Five new species, Eurhadina (Singhardina) dissimilis, E. (S.) flatilis, E. (S.) fumosa, E. (S.) furca and E. (S.) immatura spp. nov., and two new records, E. (S.) krispinilla rec. nov., E. (S.) pookiewica rec. nov. of the leafhopper subgenus Eurhadina (Singhardina) Mahmood from China are described and illustrated and a key to all members of the E. (S.) robusta species group is provided.

In this study, 50 species of the leafhopper subgenus Eurhadina (Singhardina) Mahmood from China are reviewed based on comparative morphological characteristics, including 14 new species: Eurhadina (Singhardina) amacularis, E. (S.) extensa, E. (S.) flaviscutella, E. (S.) foliiformis, E. (S.) galacta, E. (S.) gracilifurca, E. (S.) lata, E. (S.) parilintanonica, E. (S.) quadrimacularis, E. (S.) recta, E. (S.) scalesa, E. (S.) scamba, E. (S.) scandens and E. (S.) uprotrusa sp. nov. Four additional species E. (S.) fasciata, E. (S.) jarrayi, E. (S.) prima and E. (S.) zadyma are recorded from China for the first time. Two new synonymies are proposed. Eurhadina (Singhardina) flavescens Huang et Zhang, 1999 syn. nov. is synonymized with Eurhadina wuyiana Yang et Li, 1991 and Eurhadina rubromia Cai et Kuoh, 1993 syn. nov. is synonymized with Eurhadina (Singhardina) biavis Yang et Li, 1991. A key to all Chinese Singhardina species is also provided.

After eight generations of laboratory selection with β-cypermethrin, a P. okadai strain was cultivated that displayed a 10.04-fold increase in resistance (RS) relative to the susceptible strain (SS), with an estimation of heritability (h²) of 0.34. Compared with the SS, the developmental duration of the eggs was significantly prolonged (p < 0.05); however, the pupal stage duration was shorter, with no statistically significant difference. Moreover, the levels of GSTs, CarEs, and CYP450 activity were notably higher in the RS than in the SS. In addition, the level of CarE and CYP450 activity in the RS was significantly higher in the midgut (MG), fat body (FB), and Malpighian tubules (MTs) compared to the SS; however, the GSTs showed no statistically significant difference in the MTs. These results suggest that P. okadai‘s resistance to β-cypermethrin could be selected rapidly and the decreases in the intrinsic rate of increase (r) observed in the RS are likely due to mutations in the detoxification enzyme genes under the strong selection pressure exerted by β-cypermethrin. The increased activity of GSTs, CarEs, and CYP450 was associated with β-cypermethrin resistance in the RS of P. okadai. The data reported herein provide a foundation for future studies on the mechanisms responsible for β-cypermethrin resistance in P. okadai.

Background: Phortica okadai (Diptera: Steganinae) is the primary vector of the zoonotic eyeworm Thelazia callipaeda (Nematoda: Spirurida). However, standardized laboratory rearing protocols for this vector are still lacking, which limits research on its biology and vector competence. Methods: We evaluated the effects of five diets (fermented apple, pear, banana, and two artificial diets) on life history traits of P. okadai using age stage, two sex life table analysis under controlled conditions (28 ± 1 °C, 75 ± 5% RH, 14:10 h L:D). Life table parameters and population dynamics were analyzed with TWOSEX-MSChart and TIMING-MSChart (100,000 bootstrap replicates). Results: All tested diets supported complete development. Fermented pear yielded the shortest pre adult duration (17.34 days), the highest fecundity (116.6 eggs per female), and the greatest intrinsic rate of increase ( r = 0.0902/day). Population projection showed that 10 initial eggs on fermented pear produced more than 1,200 adults within 90 days, which was approximately 10 fold higher than on other diets. Conclusions: Fermented pear is the most suitable substrate for establishing laboratory colonies of P. okadai . These findings facilitate vector competence studies and indicate that pear orchards are potential high risk habitats for T. callipaeda transmission, supporting targeted One Health surveillance and control.

Phortica okadai, a vector of Thelazia callipaeda, is associated with an increasing incidence of thelaziasis. The complex habitat and chemosensory system of P. okadai are critical for its proliferation and expansion. However, ultrastructural data across developmental stages remain limited. This study used scanning electron microscopy to examine the ultrastructure of P. okadai developmental stages, with a focus on head sensilla. The results showed that the eggs of P. okadai are dark brown and cylindro-oval. The larvae are vermiform, divided into 11 segments. The pupae are marked by a conspicuous respiratory tubercle, and the posterior spiracle contains three distinct spiracular slits. Among five types of sensilla (trichoid, intermediate, chaetica, coeloconic, and basiconic), coeloconic, intermediate, and trichoid sensilla were predominantly found on the antennae, while basiconic and chaetica sensilla were distributed on both the antennae and the maxillary palps of P. okadai. The analysis revealed that the absence of dorsal appendages on the eggs distinguishes P. okadai from D. melanogaster. Males have longer antennae and exhibit sexual dimorphism in the length of sensilla (ChII, TB, and LB). This study provides the first comprehensive ultrastructural characterization of P. okadai developmental stages and head sensilla, laying a foundation for species identification and olfactory system research.