palpi black, piceous or chestnut, labrum black. Pronotum yellow or mustard yellow, subquadrate or quadrate, nonfoveate or bifoveate with small round foveae, not shagreened. Scutellum black. Elytra yellow or rufous, with three black or metallic black blue bands, basal and middle bands connected together, so two yellow maculae are bounded on elytra basis. Posterior band on each elytron ring-shaped (sometimes opened). Epipleura completely yellow, sutural angle of elytron round, punctation scattered, coarse. Abdomen yellow. Legs yellow or yellow ocher, male protibiae thickened. Aedeagus symmetric,with four internal sac sclerites.

 

Known distribution

Honduras, Nicaragua, Costa Rica

 

Host plants

Unknown

 

Potential problems with identification

Diabrotica chontalensis is very similar to many of the "oculate" species such as D. gratiosa Baly, D. adelpha Harold, D. bioculata Bowditch, D. pulchella (Jacquelin-du-Val) and D. godmani Jacoby. They can be separated by the following features: scutellum of D. chontalensis is black, but yellow in D. bioculata, D. pulchella and D. godmani. The shape of the internal sac sclerites allows to distinguish D. chontalensis from all other species too. Sclerite 4A is an elongate spine. Sclerite 4C is quite remarkable; it is a thick, bent, and pointed hook bearing 4-6 large teeth apically.
Diabrotica chontalensis is particularly similar to D. biannularis Harold and D. spilota Baly. The only feature allowing to distinguish D. chontalensis and D. biannularis is female antennae length. Female antennae are very short in D. biannularis, do not exceed a half of elytron length, in D. chontalensis female antennae exceed two thirds of elytron length. Antennae in D. biannularis are thinner than in D. chontalensis. There is no difference in the internal sac armament of the aedeagus in both species. According to Jacoby (1887) the only feature allowing to distinguish D. chontalensis is "very short second and third joints of the antennae, these joints being of exactly the same length". The antennomeres 2 and 3 are about the same lenght in D. biannularis and D. chontalensis. The antennomere 3 is only slightly longer than 2 in D. spilota, however length may vary between specimens. Sclerite 4C in the internal sac of aedeagus is slightly longer and slender in D. spilota than in D. biannularis and D. chontalensis. Diabrotica spilota is slightly larger than D. biannularis and D. chontalensis. It is possible that all three names belong to the same species. Jacoby (1887) noted about D. spilota: "there are, however, varieties before me in which the spots of the elytra are either transversely or longitudinally connected". Thus D. spilota is most likely an example of an extreme pattern reduction in D. biannularis. Finally, Baly (1886) gave Mexico as a locality for D. spilota. Smith and Lawrence (1967) wrote that "It is possible that the Mexico record given by Baly is a misinterpretation of a [Magd] handwritten label". It seems that Mexico record was true and D. spilota range may be from Mexico to South America.