Intraguild predation and successful invasion by introduced ladybird beetles

Abstract

Introductions of two ladybird beetle (Coleoptera: Coccinellidae) species, Coccinella septempunctata and Harmonia axyridis, into North America for aphid biocontrol have been followed by declines in native species. We examined intraguild predation (IGP) between larvae of these two exotic species and larvae of the two most abundant native coccinellids in eastern Washington State, C. transversoguttata and Hippodamia convergens. In pairings between the two native species in laboratory microcosms containing pea ( Pisum sativum) plants, neither native had a clear advantage over the other in IGP. When the natives were paired with either Harmonia axyridis or C. septempunctata, the natives were more frequently the victims than perpetrators of IGP. In contrast, in pairings between the exotic species, neither had an IGP advantage, although overall rates of IGP between these two species were very high. Adding alternative prey (aphids) to microcosms did not alter the frequency and patterns of relative IGP among the coccinellid species. In observations of encounters between larvae, the introduced H. axyridis frequently survived multiple encounters with the native C. transversoguttata, whereas the native rarely survived a single encounter with H. axyridis. Our results suggest that larvae of the native species face increased IGP following invasion by C. septempunctata and H. axyridis, which may be contributing to the speed with which these exotic ladybird beetles displace the natives following invasion.

The multicolored Asian ladybeetle Harmonia axyridis (Coleoptera: Coccinellidae) in Quebec agroecosystems ten years after its arrival

“…Several crops monitored in our study presented a predominant proportion of H. axyridis in the different years of the study (Figs 1, 2). The arrival of the multicolored Asian ladybeetle has been associated with significant changes in native guild structures (Tedders & Schaeffer, 1994;LaMana & Miller, 1996;Brown & Miller, 1998;Michaud, 2002;Snyder et al, 2004). The consequences of such an invasion may also adversely affect other natural enemies of aphids such as hover flies, lacewings, gall midges, and hemipteran predators by exploitative competition and intraguild predation (Horn, 1991;Koch et al, 2003;Lucas et al, 2007).…”

“…Harmonia axyridis is thought to affect indigenous ladybeetle species either by exploitative competition or by intraguild predation (Hironori & Katsuhiro, 1997;Yasuda & Ohnuma, 1999;Dixon, 2000;Kajita et al, 2000;Yasuda et al, 2001;Michaud, 2002;Snyder et al, 2004;Lucas et al, 2007). Its establishment was followed by important decreases in natural populations of several local ladybeetle species such as Brachiacantha ursina (Fabricius), Cycloneda munda (Say) and Chilocorus stigma (Say) (Colunga-Garcia & Gage, 1998).…”

Laboratory studies on intraguild predation and cannibalism among coccinellid larvae (Coleoptera: Coccinellidae)

“…Snyder et al (2004), using pairs of larvae of these two species, in which the fourth instar larva was the "predator" and the third instar larva the "prey", record that IGP occurred in more than 80% of the replicates but neither of the two species had an advantage over the other.…”

“…Among these, the high incidence of intraguild predation (IGP) by this species of native ladybirds is one of the most studied both in the Neartic (Kajita et al, 2000;Michaud, 2002;Snyder et al, 2004;Yasuda et al, 2004) and Palearctic regions (Burgio et al, 2002;Hautier et al, 2008;. Laboratory and field assessments suggest that H. axyridis may be a top predator of several native species and the cause of a decrease in guild diversity (Nault & Kennedy, 2003;Roy et al, 2006;Snyder & Evans, 2006;Pell et al, 2008;Brown et al, 2011).…”

Oviposition-deterring effects of conspecific and heterospecific larval tracks on Cheilomenes sexmaculata (Coleoptera: Coccinellidae)

“…High arrival and oviposition may occasionally cause a considerable mortality rate among the progeny (Osawa, 1993). If finite aggregates of prey are prematurely depleted, overcrowded larvae suffer from cannibalism (Michaud & Grant, 2003;Snyder et al, 2004) and attack prepupae and pupae (Takahashi, 1989). Along with cannibalism, interspecific predation occurred in the field and in the laboratory (Dimetry, 1976a, b;Agarwala & Dixon, 1992).…”