Hilgendorf. — Insect-life at Cass Mountain Biological Station. 139 



1. The Tussock Grass-land. 



Large numbers of yellowish-white moths rise from the tussocks at every 

 step. These are chiefly Grambus flexuosellus, but Scoparia salbulosella is 

 almost equally common. Crambus simplex and ('. ramosellus also occur. 

 These all have a wing-span of about 23 mm., and the Scoparia has pale- 

 grey front wings. The metallic-blue butterfly Chrysophanus boldenarum, of 

 22 mm. wing-span, nutters about the open spaces a few inches from the 

 ground, and sinks from sight as it folds its wings over its back and displays 

 only their mottled-grey undersides. The large attractive butterfly Argyro- 

 phenga antipodum flies lazily or sports merrily, usually in pairs, a few feet 

 from the ground. This insect displays one of our best examples of pro- 

 tective coloration adapted to a special environment. The expanse of the 

 wings is 45 mm., and their upper surfaces as well as the lower surfaces of 

 the front pair have a rich brown background with bold orange masses, 

 picked out with black and white spots. The remaining surfaces — namely, 

 the lower ones of the back wings — have a buff background with longitudinal 

 bright-silver stripes. The insect is most conspicuous while on the wing, 

 but as soon as it settles on a tussock, its invariable resting-place, it becomes 

 quite invisible : it exposes the buff and silver surfaces of its wings, which 

 harmonize with the leaves of the tussock to an almost incredible degree of 

 exactness. Occasionally Chrysophanus salustius, a yellow and black butter- 

 fly of 27 mm. wing-spread, may be seen flying low down, especially near 

 the shrub-land, and a few moths of the night may be accidentally disturbed. 

 The blow-flies will always be hovering round, and the eye will be caught by 

 the furtive flights of several other Diptera, usually protectively coloured. 

 The repulsive bristly Hystricia pachyprocta, with a stout yellow body 15 mm. 

 in length, and the somewhat smaller Macquartia kumaraensis and M. subtilis, 

 often remain stationary long . enough to permit of observation ; while the 

 darting Limnia striata, 7 mm. long, and with curiously mottled wings, will 

 usually require a grab with the hand to effect its capture. Two smaller 

 flies that will hardly be noticed may be captured in scores by walking along 

 with a net held near the surface of the tussock. One of these is probablv 

 an undescribed species of Trypeta, and the other may be a representative of 

 a new genus of the family Dexiidae. Itamus varius, a predatory fly, 17 mm. 

 in length, is very common. 



Among the Hymenoptera the attractive Ichneumon solicitorius , with a 

 yellow and black parti-coloured body, 15 mm. long, is frequently seen. 

 Lissonota flavopicta, 10 mm. in length, with an ovipositor as long again, 

 also occurs, as well as two other ichneumons that have not so far been 

 identified. The common native bee, Dasycolletes hirticeps, with its bright- 

 golden hairs on thorax and legs, is commonly seen working among the 

 flowers of the introduced Hypochaeris radicata, and probably assists in the 

 spread of this weed, which is the commonest introduced plant on the 

 tussock-land. It may be noted here, for as far as it bears on insect-life, 

 that this plant opens its flowers only from 8.30 a.m. till 3.30 p.m. even on 

 the longest and most sunshiny days of the year. Another bee, 9 mm. in 

 length, black but with downy white hairs on the thorax, also occurs on the 

 tussock, but has not so far been identified. Specimens of the Coleoptera are 

 not common. Down on the ground our handsome metallic black and green 

 Trichosternus antarcticus, up to 30 mm. long, may be seen hurrying along, 

 and dead specimens may be found in scores or hundreds lying on the gravel 

 between the railway-lines. As this beetle is incapable of flight, it is diffi- 

 cult to see how it manages to climb over the rails, or how, once having 



