Morphological Variants of Aedes aegypti Collected from the Leeward Island of Antigua

Abstract

Nineteen Aedes aegypti larvae were collected in rural Antigua, West Indies, from an 18-liter plastic bucket. The location was in a rural area at the northern end of Antigua bordering the coast of Dickenson Bay and approximately 50 m south of Halcyon Cove Beach (17 degrees 09'42.54"N, 61 degrees 50'44.50"W; elevation 16 m). Atypical morphology was noted in larvae and 3 reared adult females. Fourth instars showed a reduction in length of the lateral hair on the saddle (seta 1-X) with measurements ranging from 0.36 to 0.57 the length of the saddle. Two atypical female specimens displayed an abundance of dull white to gold scales that blanketed the abdomen. A 3rd specimen bore fine, golden scales on the mesonotum and bronze scales on the vertices of the head. These adult specimens demonstrated morphological characteristics that closely parallel described mutations, although the genetic basis for these characters was not confirmed. The remaining adults in the collection were morphologically typical. Adults and larvae were compared to field populations from Florida, Bahamas, and Antigua, as well as to the Rockefeller strain maintained at Rutgers University.