Long‐term changes in communities of native coccinellids: population fluctuations and the effect of competition from an invasive non‐native species

Abstract

Abstract. 1. We assessed the changes in abundance and community composition of native species of coccinellids (Coleoptera: Coccinellidae) on deciduous trees that occurred between 1970s and 2010s, in the Czech Republic.2. As the composition of adult communities varies with host plant and season, coccinellids were sampled in May-June from Acer, Betula and Tilia trees using a standardised sweeping method. This was done before (1976)(1977)(1978)(1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)) and after (2011)(2012)(2013)(2014)) the arrival of Harmonia axyridis in 2006, with interim samples from a period immediately before it arrived in the Czech Republic (2002Republic ( -2006.3. Twenty-one native species were identified in the total sample of 2674 adults. The abundance of Adalia bipunctata, Coccinella quinquepunctata and Propylea quatuordecimpunctata decreased over the whole period sampled. Declines in abundance of these species were already evident prior to the arrival of H. axyridis. Recent declines in Adalia decempunctata and Calvia quatuordecimguttata followed the arrival H. axyridis. Their abundance was increasing prior to the arrival of H. axyridis, but decreased following its invasion and the latter species might have affected their decline. The abundance of only one species, Calvia decemguttata, increased. Although the abundance of many species decreased and the frequency of some species varied, the diversity of native coccinellid populations (Shannon index) was similar over the 40 years of this study.4. The changes in species composition can in part be attributed to H. axyridis, the role of other factors (e.g. climate change, habitat degradation) in the long-term fluctuations in abundance of coccinellids should be considered in future assessments.

Biodiversity and predatory potential of coccinellids of rice ecosystems

“…Coccinellid communities usually consist of a few dominant and several less common and even rare species. Some communities, including those in agricultural crops, are species poor, although abundant in terms of the number of individuals (Honek et al, 2016). Changes in coccinellid communities in rice ecosystem are due to agricultural practice, habitat deterioration, invasion of non-native species and climate change (Honek et al, 2017).…”

Native ladybird decline caused by the invasive harlequin ladybird Harmonia axyridis: evidence from a long‐term field study

“…There are very few published long‐term studies of ladybird communities in Europe, and even fewer that have encompassed the early invasion phase of a non‐native species (but see Honěk et al ., , ). Our study shows a clear change in the ladybird community on lime trees over an 11‐year period in which H. axyridis invaded England, with an association between ladybird native status ( H. axyridis or native) and year (Fig.…”

Harmonia axyridis (Coleoptera: Coccinellidae): Smelling the rat in native ladybird declines

“…Honek et al (2016), using datasets extending over 39 years, have shown that A. bipunctata was already declining in Europe before the arrival of H. axyridis. It is tempting to suggest that this decline might have occurred because of decreasing air pollution or other anthropogenic effects, leading to lower aphid populations generally.…”