The finding of
Panstrongylus geniculatus
nymphs inside a house in northeastern Antioquia, Colombia, and the reports
related to their increasing presence in homes suggest the need for surveillance
methods for monitoring the invasion processes. We analyzed the morphological
differences between a wild population and its laboratory descendants, using
the techniques of geometric morphometry, with the idea that such differences
might parallel those between sylvatic and synanthropic populations. The
analyses over five generations showed differences in size but not in shape.
Head size and wing size were both reduced from sylvatic to laboratory populations,
but the decrease in head size occurred only up to the second generation
while the decrease in wing size proceeded up to the fifth generation. In
contrast, although a decrease in sexual size dimorphism has been proposed
as a marker of colonization in human dwellings, we did not detect any significant
loss of dimorphism between sexes of
P. geniculatus
over the five generations studied. We conclude that size changes may have
a physiological origin in response to a change of ecotopes, but more than
five generations may be required for the expression of permanent morphological
markers of human dwellings colonization.