THE PRACTICAL ENTOMOLOGIST, 



109 



figured in the perfect state in tlie New York Reports III, 

 p. 188. These Ground Fleas are quite distinct from the 

 true Fleas, and belong to the same Porfwro family as those 

 lead-colored, wingless, jumping insects, comrnonlj' found 

 in small numbers under old logs, and appertaining to the 

 genus Polara. The most correct English name for these 

 Ground Fleas is '-Springtails," as both genera have a pro- 

 cess at their tails, which, when bent under their bodies 

 and suddenly released, enables them to jump like a flea. 

 In Sminthur'us this process is two-forked, and is very dis- 

 tinctly seen in the specimens sent, though, as is usually 

 but not invariably the case with insects — for example, it 

 is just the reverse with the Dragon-flies— the larva is 

 much more elongate than the perfect insect. The loca- 

 tion of these "Springtails," in a Natural system, has per- 

 plexed systeniatists much. As they have a distinct head 

 with two antennre and six legs, although they never ob- 

 tain wings, the least obiectionable course, perhaps, is to 

 unite them with the Dragon-flies, May-dies, Shad-flies, 

 Ac. (Sub-order Pseudnneuroptera). The genus Podura is 

 derived from two Greek words signifying "foot-tail," and 

 the genus Snmithurm from two Greek words signifying 

 "Rat-tail." The latter term has hitherto been often in- 

 correctly printed "Smynthurus," and it has been still 

 further perverted by Dr. Fitch, by printing it eight times 

 over in the passage already referred to, as "Symnthurus." 



I do not believe that any of these insects are injurious 

 to living vegetation, though Dr. Fitch thinks that "when 

 a Flea-beetle [Siltica] perforates a hole in a leaf, these 

 Garden Fleas afterwards gather around the perforation to 

 feed upon the soft matter which is there formed by the 

 evaporation of the exuding juice." In the perfect state 

 the Garden Flea is said to be scarcely half the size of a 

 mustard seed, and of a dull black color, so that they re- 

 semble grains of gunpowder. In all probability they 

 found congenial food in the decaying vegetable matter of 

 your hotbeds, and will do your young plants no material 

 injury. If, however, you wish to get rid of them, dusting 

 the plants with ashes, sulphur, Ac, is said to be an effica- 

 cious remedy ; but I should not like to vouch for it myself. 



A;al9U3. Kiutucky. — As you have now sent on speci- 

 m'^ns of those flies which you bred from the Blackberry 

 gall, (which, by the way, reached me in good order), I 

 cm tell you what they are. Those of which you sent se- 

 ven specimens, (1 ■£, 6 ? ), are the true makers of the gall 

 — the Dinstrophus nebulosus of Osten Sacken, rather small 

 specimens, however. In this gall-making genus, as you 

 will observe, the abdomen is evidently composed of se- 

 veral segments. Those of which you sent two specimens, 

 both females, are the Autax sylvesiris of Osten Sacken, and 

 are Guest-gallflies. In the female of this genus, the ab- 

 domen is apparently composed of but a single segment — as 

 is also the' case in both sexes of certain other genera of 

 Guest-gallflies, but never in either sex of any known ge- 

 nus of true Gallflies — but what is very remarkable, and 

 specially characteristic of the genus Aulax, the abdomen 

 of the male is apparently composed of two segments. The 

 third insect, of which you send only puijae, and the wing- 

 ed fly of which has, as you correctly remark, but a single 

 vein in the front wings, does not belong to the Gall-flies 

 {Ct/nips family) at all, but to the Ckaleis family, and is 

 neither a Gall-maker nor a Guest-fly, but a parasite, feed- 

 ing in the larva state upon the bodies of the larvse of the 

 Gallflies, and not, as the latter do, upon the substance of 

 the gall itself. It probably belongs to the group Eurvto- 

 ma of the Chalcis family, of which both Osten Sacken 

 and myself have bred a representative from this same 

 gall ; and from your description all your specimens are 

 females. In this particular case, there is no direct evi- 

 dence that the Diastrophus is the Gall-maker and the 

 Anlax the Guest-fly, and not the reverse, inasmuch as 

 both insects inhabit cells placed promiscuously side by 

 side, in one and the same gall. But as Osten Sacken bred 

 this same Aulax frpm a very distinct Blackberry gall, 

 producing a very distinct Diastrophus, this is pretty 

 strong, indirect evidence. Suppose, for example, that 

 this Aulax is the real maker of your Blackberry gall. 

 Then one of two things necessarily follows, either, 1st, 

 that the same insect produces two entirely distinct galls 

 on the same genus of plants, or, 2d, that the same insect 

 is a Gall-maker in the case of one Blackberry gall and a 

 Guest-fly in the case of the other gall. This latter sup- 

 position is as contrary to all entomological analogy, as 

 it would be to all ornithological analogy, to suppose that 

 our American Cowbird or the European Cuckoo some- 



times builds a nest for itself and sometimes lays its eggs 

 in the nests of other birds. The former supposition, from 

 a large experience with gallmaking insects, I believe to 

 be utterly untenable. Therefore, the Aulax cannot, al- 

 lowing the above data to be correct, make your Black- 

 berry gall; which was the thing to be proved. 



Jamea Barratt, Mass. — The blue, long-horned beetles, 

 over i inch long, which you split out of Yellow Pine (Fi- 

 nns mitis), arrived in excellent order, and are the Calli- 

 dium antennatum of Newman. You will lind a good color- 

 ed figure of the species in Harris's Injurious Insects, 

 (Plate II, fig. 11). Harris mentions its being very inju- 

 rious to the Pine in New England, but supposing it to be 

 identical with a similar species found in Europe, has 

 named it as C. violaceum. Possibly it may turn out in 

 the end that Harris was right. The two you sent were, 

 as you rightly supposed, male and female, the male dif- 

 fering from the female not only in having much longer 

 antennjB, but in having a remarkable shield-like plate 

 sculptured on his thorax, which is not seen in the other 

 sex. There is another v^ry similar species — the Callidi- 

 2ifn iantkinuTti of LeConte — which infests the Red Cedar, 

 and which Dr. Fitch believed to be a mere variety of your 

 species. But in the Red Cedar insect the male never has 

 the shield-like plate on the thora.T always met with in 

 the Pine insect, besides four other difi'erences which I 

 have pointed out. (See Proceedings V, p. 20G — 7, and' 

 Fitch N. Y. Rep. II, ? 2,37.) 



Clias. H. Peck, N. Y. — The Plant-louse found on Pinus 

 strobus is doubtless the Lachnus strobi of Fitch, though 

 you send no winged individuals, which according to Fitch 

 are scarce. In this genus I believe that the females do 

 not acquire wings at all ; at all events it is so in Lachnus 

 caryce. I should be glad of some winged specimens, if you 

 can meet with such and have them to spare. The eggs 

 on the pine leaves are identical with those received from 

 Mr. Orton of Ohio, (see Piiactical En'tomolocist II, p. 84,) 

 and are laid, I have little donht, hy the Lachnus. As to 

 the litLle black Bark-louse found on Sumac (Rhus glabra), 

 it is the most extraordinary insect I have seen for a long 

 time, having two enormous lateral plates to its thorax, . 

 the front one sweeping forwards so as to enclose the large 

 head upon each side, and give the whole insect somewhat 

 the appearance of a Tortoise-beetle (Cassida). I can find 

 no genus to which it can be referred with any propriety ; 

 and so far as I am aware, the species is new to science. 

 In fact, the Bark-lice have never been much worked at 

 by any one in this country, anomalous and otherwise in- 

 teresting as the family is. You will do well to try and 

 obtain the winged males of this species, though probably 

 they will be found, as usual in this family, to be very 



John Townley, 'Wise. — The cut-worms sent all belong 

 to the same species, except a single darker-colored one, 

 which is probably the one which you noticed yourself as 

 being darker-colored than the others, and which you 

 found feeding on peas. As some of the above were taken 

 by you feeding on the buds of trees, grape-vines and rose- 

 bushes, and some were taken cutting peas and lettuces, 

 it seems to follow that, in this particular case, the same 

 species varies greatly in its habits. I should add, how- 

 ever, that three or four specimens were killed on the road 

 by their friends by way of provision, and that those 3'ou 

 had insulated in the paper box, bored their way out and 

 got mixed up with the rest. Neither of the two species, 

 which reached me alive, agrees with any of Mr. Riley's 

 three described species. Besides the plants above men- 

 tioned, you say that you have found cut-worms "eating 

 the buds of lilacs, of the Tartarian honeysuckle and of 

 the common Snow-ball shrubs;" and that round the last 

 two you "had tied branches of the Norway Spruce, which 

 did not stop them. Bright tin, however, they cannot 

 climb up." This agrees exactly with what Mr. Riley has 

 said on the subject. 



Xhos. L. J. Baldwin, Del. — The specimens of Potato 

 Scab were received in excellent order. I hope for more 

 during the summer. 



Eobt. L. 'Walker, Penna. — The small light-green insects 

 on your Currant leaves are the common Currant Plant- 

 louse (Aphis ribis), which I briefly referred to in my re- 

 cent Paper on Plant-lice. The best way to get rid of 

 them, is to catch a number of the Lady-birds that prey 

 on them, and scatter them among your bushes. 'With a 



