Evaluation of three molecular markers for identification of European primary parasitoids of cereal aphids and their hyperparasitoids

Abstract

Aphids are major pests of cereal crops and a suite of hymenopteran primary parasitoids play an important role in regulating their populations. However, hyperparasitoids may disrupt the biocontrol services provided by primary parasitoids. As such, understanding cereal aphid-primary parasitoid-hyperparasitoid interactions is vital for a reliable parasitoid-based control of cereal aphids. For this, the ability to identify the different primary and hyperparasitoid species is necessary. Unfortunately, this is often difficult due to a lack of morphologically diagnostic features. DNA sequence-based species identification of parasitoids can overcome these hurdles. However, comprehensive DNA sequence information is lacking for many of these groups, particularly for hyperparasitoids. Here we evaluate three genes [cytochrome c oxidase subunit I (COI), 16S ribosomal RNA (16S) and 18S ribosomal RNA (18S)] for their suitability to identify 24 species of primary parasitoids and 16 species of hyperparasitoids associated with European cereal aphids. To identify aphelinid primary parasitoid species and hyperparasitoids, we found 16S to be more suitable compared to COI sequences. In contrast, the Aphidiinae are best identified using COI due to better species-level resolution and a more comprehensive DNA sequence database compared to 16S. The 18S gene was better suited for group-specific identification of parasitoids, but did not provide resolution at the species level. Our results provide a DNA sequence database for cereal aphid primary parasitoids and their associated hyperparasitoids in Central Europe, which will allow further improvement of our understanding of cereal aphid-primary parasitoid-hyperparasitoid interactions in relation to aphid biological control.

Surveys of stink bug egg parasitism in Asia, Europe and North America, morphological taxonomy, and molecular analysis reveal the Holarctic distribution of Acroclisoides sinicus (Huang & Liao) (Hymenoptera, Pteromalidae)

“…This study highlights the value of DNA barcoding in the identification and delineation of species in Hymenoptera (Stahlhut et al 2013). Overall, this research expands the barcoding sequence database for parasitoids and hyperparasitoids and provides a foundation for additional molecular studies aimed to a better understanding of the biocontrol services provided by parasitoids (Gariepy et al 2007;Ye et al 2017;Halim et al 2018).…”

Resolving the Taxonomic Status of Potential Biocontrol Agents Belonging to the Neglected Genus Lipolexis Förster (Hymenoptera, Braconidae, Aphidiinae) with Descriptions of Six New Species

“…However, easy access to DNA sequence information has now enabled integrative taxonomy which combines morphological/ecological and molecular data to clarify species boundaries. The barcode region of COI is by far the most widely utilized molecular marker used for molecular studies on the subfamily Aphidiinae [ 30 , 44 , 45 ]. Aside from aiding the identification of the newly collected specimens, this gene region aids the delineation of species boundaries, an approach of particular value for aphidiine genera that are suspected to include cryptic species complexes [ 46 , 47 , 48 , 49 ].…”

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

“…Braconidae is one of the largest hymenopteran families in Europe, with 3500 recorded species (van Achterberg, 2013), among which 18 are considered to be alien species (Rasplus et al, 2010;Petrović et al, 2013Petrović et al, , 2017. However, the poorly known taxonomy of parasitoids has frequently resulted in overlooked alien parasitoid species (Ye et al, 2017). Seven out of 18 alien braconid species belong to the subfamily Aphidiinae.…”