Nysius caledoniae Distant, 1920

Eyles, A. C. & Malipatil, M. B., 2010, Nysius caledoniae Distant, 1920 (Hemiptera: Heteroptera: Orsillidae) a recent introduction into New Zealand, and keys to the species of Nysius, and genera of Orsillidae, in New Zealand, Zootaxa 2484 (1), pp. 45-52 : 46-49

Nysius caledoniae Distant, 1920

( Fig. 1−4, 6−7 )

Length 4.05−4.56 (female 4.37−5.05); width 1.25−1.48 (1.54−1.72). Head: width 1.13 (1.21); vertex width 0.56 (0.62); length of face 0.84 (0.93); anteocular length (measured with head tilted back to bring that part into the horizontal plane) 0.33 (0.38); distance between anterior of eye and apex of antennal tubercle 0.12 (0.13). Antennae: length of segments 0.33: 0.75: 0.60: 0.80 (0.34: 0.77:0.63: 0.81). Labium: length 2.05 (2.24). Pronotum: length 0.88 (0.97); width at posterior 1.36 (1.54). Scutellum: length 0.62 (0.68); width 0.82 (0.90). Corium: length 2.10 (2.39); length of basal (parallel-sided) part of embolium before arcuation 0.60 (0.64). Membrane: length 1.92 (2.14); length of part posterior to apex of corium 1.06 (1.14).

Colour ( Fig. 1, 2 ): Stramineous, with dark brown to black markings mainly on head, pronotum, and scutellum. Head black or brown with a wide mid-longitudinal orange stripe (sometimes partly obscure). Eyes reddish-brown, with inner margin yellow. Antennae stramineous or orange; first segment yellow, with a subapical brown band on outer half, and a brown band or part band in middle; second and third segments brown at extreme base (second sometimes brown at apex); fourth segment sometimes darker at apex. Bucculae pale.

Pronotum stramineous, with subanterior black transverse band; posterior lobe with four brown blobs near posterior margin, and three longitudinal brown stripes (one on midline). Scutellum with tri-radiate ridge orange or pale at least at extremities; remainder usually brown or black, except for lateral margins. Hemelytra with the following brown: claval commissure, usually two spots at base of clavus (at least one on inner margin), base of embolium, three spots along apical margin of corium, and one on vein Cu near middle (rarely absent). Membrane hyaline.

Legs stramineous; femora with small brown spots. Tibiae brown at base and apex; first tarsomere brown at apex; third tarsomere brown. Ventral surface in male with evaporating area (around ostiolar peritreme) pinky-mauve; peritreme white, with posterior margin sometimes pink. Coxal covers white. Propleuron with anterior and posterior margins orange. Metapleuron pale on posterior margin. Remainder of underside mainly dark brown, abdomen in posterior third pale mid-ventrally, and with a pale longitudinal stripe laterally. Female similar, with more pale on abdomen; some females with fourth antennal segment darker (orangebrown).

Structure: Macropterous; sides of narrow straight basal part of embolium parallel before arcuation ( Fig. 1, 2 ); costal margin moderately arcuate (less arcuate than in N. huttoni ). Pronotum, scutellum, and hemelytra with long erect or semi-erect setae as well as short decumbent pubescence. Dorsal surface of head distinctly punctate in longitudinal rows, the spaces between rows appearing as prominent longitudinal ridges. Three or four punctures at posterior of clypeus often forming a distinct wide V-shaped trough. Dorsum sunken below level of top of eyes, and relatively flat or level. Labium reaching hind coxae. Scutellum with apex rounded and upturned. Hemelytra with a full double row of punctures following claval suture (one row on each side of the suture). Paramere ( Fig. 6, 7 ) elongate, not sharply curved.

NYMPH (fifth instar): Colour: Brown and pale yellow, abdomen with much red. Head, pronotum, and anterior two-thirds of wing pads, with alternate pale yellow and brown longitudinal stripes ( Fig. 3 ). Antennae black. Under surface of head with a wide pale stripe. Anterior margin of pronotum pale yellow. Area behind pronotum with two wide pale yellow longitudinal stripes near midline. Posterior third of fore wing pads mostly dark brown. Hind wing pads pale yellow on visible (inner) part. Dorsal surface of abdomen with small pale yellow spots on red ( Fig. 4 ). Femora dark brown to black, with apices pale. Tibiae brown, with apices dark; becoming progressively paler towards base (hind tibia with a broad paler band near base).

Measurements from a single nymph: Length 3.63; width 2.17. Head: width 1.14; vertex width 0.75; length of face 0.80; anteocular length 0.38; distance between anterior of eye and base of antenna 0.16. Antennae: length of segments 0.23: 0.50: 0.40: 0.66. Labium: length 1.70. Pronotum: length 0.65; width at posterior 1.63; width of lateral carina 0.08. Wing pad: length (from pronotum) 1.20; width of lateral carina 0.10.

MATERIAL EXAMINED. New Zealand (13 specimens): 1 male, 1 female Auckland Botanic Gardens, African Garden , 23 Feb 2007, T. Marais & O. Prouse ; 1 male, African Garden , on buttonbush shrub, Berzelia lanuginosa (Bruniaciae) 5 Dec 2007, A. C. Eyles ; 4 males, 5 females, 1 fifth instar nymph Auckland, Bastion Point , on Senecio in flower, 4 Dec 2007, A. C. Eyles .

Lord Howe Island (18 specimens): 5 males, 5 females, The Clear Place , on Sonchus asper , 12 Dec 2002, A. C. Eyles ; 2 males, 2 females same data except taken on Cassinia tenuifolia in flower ; 1 female same data except on batswing fern ; 1 male, 2 females Lagoon Beach , on Cakile edentulata , 8 Dec 2002, A. C. Eyles .

Deposited in New Zealand Arthropod Collection, Landcare Research, Auckland, New Zealand ( NZAC) ; Plant Health and Environment Laboratory, MAF Biosecurity New Zealand, Ministry of Agriculture and Forestry , Auckland, New Zealand ( PANZ) ; Museum of New Zealand Te Papa Tongarewa, Wellington, New Zealand ( MONZ) ; Lincoln University, Lincoln, New Zealand ( LUNZ) ; the Australian Museum, Sydney ( AM) ; and Victorian Agricultural Insect Collection, Department of Primary Industries, Knoxfield , Australia ( VAIC) .

DIAGNOSIS: Nysius caledoniae is distinguished from N. huttoni by the much larger size (4.05−5.05 mm vs. 2.38−4.34 mm), much paler third and fourth antennal segments, flatter vertex, longitudinal ridges on dorsum of head, conspicuously long macropterous form in all specimens seen,⎯with basal part of embolium parallel and longer before arcuation, the rounded upturned apex of scutellum, and by the longer and less sharply curved paramere (compare Fig. 6−7 with Fig. 8−9 ). Fifth instars are distinguished from those of N. huttoni by the larger size, greater head width, and presence of alternate yellow and brown longitudinal stripes on wing pads and pronotum (compare Fig. 3−4 with Fig. 5 ).

DISTRIBUTION: In New Zealand, so far known only from Auckland. Between 28 February and 2 March 2010 A. C. Eyles looked briefly for this bug, mainly on Sonchus at some roadside places between Stratford, Taumarunui, Te Kuiti, and Mangakino, but did not find it. D. A. Slade, a horticultural consultant, also kept an eye out for this species during March 2010 when examining crops of lettuce, radicchio ( Cichorium intybus ), calla and flowers in Northland, Auckland, Bay of Plenty, Waikato, and Wairarapa, and of mainly calla, lettuce and capsicum in Canterbury, but he did not see any Nysius .

Taking into account the five synonyms ( Malipatil 2010), we can now give a more accurate wider distribution: Tasmania and Australia; the string of islands: Lord Howe, Norfolk, New Caledonia, New Hebrides, Vanuatu, Solomons, Caroline, Marianas, Philippines, Bonin; then going east: Fiji, Samoa, Niue, Hawaii (accidental introduction ⎯see Ashlock [1967]); and finally going west: Christmas and Cocos Islands. N. caledoniae is a relatively widespread species. It was readily dispersed by humans especially during the Second World War ( Sweet 2000). A more detailed distribution must await examination of localities on the many specimens in collections, particularly in the Bernice P. Bishop Museum, Honolulu.

HOST PLANTS: The preferred food of N. caledoniae appears to be Asteraceae : Emilia and Erigeron ( Usinger 1946) ; Sonchus oleraceus , Erigeron linifolius , and Gnaphalium purpureum ( Evans 1929) ; Cotula coronopifolia ( Evans 1936) ; and our own herein recorded findings on Sonchus asper , Cassinia tenuifolia , Senecio , and the wild brassica Cakile edentulata . In Hawaii it breeds abundantly on a variety of weeds: Emilia sonchifolia , Erigeron canadensis , Sonchus oleraceus , Pluchea indica , and P. odorata ( Sweet 2000) .

LIFE HISTORY: Whether Smith’s (1927) life history study was on N. vinitor Bergroth, 1891 or N. clevelandensis Evans, 1929 [= N. caledoniae ] is unclear, and may well have been on both species. It certainly included N. clevelandensis , as the type male has, among other labels, “J. H. Smith,” “ Nysius sp. female and male (in cop.) lab. 22,” and “Loc⎯Cleveland” (see Malipatil 2010). Evans (1936) noted that Smith’s study was probably on N. clevelandensis . However, Smith’s (1927) figures of the adults, when one considers the shape of the costal margin basally, are clearly of N. vinitor (compare with figures in Evans 1929, and Malipatil 2010). Evans (1929) stated that the material sent by Mr R. Veitch contained both species. Further, in a footnote on the front page of the paper by Smith (1927), initialled “R. V.,” Mr Veitch makes it clear that the specimens he sent to London were a sample of the “insect dealt with in this paper.”

In case the adults figured were not reared, a check of labels on J. H. Smith material of N. vinitor in the British Museum of Natural History, London (NHM), and in Brisbane’s Queensland Museum (QM) and Queensland Department of Primary Industries and Fisheries (QDPI) collections, would settle the matter if any has a laboratory number or other evidence such as the word “reared.” M. Webb informs us (personal communication) that the NHM holds none of Smith’s N. vinitor material (only N. clevelandensis ), which indicates to us that the N. vinitor material was returned to Australia, probably via Evans. C. Burwell advises that QM does not hold any of Smith’s N. vinitor material. The J. W. Evans collection is housed in AM, but does not contain any specimens of Nysius (D. Britton, personal communication). At the time of writing, the QDPI collection was packed ready for relocation, so any possible resolution of this matter must meanwhile remain on hold.

REMARKS: Eyles and Ashlock (1969) mention an undescribed Lord Howe Island species of Nysius (which P. D. Ashlock had seen) which has a full double row of punctures following the claval suture. We are certain that this is that species. It was never described as a distinct species from Lord Howe Island, has now reached New Zealand where it has become established in Auckland, and, following publication of Malipatil’s (2010) revision, can now be named and identified as N. caledoniae .

Figures

FIGURES 1−9. 1−4 Nysius caledoniae: 1, male (Pukekohe); 2, male (on left) and female (Bastion Point); 3, fifth instar showing dorsal markings on head and thorax (Bastion point); 4, another view of same to show abdominal markings (body length 3.63 mm, head width 1.14 mm). 5, Nysius huttoni fifth instar (mean body length 2.52 mm, mean head width 0.78 mm) [from Eyles (1960)]. 6−9 left paramere: 6, of N. caledoniae in situ dorsal view (Auckland Botanic Gardens); 7, same when turned slightly to the left; 8, of N. huttoni dorsal view (Waipukurau); 9, same one-quarter turn to the right (attachment at bottom left).