Studies on the identity of the parasitoids Aphidius colemani and Aphidius transcaspicus (Hymenoptera: Braconidae)

Abstract

Abstract. The taxonomic status of the aphid parasitoid Aphidius colemani Viereck has been questioned, especially in regard to Aphidius transcaspicus Telenga (Hymenoptera: Braconidae). The genetic association between A. colemani and A. transcaspicus was studied by cross mating individuals of A. colemani and A. transcaspicus (A.c.& × A.t.% and A.c.% × A.t.&) and applying appropriate molecular methods. The cross mating resulted in offspring (female and males) that were fertile. Therefore, the cross mating assays performed in an artificial environment showed that these two populations are potentially compatible. The mean number of mummies that developed and the sex ratio of the offspring of each cross were similar. Most of the male and female offspring from each cross were assigned to A. transcaspicus. Furthermore, the genetic divergence between the ribosomal internal transcribed spacers (ITS2) of the A. colemani and A. transcaspicus studied was 16%. These results indicate that A. colemani might be a complex of species with different morphological and biological characters attacking different host aphids.

Characterization of Hymenopteran Parasitoids of Aphis fabae in An African Smallholder Bean Farming System Through Sequencing of COI ‘Mini-barcodes’

“…DNA barcoding has since been used to confirm that these species are genetically distinct [22,37], which is supported by the findings of this study. However, it has been reported that despite being genetically determined to be different species, A. transcaspicus and A. colemani are able to mate and produce fertile offspring, suggesting that A. colemani might be a complex of different species [37]. Further sequencing and cross mating studies may be needed to verify the relationship between these two species.…”

“…Historically, Aphidius transcaspicus Telenga and Aphidius platensis Brethes have been misidentified as A. colemani [38] due to morphological similarities and overlapping distributions [22]. DNA barcoding has since been used to confirm that these species are genetically distinct [22,37], which is supported by the findings of this study. However, it has been reported that despite being genetically determined to be different species, A. transcaspicus and A. colemani are able to mate and produce fertile offspring, suggesting that A. colemani might be a complex of different species [37].…”

“…It has been widely used in biological control programs since the 1970s [36] and is reared on a commercial scale for aphid control in more than twenty countries [34]. Despite the widespread use of A. colemani , there remains uncertainty regarding the classification of this species [37]. Historically, Aphidius transcaspicus Telenga and Aphidius platensis Brethes have been misidentified as A. colemani [38] due to morphological similarities and overlapping distributions [22].…”

Identification of molecular markers for DNA barcoding in the Aphidiinae (Hym. Braconidae)

“…To help future studies, we would like to emphasize that despite persistent efforts, we failed to amplify two genes potentially useful for the barcoding of Aphidiinae: EF1alpha (Belshaw & Quicke 1997; Sanchis et al. 2001) and ITS2 (Garantonakis et al. 2009).…”