Intraguild predation involving Harmonia axyridis: a review of current knowledge and future perspectives

Abstract

9 Abstract As an effective generalist predator of aphids and other hemipteran pests 10 H. axyridis has been a successful biological control agent. However, the very functional 11 traits that have contributed to its success in this regard also implicate it as an intraguild 12 predator that poses a significant risk not only to the diversity of other natural enemies of 13 Hemiptera (and their associated ecosystem services), but to biodiversity more widely. In 14 this paper we will specifically review the existing data on intraguild predation involving 15 H. axyridis, and consider the strength and symmetry of such interactions both within its 16 native guild and within exotic guilds where it has established as an invasive alien. We will 17 use these studies to interpret the observed population declines in predator diversity in the 18 field, predict species at risk in regions not yet invaded and consider implications for 19 resulting ecosystem services. We will also indicate gaps in our knowledge that require 20 further study in order to identify opportunities for mitigation.21 Keywords Coccinellidae Á Harmonia axyridis Á Aphidophagous guild Á 22 Intraguild predation Á Predators Á Parasitoids Á Pathogens Á Ecosystem services 23 Introduction 24 Terrestrial ecosystems support a diversity of species that are directly and indirectly linked 25 to each other within food webs that span multiple trophic levels. Natural enemy species (in 26 the context of this paper we will collectively call these 'predators' as they all have a trophic 27 relationship with their hosts/prey) contribute to the population regulation of species in both

Harmonia axyridis: What will stop the invader?

“…It has been demonstrated that H. axyridis is more aggressive than other invasive and indigenous species in many laboratory experiments (Hironori and Katsuhiro 1997;Cottrell and Yeargen 1998;Yasuda and Ohnuma 1999;Yasuda et al 2001;Cottrell 2004;Soares and Serpa 2007;Pell et al 2007;Ware and Majerus 2007). The incidence of IGP, in laboratory studies, was 65% for the interactions between all stages of H. axyridis (intraguild predator) and the indigenous C. maculata (intraguild prey), and 75% for H. axyridis and the invasive P. quatuordecimpunctata (Labrie et al unpublished data).…”

“…Harmonia axyridis is a highly efficient intraguild predator (Hironori and Katsuhiro 1997;Cottrell and Yeargen 1998;Yasuda and Ohnuma 1999;Yasuda et al 2001;Cottrell 2004;Soares and Serpa 2007;Pell et al 2007;Ware and Majerus 2007). However, eggs and first and second instar larvae are not well protected from other competitors.…”

Behavioral and Immunological Features Promoting the Invasive Performance of the Harlequin Ladybird Harmonia axyridis

“…Native ladybeetle populations have declined in most areas where H. axyridis has been introduced (Camacho-Cervantes et al, 2017) and this is often blamed on interference competition via intraguild predation (Pell et al, 2008). More specifically, H. axyridis is considered a top-level predator in the aphidophagous guilds, reflecting its direct predation behavior toward eggs and larvae of native coccinellids as well as non-coccinellid aphidophagous species, such as hoverflies and lacewing (Wells et al, 2017).…”

Characterization of a newly established aggregation of the invasive ladybeetle Harmonia axyridis and current status of the invader in Spain

“…The arrival of H. axyridis is associated to drastic changes in coccinellid assemblages all around the word (Colunga-Garcia & Gage, 1998;Michaud, 2002;Lucas et al, 2007a,b;Pell et al, 2008;Bélanger & Lucas, 2011;Roy et al, 2012). Catalonia has a diverse agriculture dominated by winter cereals, maize, alfalfa, vegetables in open air and greenhouse, fruit orchards and vineyards.…”