Rhopalotococcus, Williams, 2007

Williams, D. J., 2007, Scale insects of the families Asterolecaniidae and Eriococcidae (Hemiptera: Coccoidea) in New Caledonia, Journal of Natural History 41 (21 - 24), pp. 1343-1366 : 1356-1358

Rhopalotococcus gen. nov.

Type species. Rhopalotococcus dugdalei sp. nov.

Description

Adult female elongate-oval, abdomen gently tapering to narrow posterior segments, anal lobes poorly developed or apex of abdomen rounded, derm membranous but sometimes nodulose or stippled on posterior segments. Apical setae flagellate. Antennae each with six or seven segments, segments narrowing towards apical segment. Legs well developed, without translucent pores. Claw slender, with a minute denticle near tip and with knobbed digitules longer than claw. Anal ring ventral, situated a short distance from apex of abdomen, semi-circular to transversely oval, without cells, with two to four setae. Suranal setae, when present, short and pointed. Frontal lobes absent. Dorsal setae slender, flagellate. Dorsal macroducts absent. Ventral macroducts present on abdomen and in medial area of thorax. Quinquelocular pores present on venter only, either next to spiracles only or also sparse on abdomen. Microducts present or absent. Cruciform pores absent.

Etymology

The name is based on the Greek word ‘‘ Rhopalotos ’’ meaning club-shaped, alluding to the shape of the body, combined with the generic word Coccus , and is masculine.

Comments

In lacking well-developed anal lobes but possessing legs and antennae either with six or seven segments, with macroducts and an anal ring that is semicircular to transversely oval, this genus could qualify as a member of the ovaticin group as defined by Miller and McKenzie (1967). The name of the group, at present without tribal or familial status, is based on characters of the genus Ovaticoccus Kloet. Most species of Ovaticoccus , as defined by Ferris (1955), Boratyński (1958), and Miller and McKenzie (1967), possess enlarged setae but in O. californicus McKenzie , a species with slender setae only, there are macroducts and quinquelocular pores on the dorsum, and cruciform pores are present. O. senarius McKenzie also lacks enlarged setae but macrotubular ducts are present on the dorsum, and the anal ring is circular. Although O. amplicoxae Williams and Martin (2003) was doubtfully included in Ovaticoccus , the abdomen tapers, the anal ring is cellular, the setae are all slender and flagellate, quinquelocular and cruciform pores are present on the dorsum and venter, and the enlarged hind coxae possess translucent pores. These characters would exclude the species from Rhopalotococcus .

Geographically, the nearest genus to Rhopalotococcus is the Australian genus Phacelococcus Miller , as revised by Gullan and Strong (1997). There are no enlarged setae in Phacelococcus , the anal lobes are not developed to any extent, and the posterior edge of the abdomen is rounded. Macrotubular ducts may be present or absent on the dorsum and microtubular ducts are present. Other distinguishing characters of Phacelococcus are quinquelocular pores present either in dense clusters or densely scattered. Furthermore, the anal ring is circular or U-shaped and is cellular.

Although Pseudochermes Nitsche is a Palaearctic genus, it is similar to Rhopalotococcus in the shape of the anal ring but the ring in Pseudochermes is cellular as shown by Williams (1985). There are a few enlarged setae present, quinquelocular pores and macrotubular ducts are present on both the dorsum and venter, microducts are present but cruciform pores are absent.

There are two genera, possibly Gondwanan in origin in South America, that are similar to Rhopalotococcus . Tectococcus Hempel , as discussed by Ferris (1958) and in a key to South American genera of Eriococcidae by Hodgson et al. (2004), has a similar shape to that of Rhopalotococcus but there are enlarged setae on the dorsum, and macrotubular ducts and quinquelocular pores are also present on the dorsum. The galls induced by the type species, T. ovatus Hempel , apparently, are similar in shape to those induced by species of Rhopalotococcus . Another genus, Melzeria Green , discussed recently by Miller and Williams (1998), possesses dorsal macrotubular ducts with associated setae at each orifice, there are translucent pores on the hind coxae and the anal ring is circular without cells.

It would be difficult to include the two new species discussed here in any of these genera or to expand the definitions of these genera to include the species, and the only course open is to include the new species in a new genus.

Hoy (1958) described Capulinia orbiculata Hoy on Metrosideros orbiculata and M. umbellata from New Zealand but in this eriococcid species, the antennae and anterior and middle pairs of legs are reduced to tubercles, and the hind legs are in the form of elongate processes showing signs of normal segmentation. Clearly this species is not congeneric with the two new species.

The second-instar female of one of the new species of Rhopalotococcus is described but the single first-instar nymph available is incomplete and is not satisfactory to illustrate.

Key to adult females of Rhopalotococcus

1 Hind legs with tibia + tarsus conspicuously longer than those of first and second legs. Antennae seven-segmented. Microducts absent. Anal ring with two setae only, suranal setae absent............ metrosideri sp. nov.

2 Hind legs with tibia + tarsus about same size as those of first and second legs. Antennae six-segmented. Microducts present. Anal ring with four setae, suranal setae present............... dugdalei sp. nov.