NATURE KNOWLEDGE BEETLE AND STICK-SPIDER

Press, Volume LXXI, Issue 21404, 21 February 1935, Page 2 (Supplement)

NATURE KNOWLEDGE BEETLE AND STICK-SPIDER

A reader at Riverside, Ashburton, has sent me in a specimen of a fairlv common beetle (Cilibe oparula); it is a member of a very large family (Tenebrionidae) of which the members display great diversity in size and shape; the majority are found on the ground, .sndcr logs and stones, or under the ijark of trees. Thi.s family provides a number of exceptions to one clause of the simple definition (which was not intended to be exhaustive) of a beetle, given some weeks ago. Many of the ground-inhabiting species lack hindwings, the forewings or "elytra" (often popularly called "wing-cases") are soldered together mid are immovable; in the species under discussion there is a long groove Indicating the position in vhich the division would normally cccur. Our particular beetle, a sombre black insect about two centimetres long, is one of the forms which occur under logs and stones; a noticeable feature is the distinct flange which edges the body, excluding the head. The joints towards the extremities of the antennae, which are shortish, are distinctly globular in

fo.-in. The larva feeds upon well rcitect wood and is found under logs; it is an elongate, darkish brown creature with well developed legs: the upper and lower surfaces of the segments are furnished with horny plates; in form it is subcylindrical, i.e., it is not truly '•vlindrieai, being somewhat flat-t.'-ncd. •J'n.ro are numbers of other species >-.> Cilibe in New Zealand, some V,cin? rather difficult to distinguish ivim one another. Thr Thorax in Insects—While we fl.-f r.ry the subject of. beetles it v.'culd be as well to remark briefly upon the thorax of insects. Large ".umbers of beetles are clearly di- • :.;bk: into three regions of which the one immediately behind the head is often referred to simply is :h« "thorf.x"; in reality this is only a portion of the thorax, the remaining portion coming behind 'he second division and being covered by the forewings or elytra. So we perceive a pitfall for the uninitiated in naming the insect body, the major apparent divisions may not coincide with the anatomical divisions of head, thorax, and abdomen. Hence the more reliable policy is to remember that the thorax 'if the insect is the region or combination of regions bearing the organs of locomotion, i.e., the legs and the wings. The beetles are not the only in-tects-in ..which the clearly apparent

(By A.V.C.J

divisions would lead to difficulty or misconception if the position of the legs and wings were disregarded. •*• A STICK-INSECT Barbara de Lambert, Christchurch, has sent a specimen of a quite common stick-insect; it rejoices, at least it should, in the name Argosarchus Horridus. It is a long, slender insect, wingless, with long, slender legs placed far apart; the head is small and oval, the eyes are simple and small, and the antennae shortish in proportion to

the size of the creature; thorax and legs are armed with short spines; the colour is dull brown, with irregular paler patches. The female, which is about six inches long in body and considerably larger than the male, lays her eggs singly, dropping them at random upon the ground; the young are similar in form to the adults. These creatures are vegetarians, and are often fairly common on manuka and astelia; they move about iiiv a very deliberate and, to my mind, stealthy manner. This creature belongs to the family Phasmatidae, which comprises the stick- and leaf-insects; the family is one of those constituting the order Orthoptera, which contains the cockroaches, locusts, grasshoppers, crickets, and mantids. (Note the thorax in this insect; it is composed of several segments and extends well down the body.)

' Astelia —A native plant; grows in clumps on ground or in forks of trees; long, slender, graceful, lightish green leaves, three to six feet long and about one and a half inches broad; three prominent ribs give the leaf a channelled construction. ,