SAWANTWARI: see SAVANTWADI.
the name given to members of the division Symphyta of the order Hymenoptera (q.v.), characterized by the broad base to the abdomen, where it joins the thorax, and by the wing-veins being less reduced than in other members of the order. Their name is derived from the fact that the lower or anterior blades of the ovipositor are toothed and saw-like. Their larvae are usually caterpillars and in most cases may be distinguished from those of moths and butterflies by having six or more pairs of abdominal feet and only a single pair of simple eyes or ocelli. When disturbed they roll themselves in a spiral fashion and some species discharge a thin fluid from glands above the spiracles. The females lay their eggs in incisions in plants, cut by the saw like blades of the ovipositor, and the larvae are vegetable feeders. Species of several genera, notably Pontania, form galls on willows.
The cause of the gall is stated to be a secretion injected along with the egg, and it has been suggested that it contains an enzyme which acts upon the plant so as to induce gall-formation. Repro duction in saw-flies is of considerable interest : in many species males are unknown and parthenogenesis (q.v.) is the rule. In the gooseberry saw-fly the unfertilized eggs give rise only to males, while the fertilized eggs produce individuals of both sexes, fe males predominating.
The true saw-flies belong to the large family Tenthredinidae and the larvae of many of these are injurious to plants. Thus, the gooseberry saw-fly, Nematus ribesii, is very destructive to that plant and to currants, while the pear slug, Caliroa limacina, attacks pears. These two species and also the larch saw-fly, Lygaeonematus erichsonii, have been accidentally imported from Europe into North America where they have likewise become de structive. Other harmful species in Europe are Athalia spinarum, the turnip saw-fly, and Lophyrus pini, which attacks plantations of Scotch firs. The best remedy is to shake off and destroy the young larvae from bushes, where practicable, or to spray with an arsenical wash. The small families Cephidae and Siricidae have larvae that are borers. The Cephidae include the stem saw-flies, and the best-known species is Cephus pygmaeus, which attacks wheat. Although seldom causing appreciable injury in Britain it is destructive in North America, where Janus integer, the stem girdler of the currant, is also troublesome. The Siricidae bore into solid timber and are known as wood-wasps or horn-tails. Sirex gigas is the most familiar European wood-wasp and is not un common in Britain. (A. D. I.)