Caste composition of 31 Vespa velutina colonies collected in France between April and December from 2012 to 2014.

Colonies typically produce only workers until the end of summer (end of August) and then produce males and new queens [24, 27]. In the populations sampled in this study, males were reared before the reproductive period. The numbers of workers, gynes (new reproductive queens), and males found in each colony are provided, as are the percentages of males (of all adults) and of diploid males (of all randomly sampled males). Q+: queenright colonies; Q-: queenless colonies.