Attalea palms provide primary habitat to Rhodnius spp., vectors of Trypanosoma cruzi. Flying
from palms, these blood-sucking bugs often invade houses and can infect people directly or
via food contamination. Chagas disease (CD) risk may therefore increase when Attalea
palms thrive near houses. For example, Attalea dominate many deforested landscapes of
eastern Amazonia, where acute-CD outbreaks are disturbingly frequent. Despite this possible
link between deforestation and CD risk, the population-level responses of Amazonian
Attalea and their resident Rhodnius to anthropogenic landscape disturbance remain largely
uncharted. We studied adult Attalea palms in old-growth forest (OGF), young secondary forest
(YSF), and cattle pasture (CP) in two localities of eastern Amazonia. We recorded 1856
Attalea along 10 transects (153.6 ha), and detected infestation by Rhodnius spp. in 18 of 280
systematically-sampled palms (33 bugs caught). Distance-sampling models suggest that, relative
to OGF, adult Attalea density declined by 70?80% in CP and then recovered in YSF.
Site-occupancy models estimate a strong positive effect of deforestation on palm-infestation
odds (?CP-infestation = 4.82?1.14 SE), with a moderate decline in recovering YSF (?YSF-infestation
= 2.66?1.10 SE). Similarly, N-mixture models suggest that, relative to OGF, mean vector
density sharply increased in CP palms (?CP-density = 3.20?0.62 SE) and then tapered in YSF
(?YSF-density = 1.61?0.76 SE). Together, these results indicate that disturbed landscapes may
support between ~2.5 (YSF) and ~5.1 (CP) times more Attalea-dwelling Rhodnius spp. per
unit area than OGF. We provide evidence that deforestation may favor palm-dwelling CD
vectors in eastern Amazonia. Importantly, our landscape-disturbance effect estimates explicitly
take account of (i) imperfect palm and bug detection and (ii) the uncertainties about infestation
and vector density arising from sparse bug data. These results suggest that
incorporating landscape-disturbance metrics into the spatial stratification of transmission risk
could help enhance CD surveillance and prevention in Amazonia.
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