life cycle of Nebria brevicollis and Pterostichus melanarius

[countrybob]

Hi I am trying to find some general info on ground beetles, specifically Nebria brevicollis and Pterostichs melanarius when do they breed? lay eggs? hatch? pupate? are they dormant over winter? if some one could point me in the direction of a suitable book It would be most appreciated, alternatively if you could even post the info if you know that would be great

Cheers,

[Paul mabbott]

A good starting point for anything to do with the Carabidae is Ground Beetles by Trevor Forsythe, Richmond Publishing - Naturalists Handbooks # 8. Like most other books (Lindroth, Luff &c) this concentrates mainly on identification but has summary chapters on life cycle &c..

The species that you mention are relatively long-lived (2-3 years) however their life cycle varies considerably depending on geographic location, weather and habitat.
Most, but not all carabids have three larval stages before brief pupation.
The larger-bodied Pterostichus spp tend to eclose in spring having overwintered as larvae deep in the soil. They are very active in spring-summer before becoming dormant early in autumn (or late summer if hot and dry) and overwintering.
Nebria brevicollis usually emerge in late summer/early autumn (whenever the rains start) and thus their first overwintering is as the adult (imago). However, in some places, their cycle will be the same as Pterostichus, emerging in the spring. Why there is this variation of life cycle has not become apparent to me!

When I get the time I'll look up some more references ....

[countrybob]

cheers will check that book out thanks for that