Observe and record the hatching of the tiny worm, its feeding, growth, forming of chrysalis, development into adult.
Frequently little yellow silken cocoons are found in vivaria where cabbage-worms are kept; these are cocoons of a parasite (braconid) that infests the worm.
Because of the ease with which the cabbage-butterfly may be obtained and the rapidity of its development in the various stages, it is very suitable as a type for the study of metamorphosis.
The sulphur, or puddler (called by the latter name because of its habit of settling in groups around the edges of the water holes), is also a suitable type. The larvæ in this case must be fed on clover.
THE TUSSOCK-MOTH
Begin the study of this insect in June and July by observing the larvæ feeding on the foliage of the horse-chestnut and other shade trees, and direct attention to their destructiveness.
In observing the larvæ, note the size, movements, legs, colour, coral red head, tufts of hair on the back, and the three long plumes.
Watch the birds among the trees to discover whether they eat the larvæ.
Of what use are the tufts of hair? Do the larvæ feed by biting or by sucking? Describe the damage done by the larvæ.
Collect a number of these larvæ and place them in the vivarium with some twigs of horse-chestnut. Observe the spinning of the cocoon and, about two weeks later, look for the emergence of the adult moths.