Identification of two leafminer parasitoids (Hymenoptera: Eulophidae),Neochrysocharis formosaandProacriassp. from Australia, with both showing thelytoky and infection byRickettsia

Abstract

Liriomyza huidobrensis, L. sativae and L. trifolii are polyphagous agromyzid leafminers that have recently arrived in Australia, posing a threat to Australian vegetable and ornamental crops. Adventive and endemic hymenopteran parasitoids of agromyzid leafminers already present in Australia should assist in the management of these invasive agromyzid species. Neochrysocharis formosa (Hymenoptera: Eulophidae: Entedoninae) is an idiobiont endoparasitoid commonly attacking Liriomyza spp. in many countries, but it has not been formally identified in Australia. This study provides the first confirmed Australian record of N. formosa as well as an unidentified Proacrias species, another entedonine species. Females of both species were reared from several adventive and endemic agromyzid leafminers in southern Australia. Laboratory cultures of both species established the presence of thelytokous reproduction. DNA barcodes (5′ COI, 3′ COI, ITS1, ITS2, 28S) were used to delineate species boundaries, with the 5′ end of the mitochondrial COI sequences pointing to multiple cryptic lineages among N. formosa. Additionally, 16S rRNA sequencing indicated that both species were infected with a Rickettsia bacterium, which is related to the Rickettsia present in thelytokous populations of N. formosa in Japan and China. These findings expand records for parasitoids attacking leafminers in Australia and highlight the potential for an endosymbiont to produce thelytokous strains that could provide for more efficient biocontrol agents for augmentative release.

Molecular identification of hymenopteran parasitoids and their endosymbionts from agromyzids

“…In N. formosa, only one COI haplotype (NF_5COI.03) was found in Queensland and this is a single base pair different to N. formosa collected in Victoria (NCBI: OK076721, NF_5COI.02). Interestingly, NF_5COI.02 and another N. formosa haplotype collected at the same location, NF_5COI.01 (NCBI: OK076720), were found to be thelytokous (Xu et al, 2022). Given no males of N. formosa were collected from Queensland in this study and all specimens were infected with Rickettsia, it is possible that NF_5COI.03 is also thelytokous.…”

“…Both N. formosa and N. okazakii were infected with the same Rickettsia sp. based on 253 bp COI sequence data, which is identical to N. formosa previously screened from Australia, Japan, and China (Xu et al, 2022). The Rickettsia sp.…”

“…Lambkin et al (2008) found unidentified Neochrysocharis sp. from P. plantaginis and P. syngenesiae, and field collections in Victorian have found N. formosa reared from L. brassicae, L. chenopodii, P. plantaginis and P. syngenesiae (Coquilleau, 2020;Xu et al, 2022). Currently, only female wasps have been found in Australia and thelytokous strains of N. formosa have been recorded in Japan and China which are associated with Rickettsia infection (Hagimori et al, 2006;Zhang et al, 2014;Yang et al, 2017;Xu et al, 2022).…”

“…Prior studies already provide detailed molecular and morphological data on N. formosa and Z. latilineatum (Perry and Heraty, 2021; Xu et al, 2022), so we compared our COI data with these sequences. For N. formosa, Xu et al (2022) found two 5 ′ COI haplotypes (NCBI: OK076720, NF_5COI.01 and OK076721, NF_5COI.02) from Victorian collections. In this study, we only found one 5 ′ COI haplotype (NF_5COI.03) for N. formosa from Queensland, which is a single base pair different from NF_5COI.02.…”

Forecasting the potential distribution of invasive leafminer pests, Liriomyza spp. (Diptera: Agromyzidae), and their natural enemies

“…The invasion of L. sativae , L. trifolii and L. huidobrensis will see them entering ecosystems that harbour established agromyzids, such as Liriomyza brassicae (Riley), Liriomyza chenopodii (Watt), Phytomyza syngenesiae (Hardy), and Phytomyza plantaginis Goreau, as well as their parasitoid wasps, consisting of a range of eulophid wasps, such as Diglyphus isaea (Walker), Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Walker) and Zagrammosoma latilineatum Ubaidillah, as well as a range of braconid wasps ( Opius spp.) and pteromalid species such as Trigonogastrella parasitica Girault (Ridland et al 2020; Xu et al 2022). Based on overseas data, these parasitoids are expected to attack L. sativae , L. trifolii and L. huidobrensis where they co‐occur in Australia (Schuster & Wharton 1993; Zaifu et al 1999).…”