| Název článku: | Hibernace imag chrousta maďalového (Melolontha hippocastani fabr.) (Coleoptera, Scarabaeidae) v podmínkách nížinných borů Česka |
|---|---|
| Číslo: | 3 |
| Rok: | 2022 |
| Autor: | Emanuel Kula |
The forest cockchafer (Melolontha hippocastani Fabr.) is a significant European polyphagous pest in forests. Both the adults and grubs damage trees. During hibernation – from pupation (VII) to leaving the soil (IV), changes in the position of the adults in the soil were observed every month. The grubs of future males finished feeding earlier and pupated. The males hatched earlier than the females. The males’ greater tolerance to cold compared to females was proven under laboratory conditions, which is also related to the shallower depths at which males overwinter. An analysis of the position of the pupae (in July) and the imagoes (in September) indicates that some individuals did not stay at the place of hatching but descended lower if the soil temperature did not drop below 7°C. Hibernating males and females start to ascend toward the surface in January and February, respectively, even at soil temperatures below 5°C. The observed commencements of swarming lead to the conclusion that a necessary condition is an air temperature of >10°C and a soil temperature of >7°C for a period of 7–10 days.
