THE ENTOMOLOGIST. ISO 



Life-history of Boinhyx castrensis. — The mass of eggs 

 laid by the female of Bombyx castrensis is one of the most 

 beautiful and intei*esting objects in nature : it is about an 

 inch in length, and of the thickness of a goose-quill ; the 

 eggs are imbedded in a most tenacious glue, which is not 

 soluble in water, and form a compact cylinder, the axis of 

 which, being the flowering-stem of some grass, is easily with- 

 drawn when shrunk by desiccation ; the eggs are deposited 

 in very regular oblique series, and resemble a number of 

 strings of minute beads wound spirally around the grass and 

 then closely compressed together : each of these cylindrical 

 masses contains about six hundred eggs, each individual is 

 obscurely pear-shaped, the smaller end being inside and 

 touching the grass-stem, but never adherent, for although 

 the sides of the egg are so abundantly provided with glue, 

 the two ends are entirely without it. The young larvae emerge 

 in May, and very speedily construct a web in which to 

 reside : compared with that of Bombyx neustria this web is 

 thinner and less opaque, and, owing to its being spun 

 amongst the low plants on which tlie caterpillars feed, it is 

 less noticeable : these webs are generally very near the 

 ground, and are extremely abundant where they occur at all. 

 After a time the larva forsakes its tent-like domicile, and 

 entirely abandons its gregarious habits. When full-fed it 

 rests on its food-plant in a nearly straight position, and is 

 veiy easily shaken off, generally falling on its back, when it 

 ' immediately turns over and begins to crawl ; it never feigns 

 death or rolls in a ring, but under all circumstances main- 

 tains a limpid and flaccid character ; in this respect differing 

 from such true Bombyces as Familiaris, Quercus, Rubi and 

 Trifolii. The head is of almost exactly the same width as 

 the 2ud segment ; the body is of nearly uniform substance 

 throughout, the back being rather convex, and having the 

 divisions of the segments distinctly marked ; the sides being 

 dilated, and the dilated portions being broken up into wart- 

 like lobes by transverse folding ; the belly being rather flat- 

 tened, the claspers rather long, but remarkably small at the 

 extremities ; the head and body are clothed with silky hairs 

 of various lengths, but nowhere sufficiently abundant com- 

 pletely to conceal the skin : the colour of the head is bluish 

 gray, minutely dotted with black ; that of the body is rich 



