80 MARYLAND AGRICULTURAL EXPERIMENT STATION. 



this it was found that heavy Avatering will cause these grubs to rise to the 

 surface of the ground. "We have, then, simply to pour an abundance of 

 water upon the affected soil and when the grubs begin to appear upon the 

 surface of the ground, to treat them thoroughly with the emulsion at one 

 part to fifteen of water. Then, after say twenty-four hours, pour on 

 more water to carry the insecticide further down into the soil. The 

 economy of this plan may be shown by the following facts: One barrel 

 of kerosene costing 8-4.50, and a sufficieiit quantity of soap to make half a 

 barrel of strong soapsuds, costing, say, twenty-five cents, will make a bar- 

 rel and a-half of standard emulsion or twenty-two and-a-half barrels of 

 the dilute emulsion. This will be amply sufficient to treat an acre of 

 strawberries and even more upon a porous soil. Upon large field crops 

 this process would prove too expensive, but as a matter of fact, this insect 

 is always most abundant upon small, clioice, heavily manured or mulched 

 crops, and there is seldom any occasion for treating field crops. 



A most interesting case was repoi'ted to me the present season by Col. 

 Wright Rives, of Kives Station, Md., near the College. An acre of choice 

 celery upon his place was found to be fairly teeming with these grubs. 

 They did not seem to injure the celery by attacking the roots, but dam- 

 aged it by carrying dirt into the heart and inducing rot by contact with 

 their acid excrement. Upon investigation I felt quite certain that the 

 heavy nnilching and large masses of rotting straw which had been accu- 

 mulated in the neighborhood, had served to attract the parent beetles, 

 and thus induce their concentration upon the celery beds. The experi- 

 ments Avhich Mr. Lull has recently made upon Col. Eives' place prove 

 that the aiiplication of the standard kerosene emulsion, as above recom- 

 mended, or at the rate of one part to fifteen of water, does not injure the 

 celery in the slightest, while it kills the larva? when they ar-e at or near 

 the surface of the ground. Experience this autumn with these larv» 

 shows that in addition to the food-haldts already indicated, they are, on 

 occasions, quite inclined to be carnivorous, so that when several are 

 placed together in a breeding-cage or jar they invariably feed to some ex- 

 tent upon each other. 



As this larva has not yet been fully described, I close this article 

 with a technical description, which will have some entomological value, 

 though descriptions of these Lamellicorn larAa? are necessarily unsatis- 

 factory except by comparison with other allied forms. 



Allorhina nitida. — Full grown larva. — Length, 40 millimetres, 

 somewhat largest posteriorly, sub-cylindrical, broader at thorax and 

 eighth and ninth abdominal segments, which are materially swollen. 

 More flattened ventrally, with a distinct swollen lateral ridge just below 

 the stigmata, which rather increases the flattened aspect of the venter. 

 General color, glassy yellowish Avhite, inclining to- green or blue towards 

 the extremity. Head, rather small, flattened, well inserted into the 

 prothoracic segment, chestnut brown in color. Dorsal surface of the 

 body strongly transversely corrugate or wrinkled, each of the chief seg- 

 ments having three distinct ridges, the Avhole body studded with short, 

 thick vellowish bristles, which are most dense on the dorsal ridges and 



