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A review of the leafhopper tribe Deltocephalini in Pakistan is provided, including comprehensive illustrated keys to all genera and species, along with their diagnosis and distribution. A new species of Paramesodes is described, P. dirensis sp. nov., which was discovered in the Upper Dir District of Khyber Pakhtunkhwa, Pakistan. A detailed description of this new species is provided together with photographs for visual reference. This tribe now has three genera and 13 species from Pakistan. The genus Deltocephalus Burmeister includes two species, and Maiestas Distant has nine species; Paramesodes Ishihara is now represented with two species.

Insects have highly variable reproductive systems, reflecting a diversity of reproductive strategies and adaptations. Such variation has been widely used to classify and estimate phylogenetic relationships. Here, the morphology and ultrastructure of the internal reproductive systems of two leafhopper species are described and illustrated, using both light and transmission electron microscopy, and representing two tribes of Deltocephalinae: in Chiasmini, Nephotettix cincticeps (Uhler, 1896), and in Deltocephalini, Deltocephalus vulgaris (Dash & Viraktamath, 1998). Tables comparing the morphology of male and female internal reproductive structures of these studied species are provided and indicate that the main differences are in the relative shapes, sizes, and colors of these structures. The overall structure and organization, including details of the ultrastructure, of these two leafhopper species’ male and female internal reproductive systems are very similar to those of previously studied leafhoppers. The main differences observed among species include the number of testicular follicles, the relative position of seminal vesicles and the degree of development of the accessory glands in the male, the number of ovaries, and the shape and color of the vagina and spermatheca in the female.

The genus Cicadula Zetterstedt is reported for the first time from Pakistan with a newly recorded Cicadula simlaensis Viraktamath & Yeshwanth. In addition, Platymetopius fidelis (Distant) is also rediscovered from Pakistan and studied here. A brief diagnosis along with the digital photographs of the habitus and male genitalia of both species are provided. General distribution of these species in both Palaearctic and Oriental regions is also briefly discussed.

The grassland leafhopper tribe Chiasmini (Cicadellidae: Deltocephalinae) presently comprises 324 described species worldwide, with the highest species diversity occurring in the Nearctic region but a greater diversity of genera occurring in the Old World. In China, this tribe comprises 39 described species in 11 genera, but the fauna remains understudied. The complete mitogenomes of three species of this tribe have been sequenced previously. In order to better understand the phylogenetic position of Chiasmini within the subfamily Deltocephalinae and to investigate relationships among Chiasmini genera and species, we sequenced and analyzed the complete mitogenomes of 13 species belonging to seven genera from China. Comparison of the newly sequenced mitogenomes reveals a closed circular double-stranded structure containing 37 genes with a total length of 14,805 to 16,269 bp and a variable number of non-coding A + T-rich regions. The gene size, gene order, gene arrangement, base composition, codon usage, and secondary structure of tRNAs of the newly sequenced mitogenomes of these 13 species are highly conserved in Chiasmini. The ATN codon is commonly used as the start codon in protein-coding genes (PCGs), except for ND5 in Doratura sp. and ATP6 in Nephotettix nigropictus, which use the rare GTG start codon. Most protein-coding genes have TAA or TAG as the stop codon, but some genes have an incomplete T stop codon. Except for the tRNA for serine (trnS1(AGN)), the secondary structure of the other 21 tRNAs is a typical cloverleaf structure. In addition to the primary type of G–U mismatch, five other types of tRNA mismatches were observed: A–A, A–C, A–G, U–C, and U–U. Chiasmini mitochondrial genomes exhibit gene overlaps with three relatively stable regions: the overlapping sequence between trnW and trnC is AAGTCTTA, the overlapping sequence between ATP8 and ATP6 is generally ATGATTA, and the overlapping sequence between ND4 and ND4L is generally TTATCAT. The largest non-coding region is the control region, which exhibits significant length and compositional variation among species. Some Chiasmini have tandem repeat structures within their control regions. Unlike some other deltocephaline leafhoppers, the sequenced Chiasmini lack mitochondrial gene rearrangements. Phylogenetic analyses of different combinations of protein-coding and ribosomal genes using maximum likelihood and Bayesian methods under different models, using either amino acid or nucleotide sequences, are generally consistent and also agree with results of prior analyses of nuclear and partial mitochondrial gene sequence data, indicating that complete mitochondrial genomes are phylogenetically informative at different levels of divergence within Chiasmini and among leafhoppers in general. Apart from Athysanini and Opsiini, most of the deltocephaline tribes are recovered as monophyletic. The results of ML and BI analyses show that Chiasmini is a monophyletic group with seven monophyletic genera arranged as follows: ((Zahniserius + (Gurawa + (Doratura + Aconurella))) + (Leofa + (Exitianus + Nephotettix))).

Keys to all levels of the subfamily Deltocephalinae (Hemiptera: Cicadellidae) of Pakistan are provided based on published records and original data from recent research. Checklists to the genera and species of Deltocephalinae are also given. A total of 49 genera with more than 100 species are now known from Pakistan. Two new synonyms are proposed, i.e., Cicadulina striata Ahmed, 1986 a junior synonym of Cicadulina chinai Ghauri, 1965, syn. nov. and Macrosteles parafalcatus Naveed & Zhang, 2018 a new junior synonym of Macrosteles indrina (Pruthi, 1930), syn. nov.