Unaspis MacGillivray, 1921

Niu, Minmin & Feng, Jinian, 2019, Two new species of the genus Unaspis MacGillivray, 1921 (Hemiptera: Coccomorpha: Diaspididae) from China, Zootaxa 4555 (4), pp. 573-580 : 575

Genus Unaspis MacGillivray

Unaspis MacGillivray, 1921: 308 .

Type species. Chionaspis acuminata Green by monotypy and original designation.

Generic diagnosis. Scale cover of adult female brownish, elongate, usually with a median longitudinal ridge; exuviae terminal. Scale cover of second-instar male white, felted, elongate and with a median ridge.

Diagnosis. Body elongate, nearly fusiform, widest at metathorax or abdominal segment I. Derm membranous or sclerotized throughout on the cephalothorax and abdominal segment I. Antennae each with 1 or 2 setae, occasionally more. Anterior spiracle associated with a compact cluster of disc pores, posterior spiracle with usually fewer or no associated disc pores.

Pygidium with margin slightly rounded. Median lobes usually well developed, rounded or serrate, non-zygotic, with a pair of minute marginal setae between the bases; in some species, median lobes parallel and separated from each other by quite a wide space, but in other species set close together basally and divergent distally. Second lobes bilobulate, lobules well developed and rounded. Third lobes similar to second in shape and size. Gland spines well developed, absent from between median lobes; usually present singly or in pairs between other lobes, more numerous on margins of free posterior abdominal segments; becoming conical duct tubercles on the ventral surface on more anterior abdominal segments.

Marginal macroducts usually numbering 7 on each side of pygidium: absent from between median lobes, each side with 1 between median and second lobes (on abdominal segment VII), and 2 on each of segments IV, V and VI. Dorsal macroducts numerous, scattered loosely over whole pygidium. Ventral conical duct tubercles sometimes present. Anus rounded, situated near centre of pygidium. Perivulvar pores present or absent ( Rao 1949, Tang 1986, Williams and Watson 1988, Zeng 2000, Watson 2015).

Comments. Members of this genus, like others in the subfamily Diaspidinae, have an elongate body and bilobulate second pygidial lobes. Unaspis is distinguished from other genera, especially Chionaspis Signoret (1868) , by having non-zygotic median lobes; moreover, the dorsal ducts are numerous and scattered loosely over the whole pygidium in Unaspis , in contrast to those in Chionaspis . Lepidosaphes Shimer, 1868 is similar to Unaspis in body features, but differs by having a pair of gland spines between the median lobes that are absent in Unaspis .