NATURE NOTES.

New Zealand Herald, Volume LXI, Issue 18711, 17 May 1924, Page 19 (Supplement)

NATURE NOTES.

NEW ZEALAND ORCHIDS.

By 3. DBTODIOSD, F.L.S.j T.Z.3.

Two new species have been added to New Zealand's list of orchids. About 5000

species of the interesting cosmopolitan order of the Orchidas are known, and of that total New Zealand has about fifty-five.

She shares possession of a few with Australia and other countries, but most of the

fifty-five- belong to her alone. The two new species are- the cup orchid and the pouch orchid. Both, as far as is known, I grow only near the village of Is.aitaia, Mangonui County, where they were discovered by Mr. H. B. Matthews. On one occasion be collected about 100 individuals of the cup orchid and 70 of the pouch orchid. A few years later he found that in the three places where he had collected the cup orchids the tea-tree in which the} grew was cleared for agricultural purposes', and the orchids with it. Unless the cup orchid is discovered in some other place it will not be available to students. It is a slender plant, with a hairy stem, narrow leaves, small round tubers and greenish flowers, furnished with a tiny cup at the point of an appendage. The pouch orchid also has a slender hairy stem, but its flowers are pink, and small coalescing wings in the flower form a capacious pouch.

Mr. Matthews, who kept- both species in cultivation, found that they seeded freely and • showed practically no variations. The popular names of these little herbs have been Latinised in their official titles. The cup orchid is Petaloehilus—-lip calvciformis, and the pouch orchid is Petaloehilus saccatus. Both new species, superficially, resemble a small pinkflowered native orchid found on grassv hills in the North Island and the South Island, Caladenia minor, and their affinities are with it. A common New Zealand orchid, Earina suavcolens—the sweet-, scented bloomer of the spring—by the way, should be .showing its short, stiff racemes of white flowers now, as it favours autumn and early winter; a relative that blooms in the spring has given these species their name.

Mr. W. W. Smith, New Plymouth, for many years lias observed small scorpionlike creatures in the nests of native ants, usually in nests under, large stones in open sunny places. The - pseudo-scorpions' persistent occurrence in the ants' homes led him to experiment with the little interlopers. He placed six of them :on fine damp soil in a small glass jar, kept them in a dark but airy place, and . provided them with living ants belonging to several species, in order to discover the relations and attitude of the two dissimilar/ creatures to each other. Eight worker 'ants placed in the jar were not molested by the' pseudo-scorpions, but the eggs and immature forms of ants were eaten._ The eggs and young of aphis and scale-insects also were taken, and adults were untouched. Mr. Smith has shown that the pseudo-scor-pions may be impelled by hunger to take the eggs of young . insects in; ants' rests, but he is making further experiments to discover definitely why pseudo-seojpions frequent the nests. His observations show that both sexes of the pseudo-scorpions are more plentiful in nests under stones on the open river-flats of Canterbury than in nests searched by him in the North Island.

In examining communities of plants and small creatures between high-tido and lowtide of sea beaches, Mr. W. R. B. Oliver, Wellington, collected evidence.* that, the external shell is the principal: character-by •which the creatures that live in those places conserve moisture' during the tide's retirement. The' great strength. of most shells shows that they are intended mainly for defence, but Mr. Oliver points out that shells are possessed by all creatures habitually exposed to the air between tides and. that the shells must operate, largely as retainers of moisture. "Shells vary greatly in shape, and are possessed by creatures separated widely in classification, and diverse in origin." Mr, Oliver writes, "That there is a direct relation between the presence of a shell and the degree of exposure to air to which the owner is subjected may be inferred from the fact that many molluscs that live below low-tide mark have no shells, or only a small one covering parts of the viscera. Many creatures that live near low-tide mark and are; exposed to the air for only a short term each , day, do not secrete shells, but their integument assumes a tough, leathery texture." Mr. Oliver accounts. for the varied . forms of animals and plants between tide-marks by the wide range of conditions that prevail there as a result of regular alternations in the quantity of water supplied by the rise and fall of the tide. In that belt, he states, are representatives of all classes of. organisms, ranging from fishes to; unicellular seaweeds; and the one character by which they are classed together is their capacity to endure 'times of complete submergence, as well as to tolerate exposure to the air, every day. - _ '

"Tuis, bellbirds, tomtits, grey warblers, ground larks and fantails are common in gardens here," Mr. L. E. Kelioe writes from Greymouth. ''Strange to? say, ,the tui and bellbird favour the Australian ; gum trees and the Pinus insignis as singing and sunning chambers. Among common introduced birds are song thrushes blackbirds, chaffinches, hedge-sparrows, goldfinches, skylarks and starlings. •; Out in the . bush recently I heard strong musical notes, which I thought were uttered by a. bellbird, but a: glimpse of . the songster led me to believe that it was.a nativ« thrush. Boys who go into the bush . tel me that they are familiar with two kind: of thrushes. . One often seen near settle jr.outs sink's tc the world from a_ higl single bough; the other, seen further in th< bush, they describe as a darker, reddish brown. They have promised to observe thi: bird more carefully. This, evidently, 1 the South. Island thrush. It is larger thai the song-thrush, is olive-brown above, oil vaceous streaked with white below, an< tinged with yellow 'on the abdomen, thi tail and parts of the - wings are reddish It has the same Maori name as its Norfcl Island cousin, Piopio. V ■

The commonest leaf-miner in New Zealand, a very small fly, introduced ; from other countries, exemplifies the doggerel verse that fleas have smaller fleas to bite them, and those smaller still, and so ad infinitum. Adults of this fly are only two millimeters long, but most of them seem to be attacked by still : smaller parasites. The flies are attacked in their grub stage, and many of them, on account of this enemy, never attain the perfect stage. Mr. M. N. Watt, Wanganui, who has studied insect miners and tunnellers for some years, and lias kept these particular flies in observation jars, reports that;- no less than 90 per cent, of the grubs perished from the parasites' attacks. V The miner, which is known as the thistle-fly, favours leaves of the - sow-thistle;' Scotch - thistle, ' dandelion, Cape weed, dahlia, daisy and other introduced plants, but does not seem to be attracted by native plants. Its body is dark grey mostly, with pale green sides.

Mr Watt, through, a has- watched a • female lay her eggs.; She lowers her ovipositor until it is at right-angles to the surface of a . leaf, thrusts it through :the outer skin of the leaf, which " she prises up until a minute scmicular pocket is formed. The ovipositor, is withdrawn in a very short time, and a, .single egg is loft in the pocket, which is visible to the naked eve as a small white spot on the leaf, The. mining is done •by }the grub,. and ,in the mine the ■< chrysalis ■ lives until it develops into a perfect insect. A■« grub ; hatches about six days after - the egg is laid, and spends nine 1 days?in the - grub stage, ! and twelve or thirteen" days : are spent an the next stage, -until the fly is ; ready for, th? perfect .stag®, and the freer Ufa on the wing.