Harmonia axyridis: What will stop the invader?

Abstract

In recent years Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) has become a very popular insect among biological control practitioners and scientists, not only for its potential to be an efficient biological control agent but also because it is considered invasive. Individuals of this species were deliberately introduced into several countries for biological control of different arthropods pests. However the predator itself became an invasive species, affecting the dynamics and composition of several guilds through direct or indirect interactions with established species, including intraguild predation. In this paper we discuss the reasons why the species has a high invasiveness and what are the limits to invasion by this species. It is not clear if the invasiveness of the beetle is linked to its biological, ecological and behavioural abilities, or to other factors such as invasibility and interactions between the invaders, the noninvaders, and the habitat, which may in part explain the reasons of its success and help us to answer the question ''what will stop the invader?'' We also discuss the reason for the absence of the predator in the Azores islands. Despite the intentional introduction of H. axyridis in the Azores and the high number of individuals released, there are no records of this species in the wild, despite recent extensive sampling effort. In this paper we discuss the reasons for the apparent failure or the delay in establishment of the predator. One factor which may hamper the establishment of H. axyridis in some of the Azores islands is the absence of winter

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

“…Van Lenteren et al (2008) defined H. axyridis as a potentially risky species for Northwest Europe and Brown et al (2008) predicted than the expansion of the invader in Europe would occur mainly to the northern and eastern countries and that the spread southward is uncertain (see also Kontodimas et al, 2008;Soares et al, 2008). However, the reports of Kulijer (2010) in Bosnia-Herzegovina, Stankovic et al (2011) in Croatia and the present study, demonstrate the high potential of invasion in southern Mediterranean countries.…”

Coccinellids in Biological Control

“…axyridis failed to establish in the Azores despite a series of releases in the 1990s and earlier (Borges et al 2005 ). Soares et al (2008) hypothesized extrinsic ecological or environmental factors as potentially responsible, but such failures may simply be due to founder effects in the source material -i.e. the introduction of small groups of individuals coincidentally lacking genetic composition immediately suited to local conditions.…”

The aggregation behavior of Harmonia axyridis in its native range in Northeast China

“…Unfortunately, this euryphagous predator has also become an aggressive invasive species in regions where it has been introduced, either intentionally or inadvertently, and has impacted native ecosystems and non-target insects (Williamson 1996;Koch 2003;Kajita et al 2006;Majerus et al 2006;Soares et al 2008). A high degree of phenotypic plasticity and strong intra-guild predation abilities are among the attributes that have contributed to invasive H. axyridis populations dominating assemblages of native coccinellid species (Brown and Miller 1998;Hesler et al 2001;Alyokin and Sewell 2004;Hodek and Michaud 2008;Brown et al 2008a, b;Lombaert et al 2008).…”

“…High colour contrasts on the surface of buildings tends to attract migrating beetles (Nalepa et al 2005). With the advent of invasive populations in Europe and elsewhere the species is alien, considerable research attention has been directed toward studying the biology and behavior of H. axyridis in these novel habitats (Kenis et al 2008;Pell et al 2008;Soares et al 2008). Apart from some work in Japan (Osawa 2001), little is known about the overwintering behavior of indigenous H. axyridis populations in Asia compared to what is known of invasive populations in alien regions.…”