Relative expression levels of genes encoding dopamine receptors.

(A) Big Dop1, (B) BigDop2, (C) BigDop3, and (D) BigDopEcR. Numbers in bars indicate numbers of samples examined. Significant differences between castes were examined by Mann-Whitney U-test.</p

Data of behavioral activities in gynes with flupentixol injections.

Data of behavioral activities in gynes with flupentixol injections.</p

Effects of dopamine injection into 7–9-day-old workers on behavioral activities.

(A) Locomotor activity, (B) light avoidance, and (C) proportion of flying individuals. Numbers in parentheses indicate numbers of samples examined. Differences among groups were analyzed by the Kruskal-Wallis test (**P ++P #P < 0.05). DA: dopamine.</p

Effects of dopamine receptor antagonist flupentixol injection into 7–9-day-old gynes on behavioral activities.

(A) Locomotor activity, (B) light avoidance, and (C) proportion of flying individuals. Numbers in parentheses indicate numbers of samples examined. Significant correlations with flupentixol concentrations were tested by logistic regression test (#P < 0.05). Flu: flupentixol.</p

Biogenic amine levels in the brain in workers and gynes.

Biogenic amine levels in the brain in workers and gynes.</p

Effects of dopamine receptor antagonist flupentixol injection into 7–9-day-old gynes on mating acceptance.

Numbers in parentheses indicate numbers of samples examined.</p

Caste differences in behavioral activities in bumble bees.

(A) Locomotor activity, (B) light avoidance, and (C) proportion of flying individuals. Numbers in parentheses indicate numbers of samples. Significant differences between castes at the same age were examined by Mann-Whitney U-test (*P P < 0.01).</p

Biogenic amine levels in the brain in workers and gynes in bumble bees.

(A) Dopamine, (B) serotonin, (C) tyramine, and (D) octopamine. Numbers in bars indicate numbers of samples examined. Significant differences between castes were examined by Mann-Whitney U-test.</p

Relative expression levels of genes encoding dopamine receptors in the brain in workers and gynes.

Relative expression levels of genes encoding dopamine receptors in the brain in workers and gynes.</p

Data of behavioral activities in workers and gynes.

Data of behavioral activities in workers and gynes.</p