20 



THE PRACTICAL EiNTOMOLOGIST. 



The Onion-fly— & Bemedy. 



(FnOM A LETTER BY LEVI BARTLETT, N. H.) 



The "Black Onion-fly," spoketi of by Mr. Shimer, has 

 heen so injurious to the onion in this section for a number 

 of years past, that its cultivation has been nearly given 

 np. But a farmer, living about a mile from my place, 

 has raised for the three past seasons splendid crops. He 

 destroys the maggot, by pouring a small stream of boiling 

 water along the drills near the roots of the plants. His 

 ^theory is. that the ground is sufficiently heated to destroy 

 the tender maggot, but not warm enough to injure the 

 onion plant. He goes over the onion bed four times during 

 the season. This year he grew forty-two bushels of su- 

 perb onions on ten square rods of land. I do not say the 

 not water killed the maggot, but I do say his onions, like 

 those of other people's, are attacked by the maggot, but 

 they suffer no injury from them, while others lose their 

 crops that do not practice this scalding process. 



Semarks. — There is authentic proof that the larva of 

 the Peach-tree Borer may be destroyed on the same prin- 

 ciple, by hot water, without injuring the tree. Vegetable 

 organisms will often stand, without damage, a degree of 

 heat that would be destructive to animal organisms. For 

 example, every one knows that Locust seed grows all the 

 better for being scalded; whereas we are satisfied, from 

 long experience, that there is no insect that can survive 

 immersion for a few minutes in water, that is too hot to 

 hold one's finger in it for a second or two. In the New 

 fork Tribtme there was published, some years ago, a let- 

 ter from Dr. 0. W. Drew, of Waterbury, Vt., in which he 

 states that for many years the onion crop had been en- 

 tirely destroyed in central Vermont by the Onion Maggot ; 

 that "many experiments had been tried with lime, salt, 

 ashes and plaster without benefit;" and that he himself, 

 finding his own plants infested in the usual manner, " had, 

 when they were about four inches high, poured a full 

 stream of boiling water from a large tea-kettle directly 

 upon each row, and repeated the application." The re- 

 Bult, as he adds, was, that "the plants looked as bright 

 and trim as after a May shower; that he lost no more of 

 them ; and that for the first time in ten years' experience, 

 he had as fine a crop of onions as was ever seen." — Eds. 



Tbe White Fine Weevil — Bbynchoenus Strobi, Feck. 



This insect, first described by Prof. Peck, has been re- 

 described by Dr. Harris, (Injurious Insects, page 72, Ed. 

 1861), also by Dr. Fitch, {Rep. Vol. 2, No. 250). It is very 

 common in this section (Waterbury, Ct.), and is doing 

 great injury — not so much to the white pine, which is not 

 abundant, and generally so small here as to be of little 

 value as a timber tree — but to the Norway spruce, which 

 has, within a few years past, been planted, in vast num- 

 bers, in yards, lawns and cemeteries, and which it seems 

 to prefer to the native pine. 



The leading shoot of this rapidly growing ornamental 

 tree is often seen to wither and die in midsummer, and it 

 is known to every close observer that a grub causes this 

 decay — the larva of the Rhynchocnus Strobi. 



I have nothing to add to what Dr. Harris and Dr. Fitch 

 have written relating to its history, but would call atten- 

 tion to a statement that both these writers have made, viz: 

 that its ravages may be successfully checked by simply 

 removing and burning the diseased shoots. This should 

 be done in June or July, while the weevil is in the larva 

 state, and if persevered in, will rid the spruce of the only 

 formidable enemy it has, at least in those sections where 

 the ifhite pine is not abundant. 



Passing through the new cemetery in the village of 



Thomaston, Ct. a few days since, I noticed that of sixty 

 trees, at least twenty-five had had the leading shoot de- 

 stroyed the past summer, and only five or six had entirely 

 escaped the attacks of the weevil. A gentleman remarked 

 to me that these spruces were not hardy, that they winter- 

 killed. 



Our own Riverside cemetery has suffered severely, and 

 not only are uninjured trees rare, but many are reduced 

 to scraggy evergreen clumps, having lost the beautiful 

 symmetry for which this tree is so remarkable, and for 

 which it is chiefly prized. The gardenerof the Riverside 

 grounds remarked to me to-day that the work of the worms 

 was a real advantage to the trees, as it kept them down, 

 and caused them to thicken up. The unsightly appear- 

 ance of many of them makes it desirable, I think, that 

 this pollarding should be performed by a more skillful 

 workman than the weevil. 



It is, to say the least, a singular taste that crops or trims, 

 or in any way mutilates this noble species of evergreen, 

 and such a taste would no doubt be gratified could it 

 transform an eagle into a Shanghai chicken. 



This weevil is evidently on the increase here, and no 

 wonder, for, from thirty to fifty larvae are often found in 

 a single tree. Parasitic insects destroy many of the larvae, 

 but the work can only be fully accomplished by our aid- 

 ing them in the way suggested. 



Dr. Harris' description of the perfect insect or beetle is 

 as follows : — 



'Oblong oval, rather slender, of a brownish color, 

 thickly punctured, and variegated with small brown, 

 rust-colored, and whitish scales. There are two white 

 dots on the thorax; the scutel white ; and on the wing- 

 covers, which are punctured in rows, there is a whitish 

 transverse band behind the middle. The snout is longer 

 than the thorax, slender, and a very little inclined. The 

 length, exclusive of the snout, varies from one-fifth to 

 three-tenths of an inch." B. p. eassett. 



Waterbcrt, Con.\., Nov. 3d, 1865. 



The " Thrips" of the Vine-growers. — What is iti 



BY BENJ. I). WALSH. 



In one of Mr. Meeker's excellent letters, recently pub- 

 lished in the New York Tribune, I notice the following 

 passage : 



The grapes in this region [Alton, South Illinois] lost 

 their leaves through the ravages of the Thrips. This is 

 a very small insect, appearing in immense numbers; it 

 eats the leaves till they appear like shreds; the leaves of 

 the Concord are too rough and hard for its teeth. The 

 vines being bare, the birds easily find the grapes. It 

 seems to me that the real enemy is not so much the birds 

 as the Thrips. It is a question whether what is called 

 the leaf blight at Cleveland and elsewhere is not the 

 Thrips. Dr. Hall thinks there is a remedy in having a 

 garden engine, by which the leaves will be drenched with 

 a solution of soap, tobacco, and a little sulphur. One can 

 go over an acre in a short time. The engine will cost 

 %Zi.—Semiweekly N. Y. Tribune, Nov. 17, 1865. 



It is probably to this insect that Dr. Warder refers, 

 when he asks in the first number of the Practical Ento- 

 itoLOGiST, " Is our Thrips in the vineyardB the Tettigonia 

 vitis of Harris?" If Mr. Meeker's statement be correct, 

 that " it eats the leaves till they appear like shreds," it 

 certainly cannot be that insect, or any other belonging to 

 that Order, Homoptera. For all of these have no jaws to 

 eat with, but only a beak to suck sap with. I am at a loss 

 to conjecture what it can be, unless it is the larva of some 

 minute moth, or flea-beetle {Haltica.) A species of these 



