Resolving the taxonomic status of biocontrol agents belonging to the Aphidius eadyi species group (Hymenoptera: Braconidae: Aphidiinae): an integrative approach

Abstract

Species that belong to the Aphidius eadyi group have been used as biocontrol agents against Acyrthosiphon pisum worldwide. However, despite their extensive use, there are still gaps in our knowledge about their taxonomy and distribution. In this study, we employed an integrative taxonomic approach by combining genetic analyses (mtDNA COI barcoding) with standard morphological analyses and geometric morphometrics of forewing shape. We identified three species within the A. eadyi species group, viz., A. smithi, A. eadyi and A. banksae. Genetic separation of all three species was confirmed, with mean genetic distances between species ranging from 5 to 7.4%. The following morphological characters were determined as the most important for separating species of the A. eadyi group: number and shape of costulae on the anterolateral part of the petiole, shape of the central areola on the propodeum, and shape and venation of the forewings. The differences in wing shape of all three species were statistically significant, but with some overlapping. We identified A. banksae as a widely distributed pea aphid parasitoid, whose known range covers most of the western Palaearctic (from the UK to Israel). Aphidius banksae is diagnosed and redescribed.

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

“…COI haplotype diversity shows very distinct patterns within species of Aphidiinae. It ranges from almost no diversity in Aphidius uzbekistanicus , with only two haplotypes registered throughout the Holarctic (Kos et al , ), to high diversity in Aphidius banksae (Petrović et al , ). Baer et al () recorded 44 different mitochondrial haplotypes in Diaeretiella rapae (M'Intosh, 1855), although this was based on several mitochondrial genes.…”

Sizing the Knowledge Gap in Taxonomy: The Last Dozen Years of Aphidiinae Research

“…One such indicator, which is widely underestimated, is the crucial role of taxonomists in the identification of alien species. In European Aphidiinae, only five species were marked as alien (Aphidius colemani Viereck, 1912; Aphidius smithi Sharma and Subba Rao, 1959; Lysiphlebus testaceipes (Cresson, 1880); Pauesia cedrobii Starý and Leclant, 1977 and Pauesia unilachni (Gahan, 1927)) before 2010, and all were intentionally introduced as biocontrol agents [93,94]. Lysiphlebus testaceipes deserves special attention.…”

“…There are several published studies dealing with the taxonomic status of Aphidiinae species groups [37,40,41,94,[109][110][111][112], among which the most important are those about the taxonomy of biocontrol agents belonging to the Aphidius colemani and A. eadyi species groups [94,111]. It was determined that the Aphidius colemani species group consisted of three species: A. colemani, A. transcaspicus Telenga, 1958, and the almost forgotten A. platensis Brethes, 1913 [111].…”

Significance of wing interference patterns as taxonomic characters in Aphidiinae (Hymenoptera: Braconidae)

“…Wing venation, wing size, and shape have all previously been studied in the taxonomy and evolutionary relationships of the Aphidiinae (Mitrovski-Bogdanović et al, 2013;Petrović et al, 2019;Stanković et al, 2015;Tomanović et al, 2013Tomanović et al, , 2018Žikić, Stanković, et al, 2017;Žikić et al, 2009).…”