Rhodania aeluropi, Williams & Moghaddam, 2007

Williams, D. J. & Moghaddam, M., 2007, A new species of Rhodania Goux (Hemiptera, Coccoidea, Pseudococcidae) and new records of two other mealybug species from Iran, Zootaxa 1398 (1), pp. 37-44 : 38-40

Rhodania aeluropi sp. nov.

( Fig. 1 )

Description

Body of adult female on microscope slide rotund, membranous, 1.25–1.35 mm long, 1.00– 1.10 mm wide. Anal lobes membranous, barely perceptible, each with an apical seta 70­80 µm long. Antennae 170–180 µm long, with 6 segments. Legs well developed, slender, small for size of body; hind coxa 35–40 µm long, hind trochanter + femur 105–125 µm long, hind tibia + tarsus 125–135 µm long. Claw about 20–25 µm long, without a denticle; claw digitules pointed, surpassing claw in length. Tarsal digitules shorter than claw digitules, pointed. Ratio of lengths of hind tibia + tarsus to hind trochanter + femur, 1.08–1.19. Ratio of lengths of hind tibia to hind tarsus 1.08–1.25. Hind coxa with fairly large translucent pores on anterior surface only. Distal trochanteral seta about 30 µm long. Labium 50–60 µm long, shorter than clypeolabral shield. Circulus absent. Ostioles absent. Anal ring narrowly rimmed, 40–50 µm in diameter, without cells, situated either at apex or up to a distance of about twice its length from apex of abdomen; with 6 short slender setae, each 30–35 µm long. Cerarii represented by a pair of long flagellate setae, 50–60 µm long, on each anal lobe only, and with a similar seta a short distance anteriorly.

Dorsal surface with short, flagellate setae, mostly 5.0–10.0 µm long except some marginal setae 15–20 µm long on posterior abdominal segments. Disc pores present, conspicuous, each about 5.0 µm in diameter, with a distinct quinquelocular centre and with about 10 outer loculi usually with indistinct walls; numerous, distributed mostly in rows across anterior and posterior edges of abdominal segments, becoming more scattered on head and thorax. Tubular ducts present, each about 7.5 µm long, 5.0 µm in diameter, with membranous collar occupying about one­third length of duct; inner end of duct heavily sclerotized; not numerous, most frequent on midline, usually on abdominal segments III–VI, and around margins, and with only a few present in submarginal and submedial areas.

Ventral surface with similar setae to those on dorsum. Disc pores as on dorsum also with a similar distribution but frequent and more scattered on head and thorax. Tubular ducts as on dorsum, present around margins and with a few present across middle of posterior abdominal segments.

Material examined

HOLOTYPE adult ♀, Iran, Khuzestan Province, Ahvaz, on Aeluropus sp. (Poaceae) , in sugarcane fields, 18.x.2005 (H. Narreii) ( PPDRI).

PARATYPES, Iran, same data as holotype, 1 adult ♀, on same slide as holotype ( PPDRI); 2 adult ♀♀ ( BMNH) .

Etymology The name is based on the host plant name Aeluropus in the Latin genitive ending meaning ‘of’ or ‘from’.

Comments

The Palaearctic genus Rhodania Goux , at present comprising 6 species, is known to occur only in Europe apart from the type species, R. porifera Goux , which extends as far eastwards as Mongolia ( Ben­Dov, 1994). All the species live on Poaceae but R. porifera is known also on Carex sp. in the related family Cyperaceae . Goux (1935) described R. porifera originally from France as: lacking cerarii, and having 7­segmented antennae and an anal ring widely rimmed with about 15 cells and 6 short, stout setae. His illustration shows the claws with knobbed digitules. Furthermore, Goux described the diameter of the disc pores as greater than the width of the tubular ducts. A good diagnostic character is the swollen hind tibia containing translucent pores. Although Goux mentioned the disc pores without discussing the loculi, they were described as quinquelocular by Ter­Grigorian (1973), Tereznikova (1975) and Kosztarab & Kozár (1988). These authors also illustrated the anal lobe cerarii with short cerarian setae.

A second species, R. flava , was described by Goux (1936) differing from R. porifera in possessing 30 cells in the anal ring, antennae with only 6 segments, and with the diameter of the disc pores smaller than the width of the tubular ducts.

Balachowsky (1936) described Ripersia parkeri from France. It was transferred later to Rhodania as Rhodania parkeri (Balachowsky) by Kozár & Walter (1985). This species has a widely­rimmed anal ring with many cells and with long, anal ring setae, trilocular pores and multilocular disc pores, each apparently with 8 loculi, present next to the spiracular openings. The hind tarsus is not swollen (as on R. festucae Hadzibejli discussed below) and Balachowsky did not mention translucent pores. It is not clear if R. parkeri is congeneric with the type species of Rhodania .

Leonardi (1908) described Ripersia hypogaea from Italy and this was also transferred later to Rhodania by Kozár & Walter (1985) as Rhodania hypogaea (Leonardi) . In Leonardi’s (1920) illustration of this species, the anal ring is U­shaped with cells and long setae, the hind tarsus is not noticeably swollen and the anal lobe cerarii are present, each with short cerarian setae.

Another species, Rhodania occulta Schmutterer , was described and illustrated from Germany by Schmutterer (1952) and later discussed by Kosztarab & Kozár (1988). This species possesses an anal ring with 36 cells and the anal ring setae are long and slender.

Although the description of Rhodania festucae Hadzibejli (1959) is written entirely in Georgian, Hadzibejli illustrated the species with a swollen hind tarsus, a wide­rimmed anal ring with 6 short setae, and 7­segmented antennae. Translucent pores were not illustrated on the hind legs.

R. aeluropi possesses characters similar to most species presently assigned to Rhodania . These characters include the absence of ostioles, trilocular pores, multilocular disc pores, circuli,, cerarii except on the anal lobes, but has short slender setae, dorsal and ventral quinquelocular pores and wide oral collar tubular ducts. The anal ring of the new species is narrowly­rimmed, differing from the wide­rimmed ring of most other species. Furthermore, the anal lobe cerarian setae of R. aeluropi are long and flagellate, differing from the short, stiff cerarian setae in the other species. Also, the new species differs from all others in having translucent pores on the hind coxae.

The host­plant genus Aeluropus is unusual for scale insects. The only species of mealybug so far recorded from this halophytic grass genus, is Mirococcopsis rubidus Borchsenius described from Tajikistan on A. littoralis . Mirococcopsis differs from Rhodania in possessing ostioles, circuli, a normal cellular anal ring and multilocular disc pores on the dorsum and venter. These characters are shown in detail in the illustrations by Ter­Grigorian (1973) of M. avetianae Ter­Grigorian and M. stipae Borchsenius from material collected in Armenia, and in M. nagyi Kozár , illustrated by Kozár (1981) from Hungary. All three species possess long, flagellate anal lobe cerarian setae as in Rhodania aeluropi but the above characters should easily separate them.

The new species is described here because it was collected in sugarcane fields and it is entirely possible that it could be found on sugarcane in the future.

Figures

FIGURE 1. Rhodania aeluropi sp. nov. Adult female.