CHAPTER XX 



Order Lepidoptera : Moths and Butterflies 

 (Gr. Xex/?, Xe7r/5o9=a scale; TTTeyooj/ = wing). 



This order includes the Butterflies and Moths, and although 

 it is made much of by entomologists, and although, 

 owing to the depredations of caterpillars, it is an order of 

 grave concern to the market-gardener, the fruit-grower, the 

 planter, and the forester, the medical ofiicer comes in 

 contact with it only in a sort of fancy way, when patients 

 have handled caterpillars that have venomous hairs, or 

 have passed or coughed up a caterpillar. The sanitary 

 officer, again, may have to deal with grain and flour that 

 has been damaged by the larvae of certain moths. 



In the Lepidoptera the wings are covered with scales, 

 the mouth-parts form a long tube for sucking the nectar 

 of flowers, and the metamorphosis is " complete." 



The eyes are large and the antennae are composed of 

 many segments. The only conspicuous parts of the mouth, 

 as a rule, are (i) the coarse, hairy, labial palps, and (2) the 

 proboscis formed by the apposition of the extraordinary 

 long, channelled maxillae ; this in repose is coiled between 

 the labial palps. In some moths the maxillae do not form 

 a tube, or are absent altogether ; and in one small family 

 of moths the mandibles are well developed, and the maxillae 

 are used for feeding on pollen. 



The mesothorax forms the chief part of the thorax ; the 

 prothorax is a mere collar, and usually bears a pair of 

 shoulder-flaps, or patagia, which overhang the bases of the 

 front wings. For united action the wings of each side are 

 held together either (i, as in most moths) by a strong 



curved bristle, or leash of bristles, known as the frenum 



240 ■' ' 



