Feeding site selection in Rhodnius prolixus nymphs, American trypanosomiasis vector.

Area of Science:

• Vector biology
• Insect behavior
• Thermoregulation

Background:

• Kissing bugs transmit American trypanosomiasis.
• Host-seeking behavior in vectors is crucial for disease transmission.
• Thermal cues influence host-parasite interactions.

Purpose of the Study:

• To determine if Rhodnius prolixus nymphs select specific host body regions for feeding.
• To investigate the influence of local skin temperature on nymph feeding site selection.

Main Methods:

• Nymphs of Rhodnius prolixus (instars 1-5) were allowed to feed on anesthetized mice.
• Insect densities were quantified across different body regions (head, abdomen, paws, tail).
• Mouse body temperature was measured using thermal imaging and analyzed with statistical models.

Main Results:

• Nymphs distributed across the host but showed a preference for paws, especially early instars.
• A 1°C increase in local skin temperature correlated with a 9% rise in nymph density.
• Localized cooling was observed in paws and tail post-feeding, indicating blood extraction effects.

Conclusions:

• Rhodnius prolixus nymphs integrate physical accessibility and thermal cues for feeding site selection.
• This behavior likely optimizes blood acquisition in natural settings.
• Understanding these cues can inform vector control strategies for American trypanosomiasis.