THE PRACTICAL ENTOMOLOGIST. 



57 



C. p. Wickersham, Penna. — What I said in the passage 

 to which yoLi refer (Practical Estouologist I, p. lUl) was 

 that "both Harris and Fitch ignored the possibility of any 

 larvse [of the Wheat Midge] passing to the pupa state in 

 the ear, and coming out as winged Jfies the same season.'* 

 The passages you quote from Harris in no wise contro- 

 Tert this assertion, as they only refer to the larva state of 

 the insect. As to the knotty question, whether the filmy 

 membrane enveloping the full-fed larva of the Wheat 

 Midge be its moulted skin or a true cocoon, I must again 

 refer you to the passage in my Willow-gall Paper. (P/'O- 

 cecdings III, pp. 560 — 9.) You will find that I there show, 

 that in certain species of Cecidomt/ia beyond all doubt, 

 and as I maintain in all species without exception, the 

 envelop in question is not spun like the cocoon of a silk- 

 worm, nor moulted off from the body of the insect, but se- 

 creted in a gummy form from the general surface of the 

 body, just as many Plant-Hce and Bark-lice secrete a cot- 

 tony or sugary substance from the general surface of their 

 bodies. This theory disposes of your objection, that "un- 

 der a high magnifying power there is no trace of any fi- 

 bre in the so-called cocoon, while on the other hand there 

 are traces of the rings of the body of the larva." Whether 

 a pupal envelop formed in this manner is properly called 

 a "cocoon," is a mere question of words and not at all a 

 question of facts. But this whole subject is rather an ex- 

 tensive and recondite one, and I must refer you once 

 more, if yoM wish to learn my views more fully, to the 

 Paper quoted above, and to the concluding part of that 

 Paper which is now in press. 



Bich. Middleton, Penna. — In answer to your three 

 questions, 1st. Frogs and toads are generally not only 

 harmless but beneficial, as they chiefly live upon insects. 

 Toads, however, will eat strawberries; but otherwise they 

 are very useful in a garden. Frogs have the power of 

 leaping; toads have not. 2nd. All spiders feed upon ani- 

 mal food and chiefly upon insects. So far as they feed 

 upon noxious insects, they are eminently beneficial. 3rd. 

 You need not be afraid to handle any insects, except 

 Wasps and Bees, and even with these it is only the fe- 

 males that sting. It is true that there are a few hairy 

 caterpillars, the hairs of which will sting the back of the 

 hand, or any other part where the skin is thin, about as 

 badly as, and no worse than, a nettle does. But if the 

 palms of your hands are as hard and horny as mine are, 

 you may handle even these with perfect impunity, as i 

 constantly do. Again, there are a great number of insects 

 that will try to bite, when roughly handled; but no such 

 species known to me can do more than just pinch a little, 

 without penetrating the skin or inflicting any wound. 

 Moreover, there is a group of large, two-winged cannibal 

 flies, {Asiliis family,) which fly with a loud, buzzing noise 

 among herbage, and prey upon such large insects as Hum- 

 ble-bees and grasshoppers; and there are also the Water- 

 boatmen {iVbionec^a family) found exclusively in water; 

 both of which two groups will often puncture you with 

 their beaks, if you let them. There are a few Ichneumon 

 flies, too — particularly a large bluck species known as 

 Ophion morio — the females of which will often penetrate 

 the skin a short distance with their ovipositor, when 

 roughly handled. But all this is no worse than the prick 

 of a pin, as — unlike the female Bees and Wasps — none of 

 these insects have any poison-bag attached to the in- 

 strument that penetrates your flesh. 



M. M. S., Penna. — The minute white scales on the un- 

 der surface of the leaves of your Olea fragrans, are a spe- 

 cies of Bark-louse, otherwise called Scale-insect, which I 

 have not hitherto met with. If you raise one of the scales 

 at this time of the year with the point of a penknife, you 

 will find underneath it a roundish yellow louse, often ac- 

 companied by some of the minute elongate-oval eggs 

 which it has laid, and from which next spring there will 

 hatch out a fresh brood of young Bark-lice. Under a sin- 

 gle scale I was fortunate enough to find one of the males, 

 which, as is usual in this family, had two long wings, the 

 females being always wingless to the last moment of 

 their existence. In this particular species, the **Scale*' 

 is not formed of the lifeless body of the female — as. is the 

 case with the common Apple-tree Bark-louse* — but is a 

 distinct integument, constructed by the female to protect 

 herself and her eggs, and probably secreted from the ge- 

 neral surface of iier body. There is a very much larger 

 Bark-louse which I have noticed to infest the leaves of 



* Figured Practical Entomologist II, p. 31. 



the Oleander; and some few years ago the Orange trees 

 in Florida were almost entirely destroyed by another 

 species, which infests that plant in Europe, and which 

 had been accidentally imported on a single small man- 

 darin orange-tree, and spread therefrom on to an adjoin- 

 ing orange-grove. In fact, the number of distinct species 

 of Bark-lice, as of Plant-lice, is very large, each species, 

 as a general rule, confining itself to a particular group of 

 plants, and often to a single species of plants. But, from 

 the general distaste for these insects, but few observa- 

 tions have been made in N. A. upon their history. Scien- 

 tifically speaking, the Bark-lice belong to the Coccus fa- 

 mily in the Order ^omop/era. Disagreeable as many of 

 them are, we are indebted to one species for our Shellac, 

 and to another for our Cochineal. 



In order to destroy these insects, you had better wait 

 till the eggs hatch out in the spring, and then wash or 

 syringe the whole of the infested plants with moderately 

 strong lye. As lye when it is too strong is injurious to 

 plants, it would be a good plan, after you have prepared 

 it, to try it upon some plant that you care nothing about, 

 by way of experimenting; and you can then, if necessa- 

 ry, reduce its strength. Your plants will lose nothing by 

 your waiting till spring, as the old mother-lice are about 

 giving up the ghost after depositing their quantum of 

 eggs, and even the younger individuals will remain tor- 

 pid under the protecting scale until the warm weather 

 comes. If you prefer it. you will find tobacco smoke in a 

 small close apartment fully as effectual as the lye. 



The little green parasites on your rose-bushes are doubt- 

 less the Rose Plant-louse (Aphis rosoc.) The "tiny, little, 

 white creatures, like moths, upon your plants," judging 

 from your drawing, must have been a species of Psychodaj 

 a genus of Two-winged Flies allied to the Gall-gnats, and 

 in no wise injurious to plants; or perhaps a species of 

 Aleurodes,& genus closely allied to the Plant-lice and with 

 the same habits, one species of which I know to infest the 

 Crab and the Apple-tree in small numbers. 



You will greatly oblige me by mailing me a dozen or so 

 of these infested leaves, packed as soon as gathered, in any 

 little tight tin box. The specimens sent, as well as the 

 insects upon them, were completely dried up, when they 

 reached me. 



Willio C. Fish, Mass. — Your insects are, 1st. Rylastes 

 pini/ex Fitch, dark variety. 2nd. Tctraopes canteriator 

 Drap. 3rd. Colaspis ovata Say. 4th. Crj/ptocephalus, not 

 determined. 5th. Hippodamia parenthesis Say. 6th. 

 Psyllobora 20-maculaTa Say. — Haltica chalybea is quite dif- 

 ferent from No. 3, being more elongate, less globose, and 

 having thickened hind thighs. 



S. P. Monks, N". Y. — 1st. The hundred-legged worm 



which you send, and which you state to have been found 

 **in a rather damp place where there is much decayed 

 wood," does not belong to the genus lulus, which has its 

 body almost as smoothly cylindrical as a goose-quill. I 

 have forwarded the specimen to Dr. H. C. Wood of Phil- 

 adelphia, who makes the Myriapoda his special study, 

 and has published a valuable Paper on the subject, and 

 he has obligingly informed me that it is Polydesmus vir- 

 giniensisj Say. 1 have never met with the species in Illinois. 

 A^pong the Myriapoda (thousand-legged worms), there are 

 no distinct stages corresponding to the larva and pupa 

 state of Insects, the more mature scarcely differing from 

 the less mature worms, except by having a greater num- 

 ber of joints to their bodies. 2nd. The brown-black newts 

 with orange-colored spots, that you speak of, so far as 

 my observation extends, feed upon insects, &c. I usual- 

 ly find them under logs and stones in the woods, but 

 twice I have found*them in water. 3rd. I know of no 

 work on Entomology exactly suited to be put into the 

 hands of children. Harris's book is the nearest approach 

 to what you inquire for. Some day or other I may writo 

 such a work myself. 



Geo. Haines. N". J. — The flat-oval gray eggs about 3-1 fiths 

 inch long, and glued in two regular rows to the side of a 

 grape-twig, are, as you correctly suppose, those of a Caty- 

 did. 



Geo. W. Smith, Michigan. — In a future article on Wasps 

 and their habits, I will explain the phenomena which 

 you witnessed. The wasp was no doubt the common blue 

 species, known to entomologists as Sphex ccerulea. 



C. V. Biley, 111. — The Scolytus you send, which you say 

 is "very destructive in this country,*' though you do not 



