Lachnodius hirsutus (Froggatt, 1921)

Hardy, Nate B., Beardsley Jr, John W. & Gullan, Penny J., 2019, A revision of Lachnodius Maskell (Hemiptera, Coccomorpha, Eriococcidae), ZooKeys 818, pp. 43-88 : 43

Lachnodius hirsutus (Froggatt, 1921) Figs 1f, 6

Pseudopsylla hirsutus Froggatt, 1921: 6.

Lachnodius hirsutus Beardsley, 1982: 31-35.

Diagnosis.

Gall of adult female covers portion of dorsum; venter hirsute; anal ring with few setae and pores; microtubular ducts absent.

Description.

Adult female (n = 6). Body outline circular to oval; length 3.2-6.8 mm (3.2 mm for lectotype), greatest width 3.1-6.1 mm (3.1 mm for lectotype). Eyes 75-105 μm wide, on margin. Antennae six-segmented; length 850-1320 μm; with 3-4 hair-like setae on segment I, 8-18 hair-like seta on segment II, 8-11 hair-like seta on segment III, 9-15 hair-like seta on segment IV, 5-6 hair-like + one fleshy seta on segment V, and six hair-like setae + three fleshy seta on segment VI. Frontal lobes 275-750 µm long, 200-400 µm wide. Tentorial box 600-950 μm long, 200-450 μm wide, with anterior extension of the dorsal arms. Labium 200-270 μm long, 210-290 μm wide. Spiracles 250-360 μm long, 190-300 μm wide across atrium. Legs robust, increasing in size caudad, fore leg: trochanter + femur 940-1440 μm, tibia 810-1260 µm, tarsus 350-500 μm; mid leg: trochanter + femur 1020-1460 μm, tibia 890-1280 µm, tarsus 370-520 μm; hind leg: trochanter + femur 1280-1620 μm, tibia 1100-1380 µm, tarsus 500-560 μm; claw 110-160 μm; coxa with 20-44 setae, trochanter with 20-31 setae, femur with 30-70 setae, tibia with 37-75 setae, tarsus with 20-30 setae; tarsal digitules 80-95 μm long, claw digitules 68-85 μm long; translucent pores on all segments of hind leg. Anal ring 130-140 μm wide, ring thickening caudad, with 5-7 setae; ring setae 50-80 μm long. Pair of elongate caudal setae absent.

Dorsum. Derm membranous, nodulose. Dorsal setae 13-25 μm long, each tapering evenly from base to apex, scattered over dorsum. Macrotubular ducts with rim of dermal orifice 5-6 µm in diameter, duct shaft 15-18 µm long, distal (near vestibule) end constricted, ducts scattered over dorsum. Microtubular ducts absent. Dorsum delimited by dense fringe of elongate setae, each 200-455 µm long, ca. 250 setae in total on each side of body.

Venter. Ventral setae 75-210 μm long, distributed densely; elongate setae medial of each coxa 170-305 μm long; longest setae on head 260-360 μm long. Macrotubular ducts similar to those on dorsum, found wherever setae occur, in transverse band across each segment, and along submargin. Quinquelocular pores absent.

Notes.

The adult female of L. hirsutus can be distinguished from all other species by the combination of 6-segmented antennae, extremely long marginal setae (350-450 µm long), and the scarcity of quinquelocular pores, which occur only near the spiracular openings. The anal ring of L. hirsutus is also unique among Lachnodius species; it has six or fewer ring setae present, with only a few minute pores near the base of each seta.

In his redescription of this species, Beardsley (1982) omitted the length of the fourth segment from the antennal formula. The correct segment lengths (µm), from the base to the apex, are: 150, 120, 400, 200, 130, and 50. Froggatt (1921: 6) stated "The female coccids produce solid woody galls on the branchlets of eucalypts with an irregular opening on the upper surface (Fig. 1f). At female maturity, the gall of L. hirsutus probably splits open at the apex to reveal the female, because enclosed globular twig galls of nymphs have been collected in association with galls resembling those of L. hirsutus ( Gullan et al. 2005). It is not clear whether the host genus of Froggatt’s type material was Corymbia or Eucalyptus , since the original description simply says "an undetermined species of eucalyptus [sic]". The bloodwood eucalypts were not recognized as a genus ( Corymbia ) separate from Eucalyptus until more recently ( Hill and Johnson 1995).

Material examined.

Lectotype [designated by Beardsley (1982)]: Northern Territory: adult female, on slide: ex open top twig gall, Eucalyptus sp., Port Darwin, G. F. Hill, Froggatt # 629, ASCTHE101343 (ASCU); this specimen was remounted from an original Froggatt slide by JWB in April 1972. Paralectotype: Northern Territory: one adult female: same data as lectotype, ASCTHE101342 (ASCU). Additional material: Northern Territory: three adult females: ex galls on stems, Corymbia nesophila , Gunn Point, 9 July 1987, LR Miller (ANIC); Queensland: one adult female: ex gall on stem, E. tetradonta , Iron Range Nat. Park, 4.2 km E of Cooks Hut campground, on road to Portland Roads, 79 m, 12.71S, 143.32E, 21 Sep 2006, LG Cook, LGC00642 (body with 2 intact legs), NH122, NH151, NH159 (NH numbers are for individual DNA-extracted legs) (ANIC).