Molecular and morphological variability within theAphidius colemanigroup with redescription ofAphidius platensisBrethes (Hymenoptera: Braconidae: Aphidiinae)

Abstract

We have identified the following three taxa related to the Aphidius colemani species group, which are important biological control agents: Aphidius colemani, Aphidius transcaspicus and Aphidius platensis. Using partial sequences of the mitochondrial cytochrome oxidase subunit I (mtCOI) gene and geometric morphometric analysis of the forewing shape, we have explored the genetic structure and morphological variability of the A. colemani group from different aphid host/plant associations covering a wide distribution area. The topology of the maximum parsimony and maximum likelihood trees were identical with 98-100% bootstrap support, clustering A. colemani, A. platensis and A. transcaspicus into separate species. The distances among the taxa ranged from 2.2 to 4.7%, which is a common rate for the between-species divergence within the subfamily Aphidiinae. Differences in the shape of the forewing investigated within the biotypes of A. colemani group are congruent with their genetic diversification. Both A. platensis and A. colemani share a common host range pattern, and it would be interesting to estimate and compare the role of these two species in future biological control strategies against aphids of economic importance. Our results indicate that 'genetic screening' is a reliable approach for identification within the A. colemani group. The high variation in the wing shape among species, including a significant divergence in the wing shape among specimens that emerged from different hosts, makes the forewing shape and wing venation less reliable for species determination. Aphidius platensis is diagnostified and redescribed, and the key for the A. colemani group is presented.

First record of Aphidius ericaphidis (Hymenoptera, Braconidae) in Europe: North American hitchhiker or overlooked Holarctic citizen?

“…Divergence rates in relation to other species morphologically similar to A. ericaphidis or parasitizing E. scammelli were as follows: A. urticae -8.9%, A. avenaphis -10.4% and A. ervi -8.3% (Table 2). Those distances are greater than what is considered to be enough for the separation of Aphidiinae species (Derocles et al 2012, Tomanović et al 2014. Thus, after morphological description, we here support the status of this taxon with molecular analysis.…”

Hidden in plain sight: phylogeography of an overlooked parasitoid species Trioxys sunnysidensis Fulbright & Pike (Hymenoptera: Braconidae: Aphidiinae)

“…Our current analysis of sequence variation in the barcode region of COI suggests there is no clear distinction between the two genera. Genetic distances between the species analyzed are much higher than that considered to be a species boundary within Aphidiinae (Derocles et al , ; Tomanović et al , ); even T. sunnysidensis and T. auctus , with a similar morphology and the same aphid host, have a fairly high distance. Furthermore, the barcode region does not separate the species into two monophyletic groups ( Trioxys and Binodoxys ) because some differences between congeneric pairs of species were greater than those between taxa currently assigned to different genera (Fig.…”

Food web structure of aphids and their parasitoids in Belgian fruit agroecosystems

“…Parasitoid species were identified on the basis of morphological identification keys (Pennacchio ; Tomanović et al . , ; Kavallieratos et al . ; Starý & Lukáš ), and confirmed by DNA barcoding based on the mitochondrial cytochrome oxidase subunit I ( COI ) gene in cases of some sibling species.…”