Morphometric characterization of Rhodnius pictipes Stål, 1872 (Hemiptera: Reduviidae) eggs in Eastern Brazilian Amazon populations

Triatomines are potential vectors of Trypanosoma cruzi, the causative agent of Chagas disease, and are prevalent in the Amazon region of Brazil. This study focuses on the detailed morphometry of Rhodnius pictipes eggs to enhance understanding of their biology and support species differentiation. Eggs were obtained from distinct populations in Amapá (AP) and Pará (PA): two from Macapá (AP), one from Santana (AP), and one from Afuá (PA) totaling 60 eggs. External morphological structures were examined using stereomicroscopy and digital calipers, while histological sections were prepared to measure the diameter of exochorial cells using ImageJ® software. Statistical analyses of egg length, diameter, and exochorial cell dimensions were conducted using non-parametric methods due to non-normal data distribution. The results revealed significant differences in egg length among populations, particularly between Afuá and Santana, suggesting potential ecological or genetic influences, while no significant differences were observed in egg diameter, indicating conserved traits within the species. The study contribute to a deeper understanding of R. pictipes morphometry, aiding in species differentiation and potentially informing vector control strategies in regions where Chagas disease is endemic.