Neoseiulus, HUGHES, 1948

Tsolakis, Haralabos, Tixier, Marie Stephane, Kreiter, Serge & Ragusa, Salvatore, 2012, The concept of genus within the family Phytoseiidae (Acari: Parasitiformes): historical review and phylogenetic analyses of the genus Neoseiulus Hughes, Zoological Journal of the Linnean Society 165 (2), pp. 253-273 : 257-258

NEOSEIULUS HUGHES, 1948

The previously mentioned literature led to the formulation of two theories supporting supra-specific classification within the family Phytoseiidae . The genus Neoseiulus is useful for illustrating how these two theories differ and have been applied ( Ragusa & Athias-Henriot, 1983; Chant & McMurtry, 2003a). Each theory has produced a different definition of this genus, and Table 2 details the characters used for each definition. The first definition considers the shape of the insemination apparatus as a key character (apomorphy), as proposed by Athias-Henriot (1977, 1978) in the revision of the genera Cydnodromus Muma 1971 and Dictydionotus Athias-Henriot 1979 (= Dictyonotus Athias-Henriot, 1978 ), and as subsequently proposed by Ragusa & Athias-Henriot (1983) in the revision of the genus Neoseiulus . In the second definition, which is currently the most commonly used and which was reported by Chant & Yoshida-Shaul (1989), the key characters (apomorphies) are the presence/absence of idiosomal setae. These latter authors report (l.c. 223): ‘However, it is important for the reader to understand that in the present paper we are not proposing a classification system nor are we suggesting that the setal patterns reported in it represent taxa in any formal sense. This paper is intended simply to report all known dorsal setal patterns observed in the family.’ Nevertheless, these patterns were subsequently used in all taxonomic revisions carried out by Chant & McMurtry (1994, 2003a, b, 2004a, b, 2005a, b, c, 2006a, b, 2007).

Chant & McMurtry (2003a: 3) considered 268 species in the genus Neoseiulus , which they placed in the tribe Neoseiulini . Beyond the dorsal and ventral setal pattern, generic diagnosis is also based on ratios of length/width of the shields, the length of some dorsal setae, the length of peritreme, and the presence of macrosetae on legs ( Table 2). They also considered the shape of the insemination apparatus for distinguishing between species sub-groups (in the taxonomic keys provided). Ragusa & Athias-Henriot (1983), on the other hand, included only 17 species in the genus Neoseiulus . Their generic diagnosis is based essentially on the shape of the insemination apparatus, and then considers other associated characters, i.e. idiosomal chaetotaxy, dorsal adenotaxy, and position of solenostome gv3.

All the above-mentioned studies underline the difficulty in identifying valid supra-specific groups (i.e.

Ragusa & Athias-Henriot (1983) Chant & McMurtry (2003a)

Insemination apparatus *:

Adductor duct about as long as calyx, broad, soft. Accessus large, strongly indentated, thick walled, not separated from trivium by a diameter modification. Trivium prominent, globular to oviform, as wide as or slightly wider or narrower than calyx base, fused to this base but never projecting on calyx bottom. Calyx basically tubular, from 2 to 6 times longer than its average diameter.