There are thus two female openings, one for copulation, the other for oviposition, as well as a male opening.
The first act of the female after oviposition is to wrap her eggs in a casing of silk commonly called the cocoon.
Thus the characteristics of the currant-gall of Spathegaster baccarum, L., which occurs alike on the leaves and on the flower-stalks of the oak, are obviously due to the act of oviposition, and not to the functions of the parts producing it; the bright red galls of the saw-fly Nematus gallicola are found on four different species of willow, Salix fragilis, S.
Their formation from buds which normally would have yielded leaves and shoots is explained by Parfitt as the outcome of an effort at fructification induced by oviposition, such as has been found to result in several plants from injury by insect-agency or otherwise.
Pairing and oviposition take place on land; the male seizes the female round the waist.