NEW ENGLAND FARMER. 



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SAW-FLY OF THE RASPBERRY. 



Selandria hoplocampa ruhi. 



A. 

 B. 

 C. 



T>. 

 E. 



Kaspbcrry leaf, showing how it is eaten. 

 The caterpillar or worm state. 

 Cocoon of earth. 

 Perfect insect or fly. 

 The same at rest. 



IMiss Grace Darling, of New Haven, Ct., has 

 IKilitcly furnished to us an excellent drawing, from 

 ■which our engraving is made. We are much obliged 

 for this valuable contribution to the science of ento- 

 mology. On page 164 of our first volume is a very 

 instructive article, from the same source, on this 

 subject. 



Saw-flics {^TentJiredinidcp) are a numerous race of 

 insects belonging to the order Hymenoptera. They 

 are not stingers, but piercers, and are very destruc- 

 tive to vegetation, as they feed on the leaves of 

 plants. Dr. Harris, the distinguished entomologist, 

 remarks as follows of these insects : — 



" But the most striking peculiarity of these insects 

 consists in the double saws wherewith the females 

 are provided. These are lodged in a deep chink 

 under the hinder part of the body, like the blade of 

 a penknife in its handle, and are covered by two 

 narrow, scabbard-like pieces. The saws arc two in 

 number, ])laced side by side, with their ends directed 

 backwards, and are so hinged to the under side of the 

 body that they can be withdrawn from the chink, 

 and moved up and down when in use. They vary 

 in their form, and in the shape of their teeth, in dif- 

 ferent kinds of saw-flies ; Init they generally curve 

 upwards and taper towards the end, and arc toothed 

 aloiii:; the lower or convex edges. Each of the saws, 

 like a carpenter's fine saw, has a back to steady it ; 

 the blade, however, is not fastened to the back," but 

 slides backwards and forwards ujion it. Moreover, 

 the saw-blade is not only toothed on the edge, but is 

 covered, on one side, with transverse rows of very 

 fine teeth, giving to it the power of a rasp, as well as 

 that of a saw. 



" The female saw-flies use these ingeniously con- 

 trived tools to saw little slits in the stems and leaves 

 of plants, wherein they afterwards drop their eggs. 

 8oiue, it appears, lay their eggs in fruits ; for Mr. 

 "Westwood discovered their young within apples that 

 had fallen from the trees before they had grown to 

 the size of walnuts. The wounds made in plants by 



some kinds of saw-flies swell, and produce galls or 

 knobs, that serve for habitations and for food to their 

 young. The eggs themselves, of all these flics, are 

 found to grow, and increase to twice their former 

 size after they are laid, probably by absorbing the sap 

 of the plant through their thin shells. Most of the 

 larva; or young of the saw-flies strikingly resemble 

 caterpillars, being usually of a cylindrical form, of a 

 greenish color, and having several pairs of legs. 

 Hence they are someti:nes called false caterpillars." 



In the communication referred to. Miss Darling 

 remarks, that sijecimens of the saw-fly of the rasp- 

 berry had been sent to Dr. Harris, of wliich he 

 remarked as follows : — 



" It appears to be an undescribcd insect. It bo- 

 longs to the genus selandria, and resembles in form, 

 and size the saw-fly of the rose, {selandria blenocampa 

 rosfl',)*but is referable to a different group of the 

 genus called hoplocampa by Hartig, on account of the 

 spines with which the larva is armed. The insect 

 may be named selandria {hoplocampa') ruhi, the latter 

 term being given in allusion to the scientific name 

 {rubus) of the ra.spbcrry." 



There are various ways of destroying saw-flies. A 

 solution of whale oil soap is usually cfTcctual. It 

 should be strong — one part of soap, in measure, to 

 thirty-six parts of water. It should be applied after 

 the sun is nearly down, or on a cloudy, but not rainy 

 day, else, with the sun, it will destroy the foliage. 



As the saw-fly of the rasi)berry resembles that of 

 the rose, it may be destroyed in the same way ; and 

 on this subject Miss Darling observes, — 



" I said, in my paper on tho saw-fly of the rasp- 

 berry, that the rose slug, being perfectly smooth, 

 ashes or lime would not stick to them. On a more 

 particular observation, I found that these slugs retired 

 to the under side of the leaf during the night, and 

 did not come out on the up])er side of the leaf to eat 

 until the dew was dried away; and by silting ashes 

 over the bushes very early in the niorning, and re- 

 peating it every few days, I saved my bushes fresh 

 and green, as the slugs did not find the ashes very 

 palatable food, while my neighbor's bushes were very 

 badly oaten." 



