The cotton leafhopper, Amrasca biguttula Ishida (Hemiptera: Cicadellidae), is a significant pest that feeds on various host plants, particularly cotton, resulting in substantial annual economic losses. Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) is an effective parasitoid that targets the eggs of various pests preventing them from hatching into harmful larvae. Its ability to be mass-reared makes it a popular choice as biological control agent in integrated pest management programs worldwide. The presence of the bacterium Wolbachia, an intracellular symbiont found in arthropods, has a profound impact on the biology of their hosts. This research examined Wolbachia strain diversity in both species using seven genes: wsp, 16S rRNA, and five housekeeping MLST genes. Additionally, the molecular identification of A. biguttula and its egg parasitoid, T. chilonis was also accomplished through the use of the cytochrome c oxidase subunit I (COI) gene. Phylogenetic exploration based on 16S rRNA, wsp, and multilocus sequence typing (MLST) revealed that A. biguttula anchorages two new Wolbachia strains along with another Wolbachia strain in its egg parasitoid, T. chilonis from supergroup (B) We enumerated Wolbachia strains in A. biguttula from both study locations in Pakistan, identifying distinct strains wAbig1 and wAbig2 for A. biguttula and wTchiB for T. chilonis. Wolbachia amplification in A. biguttula showed infection rates of 29% to 66% across seven genes, with the highest rates in Bahawalpur, followed by Faisalabad. Ten adult samples of the egg parasitoid T. chilonis from each locality were also tested, revealing infection rates of 50% to 90%, again highest in Bahawalpur. This is the first report of Wolbachia in A. biguttula populations, detecting high Wolbachia prevalence and suggesting vertical transmission. Although no additional strains were identified beyond those mentioned in the present research, further research should investigate the potential for additional strains within these populations. Wolbachia bacteria are important for pest management as they suppress pest populations, reduce disease transmission in vectors and provide pathogen resistance to hosts, while potentially increasing pest susceptibility to insecticides. As a sustainable and species-specific alternative to chemical pesticides, Wolbachia offers environmentally friendly control strategies for pests like planthoppers.
Rasool et al. (Fri,) studied this question.