Identification and molecular characterization of groundnut leaf miner in Uganda

Although the leaf miner attacking groundnut in Africa has been widely reported as Aproaerema modicella (Deventer), a common groundnut (Arachis hypogaea L.) and soya bean (Glycine max (L.) Merr.), a Pest in Indo-Asian countries, a proper taxonomic identification of the pest has not been completed. A survey for species diversity of the pest was conducted on groundnut, the common host crops for leafminer species in Uganda, across 100 groundnuts farmers' fields in four agro ecological zones during the 2016-2017 growing season. 80 specimens comprising 40 larvae, 25 pupae and 15 moths of what was thought to be A. modicella (all from groundnut) were collected from the ten survey sites, and their mitochondrial DNA (mtDNA) COI were sequenced and compared with those from the BOLD gene bank. Infestation by GLM was observed on all groundnut fields sampled with Eastern Uganda being the hot ecological spot especially Namutumba district. The mtDNA COI from all specimens of the pest, matched 100% with the sequences in BOLD belonging to Aproaerema simplexella PS1, a species occurring in Australia, and known as the soya bean moth in that country. There was very little genetic diversity between and within the populations from the ten sites, which suggested that the populations were maternally of the same origin. Conclusively, this study like other studies elsewhere in Africa confirm to the fact that the leafminer attacking groundnuts and other crops such as soya bean was A. simplexella PS1 (100% match on the BOLD system), native to Australia, which suggested that Australia may be the origin of the pest not Indo-Asian countries.