[Morphometric analysis of Panstrongylus geniculatus (Heteroptera: Reduviidae) from Caracas City, Venezuela].

Introduction: In recent years, the assassin bug, Panstrongylus geniculatus, has been found infected with Trypanosoma cruzi in rural and urban areas of Caracas, Venezuela. Although historically this insect has been considered a forest species, it has become adapted to more urban artificial environments.

Objective: The presence of sexual dimorphism was determined as an indicator of adaptation to domiciles.

Material And Methods: By Generalized Procrustes Analysis (GPA) and Elliptical Fourier Analysis (EFA), the isometric size and shape of wings, head and pronotums of P. geniculatus was assessed for actively and passively captured specimens. These were collected within domiciles in urban areas of Petare and Altagracia in Caracas City, and from rural or wild environments of Sanare in Andres Eloy Blanco in the state of Lara.

Results: Sexual dimorphism was observed in the Sanare specimens, with female wings consistently larger than male wings. Similarly, female wings and heads from bugs captured in Caracas were smaller than those of female bugs captured in Sanare. No significative differences in the conformation of the pronotum were found between male and female bugs.

Conclusions: Based on the assumption that the sexual dimorphism of bugs is reflected by smaller size in domesticated triatomines than in wild bugs, the conclusion is that Caracas P. geniculatus has become adapted to living indoors. This represents an additional risk factor for the Chagas disease transmission in Caracas.