114 



THE PRACTICAL ENTOMOLOGIST. 



J. F. Benner, Ohio. — The small pale brown beetle "do- 

 ing a great deal of damage to your grape-vines this sea- 

 son, though you had never noticed them before on the 

 grape-vine" is the Colaspis fiavida of Say. You are the 

 third correspondent from whom within the last month I 

 have received this insect with the same statement as to 

 its habits. See the "Answers" to W. J. Lawrence and F. 

 K. Phoenix in this Number of the Practical E.momolo- 



GIST. 



The three-lined leaf-beetle, bred from larvoe that cover 

 themselves with their own dung and feed on the leaves 

 of the Potalo, is the Lema trilineata of Olivier. You will 

 find it figured and described in Harris's /«;. Ins. p. 118. 

 It is very common in the Eastern States, but I was not 

 previously aware that it ever occurred in such numbers 

 as it has done with you, in the Valley of the Mississippi. 

 You say you found "about a dozen larvse together on a 

 leaf or branch." That is more than I have met with in 

 eight years near Rock Island, Illinois. Your method of 

 breeding the perfect beetle from the larva was excellent, 

 and for the benefit of those who may be similarly situ- 

 ated I will now copy it out in full. " I ],rocured a small 

 box, put some moist earth on the bottom, and on it the 

 grubs, together with the leaves on which they were, with 

 others for their food. They ate heartily for a few days 

 and on the 15th July disappeared. On examining the 

 earth. I found them in small whitish cocoons fastened to 

 the bottom of the box. I set them by and watched them 

 daily. On 30th July I found the perfect beetles in the 

 box; smd on examining the cocoons, I found them all 

 empty." 



Huron Burt, Missouri. — You say that "last year your 

 gooseberries and currants were all destroyed by a green 

 worm ; the crop was abundant, but not a berry ripened. 

 This year scarcely a worm was to be seen, and the most 

 abundant crop of berries ripened that we have ever hod. 

 The weather last year was very dry till July, and the 

 remainder of the season was excessively wet." The "green 

 worm " was probably the larva of the " Gooseberry'Saw- 

 fly," respecting which see my Article in the next number 

 of the Practical E.vto.mologist. Not improbably the ex- 

 cessive rains in July may last year have drowned out the 

 pupffi as they lay underground in their cocoons; or pos- 

 sibly some Ladybird may have taken to eating their eggs, 

 or they may have been violently attacked by some other 

 Cannibal insect or by some Parasite. On the same prin- 

 ciple, the Army-worm swarms in certain years, and in 

 other years is found in such small numbers that Farmers 

 do not notice it. And so with maiiy other Noxious In- 

 sects. I do not think that excessive heat or excessive 

 drought ever kills insects, but it has long been known 

 that in the case of the common Chinch-bug excessive 

 rains, or even a few heavy showers, will drown out their 

 eggs, which are laid at the roots of the infested plants, 

 and put a sudden stop to their multiplication. 



You say that an insect which you take for the "three- 

 lined leaf-beetle" {Lema trilineata) is very numerous with 

 you this season. "They first," you observe, "devour the 

 potato-vines, then tomato-vines, beet-tops, cabbages, the 

 weed called Careless, [a species of Amaranthus which 

 has been introduced here from Tropical America.] Bella- 

 donna and parsley; and in case of necessity they will 

 even eat horse-nettle and the different docks." It is not 

 at present known that the true "three-lined leaf-beetle" 

 is such a general feeder. Please send me specimens that 

 I may be certain of the fact. You will find a notice of its 

 habits in the "answer" to J. F. Benner in this number of 

 the Pbactical E.ntosiologist. If this is really your insect, 

 there will he a second brood of it hatch out shortly, 

 which will go underground in the larva state and not 

 come out in the perfect state till next summer. 



Henry Shimer, 111. — The gall on the root of a wild rose 

 has been described by Osten Sacken, and the gall-maker 

 is Rhodites radicum 0. S., all that you send being females. 

 The green, long-tailed parasite is a female CaUimomc, the 

 black short-tailed parasite a female £uri/toma, both ^- 

 nera belonging to the Chalcis family, and both having 

 been reared from this very gall, according to Osten Sack- 

 en. (Proc. liC. II, p. 42.) The two-winged gall-fly is Try- 

 peta solidarjinis Fitch, and its round, smooth, musket-ball 

 like gall occurs on. the stem of a species of Solidago (Gold- 

 en rod). This is the same insect, as Osten Sacken has 

 Bhown, which was erroneously believed by Dr. Harris to 

 form a similar gall on a species of Aster, and named in 

 consequence by him Trypcta aaleria. Such a mistake is 



easily made in the winter, when nothing but the dead 

 dry stem of the plant remains. The cock's-comb like gall 

 on the leaf of an elm was described by Dr. Fitch as ulmi- 

 cola; and the winged insect was first described' by my- 

 self as Thclares u/mirota. We should be glad of a male of 

 Iho Hhodites; the other species are all common. Through- 

 out the genus Rhoditca the males are comparatively rare, 

 sometimes exceedingly rare ; and they are readily distin- 

 guished from the females by lacking the acute, horny 

 "ventral valve" on the lower part of the abdomen. 



T. H. Parsons, N. Y. — The potato bug that troubles you 

 is the Lema trilineata of Olivier, which is very common 

 in the Eastern States, though in eight years collecting I 

 have only met with seven or eight specimens in Illinois. 

 You will find a good figure of the perfect beetle in Har- 

 ris's Injurious Insects, p. 118. Western men find that com- 

 mon fowls will not feed on the New Potato Bug to do any 

 good, though turkeys will. The "striped borer about one- 

 twelfth inch in diameter and three-fourths of an inch 

 long," that attacks the stem of the young Indian corn, is 

 probably a species of Gortj/na, distinct from the well- 

 known Gortyna zem of Harris, the larva of which is said 

 to be fully one inch long and not "striped," as you say 

 yours is, but "with a double row across joints 3 — 11 of 

 shining, slightly elevated black dots." The perfect moth 

 of this last is figured in Harris, Plate VII, fig. 9. You 

 will do Weil to try and rear the the moth from your larva. 

 The only general rule that can be given for breeding in- 

 sects is, to place them as nearly as possible in the same 

 situation with regard to moisture, food, heat, location <tc. 

 as they would be in if they were at large. Your insect 

 will transform into the pupa state most probably within 

 the stem of the corn that it has invaded, and most prob- 

 ably will not come out into the moth state till next 

 spring. I can of course say nothing with any certainty 

 about the worm which, as your neighbors tell you, has 

 destroyed whole acres of Sugar-maples in your vicinity 

 by feeding on the leaves, and attacks also other forest- 

 trees. Not improbably, however, it may be the well- 

 known " Palmer-worm," which in particular seasons op- 

 erates in this manner in your State. 



M. S. Hill, Ohio. — The tough brown silken cocoon, 

 about three inches long, which you found last May on an 

 Apple tree, is that oi Altacus cecropia — a gigantic moth 

 measuring nearly si.x inches across the wings, and close- 

 ly allied to the imported moth of the Ailanthus Silkworm. 

 The "small worm," that you suppose to have destroyed 

 the pupa inclosed in the cocoon and to be a true parasite, 

 is the larva of some small moth, several of which prev on 

 dead, not living animal substances, and are sometimes 

 very destructive to objects of Natural History. I found 

 a single specimen inside the empty shell of the pupa and 

 will endeavor to breed the perfect moth from it, in which 

 case I will advise you further. It was a yellow Ifl-footed 

 larva about J inch. long with a few white hairs on its body 

 and a bay-colored head. In all probability the pupa in 

 your cocoon died a natural death, and after it was dead 

 the mother-moth de])osited her eggs on the cocoon, the 

 larvae hatching out from which, crawled in at the upper 

 end, which is only partiaily closed with silk, and fell to 

 work on the carrion. There are special agents in all di- 

 rections, appointed by an all-wise Providence to clear 

 away all decaying substances, whether animal or vege- 

 table, and prevent them from becoming offensive and in- 

 jurious to health. Every day of my life I am lost in ad- 

 miration at the wondrous perfection of the system, which 

 maintains in health and happiness upon the face of this 

 earth so vast an amount of Animal Life; one species 

 checked and controlled by another, and this by another, 

 and this again by a third, so that it scarcely ever hap- 

 pens, and then only for a short time, that any particular 

 species becomes unduly numerous, except where man, by 

 his artificial arrangements, interferes with the great 

 scheme of the Creaton. 



Jas. Barratt, Mass. — I have since bred the perfect in- 

 sect from your cocoons, and it proves to be just what I 

 anticipated — the Lophyrus abietis of Harris. 



ERBATVU. 



In Practical Entomologist No. 10, p. 102, column 1, 

 line 35, for "properly speaking" read "popularly speak- 

 ing." 



