''Acanthoscelides obvelatus'' is a species of bean bruchid occurring in Mexico, Central America, and northern South America. It and the bean weevil, ''

Acanthoscelides obtectus ''Acanthoscelides obtectus'', the bean weevil, is a species of bruchid beetle. The species was described in 1831 by Thomas Say. Bean weevils feed primarily on the seeds of common beans but also feed on the seeds of peas, vetches, and many o ...

'', are sibling species and occur

sympatrically In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species s ...

throughout ''A. obvelatus range. Both species are morphologically very similar and as a result, ''A. obvelatus'' has been confused with ''A. obtectus'' by several authors. The most notable difference between the two species is that ''A. obtectus'' is multivoltine and apparently does not diapause, while ''A. obvelatus'' is univoltine and has an obligatory imaginal diapause. Due to this fact, unlike ''A. obtectus'', ''A. obvelatus'' is not a pest of stored beans. However, both species can be pests of beans in fields. The main morphological differences between the two species are: the color of the pygidium, femur, and apical antennal segment, which are orange in ''A. obtectus'' but brown-black in ''A. obvelatus''; as well as the shape of the antennae, which have longer and thinner segments in ''A. obvelatus''. The most reliable character is only found in males and concerns the shape of lateral lobes of the

aedeagus An aedeagus (plural aedeagi) is a reproductive organ of male arthropods through which they secrete sperm from the testes during copulation with a female. It can be thought of as the insect equivalent of a mammal's penis, though the comparison ...

, which are smooth and thin in ''A. obtectus'' but sclerified and thick in ''A. obvelatus''. Although both ''A. obtectus'' and ''A. obvelatus'' can be found on any bean species in the ''Phaseolus vulgaris'' group and at various altitudes throughout their range, it appears that ''A. obvelatus'' is predominantly found on '' Phaseolus coccineus'' at higher elevation while ''A. obtectus'' is predominantly found on ''

Phaseolus vulgaris ''Phaseolus vulgaris'', the common bean, is a herbaceous annual plant grown worldwide for its edible dry seeds or green, unripe pods. Its leaf is also occasionally used as a vegetable and the straw as fodder. Its botanical classification, alo ...

'' at lower elevations.

References

{{Taxonbar, from=Q2109449 Bruchinae Beetles of Central America