MOTHS 89 



touch the thorax, the middle part of the body being 

 thrown into a strong curve or loop as each " step " is 

 taken. Hence, these larvae are known popularly as 

 "loopers." Many of them are also called " stick- 

 caterpillars," because, when at rest, they have the 

 habit of holding on to the food-plant by their prolegs, 

 and stretching themselves out stiff and straight, so 

 that they resemble a shoot or twig. But this means 

 of protection, though very general in the family, is not 

 universal, a well-known exception being the conspicu- 

 ous caterpillar of the magpie-moth, 1 which is known to 

 be distasteful to most insectivorous creatures, and may 

 thus be regarded as an instance of " warning color- 

 ation." In general terms, the Geometers may be 

 described as slender-bodied moths, having the same 

 pattern on the fore- and hind-wings the wings being 

 commonly spread out when the insect is at rest. The 

 method of pupation varies greatly in different species, 

 but usually the full-fed caterpillar either spins a cocoon 

 among the leaves of the food-plant, or else buries in 

 the soil. 



The hawk-moth family 2 is represented in Britain by 

 seventeen species, several of which can only be re- 

 garded as chance migrants from the Continent. 

 Probably the commonest is the privet-hawk. 3 It is a 

 fairly good type, although some of the species e.g., the 

 poplar-hawk 4 have broader wings, and are less rapid 

 in flight. The build of the humming-bird hawk 5 is 

 also different, while its two clear-winged relatives, the 

 "bee-hawks," have a mimetic likeness to humble-bees 

 that is apt to confuse the tyro. The hairless cater- 



1 Abraxas grossulariata. 2 Sphingid.ce. 



3 Sphinx ligustri. 4 Smerinthus populi. 



5 Macroglossa stellatarum. 



