Chaetocnema confinis Crotch

Clark, Shawn M., Lillrose, Tiffany & Belo Neto, Luiz A., 2013, Leaf Beetles of the Cayman Islands (Coleoptera: Chrysomelidae), Insecta Mundi 2013 (279), pp. 1-41 : 21-22

Chaetocnema confinis Crotch

( Figure 13)

Chaetocnema confinis Crotch 1873: 75 .

Chaetocnema flavicornis LeConte 1878: 418 .

Chaetocnema perplexa Blake 1941: 177 . NEW SYNONYMY.

Chaetocnema etiennei Jolivet 1979: 641 .

Diagnosis. The body of this species is small (about 1.5 mm long), the hind femora are greatly enlarged, the alutaceous vertex has a few punctures near each eye but is medially impunctate, and the elytra are striately punctate and not pubescent. This combination of characters is not found in any other species of Chrysomelidae known to occur in the Cayman Islands.

Material examined. Cayman Islands, Grand Cayman, George Town, Green Thumb Nur., 7-XII-2009, N. Hansraj (1, FSCA).

Extralimital distribution. Blake (1941) reported C. perplexa (here regarded as a synonym of C. confinis ), or beetles closely resembling both C. perplexa and mainland North American C. confinis , from Bermuda, Cuba, Hispaniola, Jamaica, and Puerto Rico. In recent years, C. confinis has apparently spread to many areas around the world, especially in tropical latitudes ( Jolivet 2004).

Plant associations. This beetle species feeds on various plants in the family Convolvulaceae ( Clark et al. 2004) .

Comments. Blake (1941) described C. perplexa , distinguishing it from continental North American C. confinis , based solely on minor differences in the aedeagus. She stated that the two taxa are externally indistinguishable. She also stated that females, unassociated with males, are frequent in the West Indies. Entirely based on the West Indian distribution, we believe these unassociated females to be more likely C. perplexa than C. confinis . In more recent years, beetles reported to be C. confinis have apparently spread to far-flung parts of the world; however, populations in these new areas are parthenogenetic, entirely without males ( Jolivet 2004). It seems more likely that these populations originated from the West Indies, where males are rare and perhaps even absent from some islands, than from mainland North America where both sexes are common. Whatever the case, Jolivet (2004) suggested that the two names are synonymous, in spite of the minor aedeagal differences that have been reported. We concur with this view and hereby formalize the synonymy, although recognizing that a careful taxonomic reevaluation may someday result in reinstatement of the two names.