178 



THE AUSTRALIAN MUSEUM MAGAZINE. 



sects, which they catch by grasping them 

 with the spiny femur and tibia of the 

 fore legs, which close on one another 

 like the blades of a shears. ^Vlien at 

 rest a mantid stands semi-erect on the 

 middle and hind pairs of legs, while the 

 spiny fore legs are held together close 

 to the body. This attitude, suggestive 

 of prayer, has earned for them the 

 title of "praying mantids." 



Stick insects, however, are purely 

 vegetarian in their diet, and some of our 

 species are extremely voracious and do 

 a great amount of damage to the foliage 

 of our trees. Their attitude, too, while 

 resting, does not suggest any religious 

 pretence. They are chiefly remarkable 

 for their resemblance to the branches 

 and leaves of the plants on which they 

 live. So as to protect themselves from 

 the attacks of insectivorous birds and 

 other enemies, they have evolved a form 

 which enables them to escape detection, 

 and this form always consists of some 

 assimilation to their environment. Ad- 

 ded to this mimicry of form, is a. simu- 

 lation of the colours of the plants on 

 which they live; thus we find greens 

 and browns predominating, though at 

 the bases of the hind wings in some of 

 our species beautiful reds and jourples 

 are to be seen. These are, however, seen 

 only when the wings are expanded, as 

 the wings are always folded along the 

 sides of the body when the insect is on 

 its food plant so that its resemblance 

 to its surroundings may be maintained. 



Phasmas readily succumb to the ef- 

 fects of cold, and they usually disappear 

 after the first frosts. 



STRUCTURE. 



When we come to examine the 

 structure of stick insects we find 

 that the head is placed obliquely, 

 whereas in the mantids the head is bent 

 downwards. The prothorax (the seg- 

 ment which bears the first pair of legs) 

 is, as a rule, shorter than the meso- 

 thorax (the part which carries the mid- 

 dle pair of legs). The body is usually 

 long and slender, and the legs are long 

 and thrust out at awkward angles from 

 the body, so that they resemble the 

 twig-s on a branch. Some species are 



wingless in both sexes and are very 

 stick-like in form, in others the wings 

 may be present in one sex and gi-eatly 

 reduced in the other. In many cases, 

 the wings are present in the male and 

 absent in the female. The fore wings 

 (tegmina) are usually extremely short, 

 and, when at rest, cover only the basal 

 area of the hind wings. The hind wings 

 are divisible into two parts, one, the 

 fore or costal border of the wing, being 

 opaque and usually of the same colour 

 as the elytra, and the other transparent, 

 membranous and usually different in 

 colour from the hard fore border. When 

 at rest the membranous part is folded 

 beneath the harder portion. 



In the females there is a large, fre- 

 quently boat-shaped ovipositor or egg 

 laying organ, situated near the end of 

 the abdomen on the ventral surface, and 

 sometimes projecting beyond the extre- 

 mity of the abdomen. In both sexes 

 there are, in our Australian sp6cies, long 

 flattened ap^jendages which spring from 

 the under side of the last dorsal seg- 

 ment of the abdomen. As the males of 

 most of our Australian phasmas are 

 rarely seen they have been only lightly 

 touched on in this article. 



LIFE HISTORY. 



The young of stick insects, as in all 

 orthopterous insects, on emerging from 

 the egg resemble their parents, and thus 

 a metamorphosis such as we find in 

 butterflies is absent. The eggs are seed- 

 shaped and have very hard shells, which 

 serve as a capsule to protect the egg 

 contained within. The egg capsule, too, 

 has a lid at one end, Avhich is pushed 

 off by the young phasma when it 

 emerges. The eggs are laid by the fe- 

 male while feeding among the leaves of 

 the food plant, and drop to the ground 

 where they remain for a year or more 

 before the phasmid emerges. After death 

 stick insects become very brittle and 

 the antennae and legs are easily broken 

 off, whicli accounts for the mutilated 

 condition of some of the specimens 

 figured. 



Our Australian species may be placed 

 roughly in two divisions, namely, those 

 in which the mesothorax (that part of 



