What Determines Host Acceptance and Suitability in Tropical Asian Drosophila parasitoids?

Novković

2015

Ecological Research

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Local adaptation and ecological fitting are the major processes by which organisms colonize and persist in novel environments and form novel associations with unfamiliar species. In this study, we assessed the role of these two processes in the formation of associations between the parasitoid Leptopilina japonica and various host Drosophila species using laboratory populations from three different localities. Each L. japonica population was highly virulent to some Drosophila species from its original locality, meaning they used these Drosophila species as major hosts. However, major host species at a given locality were usually less successfully parasitized by parasitoid populations from different localities. These results indicate that the investigated parasitoid populations showed local adaptation in host use. We also observed cases in which unfamiliar Drosophila species were successfully parasitized or allopatric Drosophila populations were more successfully parasitized. These findings suggest that L. japonica can form novel associations with some Drosophila species in novel environments without undergoing adaptive changes, a phenomenon called ecological fitting. In this study, L. japonica also usually appeared to have oviposited well in D. melanogaster species group members irrespective of their suitability as hosts. This result suggests that the parasitoid makes oviposition decisions based on characteristics common to the drosophilids in this species group

Section: Host Associationsupporting

confidence: 81%

Section: Host Acceptance For Ovipositionmentioning

confidence: 39%

Local adaptation and ecological fitting in host use of theDrosophilaparasitoidLeptopilina japonica

Novković

2015

Ecological Research

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“…BG1 aff. ponapensis) from Bogor (Kimura and Suwito 2014), both parasitoid virulence and host resistance have species-specific components. In addition, some of drosophilid and parasitoid species showed geographic variation in resistance or virulence.…”

Section: Discussionmentioning

confidence: 99%

“…We have already reported the composition of frugivorous drosophilid flies and their parasitoids based on the trap collections using banana as bait at a low altitude location (Bogor: approximately 250 m in altitude) in west Java (Kimura and Suwito 2012). In addition, we have shown host use of these parasitoids based on laboratory experiments on host suitability and acceptance (Kimura and Suwito 2014). In this study, we carried out trap collections in two locations, Sukamantri (approximately 700 m) and Cibodas (approximately 1350 m), and analysed the altitudinal pattern of drosophilid distribution and parasitism together with previous data in Bogor.…”

Section: Introductionmentioning

confidence: 98%

Altitudinal patterns of abundances and parasitism in frugivorous drosophilids in west Java, Indonesia

Journal of Natural History

Suwito

2015

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2Abundances and parasitism rates of frugivorous drosophilid flies were studied in three localities at altitudes of 250-1350 m in and near Bogor, Indonesia. The drosophilid and parasitoid species were classified into four groups, low-altitude species, high-altitude species, species abundant at a mid-altitude location, and species occurring rather evenly from low to high locations. The ananassae and immigrans species groups were major drosophilids collected. All species of the ananassae species group were more abundant at lower altitudes, and the parasitism rate in this species group decreased with increasing altitude. Thus, the host abundance seems to affect the parasitism rate. On the other hand, the rate of parasitism in the immigrans species group showed no apparent relation with altitude or density, possibly due to that species of this species group varied in altitudinal distribution. It is also suggested that the diversity of drosophilid species affects the composition of parasitoid species.Keywords: abundance; altitude; frugivorous drosophilids; Indonesia; parasitoids; tropics. 3 IntroductionThe species diversity of and abundance of parasitoids attacking herbivore insects have been reported to show exceptional latitudinal patterns; i.e., they are more diversified and the parasitism rate is higher in the temperate regions compared to the tropics (Owen and Owen 1974;Hespendeide 1978;Hawkins et al. 1997;Hawkins 1994). However, it is still poorly understood why they show such patterns. To address this issue, studies on on the patterns along with other environmental gradients or in non-herbivorous insects could provide some clues. Péré et al. (2013) suggested in their meta-analyses that both parasitism rates and parasitoid species richness decreased with increasing elevation. In our previous studies on parasitoids attacking frugivorous drosophilids, on the other hand, the species diversity did not so much differ between the tropical, subtropical and temperate regions, and the parasitism rate was much higher in the tropics compared to the subtropical and temperate regions (Mitsui and Kimura 2010;Novković et al. 2012;Kimura and Suwito 2012). On the other hand, no information is available on the altitudinal pattern of parasitism in drosophilid flies, although a number of references have been published on the altitudinal distributions and temperature adaptations of drosophilid flies in the temperate regions (Kimura et al. 1978;Bächli 1979;Bächli & Burla 1992;Beppu et al. 1996;Mitsui et al. 2010). High-altitude temperate Drosophila species are usually heat-susceptible and are assumed to suffer high mortality in summer if they occur at low altitudes (Kimura et al. 1994;Beppu et al. 1996). In addition, some temperate species perform seasonal migration between low and high altitudes to avoid summer heat at low altitudes (Kimura and Beppu 1993;Beppu et al. 1996; Mitsui et al. 4 2010). In the tropics, however, there are few studies on the altitudinal distributions of drosophilid flies except for fragmental reports on...

“…Indeed, one or two abundant (i.e., frequently encountered) species are usually included in the host lists of most Drosophila parasitoids (Janssen et al 1988;Yorozuya 2006;Ideo et al 2008;Mitsui and Kimura 2010;Novković et al 2012;Kasuya et al 2013;Kimura & Suwito 2014). However, the exotic species D. immigrans was an unsuitable or inferior host for all of the tested parasitoid species except L. longipes, and the other exotic species D.…”

Section: Drosophila-parasitoid Associationmentioning

confidence: 99%

Prevalence of exotic frugivorous Drosophila species, D. simulans and D. immigrans (Diptera: Drosophilidae), and its effects on local parasitoids in Sapporo, northern Japan

2015

Appl Entomol Zool

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The prevalence of exotic species has various effects on native biological communities, e.g. the diversity and relative abundance of preys, predators or competitors. Here, I investigated associations of native and exotic frugivorous Drosophila species with local parasitoids in Sapporo, northern Japan, to understand the influence of exotic species on a local Drosophila-parasitoid community. Two exotic species, D. simulans and D. immigrans, comprised approximately 90% of Drosophila individuals that emerged from banana-baits, and two native species, D. auraria and D.biauraria, comprised approximately 9%. Seven larval parasitoid species were recorded from Drosophila larvae occurring in banana-baits, and six of them were examined for host use by laboratory experiments. Either or both of the two native Drosophila species were favorable hosts for four of the six larval parasitoids. Two other parasitoids seemed to use herbage-or fungus-feeding Drosophila species as major hosts. D. simulans was a favorable host at least for four larval parasitoids, but D. immigrans was not favorable for most of the larval parasitoids. Nevertheless, more than one third of parasitoid individuals emerged from D. immigrans in the field study, probably because of its extreme abundance. Thus, exotic species are assumed to affect the abundance and distributions of native parasitoid species. On the other hand, it is not certain whether the parasitoid species mediate the effects of exotic Drosophila species on native Drosophila species, because the parasitism rate was usually low.