Liriomyza trifoli (Burgers) and L.huidobrensis (Blanchard) (Diptera: Agromyzidae) occur on many agricultural and ornamental plants in Mauritius. The former is recorded on about 24 plants species and the latter on 18. With such a wide spectrum of host plants (crops, ornamental and weeds) and coupled with a high biotic potential, these two species can build up high populations during favourable climatic conditions.