100 



THE PRACTICAL ENTOMOLOGIST. 



unlike the perfect insect, you may not have recognized 

 their identity. The larva of this species will be an elong- 

 ate grub, with a hard shelly head, a soft body, no wings 

 of course, six legs in front and a single "pro-leg" or short 

 fleshv stump which it uses as a log at its tail; and the 

 color" will probably be some obscure shade of pale drab or 

 brown. It will be found sluggishly feeding on the sur- 

 face of the leaves along with the perfect insect, and as 

 soon as ever they first appear in the spring you should 

 use every exertion to destroy them. A single female larva 

 destroyed at that time may prevent the generation of a 

 hundred thousand in the course of the summer; for I 

 have little doubt this species is many-brooded, i. e. that 

 there are several generations of them in one year. 



The minute insect, which you say "appears about May 

 Ist and clusters in thousands upon the ends of the 

 branches of the grape vine, apparently doing but little 

 damage, though the leaves upon which they are found 

 curl up and cease to act a good part," is a Plant-louse and 

 probably the European species Aphis vitis. There are 

 hundreds of cannibal and parasitic insects preying upon 

 plant-lice; otherwise they would soon increase so enor- 

 mously as to destroy every green thing on this earth. In 

 the small parcel you sent, I counted between two and 

 three dozen specimens of an Aphidius—a minute 4-wing- 

 ed Fly belonging to the great Ichneumon family, the lar- 

 va of which lives inside the body of a plant-louse and fi- 

 nally destroys it. Of course they bred from the plant-lice 

 during the eight days they were on the road. As to the 

 Ants, they neither produce nor destroy plant-lice, but 

 simply attend them for the sake of the rich honey-dew, 

 which they cause them to disgorge from the honey-tubes 

 on their back. "The ants," said Linnseus one hundred 

 years ago, "ascend the trees that they may milk their 

 cows, the aphides." If you do not believe Linuxus, you 

 may see the whole operation any day with your own 

 eyes. 



T. T. Southwick, N. Y.— The Cherry-twig borers that 

 you sent were five days on the road, and were dead and 

 dried up to nothing by the time I got them. If the twigs 

 had been corked up in a quill or a small glass vial or en- 

 closed in any small tight tin vessel, they would have tra- 

 velled much better. I know of no insect working on 

 cherry twigs as they do; but until I can see good speci- 

 mens, I cannot even tell what Order they belong to. 



A. D. Chesebro, Mich. — You say you have a cornfield 

 infested with wireworms; that last year you tried ashes 

 and lime as remedies without any perceivable good result; 

 and that this year you put a handful of salt around each 

 hill and about two inches from it, which killed the corn 

 but not the wireworms. As you wish to sow your field 

 with wheat next autumn, I should recommend you to 

 plow it continually through the summer, so as not to al- 

 low either weeds or anything else to grow on it. The 

 wireworm lives exclusively on roots, and he is just like 

 one of us Christians in this respect, that he cannot live 

 without eating. But if you allow nothing to grow in your 

 field, there will be no roots for him to feed on; conse- 

 quently he must necessarily be starved out. In Europe 

 this process is called "Summer fallowing" and is used 

 extensively to destroy weeds and Noxious Insects. 



Thos. M'Graw, Wise. — Your insects arrived in miserable 

 order. Of course if you pack eight glass vials loose in a 

 box, without even wrapping up each in a separate paper, 

 some of them will get broken on the road. Besides, some 

 of your numbers, being marked with pencil on the corks 

 of the vials, I cannot read with any certainty. Here fol- 

 low the names of your insects, so far as I can name thein, 

 many being out of the vials and mashed up with broken 

 glass. Nofl, a kind of Spindle-worm, but not the East- 

 ern Goriyna. zccc. No. 2 is the larva of some moth. No. 

 5, Arrhenodes septenti-ionis. No. 6 is the chrysalis of some 

 moth. Ho. H. Ni/ctobates pensi/loanicus. No. 10, (in a box) 

 aspeciesof /«/«.■!, or hundred-legged worm, not a true in- 

 sect, but belonging to the Class Mi/rinpoda. No. 10, (in 

 vial) Lytta cinerea, our common nortliern potato-bug or 

 blister-beetle. No. 12, Cap.ms 4-vittatus, a true Bug. No. 

 13, Megachile brevis, male, a leaf-cutiing bee. No. 14, 

 Amara basillai-i.^. No. 15, Paeeilu^ lunibhndus. No. 10, 

 Fodabrus modcstus. 'So. \~i, Luc.idola alra. 'So. \^, Kealus 

 tencbrloides. No. 20, Sesia diffinis, hui too ragged and torn 

 to name with certainty.— Nos. It, IJ, IG and 17 are can- 

 nibals. No5. 1, 2, 10 (in vial) and 12 are injurious, arid 

 20 in the larva state eats houeyauckle. Nos. 5, 8, 10 (in 



box) and 18 feed on rotten wood and are harmless, and 

 No. 13 is also harmless. — I cannot tell what insect you 

 call the "common garden grub." It may be some larva 

 that is very common with you and very rare with me. 



L. E. Harmon, N. Y. — The little greenish, flat-oval 

 scales, about 4 inch long, attached to oleander leaves are 

 a foreign species of bark-louse often found on greenhouse 

 plants. Their history is nearly the same as that of the 

 common Bark-louse of the Apple tree. When the female 

 gets her full growth she attaches herself to the plant she 

 lives on, and having first laid a number of eggs under her 

 own body, finally loses all traces of organization and dies. 

 In the common Apple-tree Bark-louse these eggs remain 

 unhatohed till the following summer, but in this exotic 

 species those laid earliest in the summer hatch the same 

 season, so that the insect is many-brooded. In the spe- 

 cimens you sent I found many of the eggs already hatch- 

 ed into small but very vigorous and active young lice, 

 which had apparently been feeding on the body of their 

 mother, but would no doubt soon go forth on their own 

 hook into the botanical world. With greenhouse plants 

 the best remedy is tobacco-smoke applied in a tight place, 

 washing the leaves afterwards with a syringe; but prob- 

 ably kerosene diluted with about i or J water and sy- 

 ringed on to the whole plant would kill them. 



C. K. Yant, Ohio. — The flat turtle-shaped beetles, about 

 one-fifth inch long, infesting your sweet potato vines are 

 a common species of tortoise-beetle (Cassida), the pallida 

 of Ilerbst. There is another species with five conspicuous 

 black stripes placed lengthways on its back (the bivMata 

 of Say) which I found myself in large numbers on the 

 sweet potato in South Illinois. There is still another spe- 

 cies (the airipes of LeConte, unless my memory fails me) 

 which is a great pest on the common Morning Glory and 

 is called "Gold-bug" by the ladies. This, as well as your 

 species, changes color when alive from clay-yellow to 

 burnished gold, and the golden color is always lost in the 

 dried specimen. The larvae of all of them have the sin- 

 gular habit of hoisting an umbrella over their bodies com- 

 posed of their own excrement, for which purpose Nature 

 has given them along two-forked tail which they have 

 the power of bending over their backs, having first load- 

 ed the fork with a suitable forkful. No doubt they find 

 this useful, not only to keep off the sun, but to protect 

 them from birds and cannibal insects. 



J. Bird, Penna. — The chestnut-brown shining scales 

 about the size and shape of the half of a pea, adhering to 

 the twig of the grape-vine, are the dead bodies of the 

 Barklouse of the vine — Lecanium vitis of Linnseus — an 

 imported insect like the apple-tree Barklouse. Under- 

 neath these scales were very numerous white eggs and 

 young lice just h.atchcd out. If abundant on your vines, 

 they will do great injury, unless some kind Ladybird 

 takes to killing them. On the general Subject of Bark- 

 lice, see the Answer to L. E. Harmon in this number of 

 the Practical Entomologist. 



0. B. Douglas, Vermont. — I am now able to say, the 

 eggs having hatched out, that the chestnut-brown shin- 

 ing scales, about the size and shape of the half of a pea, 

 which you found on plum-tree twigs are a species of 

 Barklouse. They closely resemble the Barklouse of the 

 Vine but are probably distinct, the eggs being pink 

 now that they are hatching out, although three weeks ago 

 thev wore pure white. No such S]>ecics has hitherto, so 

 far as I know, been found on the Plum in this country; 

 but Dr. Fitch describes an allied species, iccaniumccrasi- 

 fcx, as found on the wild black cherry. 



t. D. Morse, Sec. Missouri State Agr. Soc. — The "eggs 

 very curiously and regularly deposited along the edge of 

 an oak leaf," and between its upper and lower surfaces, 

 are probably those of some SawUy, many of which inha- 

 bit the oak in the larva state and feed on its leaves, like 

 ordinary caterpillars. These larvse are often mistaken by 

 the inexperienced for caterpillars or the larva; of moths 

 (£c^»/o/)«<;ra),but may usually be distinguished by having 

 a greater number of legs than li^ — i.e. IS, 20 or 22. As 

 in the case of the eggs of tlie Cicada (popularly called Lo- 

 cust), the eggs of the Saw-fly derive nourishment from 

 the sap and grow thereby; which is the reason why the 

 mother-insect lays them inside the leaf and not on its sur- 

 face. Subscriptions for the Practical Entomologist are 

 receivable by the Secretary at Philadelphia. 



