Lachnodius sealakeensis 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 sealakeensis Gullan & Hardy sp. n. Figs 2d, 12

Diagnosis.

Dorsum with dermal orifice of each microtubular duct surrounded by sclerosis; marginal fringe of truncate setae; dorsal setae capitate; anal ring invaginated.

Description.

Adult female (n = 16). Body outline oval; length 0.84-1.45 mm (1.18 mm for holotype), greatest width 0.70−1.28 mm (0.90 mm for holotype). Eyes not apparent. Antennae seven-segmented; length 230-355 μm; with two hair-like setae on segment I, one hair-like seta on segment II, one hair-like seta on segment III, two hair-like seta on segment IV, one fleshy seta on segment V, two 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, 138-190 μm long, 123-155 μm wide. Labium 60-75 μm long, 60-100 μm wide. Spiracles 45-68 μm long, 25-35 μm wide across atrium. Legs increasing in size caudad; fore legs: trochanter + femur 165-250 μm, tibia 105-175, tarsus 80-125 μm; mid legs: trochanter + femur 165−263 μm, tibia 105-165 μm, tarsus 90-125 μm; hind legs: trochanter + femur 190-275 μm, tibia 110-175, tarsus 85-125 μm; claw 28-38 μm; fore coxa with six setae, mid and hind coxae each with five setae, trochanter with four setae, femur with 6-8 setae, tibia with 6-8 setae, tarsus with 7-9 setae; tarsal digitules 45-60 μm long, claw digitules 25-40 μm long; translucent pores on all segments of hind leg. Anal ring invaginated, cuticle surrounding ring sclerotic, 38-75 μm wide, with 10-12 setae; ring setae 40-73 μm long. Pair of elongate caudal setae absent.

Dorsum. Derm covered with sclerotic spicules (i.e., well-developed acanthae or microtrichia). Sclerotic urns and varioles absent but dermal orifice of each microtubular duct surrounded by sclerotic region. Dorsal setae capitate 5-7 μm long, scattered over dorsum. Macrotubular ducts absent. Microtubular ducts ca. 5 μm long, with oral rim ca. 2 μm wide, scattered over dorsum. Dorsum delimited by fringe of 110-150 setae on each side of body, each seta subconical, most setae with truncate, serrated apices, a few setae with acute apices, length of setae 25-45 μm.

Venter. Ventral setae 10-30 (mostly 20-25) μm long; elongate setae medial of each coxa decreasing in size caudad: 50-80 μm long near fore coxa, 25-30 μm long near hind coxa; longest setae on head 63-123 μm long. Macrotubular ducts each ca. 15 μm long, with oral rim ca. 5 μm wide, duct shaft subtending vestibule constricted; in transverse band across each abdominal segment. Quinquelocular pores of one size-classes: 4-5 μm in diameter, on posterior abdominal segments and around margin, small clusters around spiracles.

Etymology.

The species name refers to the type locality, Sea Lake, Victoria. The name is an adjective with the suffix derived from the Latin -ensis, denoting place or locality.

Notes.

Adult females of L. sealakeensis are most superficially similar to those of L. maculosus ; both species occur under bark, have an invaginated anus, and relatively robust, subconical marginal setae. Adult females of L. sealakeensis can be readily distinguished from those of L. maculosus by (i) the lack of dorsal macrotubular ducts (two size-classes present in L. maculosus ); (ii) dorsal microtubular ducts with sclerotic surrounds (these are unique among Sphaerococcopsis and Lachnodius spp.); (iii) capitate dorsal setae (lanceolate in L. maculosus ); and (iv) the ventral surface of abdomen with macrotubular ducts with the shaft constricted distally (not constricted distally in L. maculosus ). Capitate dorsal setae like those of L. sealakeensis are also present on adult female of Sphaerococcopsis platynotum Beardsley and S. umbilicus Beardsley. These differ from L. sealakeensis in having (i) 6-segmented antennae (7-segmented in L. sealakeensis ); (ii) hind legs much larger than fore and mid legs (all legs subequal in L. sealakeensis ); and (iii) venter much larger than dorsum (venter and dorsum subequal in L. sealakeensi ).

This is the only species treated here that was not part of JWB’s view of Lachnodius since the only known specimens were not collected until after his death. NBH and PJG share authorship of its name.

Material examined.

Holotype: Victoria: adult female, on slide: ex pit under loose bark of Eucalyptus oleosa , ca. 6 km N of Sea Lake, intersection of Lake Tyrell Road and Calder Highway, 35.45S, 142.83E, NBH and PJG, 5 Feb 2005 (ANIC). Paratypes: Victoria: 17 adult females (all on separate slides), same data as holotype, one female is DNA voucher NH47 (ANIC except 2 slides in NMV; also 2 slides deposited in QDPC in 2009 but could not be located in 2018).