Niche comparison among two invasive leafminer species and their parasitoid Opius biroi: implications for competitive displacement

Abstract

Fundamental to competitive displacement in biological invasion is that exotic species occupy the ecological niches of native species in novel environments. Contrasting outcomes of competitive displacement have occurred between Liriomyza trifolii and L. sativae in different geographical regions following their introduction. Various factors have been advanced in an attempt to explain these different competitive outcomes, although none of these explanations have addressed the effects of niche differences. We conducted field cage experiments to compare the feeding and habitat niches of the two leafminer species and their primary parasitoid, Opius biroi, when occurring together on kidney bean. A wider spatiotemporal niche breadth was found in L. trifolii (0.3670) than in L. sativae (0.3496). With respect to the parasitoid, the proportional niche similarity between L. sativae and the parasitoid was 0.3936 but only 0.0835 for L. trifolii, while similar results were found for niche overlap, indicating that stronger trailing behaviour and parasitic effects of O. biroi occurred in L. sativae. In conclusion, L. trifolii has outperformed L. sativae in occupying the ecological niche and is superior to L. sativae in avoiding parasitization by the pupal parasitoid, O. biroi.

Overwintering, cold tolerance and supercooling capacity comparison between Liriomyza sativae and L. trifolii, two invasive leafminers in China

“…However, in contrast to the overwintering and cold tolerance advantages of L. trifolii, the distribution range of L. trifolii was obviously smaller than that of L. sativae according to our previous investigations (Gao et al 2017). We considered that biotic resistance to species invasion and expansion could explain this contradictory phenomenon.…”

“…L. sativae and L. trifolii are two very closely related species that have similar morphology and can even have hybrid offspring (Sakamaki et al 2005; Tokumaru and Abe 2005). In addition, their host plant ranges are similar, and they share similar ecological niches in the same host plant (Xing et al 2017). Therefore, the invasion and expansion of L. trifolii would encounter and compete with L. sativae.…”

Hidden invasion and niche contraction revealed by herbaria specimens in the fungal complex causing oak powdery mildew in Europe

“…Beyond the reconstruction of the history of an important forest disease, our investigation illustrates the complexity of a multiple invasion in a microbial complex, emphasizing the potential role of subtle differences in the biology of closely related species, rather than strong direct competition, in the observed pattern of partial species displacement. Many other components not explored here may be involved, such as interactions with natural enemies (Xing et al 2017;Kiss 2008) or human interference (Gao and Reitz 2017). For this later point, it is interesting to note that silvicultural practices in oak forests greatly changed in the twentieth century, partly in response to powdery mildew invasion (Viney 1970), favouring high forest at the expense of coppices that were most frequent before.…”

Overwintering, Cold Tolerance and Supercooling Capacity Comparison Between Liriomyza Sativae and L. Trifolii, Two Successively Invaded Leafminers in China

“…Climatic stresses, including overwintering and cold tolerance capacity, largely determine the species distribution of leafminers (Chen and Kang 2005; Kang et al 2009). L. sative and L. trifolii are two devastating leafminers that invaded China in the 1990s and 2000s, respectively (Gao et al 2015;Xing et al 2017). L. sativae are now distributed in most provinces of China, while L. trifolii is found in only 10 provinces (Gao et al 2017a).…”

“…The invasion and expansion of L. sativae occurred earlier than that of L. trifolii by more than 10 years (Gao et al 2015). Given that L. sativae and L. trifolii share similar host plants and ecological niches (Xing et al 2017), L. trfolii should compete and displace L. sativae during their invasion and expansion. Although L. trifolii has many competitive advantages over L. sativae, the displacement of L. sativae by L. trifolii was di cult and even reversed (Wang et al 2014;Gao et al 2015;Gao et al 2017;Xing et al 2017).…”