engleski

The abundance and distribution of the ground beetles Pterostichus melanarius Ill. and Harpalus rufipes De Geer in corn fields in Croatia

Introduction: Ground beetles have often been used to study the ecological effects of different agricultural measures. Methods: The ground beetle fauna was studied during the whole growing season by placing pitfall traps in each of the 9 corn fields in 2004 and the 13 corn fields in 2005. Traps were checked biweekly. All ground beetles were identified. Pterostichus melanarius and Harpalus rufipes, two common species, were analysed to determine species distribution and abundance. Results: The total number of all ground beetle specimens was 3322 in 2004 and 1064 in 2005 respectively. The number of specimens per locality ranged between 0 and 1482 in 2004 and between 4 and 346 in 2005. P.melanarius has been found in 8 out of 9 localities in 2004 and in all 13 localities in 2005. The dominance of this species varied from 7.69 to 36% in 2004 and from 5 to 95% in 2005. According to the frequency in both years it is constant species. H. rufipes has been found on all localities in 2004 and in 12 out of 13 localities in 2005. The dominance of this species varied from 47 to 73% in 2004 and between 1.56 and 74.45% in 2005. It is constant species with frequency index of 71.8%, and in 2005 it is accessory with frequency index of 44%. Conclusions: P. melanarius was designated as eudominant on 17 fields and H.rufipes on 19 out of 22 investigated fields. Both species could be described as constant or accessory at all investigated localities.

biodiversity; ground beetles; maize; Pterostichus melanarius; Pseudophonus rufipes

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