Clípeo é um bom preditor para eficiência de ingestão, mas não para quantidade de líquido ingerido por formigas (Hymenoptera: Formicidae)

Abstract

Traits are intrinsic and measurable variables in individuals that affect their growth, reproduction and survival. In ants, several traits are related to their diets, but few studies tested the role or function of such traits. In this work, we investigated the association between clypeus and head length with the quantity and efficiency of liquid ingestion by ants. We offered sugary solution, and measured the amount and time of ingestion of 49 ant species. We also measured clypeus length, head length, and body length of each species. Mixed generalized linear models were used to relate the raw and relative to size morphological measurements against the liquid ingestion variables. We also used a model selection approach to select the “best” (more strong association) predictor for each variable. The amount of sugary liquid ingested was related with size of the clypeous, head, body and relative head length, and the best predictor selected was body size. Ingestion efficiency was related to head length, body and relative clypeous length, the latter is the best predictor selected. Ant size is a better predictor of the amount of liquid ingested, but the proportional clypeous better predicts the efficiency of liquid intake. Our work reinforces the importance of testing the ability of traits before define them, for a greater reliability in their answers.