Luzulaspis Cockerell, 1902

Tanaka, Hirotaka, Sasaki, Daisuke & Kamitani, Satoshi, 2021, A new species of the genus Luzulaspis (Hemiptera: Coccomorpha: Coccidae) from Hokkaido Island, Japan, Zootaxa 4985 (3), pp. 414-422 : 415-416

Genus Luzulaspis Cockerell, 1902

Generic diagnosis (slightly modified from Kosztarab & Kozár 1988).

Adult female. In life, waxy ovisac elongate, almost parallel sided, white, 3–6 mm long, covering dorsum of adult female almost entirely. Post-reproductive female sclerotized, ovisac shrinking and falling off, except for when specimens have been parasitized. Teneral female elongate, parallel sided, with both ends rounded or slightly tapered; dorsum flat or slightly convex; venter almost flat; typically, body yellowish with or without 2 red dorsal longitudinal stripes.

Dorsum. Body setae of different shapes and sizes, ranging from small hair-like to large conical setae, but all relatively short (each up to 20 μm long on head) and sparse (with up to 20 setae within an area between the antennal bases and procoxae on the venter). Preopercular pores, each 3–6 μm in diameter, forming a medial longitudinal band on thorax and abdomen. Tubular ducts numerous. Anal ring 45–80 μm in diameter, bearing 6 setae, each 110–180 μm long. Anal plates triangular, each with 4 apical setae.

Margin. Marginal setae spine-like or hair-like; different types of setae not intermixed.

Venter. Antennae slender, each with 8 segments. Labium cube shaped, with 5 pairs of setae; stylet loop approximately same length as labium. Legs slender, anterior legs always shortest; tibio-tarsal articulatory sclerosis present; claw digitules large, each with an expanded apical knob. Spiracular pore bands mostly composed of quinquelocular pores; each spiracular cleft containing 2 subequal, enlarged spiracular setae. Body setae of various lengths; interantennal setae of various lengths (up to 150 μm long), usually numbering 10–25 but rarely over 30 (up to 33 setae). Multilocular pores mostly each with 8–10 loculi, although sometimes with fewer or more loculi, forming transverse bands across abdominal sternites V‒VII, rarely on anterior segments. Tubular ducts of various sizes. Microducts, each 1.0–1.5 μm in diameter, normally forming a submarginal row, present also on medial areas of head, thorax, and on abdomen in some species.

Remarks. Luzulaspis is most closely related to Poaspis Koteja, 1978 , with respect to the distribution of the large ventral setae, the number of stigmatic spines, structure of the dorsal setae, and claw digitules ( Çalýþkan et al. 2015, Hodgson 1994, Koteja 1978, 1979b). To differentiate these genera, Koteja (1978) proposed in his key to genera of “Eriopeltini” that species of Luzulaspis differ from those in Poaspis in having claw digitules each with the apical knob wider than the width of the claw. However, at least a few Luzulaspis species do not have this character state, as was evident in his illustrations ( Koteja 1979b, Figs 4–5). Hodgson (1994) proposed that members of Luzulaspis have no more than 30 well-developed, long ventral setae between the antennal bases. However, in this study, we have established that this character state may not be a strict criterion for distinguishing the genera (see below). Accordingly, we suggest that the relationships between species assigned to Luzulaspis and Poaspis should be re-examined based on molecular phylogenetic analysis and evaluations of other potentially relevant morphological character states.

To distinguish Luzulaspis from Poaspis , we tentatively propose to use the number of well-developed, long ventral setae between the antennae, as did Hodgson (1994). However, we also propose here that the criterion should be looser than in Hodgson (1994); if the number of well-developed interantennal setae of the species is 33 or less, the species is considered to belong to Luzulaspis ; but if the number is 35 or more, the species is considered to belong to Poaspis . Furthermore, possession of numerous dorsal setae within an area between the antennal bases and procoxae on the venter (about 20–40) ( Koteja 1979a), and evenly scattered and comparatively long dorsal setae (about 20–40 μm on head) ( Koteja 1978) are both character states exclusive to Poaspis . These morphological characters may be helpful for assignment of species to these genera.