iOO 



THE LANCASTER FARMER. 



[July 



feed on the " Asclepias," or wild cotton, and 

 other plants of the Milkweed family. The 

 chrysalis is always found suspended by the 

 terminal segment of body to a horizontal 

 branch, a fence-rail, or some other object 

 similarly situated, and the fly issues from it 

 within ten days after it forms, if all the sur- 

 roundings are favorable ; but, if the trans- 

 formation takes place late in the season, the 

 chrysalis will remain in "status quo," and the 

 butterlly will not appear until the following 

 spring. 



W. U. II. : The mineral from Qnarryville 

 whicli you submitted to us for determination 

 is a beautiful specimen of Calcareous S^iar (a 

 crystallized carbonate of lime) with a narrow 

 transverse vein of the sulphuret of copper pene- 

 trating it nearly througli in the middle. At 

 the end it exhibits traces of specular Galena 

 {suljthuret of lead), and also there and else- 

 where traces of common quartz rock. We 

 shall duly install it in its proper place in the 

 museum of the Linnisan Society, and record 

 the thanks of the society to the generous 

 donor. 



We hope the Linnsean Society may be 

 deemed a worthy and safe depository for such 

 scientific and historical objects as a liberal 

 public may be willing to delegate to its 

 custody and care. It has no pecmiiary or 

 speculative end in view, but desires— so far 

 as the means and opportunity are accorded to 

 it — to benefit mankind, and especially the 

 community in which it is located. The new 

 departure of the society — at considerable ex- 

 pense — ought to be taken as a manifestation 

 of its ultimate aims. 



CORRESPONDENCE. 



Aphids, and What They Are. 



Mount Jot, June 21, 1878. 



The enclosed insects were taken from an early 

 cherry tree. Some of the sweet and sour cherry 

 trees in our town are alfected with them. I thought 

 it would be of some interest and satisfaction to the 

 public if j'ou would give the name and particulars of 

 these insects, where they come from, and whether 

 they will kill the trees they attack, if not driven 

 away by some means. 



The extreme ends of the limbs are the place, where 

 they have started on, which they use up as the ones 

 enclosed are used up. Their work seems to be the 

 same as that of the catcrpiller, only, instead of 

 making a web, they get wings and fly away, and the 

 query is, where do they go, or in what shape, until 

 they are seen again? Respectfully yours. 



To Professor Kathvon. A.G. 



Deak Sie : Your insects on the leaves of a 

 cherry twig were duly received and we imme- 

 diately, after examining them, committed 

 them to a street sewer, as the most convenient 

 means to destroy them. They belong to the 

 great family of "plant lice" [Aphididve), of 

 which there are a very large number of species, 

 almost every tree, shrub and plant having a 

 species peculiar to itself. Some of them are 

 indiscriminate feeders, but others confine 

 themselves to a distinct species or genus of 

 plants. The family has been very numerous 

 this season almost everywhere, owing, we 

 tliink, to the mildness of last winter, and the 

 early and abundant succulent vegetation the 

 ])resent spring and summer. The species you 

 sent us is the "cherry aphis," sometimes 

 called rather indefinitely the " black ayjh is " 

 (Aphis cerassi), and it probably confines itself 

 to the various species of the cherry — including 

 tlie wild cherry — and their varieties. In an 

 exciu'sion to Lampeter township on the 12th 

 ult. , we explored a ten-acre enclosure of wood- 

 land, in which there was much rank under- 

 growth, both annual and perennial, and there, 

 in the very middle of it, we found a young 

 cherry tree about five feet high (planted, no 

 doubt, by some bird), nearly every leaf of 

 which was crumpled and black with the same 

 species of aphids, although we did not detect 

 a single specimen on any other plant in the 

 whole enclosure. This may illustrate liow 

 very local they are in the choice of their food- 

 plant ; although these, or a species very nearly 

 allied to them, also infests the plum. In the 

 early part of the season the "Peach Aphis" 

 [Ajjfiis jKrsicoi) attacked the first leaves of the 



peach trees, and it appeared as if the crop 

 would be destroyed ; but fortunately they 

 came too early, did very little damage to the 

 blossoms, enervated the leaves, so that through 

 the cool weather, winds and rains, tlie leaves 

 were early shed and a new crop started, 

 through which millions of Aphids were dashed 

 to the ground and perished. Peach trees, 

 therefore, now look thrifty, and if the crop 

 foils, it will be from other causes than the 

 Aphids. 



These little animals have a very peculiar 

 history, and perhai)S there are very few others 

 that are endowed in the saine degree with the 

 elements of prolification and perpetuation ; 

 therefore, so long as vegetation germinates 

 and grows on this earth, we may expect the 

 presence of aphids. No doubt their creation 

 was permitted for some use, although we may 

 have failed to discover it. They at least fur- 

 nish food to a multitude of other animals that 

 we wot not of, and may also serve to check a 

 too redundant vegetation in many cases. We 

 believe we have noticed aphids every season 

 for the past sixty years, and still vegetation 

 goes on. 



" Where they come from " — well, they come 

 from very minute eggs, previously deposited 

 on the branches of the trees they infest — so 

 minute indeed that they cannot lie detected 

 by the naked eye, unless the sight is 'very 

 sharp and the observation very close. They 

 are not, however, uniform in their habits. 

 Those infesting trees and woody shrubs differ- 

 ing from those infesting succulent vegetation. 

 They have a very complex procreative func- 

 tion, adapting them to the climatic influences 

 by which they are surrounded. The first 

 brood in the spiing are excluded from the eggs 

 which have been deposited the previous 

 autumn, and these are generally all wingless 

 and highly proliflcated females. From thence 

 forward, duj'ing the continuance of warm 

 weather, they deposit no more eggs, but be- 

 come viviparous, bringing forth their young 

 alive and perfectly formed, just as mammals 

 do theirs, with this exception, however, that 

 they are born fertile and do not need the in- 

 tervention of a male. In twenty-four hours 

 after maturity the second brood will be in a 

 condition to bring forth young ; and so on 

 during the whole season. Of course these 

 operations may be disturbed or retarded by 

 unfavorable contingencies, but from ten to 

 twenty distinct germinations or mcjre, are 

 produced during the season, and if the warm 

 weather continued up to Christmas or longer, 

 and they were supplied with the necessary 

 food, they woidd continue to multipl}'. 



But when the cold winds of autumn ap- 

 proach, when juicy vegetation ceases and the 

 trees begin to drop their leaves, a brood of 

 winged males and females is produced; re-fer- 

 tilization is effected ; the females oviposit on 

 the smooth young branches ; both sexes die, 

 and the winter is bridged over by an embryotic 

 brood securely encased within the shells of the 

 eggs, which are secured to the branches liy an 

 insoluble coating of mucilage, and inviduera- 

 ble to the effects of rains, snows, frosts and 

 icy winds of winter. Of course, through vari- 

 ous casualties many of these eggs may be 

 destroyed, but still enough remain intact to 

 perpetuate the .species the following season. 



"The query is, where do they go, or in 

 what shape, until they are seen again ?" They 

 are very tender and fragile animals. Slow 

 travelers and awkward fliers, and the winged 

 females during the summer fly to other trees, 

 or to other branches on the same, and con- 

 tinue tlieir reproductions there ; but millions 

 of them are destroyed by small birds — on the 

 wing by swallows-^such as wrens, fly-catchers, 

 orioles, sylvias, and also by spiders, lady- 

 birds, lace-wings, syrphus flies and a number 

 of parasites much smaller than themselves ; 

 especially species of "Tlirips" and "chalqes- 

 flies," but perhaps the larger number of those 

 flying abroad are beaten down by heavy rains 

 and perish. If there were no natural checks 

 to their multiplication, their injiu'ies to vege- 

 tation might be fatal. 



The wheat about Chambersburg, Pa. , the 



present season, and also some fields in Lam- 

 peter township, in this county, which we ex- 

 amined, was more or less infested by the 

 "wheat aphis, ' ' [Aphis cerealis, ) but that which 

 we examined contained also an antidote in 

 the form of a minute fimgus, which destroyed 

 more than one-half of them, and the winds and 

 rains destroyed a large number of the others. 

 About ten years ago the "oat aphis" {Apjhis 

 avena), very materially injured the oat crop in 

 Lancaster county, but they passed away, and 

 only a few have apjjeared at intervals since. 

 Aphis brassica, infests the cabbage ; Apihis 

 rosea, the roses; Aphis muU, the aijples; Aphis 

 pirunus, the i)lums, &c., &c. "Will they kill 

 the trees V" They are not likely to kill large 

 and healthy trees, but the Aplds persica has 

 been known to kill or render unfit for use 

 thousands of young nursery stock early in the 

 season. Of one thing we may be well assured, 

 they will never do the trees any good, for they 

 live on sap, the very life blood of plants, and 

 when they once penetrate the tree or plant 

 they commence to pump up its juices and 

 hang on while life remains, or until they be- 

 come helplessly gorged, like so many hungry 

 leeches, and they seem to be always hungry. 

 "The remedy" — Well, there are a great 

 many remedies for destroying Aphids, but we 

 do not risk much in saying that for every 

 Aphid destroyed by a " remedy, artificially 

 applied, there are a hundred thousand that 

 fall victims to casualties in the economy of 

 nature, and if it were not for these, all human 

 effort would he but feeble in effecting their 

 extinguishment. Still, we may sometimes 

 have a favorite tree, shrub or plant, that we 

 desire to save or relieve from these noxious 

 pests by an immediate remedy, and in such a 

 case a tobacco decoction, a saponaceous solu- 

 tion, or an infusion of sumac, thrown on the 

 plants through a garden Engine with power, 

 will dislodge and kill the most of them. For 

 this piu-pose also diluted carbolic or crysilic 

 acid will be eftectual, and in some cases even 

 a strong stream of water is beneficial. Pul- 

 verized tobacco, lime, ashes, hellebore, Paris 

 green, or even road dust are more or less 

 effective. Aphids, howevei', like many other 

 insects, occur in inexplicable cycles of time, 

 which are by no means regular in their inter- 

 vals. For one or two seasons or more they 

 may be present in abundance, and then almost 

 entirely disaiipear for a numlier of successive 

 seasons, and then suddenly reappear as nu- 

 merously as liefore, and so on, perhaps until 

 the end of time. 



Lebanon, June 28th, 1878. 

 Mt Dear Sir : I found a specimen of an insect on 

 my plum tree, and being unable to ascertain what 

 it is, and its habits and qualities, I was advised to 

 send it to you for information. I send it by this 

 mail. Will you please give me such information as 

 you have on the subject. Yours truly, 



Grant Weiuman. 



Your box and insect came duly to hand. It 

 is the pujia form of a species of " Lady bird," 

 {Coccinella) but it had received some injury in 

 transit, and therefore died before the beetle 

 could be developed ; therefore, we cannot de- 

 termine the species. From its size it may 

 possibly be the novem-noUita, or "Nine-Spotted 

 Lady-bird." All, or at least many, of the 

 genus Coccinella are apliidiphagus in then- 

 habits, feeding largely on plant-lice. They 

 are amongst om- most efficient insect friends, 

 and therefore their presence on vegetation 

 should create no apprehensions prejudicial to 

 their economical status in the general har- 

 mony of nature. Wherever aphids abound, 

 these little beetles, both in their larval and 

 perfect states, will be found more or less 

 numerous, and they devour many of them, 

 and tlms in some measure check tlieir multi- 

 plication. If we have mistaken the specific 

 status of this pnpa, we liave no hesitation in 

 saying that it belongs to that " ring " at least. 

 There are some of the Coccinellid.e, (Lady- 

 bird family) however, that are vegetable 

 feeders, and in the imuijo state probably most 

 of them are polonaceous, wlien plant-lice are 

 not accessible, and conspicuous amongst them 

 is the large yellow, black-spotted "Tortoise 



