Taxonomy and biological control: Neoseiulus cucumeris (Acari : Phytoseiidae), a case study

The predatory mite Neoseiulus cucumeris (Oudemans) (Acari: Phytoseiidae) is an important biological control agent of thrips and other smell pests worl dwide. Yet, despite its economic importance, this: species is poorly define d taxonomically and cannot be reliably separated from Other species on the basis of morphology alone. Neoseiulus cucumeris has been reported from Aust ralia, although considerable confusion exists as to whether the Australian material is actually N. cucumeris or a presumed endemic species, Neoseiulus bellinus (Womersley). A morphological investigation of N, bellinus and sev eral geographical 'strains' of N. cucumeris demonstrated that: (i) N. belli nus is a distinct species, the males of which can bo morphologically separa ted from those of N. cucumeris, using setal and chemical lengths and number of teeth on the fixed digit: and (ii) N. cucumeris, or a morphologically i dentical species, is present in Australia. Despite behavioural differences, there are no significant morphological differences between the 'strains' o f iv. cucumeris. Biosystematic research is a more reliable method of specie s separation. and such a method is suggested for future work with phytoseii d mites.