242 ENTOMOLOGY FOR MEDICAL OFFICERS 



wings are closed they stand vertically upright. Some 

 authors separate as a distinct group the Skippers, which, 

 though they have the general carriage of a butterfly, are 

 stout and thick set, and have antennae that, being thickened 

 near, not at, the tip, are not truly clubbed. 



The Heterocera (eTe/oo? = different ; /ce'/ja? = antenna) rarely 

 have clubbed antennae, and usually have the wings linked 

 together by a frenum and retinaculum ; the wings, in repose, 

 usually are sloped on either side of the body. A good many 

 moths are as diurnal as butterflies, but the majority are 

 active after sunset. The moths far outnumber the butter- 

 flies in species. 



The medical officer should be able to recognise the 

 following families of moths, which include certain species 

 whose caterpillars possess spines or hairs that are known 

 to have irritating properties when they are touched : — 



SaturniidcB. Large moths, some of them enormous, found 

 in all parts of the world, and in India known as tusser- 

 silk-moths. The wings often have transparent "windows," 

 or large staring eye-like markings, or the hind wings are 

 produced into a long " tail." The caterpillars are often 

 remarkably coloured, and are ornamented with fleshy tags, 

 or with warts bearing spines which may be venomous. 



Limacodidce. Smallish, stout moths, many of which have 

 a good deal of apple-green in the colouring. The caterpillars 



Fig. 109. 



(Fig. 109) are broad and oval, and have no pseudopods ; 

 they are commonly known as slug-caterpillars; the sides 

 and back often bear warts and excrescences beset with spines 

 and hairs. The cocoon is dense and has a lid. 



Megalopygidcz. A small American family. The full-grown 

 larva of one species is said to resemble a lock of hair ; under 

 the long hair there are short stiff" poison hairs. 



