Diglyphus wani (Hymenoptera: Eulophidae) is a dominant parasitoid that attacks agromyzid leafminers.  Two reproductive types occur in D. wani: arrhenotoky (in which virgin females produce only male offspring; and virgin females mate with males to produce bisexual offspring) and thelytoky (in which virgin females produce female offspring).  As a potential biological control agent, exploring the differences in the relevant biological parameters of both strains is necessary.  In this study, comparisons between the two strains of D. wani were performed by evaluating the life table and host-killing rate.  The thelytokous strain exhibited significantly better life table parameters than its arrhenotokous counterpart.  Higher values for the intrinsic rate of increase, finite rate of increase, net reproductive rate, and fecundity were found in the thelytokous strain.  The thelytokous strain also performed better than the arrhenotokous strain in terms of net parasitism, host-feeding, host-stinging, and total host-killing rates.  Thus, populations of the thelytokous strain could grow fast and kill more hosts.  In conclusion, the thelytokous strain of D. wani may be the more promising biological agent against agromyzid leafminers compared to its arrhenotokous counterpart.  Also, since the thelytokous strain of D. wani is only known to produce females, it should be given priority in future biocontrol applications owing to the cost savings of breeding only females.

Leaf-mining flies (Diptera: Agromyzidae) are a diverse family of small-bodied insects that feed on living plant tissues as larvae.  Various species in this family are considered globally invasive and have caused great agricultural economic losses.  In China, economically important vegetable crops have been seriously damaged by these pest insects, especially by species of the genus Liriomyza.  However, these species are difficult to differentiate because of their morphological similarities, and the Chinese fauna remains poorly known.  To explore the relevant pest species in China and their phylogeny, agromyzid leafminers were collected from 2016 to 2019, and identified based on morphological characteristics and DNA barcodes.  In total, 27 species from five genera of Agromyzidae were sampled and identified, including 16 species of Liriomyza.  Both mitochondrial and nuclear genes were used to reconstruct their phylogenetic relationships and estimate the divergence time.  Highly congruent and well-supported phylogenetic trees were obtained using the Bayesian inference and maximum-likelihood methods.  This analysis revealed two main clades in Liriomyza, and clade 2 was inferred to have diverged from clade 1 approximately 27.40 million years ago (95% highest posterior density: 23.03–31.52 million years ago) in the Oligocene.  Differences were observed in the distribution patterns and host associations between the Liriomyza clades.  Clade 2 species are distributed in cool, high-latitude environments, suggesting that they may have evolved into a cool-adapted lineage.