INSECTS 269 



caterpillar, which forms little paths in the fur and develops into a moth about 

 half an inch across, with a white head and neck having in the middle of its 

 yellowish grey upper-wings three brownish spots, the lower-wings being greyish 

 white. The caterpillar of another clothes-moth (T. sarcitella) leads a similar life, 

 finally developing into a moth of about the same size, with a white spot on each side 

 at the bases of its silvery grey wings. This pest lives in woollen dresses, carpets, 

 upholstery, furs, and such-like, and is fully developed three months after its birth 

 It then winters, and in the following March or April envelops itself in a brownish 

 grey tissue, in which it is transformed into a chrysalis. The caterpillar of the tapestry, 

 or carriage, moth (T. tapetzella) lives in much the same manner. The moth, which is 

 nearly three-quarters of an inch across, has a white head and white tips to the fore- 

 wings. The female of the mischievous corn-moth (T. granella) lays its eggs in 

 the middle or end of May on grains of corn, several of which are united together by 

 the silk of the caterpillars as they creep out. This moth is half an inch across, and 

 has a whitish head and fringed fore-wings, which are slightly bent upwards when 

 the insect is at rest. In colour the wings are white, clouded with greyish brown, 

 with a pale fuscous triangular spot on the middle of the inner margin. The 

 caterpillar, which is fully grown in August or September, winters in a case made 

 of tissue and small wood-shavings, which is fixed on a beam. The pupa-stage occurs 

 in March or April, and the moth appears four weeks later ; but there is frequently 

 a second brood in August or September. 



Of the two-winged insects, flies appear in houses in very con- 

 siderable numbers, and are some of the most mischievous and annoy- 

 ing of all pests. Foremost among them are the typical flies, which are more or 

 less resident throughout the year. The sharp-mouthed fly (Stomoxys calcitrans) 

 frequents stables, although also seen in the open air, and in summer very often enters 

 rooms ; but the commonest of all in our dwellings is the familiar house-fly (Musca 

 domestica). The maggot emerges from the egg in from twelve to twenty-four 

 hours, and is full-grown in a fortnight, when it changes into the pupa, and in 

 another fortnight into the adult fly, winch produces several generations in one 

 summer, so that it sometimes becomes quite a plague. The flies are, however, 

 exposed to many dangers, and their numbers are therefore small in proportion 

 to their increase. The blue-bottle (Calliphora erythrocephala) is another fly 

 frequenting kitchens and larders during summer ; it has a black head, and a 

 glistening bluish white abdomen, marked with blackish cross-lines, the antennae 

 being reddish yellow. This fly deposits its eggs on meat, and in the wounds of 

 living animals, or on the heads of domestic fowls ; but occasionally, deceived by 

 the flesh-like smell, it lays them on certain plants. The maggot of the blue- 

 bottle — the " gentle " of the angler — is bred in considerable numbers for use as bait. 

 The hopping larvaa of the cheese-fly (Piophila casei) are often found in cheese, 

 into which they bore. The fly is about one-eighth of an inch long, of a brilliant 

 black colour, with the lower part of the face, antennas, and legs reddish yellow, 

 and the fore-legs and a ring round the thighs black. The vinegar-fly {Drosophila 

 funebris) likewise restricts itself to one description of food, being found on the 

 taps and bung-holes of vinegar, wine, or beer barrels, and wherever sweet fluids 



