Microgeographic spatial structuring of Triatoma infestans (Hemiptera: Reduviidae) populations using wing geometric morphometry in the Argentine Chaco.

GASPE MS; SCHACHTER-BROIDE J; GUREVITZ JM; KITRON U; GURTLER RE; DUJARDIN JP

JOURNAL OF MEDICAL ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2012 vol. 49 p. 504 - 514

0022-2585

ABSTRACT We investigated the occurrence of spatial structuring in Triatoma infestans (Klug)(Hemiptera: Reduviidae) populations 12 yr after the last community-wide insecticide sprayingcampaign in rural Pampa del Indio, in the Gran Chaco of northeastern Argentina. In total, 172 maleand 149 female right wings collected at 16 georeferenced sites with at least 10 individuals of the samesex were analyzed using geometric morphometry. Mean female body length and wing centroid size(CS) were signiÞcantly larger than for males. Log-transformed CS and length were signiÞcantly andpositively correlated both for males and females. Males collected in domiciles had signiÞcantly smallerCS than those collected in peridomestic structures both closed (kitchens or storerooms) or open(chicken coops), in agreement with our previous results elsewhere in the dry Argentine Chaco.Female wing CS was not signiÞcantly different between ecotopes. Wing shape analyses showed theoccurrence of signiÞcant geographic structuring in males and females combined and in males only.Male wings showed a strong association between Mahalanobis distance and geographic distance. Ingeneral, Mahalanobis distances were signiÞcantly different between collection sites located
4 kmapart. For collection sites located 4 km apart, the greater the geographic distance the larger thedifference in wing shape variables.Amongfemales, only a partial correspondence between geographicgroups and Mahalanobis distances was recorded. The strong spatial structuring found in T. infestanspopulations may be useful for the identiÞcation of putative reinfestation sources after vector controlinterventions.