Descriptions of three species of Eretmocerus Haldeman (Hymenoptera: Aphelinidae) parasitising Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and Trialeurodes vaporariorum (Westwood) (Hemiptera: Aleyrodidae) in Australia based on morphological and molecular data

Abstract

AbstractMorphological and molecular systematic investigations have confirmed the existence in Australia of three species of Eretmocerus Haldeman that parasitise either the silverleaf whitefly, Bemisia tabaci (Gennadius), or the greenhouse whitefly, Trialeurodes vaporariorum (Westwood). Two of the species Eretmocerus warrae sp. n. and Eretmocerus queenslandensis sp. n. are described. A third species is very similar to Eretmocerus mundus Mercet at both the morphological and molecular levels. However, Australian populations of E. mundus are distinct from those found elsewhere in being thelytokous, suggesting that the Australian populations are a distinct biotype; we refer to these Australian populations as E. mundus (Australian parthenogenetic form; APF) to reflect this distinction. The four gene regions investigated, mitochondrial cytochrome oxidase II, the nuclear ribosomal ITS region and the domain 2 and 3 expansion segments of the 28S ribosomal RNA gene gave separation of the species consistent with our morphological data. Studies of COII, ITS1, ITS2 and D3 indicate that these three species do not vary geographically within Australia. Field collections and laboratory studies confirm that E. queenslandensis and E. mundus (APF) parasitise only B. tabaci, while E. warrae parasitises only T. vaporariorum. Eretmocerus warrae was found across the southern half of Australia, E. mundus (APF) from northern New South Wales to northern Queensland, and E. queenslandensis in northern Queensland. The molecular data indicate that E. queenslandensis is conspecific with an undescribed Eretmocerus species from Hong Kong.