Median survival times (TL₅₀) of stingless bee workers (<i>Melipona quadrifasciata anthidioides</i>) reared on imidacloprid-contaminated diets containing increasing doses of the insecticide.

<p>Median survival times (TL₅₀) of stingless bee workers (<i>Melipona quadrifasciata anthidioides</i>) reared on imidacloprid-contaminated diets containing increasing doses of the insecticide.</p

Survival plots of stingless bee workers (<i>Melipona quadrifasciata anthidioides</i>) reared on imidacloprid-contaminated diets containing increasing doses of the insecticide.

<p>The survival curves of workers bees exposed to imidaclorpid doses between 0.28 e 28 µg a.i./bee were not significantly different and were therefore coded with the same color (i.e., blue).</p

Volume of the mushroom bodies in the brains of the stingless bee workers (<i>Melipona quadrifasciata anthidioides</i>) reared on imidacloprid-contaminated diets during the larval period.

<p>The symbols represent means and standard error.</p

Effect of larva ingestion of imidaclorprid-contaminated diet on the distance walked (A), walking velocity (B), resting time (C) and number of stops in the arena (D) of individual adult workers (at different ages following emergence) of the stingless bee <i>Melipona quadrifasciata anthidioides</i>.

<p>The symbols represent means and standard error.</p

Serial histological sections of the brain of a stingless bee worker (<i>Melipona quadrifasciata anthidioides</i>).

<p> The edges of the mushroom bodies are delineated with white lines. The sections are ordered such that A, D and H represent the beginning, middle and end of the structure, respectively. MC, median calyx; LC, lateral calyx; VL, vertical lobe; MB, mushroom bodies; Oce, oceli; Ant, antennal lobe; OL, optic lobe; CB, central body. Bar: 500 µm.</p