491 ARTHROPODA. 



floor, etc., and give rise to pupse, both without traces of wings. 

 Yet fleas and flies differ in tliat tlie fleas have similar body somites 

 but the haustellum is lacking, the sucking tube being formed 

 of labrum and mandibles, while the sharp maxillse puncture the 

 skin. Besides Fulex irritaiis,* the flea that attacks man, many 

 other species occur on other animals. In warm countries the jigger 

 or chigoe, SarcojjJisylla penetrdns* attacks man, the female boring 

 into the skin, usually under the nails, and there laying the eggs. 

 Order XI. Lepidoptera. 

 This group of butterflies and moths is the most sharjoly limited 

 of any order of Hexapods. The wings, both j)airs of which are 

 well developed (rarely lacking, as in many female Psych idffi and 

 some Geometridai), are covered with scales (flattened hairs), and 

 to these are due the frequently brilliant color joatterns. Frequently 

 the fore and hind wings are united by hooks {frenulum) on the 

 latter, engaging in a retinaculum in the fore wing. The mesothorax 

 is large and the smaller jjro- and metathorax are closely united to 

 it, giving the region a distinctness from head or abdomen. The 

 mouth parts are peculiar (fig. 489), although foreshadowed in the 

 Phryganids, and not fully developed in the Microlepidoptera. The 

 mandibles are rudimentary or absent, while the fused maxillaj, 

 greatly elongate, form the proboscis. Maxillary and labial palpi 

 are present, the former smaller and often degenerate. The de- 

 velopment is holometabolous; the larvae, frequently called cater- 

 pillars (fig. 502), have biting mouth jjarts, the mandibles veiw 

 strong; and also silk glands (sericteria), a pair of internal organs 

 which open together on the labium and produce a secretion hard- 

 ening to silk; besides the thoracic legs, prolegs, two to five pairs, 

 are present. The pupaa are usually pupa? obtecta?, and are rarely 

 free. In some the pujiffi are ornamented with golden spots, whence 

 the name chrysalides often applied to them. 



Sub Order I. MICROLEPIDOPTERA. Small, iiicoiispicuous ; at rest 

 holding the wings horizontally over the back ; maxillary palpi very large ; 

 proboscis small. TineidzE ; the larvas form a tube of the food material 

 which they carry around with them. Tinea peUioneUa* the clothes 

 moth. ToRTRiciD.E ; the larvie roll leaves into a tube. Carpocapsa 2}omo- 

 nella* the codlin moth, the hirva* infesting apples. 



Sub Order IT. GEOMETRINA. Moths slender, the wings in pattern 

 and shape recalling those of butterllies, but held horizontally when at 

 rest; 'tongue' (proboscis) small; larvie with two, rarely three, prolegs, 

 known as span or measuring worms from their gait. Species numerous. 

 C-auker worms (Paleacrita veriKi/a* Alosophila pometaria* females 

 wingless), Diastictis ribearia* currant worm. 



