Hemiodoecus leai China , 1924

Wakelin, Michael D. & Larivière, Marie-Claude, 2014, First New Zealand record of the Australian species Hemiodoecus leai China, 1924 (Hemiptera: Peloridiidae); a hitchhiker on moss, Zootaxa 3884 (1), pp. 95-100 : 96-100

Hemiodoecus leai China, 1924

Hemiodoecus China, 1924: 199 . Type species: Hemiodoecus leai China, 1924 , by monotypy.

Description. Adult ( Figs 3 , 7 ). Body length 2.95–3.63 mm. Dorsal colour yellowish brown with darker brown areas on paranota as well as basally and apically on tegmina. Head. Anterior margin convex on either side of median notch. Areolae rather large, triangular-rounded. Thorax. Pronotum broad, 1.4 x as wide as head between eyes. Tegmina with vein C strongly curved basally, hence humerus appearing rounded or somewhat angular; costal margin distinctly concave in basal third and then slightly sinuate; subcostal cell slightly widened apically or not. Abdomen. Male genitalia—Parameres ( Fig. 4 ) slender, suboval, acutely rounded apically. Aedeagus ( Fig. 5 ), in anterior view, rather narrow, slightly convex on each side, blunt apically. Female genitalia—Tergite 9 ( Fig. 6 ), in lateral view, with rather straight dorsal margin and long, acute apical process. Other characters as in Burckhardt (2009: 196).

Material examined. 4 males, 4 females ( NZAC) as follows: NEW ZEALAND DN Dunedin, Opoho Creek , 45°51'22"S 170°32'02"E, 23 Nov 2011, M. Wakelin, caught in pitfall trap , 1 female ( NZAC0408145 ) ; same locality, 45°51'22"S 170°32'02"E, 5 Dec 2011, M. Wakelin, brushed from moss on rock , 1 female ( NZAC04081446 ) ; same locality, 45°51'22"S 170°32'02"E, 20 Dec 2011, M. Wakelin, moss on rock, 1 dead female ( NZAC04081447 ) ; same locality, 45°51'22"S 170°32'02"E, 16 Feb 2012, M. Wakelin, swept from moss on rock , 1 male ( NZAC04081448 ) ; same locality, 45°51'35"S 170°31'57"E, 27 Apr 2012, M. Wakelin, swept from moss on rock , 1 female ( NZAC04081449 ) ; same locality, 45°51'22"S 170°32'02"E, 9 May 2014, M. Wakelin, swept from moss on rock , 3 males ( NZAC04081450 , NZAC04081451 , NZAC04081452 ) .

Geographic distribution. Australia (New South Wales, southwestern Victoria, Tasmania) ; New Zealand, South Island, Dunedin, Opoho Creek (introduced) .

Notes on biology. The following observations were made of three captive individuals, one adult male and two female nymphs that were reared to adults, and several nymphs that have emerged in captivity. The mossbugs were held in a square plastic container (c. 15 cm wide by 8.5 cm high) lined with paper towel, covered with perforated plastic film, and containing about 20 individual moss plants. The moss rhizoids and stems were wrapped in toilet tissue and sprayed once a week with water to keep moist. The container was kept on a bench in an uninsulated Dunedin garage so ambient temperature and humidity would approximate nearby forest conditions. Observations were made on a regular basis, between the hours of 7:00 and 22:00, by eye or using a stereo microscope. Feeding was similar for male, female and nymph; appeared to take place on the mosses Ptychomnion aciculare (Ptychomniaceae) , Weymouthia mollis , W. cochleafolia (Meteoriaceae) , Bartramia sp. (Bartramiaceae) , and Polytrichadelphus magellanicus (Polytrichaceae) —widespread in New Zealand and present in Australia and southern South America—and could continue for extended periods, up to 19 days. Activity was similar for male, female and nymph; they were ‘inactive’ (possibly feeding) for approximately 70% of the time; each period of inactivity ranging from one hour to 25 days. Generally the bugs remained in the basal third of moss fronds ( Fig. 8 ), sometimes going deep into the rhizoid mat. They only occasionally moved across open terrain between fronds, were not seen jumping or climbing from the container and did not appear to be nocturnal. There was little reaction to contact with other organisms (a snail and a mite) but some kind of signalling may have occurred when a nymph’s final moulting seemed to attract two other adult peloridiids. Moulting to adult was observed in two female nymphs, occurred in the early morning, facing downwards on a vertical stem. Prior to moulting, one nymph did not appear to feed and moved less than 1 cm over 26 days. After moulting, there was little activity, the newly emerged adults apparently not feeding or moving for 12 and 14 days. Seasonality. Adults were found in February, April, August and December; nymphs were found in January, February, April and August suggesting nymphs and adults may overwinter. Lifespan for a captive adult female was 15 months; another female and male kept in captivity are still alive after 21 and 25 months respectively. Reproduction. H. leai has paired ovaries each with five ovarioles and a spermatheca ( Pendergrast 1962); upon dissection, one ovigerous female collected in December was observed to have about six fully formed eggs. Sixteen nymphs were found to have emerged in captivity between November and June. The eggs could have been laid as a result of mating observed 13 or 16 months prior in August and November. Alternatively the original moss collected may have contained eggs, indicating a minimum incubation of 22 months. It is not clear if the eggs were laid by one or both females, at one time or progressively over a longer time or if the nymphs emerged together. The 16 nymphs were noticed over a six month period; they developed slowly, most moulting to the second stage after about one month; only two nymphs moulting to the third stage after seven months; six nymphs died as first or second instar.

Remarks. Burckhardt (2009) keyed H. leai against the world fauna, described the adult and fifth instar nymph, and provided information on distribution and habitat in Australia (e.g., moss in rainforest, including Nothofagus , or sphagnum moss bogs at higher altitudes in the mountains of southeastern Australia).

Figures

FIGURES 1–6. Hemiodoecus leai. Fig. 1, schematic view of head (ventral). Xenophyes cascus. Fig. 2, schematic view of head (ventral). Hemiodoecus leai. Fig. 3, habitus drawing, dorsal view of female (scale bar 1 mm); fig. 4, male paramere, schematic view (lateral); fig. 5, male aedeagus, schematic view (anterior); fig. 6, female tergite 9, schematic view (dorsal).

FIGURES 7–9. Fig. 7, Hemiodoecus leai habitus photo, dorsal view of male (scale bar 1 mm); fig. 8, recently emerged female and its final instar exuviae; fig. 9, moss covered rock (see arrow) in typical mossbug habitat at Opoho Creek, Dunedin.