Phenology and Distribution of Some Pterostichus (Coleoptera: Carabidae) of Eastern Canada

• Published in: Journal of the New York Entomological Society 1970-12, Vol.78 (4), p.215-236
• Main Author: Barlow, C. A.
• Format: Article
• Language: English
• Subjects: Beetles; Eggs; Entomology; Female animals; Gravid females; Insect larvae; Ova; Ovaries; Population ecology; Species
• ISSN: 0028-7199; 1937-2361

The seasonal occurrence and ecological distribution of five Pterostichus species were analyzed by pitfall trapping. Two species, melanarius and coracinus, exhibited one activity-abundance cycle per year which extended from May or June to September or October. Reproduction occurred throughout most of this cycle. These species apparently overwinter both in the larval stage and as teneral adults. The remaining species, pensylvanicus, lucublandus, and mutus, each showed two cycles per year. The first extended from April to July during which reproduction occurred. A period of decreased abundance and activity in midsummer was followed by a second cycle of varying length and intensity between September and November. This was a non-productive cycle composed of progeny of the spring reproductive period. These three species apparently overwinter almost entirely as teneral adults. P. pensylvanicus was taken mostly in wooded areas, while lucublandus occurred almost entirely in non-forested areas. The remaining species were found both in forest and open areas: coracinus principally in forest or forest edge, mutus also mainly in forest but also in some open areas, and melanarius mostly in grassland with some woods. No temporal or sexual difference in distribution was noted.