A HISTORY OF ESSEX resulting larvas, which are speedily developed, are so numerous and voracious that they soon make extensive clearances in all directions. In 17823 many thousands of acres were destroyed by them, and in 18356 our own county suffered very severely from their ravages. At a later period they devastated the fields in the neighbourhood of Tollesbury, but happily their visits are few and far between, and during many recent years entomologists who have been desirous of obtaining specimens for their cabinets have sought for them in vain, though a few were obtained in Essex, Suffolk and elsewhere in 1900. It is said to feed also on charlock and to prefer that plant to turnip when there is a sufficient supply. The Gooseberry Sawfly (Pteronus ribesii) is also occasionally very destructive to the currant and gooseberry crop. A few years ago it entirely denuded all the bushes about Colchester of their leaves, but the disease speedily produced its own remedy, for so numerous were the larvae that they consumed all the available food long before they reached maturity, and apparently the whole brood perished from starvation. After leaving the naked bushes they wandered about seeking vainly for food elsewhere, and at this time the pathways in the neighbourhood of market gardens were black with their dead bodies, which for several days emitted a sickly odour that compelled attention. Another species (Hoplocampa testudinea) deposits its eggs in the apple blossom, and the larvas feed in the young fruit, causing it to fall when about half-grown. Probably the damage thus done is generally set down to the Codling Moth (Carpocapsa pomonella) for both feed after a similar fashion ; the Sawfly however does not seem to be very abundant, at least in north Essex, and has only been found there in the early summer fruit. As soon as the fruit falls to the ground the larvae proceed to make themselves scarce, so that many apples may be opened and few larvas found, and as these are by no means easy to rear, the insect is very scarce in collections and probably few entomologists have ever seen it. The Corn Sawfly (Cephus pygmceus) is another insect with an evil reputation on the continent, its larvas feed in the interior of corn stems, but any damage they may do in this country is seldom if ever brought home to them, though seeing how very abundant the perfect insect is in our own fields in the early summer, one would think it must be to some extent injurious. The two species of Sirex (S. gigas and S. juvencus) are large handsome insects with powerful ovipositors adapted for boring into the solid wood of fir trees, to which they are accused of being very destructive. In this country they are far from common, and though they are sometimes met with about Colchester they never there attack healthy standing trees, but only such as are dying or have been felled. No doubt they do attack larch and spruce posts and take possession of any trees that have been left unduly long on the ground after they have been felled, and speedily render these good for nothing but firewood. Many of the Sawflies are very beautiful, and the problems connected 1 06
