Candovia robinsoni Brock & Hasenpusch, 2007

Brock, Paul D. & Hasenpusch, Jack, 2007, Studies on the Australian stick insects (Phasmida), including a checklist of species and bibliography, Zootaxa 1570 (1), pp. 1-81 : 8-13

Candovia robinsoni Brock & Hasenpusch , spec. nov. [Robinson’s Stick-insect]

( Figs. 1–12 )

Description

Male (holotype) ( Figs. 1–5 ): Small, slender dark brown insect, slightly mottled with darker flecks. Body length 40 mm.

Head: Longer than wide, eyes small. Slightly raised area between eyes, dark central longitudinal line on this elevation only, crescent shaped anteriorly. Antennae with 40 rather indistinct segments, paler alternate segments towards tip, exceeding length of fore legs.

Thorax: Elongate, mainly smooth with few sparse granulations. Pronotum marginally shorter than head, with bold central indentation and lines beneath. Mesonotum over five times length of pronotum,

Metanotum almost three times shorter. Black central spot present at posterior of mesonotum.

Abdomen: Elongate, smooth, with a few small black spots and blotches. Subgenital plate compact, reaching over half length of 9th abdominal segment; anal segment shorter than 9th abdominal segment, emarginated in centre; cerci short and slender, rounded at tip.

Legs: Slender and fairly elongate.

Paratype males (10 specimens).

Same as holotype except for minor size differences (body length 40–42 mm), but one was rather darker in life, along with the corresponding female.

Paratype females (3 specimens) ( Figs. 6–9 )

Small, plump fairly plain green insects in the wild, but a darker form, mottled with darker flecks was found in copula. Mouthparts are orange. Body length 52–61 mm.

Apart from obvious size and colour differences, description as in male. In the female, however, the abdomen is carinate, with several lines. End of anal segment subtruncate, slightly emarginated in centre. Operculum flat, tapering sharply to almost pointed tip, just exceeding end of 9th abdominal segment. The smaller ♀ (AMSA) has the left leg and right tibia broken off and missing.

Egg ( Fig. 12). Almost oval, heavily sculptured and rugged capsule, broad central micropylar plate, darker, inset, with surrounding area swollen. Operculum flat, except for short capitulum, minimal sculpturing present. Capsule length 2.2 mm, width 1.2 mm, height 1.4 mm.

Holotype ♂, Australia: New South Wales, Barren Grounds Nature Reserve , Nr. Robertson, 14.ii.2007, P.D. Brock ( AMSA) . Paratypes: All Australia: ♂, same data ( AMSA), ♀, same locality, iii.2000 M. Robinson ( AMSA), ♂, ♀, New South Wales, Rose Ella, Mt. Murray, Nr. Robertson, 15.ii.2007, P.D. Brock ( ANIC), 4♂, New South Wales, Springcroft, Mt. Murray, Nr. Robertson, 15.ii.2007, P.D. Brock ( BMNH), ♂, ♀, New South Wales, Rose Ella, Mt. Murray , Nr. Robertson, 15.ii.2007, P.D. Brock ( BMNH), 3♂, New South Wales, Springcroft, Mt. Murray , Nr. Robertson, 15.ii.2007, P.D. Brock (P.D. Brock coll.). Eggs (not paratypes) have also been deposited in each collection mentioned above .

Distribution

So far found in pockets of temperate rainforest in a small part of the Southern Highlands, New South Wales, near Robertson , but likely to be reasonably widespread. In addition to the localities / specimens mentioned, nymphs were observed just outside Barren Grounds Nature Reserve and at Robertson Nature Reserve . It may be the same species collected at Barrington Tops , New South Wales ( ANIC, listed as ‘ Parasipyloidea sp. 13, ♂ c. 43mm, ♀ c. 68mm), but this ‘form’ has rather longer cerci in the female; eggs are similar .

Notes

This species is easily distinguished from other Candovia species by its short size (males of other species are 50 mm +, females 70mm +) and stout appearance of the female. At Barren Grounds, several nymphs and two adult males were exclusively found on Lomandra (Lomandraceae) , an unusual phasmid food plant. However, this species turned out to be a versatile feeder observed on Acer palmatum (Aceraceae) , Doryphora sassafras (Monimiaceae) , Hypericum (Clusiaceae) , Magnolia (Magnoliaceae) and Rosa (Rosaceae) . Numerous nymphs were found on one small Hypericum shrub along the roadside, also a darker coloured mating pair ( Fig. 11 ), giving these individuals a rather different appearance. In different conditions, these insects gradually changed colour. The orange mouthparts in females may be a warning to possible predators, in any case these insects readily emit a secretion when disturbed, otherwise remain remarkably well hidden in the daytime.

Derivation of name

Named after Martyn Robinson (Australian Museum, Sydney), a very knowledgeable naturalist who informed the authors about this delightful little species, prompting a search for these insects in the Robertson area.

*(paratypes 40–42 mm) +Apart from length, other measurements exclude the 52mm specimen

Figures

FIGURE 1. Candovia robinsoni holotype male (AMSA), 40 mm.

FIGURE 2. Candovia robinsoni end of abdomen in FIGURE 3. Candovia robinsoni end of abdomen in holotype holotype male, dorsal view. male, lateral view.

FIGURE 4–6. Candovia robinsoni. 4. end of abdomen in holotype male, ventral view. 5. male on Lomandra. 6. Candovia robinsoni female paratype (AMSA), 52 mm

FIGURE 7–9. Candovia robinsoni. 7. end of abdomen in female paratype (BMNH), dorsal view. 8. end of abdomen in female paratype (BMNH), lateral view. 9. end of abdomen in female paratype (BMNH), ventral view.

FIGURE 10. Candovia robinsoni mating pair (Mt. Murray), female feeding on Rosa flower.

FIGURE 11. Candovia robinsoni mating pair (Mt. Murray), unusual darker colour form.