Molecular evidence for the association of swarm forming desert locust, schistocerca gregaria gregaria (Forskål) in pakistan with highly prevalent subspecies in sahara desert of africa

Abstract

Locust commonly known as short horned grasshopper is one of the most dangerous agricultural pests worldwide. There are various important species of large swarms forming of desert locusts found in different regions of the world. In early 2020, in Pakistan, huge swarm of desert locust infestation was observed in different provinces of Pakistan. Precise and correct identification of any pest is very important to start a proper control strategy against it. The current study was conducted to identify and characterize locust species and to determine their association with other swarm forming locust species worldwide. Morphological features and molecular characters were observed using digital camera and PCR technique, respectively. For molecular identification, DNA was extracted through CTAB method and polymerase chain reaction was performed using mitochondrial cytochrome oxidase I (COI) gene based primers. Gel electrophoresis of the PCR products of desert locusts indicated a 710bp amplified DNA fragment on 1.5% agarose gel. DNA sequence analysis of PCR product indicated that specimens shared a 99-100% identity with Schistocerca gregaria gregaria) (Forskål, 1775). Molecular phylogenetic analysis and evolutionary divergence study also revealed the formation of same cluster in phylogenetic tree with that of specific subspecies S. g. gregaria which further deviate genetically not only from closely related subspecies (S. g. flaviventris) but also other species reported from various countries. Migratory pattern of S. g. gregaria from Africa to Asia and neighboring countries with their potential routes also suggested developing sustainable policy to counter internal as well as external threat. This is the first report of molecular identification of S. g. grgaria and its association with most prevailed subspecies of Sahara desert in Northern Africa. Desert locust, S. g. gregaria is very destructive polyphagus pest therefore, immediately; control measures should be adopted to stop its further spread and infestation in Pakistan.