Lachnodius newi Beardsley, Gullan & Hardy

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 newi Beardsley, Gullan & Hardy sp. n. Fig. 10

Diagnosis.

Dorsum without sclerotic invaginations; marginal fringe of curved setae; anal ring invaginated.

Description.

Adult female (n = 1). Body outline of holotype slightly oblong; length 1.98 mm, greatest width 1.35 mm. Eyes 33 μm wide. Antennae seven-segmented; length 490 μm; with seven hair-like setae on segment I, ca. four hair-like setae on segment II, ten hair-like setae on segment III, four hair-like seta on segment IV, two hair-like setae + one fleshy seta on segment V, three hair-like setae + one fleshy seta on segment VI and six hair-like setae + three fleshy setae on segment V. Tentorial box with anterior extension of the dorsal arms, 245 μm long, 168 μm wide. Labium 98 μm long, 123 μm wide. Spiracles 115-130 μm long, 75-82 μm wide across atrium. Legs increasing in size caudad; fore legs: trochanter + femur 360 μm, tibia 340 µm, tarsus 130 μm; mid legs: trochanter + femur 385 μm, tibia 350 μm, tarsus 140 μm; hind legs: trochanter + femur 390 μm, tibia 335 µm, tarsus 133 μm; claw 38-40 μm; fore coxa with six setae, mid and hind coxae each with five setae, trochanter with four setae, femur with ca. 12 setae, tibia with 14-16 setae, tarsus with ten or eleven setae; tarsal digitules 63-70 μm long, claw digitules 48 μm long; translucent pores on all segments of hind leg. Anal ring invaginated, cuticle surrounding ring sclerotic, 78 μm wide, with 12 setae; ring setae 63-75 μm long. Pair of elongate caudal setae absent.

Dorsum. Derm densely covered with sclerotic spicules (i.e., well-developed microtrichia). Sclerotic urns and varioles absent. Dorsal setae ca. 3 μm long, scattered over dorsum. Macrotubular ducts ca. 10 μm long, with rim of dermal orifice ca. 5 μm wide. Microtubular ducts ca. 5 μm long, with rim of dermal orifice ca. 2 μm wide, scattered over dorsum. Dorsum delimited by fringe of ca. 180 setae on each side of body; each seta slender and recurved, length of setae ca. 13 μm, each setal socket surrounded by irregular patch of sclerotic cuticle.

Venter. Ventral setae 10-40 μm long; elongate setae medial of each coxa decreasing in size caudad: ca. 68 μm long near fore coxa, ca. 45 μm long near hind coxa; longest setae on head ca. 105 μm long. Macrotubular ducts each ca. 15 μm long, with rim of dermal orifice ca. 5 μm wide, found along margin and in transverse band across each abdominal segment. Quinquelocular pores 5 μm in diameter, dense on posterior abdominal segments, clustered around spiracles.

Etymology.

This species is dedicated to Dr TR New, of the former Department of Zoology (now Ecology, Environment and Evolution), La Trobe University, who accompanied JWB during many collecting trips made in Victoria during 1971-72, and who guided JWB to the spot where this species was discovered. The species epithet is a noun in the genitive singular.

Notes.

The holotype is the only specimen known for this species, but it is distinctive. The specimen is relatively small and probably not fully expanded. However, the modest size of the antennae and legs, in comparison with other twig gall-inhabiting species (e.g., L. lectularius ) suggests that even fully expanded adults of L. newi would not measure much more than 4 mm long. The adult female of L. newi would be confused most easily with those of L. melliodorae , as both species have strongly recurved marginal setae. The adult female of L. newi can be distinguished from those of L. melliodorae by lacking urn-shaped sclerotic structures on the dorsum (present in L. melliodorae ). In their place are heavily sclerotized microtrichia. The adult female of L. newi can be further differentiated from those of L. melliodorae by having no dorsal macrotubular ducts with a seta touching the rim of the dermal orifice (some present in L. melliodorae ) and by lacking long setae at the middle of the posterolateral edge of antennal segment III.

Material examined.

Holotype: Victoria: adult female, on slide: ex shallow pit gall in twig, Eucalyptus viminalis , Otway Ranges, Parker Road, heath area, 27 Oct 1971 JWB, V-168 (ANIC).