Is the Multicolored Asian Ladybeetle,Harmonia axyridis,the Most Abundant Natural Enemy to Aphids in Agroecosystems?

Abstract

The multicolored Asian ladybeetle, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was introduced into Western Europe in the late 1990s. Since the late 2000s, this species has been commonly considered one of the most abundant aphid predators in most Western European countries. In spite of the large amount of research on H. axyridis, information concerning its relative abundance in agroecosystems is lacking. This study aims to evaluate the abundance of H. axyridis within the aphidophage community in four crops situated in southern Belgium: wheat, Triticum aestivum L. (Poales: Poaceae), corn, Zea mays, potato, Solanum tuberosum (Solanales: Solanaceae), and broad bean Vicia faba (Fabales: Fabaceae). In order to assess the species diversity, the collected data were analyzed by considering (1) the species richness and (2) the evenness according to the Shannon diversity index. Eleven aphidophages were observed in every inventoried agroecosystem, including five abundant species: three coccinellids, the seven-spotted ladybug, Coccinella septempunctata L. (Coleoptera: Coccinellidae), the 14-spotted Ladybird, Propylea quatuordecimpunctata, and H. axyridis; one hoverfly, the marmalade hoverfly, Episyrphus balteatus De Geer (Diptera: Syrphidae); and one lacewing, the common green lacewing, Chrysoperla carnea Stephens sensu lato (= s.l.) (Neuroptera: Chrysopidae). Harmonia axyridis has been observed to thrive, breed, and reproduce on the four studied crops. Harmonia axyridis is the most abundant predator of aphids in corn followed by C. septempunctata, which is the main aphid predator observed in the three other inventoried crops. In wheat and potato fields, H. axyridis occurs in low numbers compared to other aphidophage. These observations suggest that H. axyridis could be considered an invasive species of agrosystems, and that potato and wheat may intermittently act as refuges for other aphidophages vulnerable to intraguild predation by this invader. Harmonia axyridis is not the most abundant aphid predator in the main Belgian crops.

Do flower mixtures with high functional diversity enhance aphid predators in wildflower strips?

“…In addition, other studies conducted in the same region report a very low density of ladybeetles in 2015, indicating that their abundance was low that year in the region of Gembloux (Fassotte, 2016;. Similar annual variability in ladybeetle abundance is reported in Belgium (Vandereycken et al, 2013).…”

Population dynamics of potential bioagents of mustard aphid, Lipaphiserysimi(Kaltenbach) on different cultivars of rapeseed-mustard

“…There were changes in the abundance of natural enemies in different cultivars through the years as well as among cultivars within a year. There may be different causes like climate (Rotheray and Gilbert, 2011), prey density on different cultivars (Thalji, 2006), insolation, quality of host plants (Alhmedi et al, 2009), and adjacent habitats (Alhmedi et al, 2009;Vandereycken et al, 2013). Straub and Snyder (2006) demonstrated that coccinellids are the key species in a natural enemy guild in organic brassica fields in Canada and cabbage aphid, Brevicoryne brassicae.…”

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

“…Both species occur in trees prior to moving to crops in spring and after harvest in late summer, and in early autumn, they again occupy trees (Honek, , ). They mainly breed in crops (Honek, , ) where they are unlikely to be subject to intensive competition from H. axyridis (Vandereycken et al ., ,b; Honek et al ., ). Very few C. quinquepunctata were recorded on trees during P2 and P3.…”