Assessment of prey overlap between a native (Polistes humilis) and an introduced (Vespula germanica) social wasp using morphology and phylogenetic analyses of 16S rDNA

Abstract

In newly invaded communities, interspecific competition is thought to play an important role in determining the success of the invader and its impact on the native community. In southern Australia, the native Polistes humilis was the predominant social wasp prior to the arrival of the exotic Vespula germanica (Hymenoptera: Vespidae). Both species forage for similar resources (water, pulp, carbohydrate and protein prey), and concerns have arisen about potential competition between them. The aim of this study was to identify the protein foods that these wasps feed on. As many prey items are masticated by these wasps to the degree that they cannot be identified using conventional means, morphological identification was complemented by sequencing fragments of the mitochondrial 16S rRNA gene. GenBank searches using blast and phylogenetic analyses were used to identify prey items to at least order level. The results were used to construct complete prey inventories for the two species. These indicate that while P. humilis is restricted to feeding on lepidopteran larvae, V. germanica collects a variety of prey of invertebrate and vertebrate origin. Calculated values of prey overlap between the two species are used to discuss the implications of V. germanica impacting on P. humilis. Results obtained are compared to those gained by solely 'conventional' methods, and the advantages of using DNA-based taxonomy in ecological studies are emphasized.

Life history plasticity magnifies the ecological effects of a social wasp invasion

“…For vouchers, we sequenced the 16S and COI genes as described for diet items. Phylogenetic analyses were used to confirm molecular identifications, adapting the methods of Kasper et al (22). [2005][2006][2007] in HAVO and HALE, we sampled arthropod densities before and after the removal of V. pensylvanica colonies at removal and control sites.…”

“…Diet samples were PCR-amplified using LRN13398 and LRJ12887 primers (22) to amplify 500 -650 bp of the mitochondrial 16S rDNA gene. For reaction conditions, refer to SI.…”

“…We used molecular analyses to identify masticated diet items collected from Ϸ50 returning foragers at each of 10 colonies (5 in HAVO and 5 in HALE). We identified diet items by sequencing the 16S rDNA and COI genes following Kasper et al (22) and Magnacca and Danforth (23). We extracted DNA from 93% of samples (n ϭ 465), 90% of which were identified at least to the family level using a combination of BLAST searches, comparisons with voucher specimens collected on site, and phylogenetic analyses.…”

Detecting arthropod intraguild predation in the field

“…There is an urgent need to develop strategies for assessing these important different issues. Paralleling the situation in the field of invasion biology (see Lawson Handley et al 2011), despite continuous advances in methodology (Harwood and Obrycki 2005;Kasper et al 2004), molecular techniques are seldom used in the field of ERA to answer biological control questions such as those concerning trophic interactions. This review evaluates the use of immunological, chemical and molecular approaches to determine levels of intraguild predation by BCAs, in the field.…”

Traits related to biological invasion: A note on the applicability of risk assessment tools across taxa

“…Life history and environmental traits related to invasion, highlighting the suggested differences between invasive and native insects that were found through an extensive literature review. Parasitoids more likely to establish than predators (Kimberling 2004) A, C Taxon Diptera and Lepidoptera fastest to disperse, Coleoptera slowest (Paynter and Bellgard 2011) Invasive species predominantly Hemiptera (56.4 %), Lepidoptera (14.9 %), and Hymenoptera (12.9 %) (Matosevic and Zivkovic 2013); Invasive species predominantly Homoptera (39 %), Coleoptera (19 %), Lepidoptera (13 %), and Hymentoptera (13 %) (Mattson et al 2007); Invasive species predominantly Coleoptera, Sternorrhyncha, and Psocoptera (Kenis et al 2007); Homoptera and Lepidoptera most likely to establish (Peacock and Worner 2008) C Feeding method Miners, borers, and leaf-rollers disperse faster than external feeders, and root-, rosette-, and seed-feeders (Paynter and Bellgard 2011) Internal feeders more likely to establish than external feeders (Kimberling 2004) Insects that use single host species are more likely to establish than those that use multiple hosts (Mondor et al 2007) C Diet breadth Diet breadth or Host specificity Invasive insects have a wide diet breadth (generalist) compared to natives (Moller 1996, Cervo et al 2000, Kasper et al 2004, Kimberling 2004, Moeser and Vidal 2005, Snyder and Evans 2006, Mondor et al 2006, Ward and Masters 2007…”