Diapause survival and post-diapause performance (i.e., if a queen starts to
lay eggs) of in total 2210 bumblebee queens (Bombus terrestris) were measu
red under different diapause regimes: 5 temperatures (-5, 0, 5, 10 and 15 d
egrees C) in combination with 5 durations of exposure (1, 2, 4, 6 and 8 mon
ths).
The results show that weight at the start of diapause determines to a large
extent whether a queen will be able to survive diapause. Queens with a wet
weight below 0.6 g prior to diapause did not survive, but for those queens
exceeding this threshold a higher pre-diapause weight did not increase the
ir post-diapause performance.
There was no effect of temperature on diapause survival; 76% of the varianc
e in survival could be explained by the duration of the treatment. Neither
temperature nor duration of exposure had an effect on post-diapause perform
ance. The preoviposition period of the queens that laid eggs was also deter
mined. The preoviposition period was affected by both temperature and durat
ion of exposure: the preoviposition period decreased with decreasing temper
ature but also with increasing duration of the treatment.