Detecting seasonal variation in composition of adult Coccinellidae communities

Following its recent global spread, H armonia axyridis ( C oleoptera: C occinellidae), an aphid predator of E ast P alearctic origin, dominated local coccinellid communities. While long‐term trends in this change are well documented, little is known about seasonal changes. 2. Seasonal changes in communities of adult C occinellidae were investigated in central E urope ( P rague), from A pril to N ovember in 2010–2014. The beetles were collected at 2‐weekly intervals by net‐sweeping particular stands of trees ( T ilia spp., A cer spp. and B etula sp.). The numbers of beetles caught were recalculated per unit effort, and average species abundance and community richness, dominance and diversity were calculated for each 2‐week period. 3. Frequencies of 21 established species varied throughout the vegetative season and general trends in this variation were similar in each of the 5 years of this study. In M ay– J une the abundant species was A dalia decempunctata , which was later replaced by H armonia axyridis as the most abundant species in late summer. C occinella septempunctata colonized trees occasionally in summer. This sequence of species substitution occurred every year and was reset during winter. Species richness decreased and dominance increased during the course of each vegetative season. The diversity of the coccinellid community ( S hannon index H ′ ) significantly decreased during the course of the vegetative season. This was caused by a gradual increase in the dominance of H. axyridis , the abundance of which explained 88% of variation in H ′ . 4. The existence of a significant seasonal difference indicates that it is important to take this into consideration when comparing coccinellid communities.