Gentry, Thos. G.

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Utah State University DigitalCommons@USU Ga Bee Lab 1-1-1874 Notes on Megachile centuncularis Thos. G. Gentry Follow this and additional works at: https://digitalcommons.usu.edu/bee_lab_ga  Part of the Entomology Commons Recommended Citation Gentry, Thos. G., "Notes on Megachile centuncularis" (1874). Ga. Paper 128. https://digitalcommons.usu.edu/bee_lab_ga/128 This Article is brought to you for free and open access by the Bee Lab at DigitalCommons@USU. It has been accepted for inclusion in Ga by an authorized administrator of DigitalCommons@USU. For more information, please contact digitalcommons@usu.edu. "'tt\. -'I f. .. ,. . 'l::.t~•·: 170 paler than the wings, but I can Al. ex. -.¡\ inch. The larva is white, without maculae, but with the anterior rnargin oí the first segrnent b;own. A. l1ydranga:ella. N. sp. The mine and larva only of this species is known, and succeeded in rearing the imago. The mine, larva and case resernble those of A. 11iticordifalie/la, but are perhaps a little srnaller. It mines the leavcs of the wild Hydra11gea ( H. 11ivea.) Dr. Clemens states that the species described by him mine the leavcs-of the various plants in the latter part of August ·and in September, from . which I infer that he found them only at that time. But the mines of a!T ~he species may be found as early as the first of July, and in increasing: numbers from that time until the fall of the leaves. I have reared A .. cor11ifoliella in the latter part of July, from leaves gathered in that month,. · and have found the mines and larvae of all the other species, though I have only succeeded in rearing th'! other species in the spring from mines. gathered in the fall. NOTES ON THE "LJST" OF 1868. BY AUG. R. GROTE, Curator of Artimlata, Bu/falo Soc. o/ Natural Sdmces. Preparatory to a fresh edition of the "List of Lep. ," of 1868, a fer memoranda of the nece ssary changes will be published. Sesia 1mifor111is, p iii. This species is distinct frorri thysbe, and has been noticed by Mr. Lintner in his valuable "Entomological Contribu•.' tions." Mr. Couper found it on Anticosti. This can not be SeJill ruficaudis Kirby, the description of which is · given on p. 27 of the "Synonymical Catalogue" of 1865. Kirby says: two first segments r:J the body yellow olive, two next hlack, the rest ferruginous with yellow olive spots. Uniformis has the first segments yellow olive, the next dee¡> ferruginous, the next again olive, and the anal hairs black, with ferruginma central tufc. In fact, Kirby's description rather resembles d(ffinis in the, body parts. And from his comparison with jucijtJrmis, we should think., 'fHE CANADIAN ENTOMOLOGIST. 171 at once of dijfi11is. But the terminal segments in dijfinis are not " ferru-• ginous" any more than in tmiformis, and so Kirby may have had a boreal species we do not yet know before him. From his description there is. no more correspondence with 1mifarmis than with tl1ysbe; rather <loes his. _ description agree with f11scica11dis as to the abdomen terminally. ' Cressonia juglandis, p. iv. To this species must be cited Sm. -pallens-o( Mr. Strecker, whose figure represents a ?ale ~ specimen of C. j,tgla11dis, without the median shade on thc forewings. Belfrage has sent C. j11gla11dis from Texas. Dysodea 11-P· vi. This generic name 1s preoccupied and must give ny to that of Platythyris. Mr. Walker 's type of Vamia appcars .. distinct. We have probably but one species which should be known as · /'fatythyris omlatana. Boisduval's figure and description of Vitrina do--DOt agree with our species, and probably vitrina represents omlatana in Europe. Much confusion has üccurred through Dr. Clemens having described the species figured by us, Am. Lyc. Nat. Hist., N. Y., vol. viii,. pi. 13, figs. 4-5, as one of the Tortricidre, and without referring to-' Boisduval's original illustration of the genus. A second species is -al\erwards described by Dr. Clemens under the narne of D_ysodia mar-- prilana, which I have never seen. Consult Am. Soc. Beige, T. 7, PI. 1 , ---: for an illustration ot the embryonic stages of Thyris. They seem . to -~ correspond generally very well with Dr. Clemens' characters of the lan·a . o( Dysodea. NOTES ON MEGACHILE CENTUNCULARIS. BY THOS •. G. GENTRY. GERi\lANTOWN, PA. so mttch has been written upon the habits of our ordinary · Leaf-cutting Bee, it would seem presumptuous for me to offtr anything 6irther in connection therewith. But a few facts which came to my notice · ttcently are sufficiently interesting and impurtant to merit publication. Duri'ng the latter part of J une, 1873, severa! ce lis, a half a do zen in 1111mber, were sent to me by a fritnd, who had accidentally brought them IO light while digging underneath the shade of a Spira:a t()J;ymbosa. They wtre found in close proximity to each other, arranged in a nearly liorizontal position, at a depth of three inches below the surface of the -172 THE CAN ADIAN E~TO)lOLOGIWf. ----- ---- - -- -- ---- - ----- - 04• --- ---- --,ground. The soil was comparatively solid. From the freshness of the leaves which composed the cells it would seem tha:t the work had bat lately been accomplished, but after the examination of a frw, it ,ns evident that some time had elapsed, since the larvae had attained lo -considerable dimensions. The cells were nearly three-quarters of :rn inch in length, with a • diameter of one-fourth of an inch. They were constructed of nearly . perfect lea ves of Spirrua corymbosa, instead of those of the various specics -of Rose. The outermost circle of lea.ves, three in number, had their margins slightly overlapping on the exterior, ea.ch piece forming an are oí · .a circle of 120 degrees. Within these were other three, arrangcd .alternately with them ; others, again, alternating with the latter, and so -on until there were no less than six circles, having eighteen pieces in a!L Each succeeding individual !ayer from without inwardly projected but ,slightly beyond its predecessor, having but a slight resemblance ·11 to a long sleeve with folds u pon it," as has been affirmed by writers. The mouth of each cell was closed by six circular pieces -of lea ves, nipped from the same plants. These were a trifle larger than the mouth of the -cell, and when in position presented J. concave surface facing outwardly. It is obvious that the whole structure is a striking proof of adaptation to an end. If the cell had been arranged vertically, its structure would -doubtless have afforded water a ready access to the larva and its food, and ·thus have defeated the object which nature had in view. ln the horizontal position the tile-like arrangement in the exterior, acts as a sort of roofby which the water is turned off. The concave arrangement of the circular pieces subserves a similar purpose. The freshness of the leaves was -due, no doubt, to the protection which the enveloping earth afforded. , The chemical rays of sunlight, which act upan the parenchymatous material of the leaf, when deprived of its vitality, converting the green .and granular chlorophyl into others of a brownish hue, operate with lcss intensity at the depth of three inches. The comparative absence d moisture in the ground, no doubt, prevents oxidation; there being ample moisture at the same time to insure softness and prevent rigidity. During the early part of last April ( 1874), severa! cells were· brought ., to me by one oí my pupils, which, on a superficial examination, appeared to be the mud cells of our ordinary Pdoprew, the mud-dauber. Thej were found adherent to the rafters of an unplastered attic. The ceth ·were arranged side by side in numbers of three . On the exterior thele THE C.-\N.-\DL\N ENTO)IOLOGIST. 173: were no shallow grooves, denoting lines of demarcation. With this -animportant difference, the general ontline of the mud mass, with its combination. of pellets, was exactly sirmlar to that constructed by the · mud-dauber. Had the lines of separation existed, I should have had no-hesitancy in characterizing it as a case either of usurpation of instinct upon the part of the Mcgachilc, or one of confiscation of property .. Within, exposed to view by detachment from the aforesaid rafters, were· ,what I supposed to be the leafy cells ol M c;,;achile. The length of these-and the peculiar disposition of their parts, materially different from what J had always oh served, operated upon my mind to such an extent that I ns almost constrained to believe that I had met with something altogethe~ -new to science, or else that I had been fortunate enough to discover a spccies of Pcl,p 1elfs with 1lfQ;ach ilc-lik e habits. Ea.ch cell was one and one-eighth inches in length, with a diameter · sli~htly excecding one-fourth of an inch. It was built of elliptical pieces snipped from the lea.ves of a species of Spirreci ( S. corymbosa, it seemed . to me.). The pieces were of less dimen sions than those before alluded . to, and arranged somewhat on a similar plan, except that there was a ' ltrong appearance of a double cell , as if the inferior concavity of o:1e ccll had been deposited in the superior concavity or mouth of the other. This resemblance held true to a certain extent, but the absence of a dear line of division between the t\\"o seemed to militate against the . idea oí a double arrangement . . Having kept a few of the cells a reasonable length of time, until all , hope of seeing insects emerge therefrom had vanished, I began the work ·_oí destruction by carefully pulling sorne of them to pieces. " 'hile engaged in my labor I was led to notice the comparative ease with which · tach relative structure separated in the middle. Within the aperture of one cell was a cylindrical pouch , composed of pure silk, glazed within by an oily secrelion from the larva. This containsd a perfect, but dead bec, which was readily identified as 1J[egachile cmt1111mlaris. The lower half of the same enclosed a similar silken sack, with fragments of legS',-wings, antennre and complete body segments, with a mass of debris which showed the clearest evidence of the ravages of sorne ruthless destroyer. Under a glass of modera.te power, I had little difficulty in recognizing the bgments as part s of a .Jfegad1ilc similar to the above. This last fa.et impressed me as peculiarly interesting and no,·el, as. ~01Ying the economy which exists and is pracliced among . certain . .. ... ~  ia ~\ -~ ·-~:? •Qii.i 'f., .. ) ( ' t:~,r,;-~J . 1;-...... ' - ~,fC.'. .. (: .... ,....,.~ lC:,,:w' ; ';:;.e~: 174 THE CANADIAN ENTOMOLOGIST, individuals oí this species. To construct the inner leafy cells, with their numerous parts, is a labor of little moment when contrasted ,~ith . the hours that must be spent in moulding the clay for the outer s1de mto ·small pellets , and then adjusting them to their proper positions. T~e -existence of two bees in separate cases of silk, one above the other, 1n the same earthy apartment, seems to imply the existence of a _double leafy -cell, even though a partition between the two should be wantmg . It would appear that the deposition of one cell upon another would -defeat the object which the mother Megacltile had in view. On tl-.e supposition that oviposition in the upper cell took place subse~ue~tly to that in the lower, the time of leaving the egg would be earher m the latter the larva would sooner mature, and the . perfect insect would be -_prep:red to leave its prison-house anterior to its associate, and, unable to effect its exit by reason of the narrowncss of its domicile, would perish. This, doubtless, would be the upshot rJ . the affair if similar cells in like situations should be built in the summer ,season. But as far as I have had any experience in the matter, the summer abodes of Megacltile are single, a few inches below the surface rJ · the ground, and generally under the shelter of so~e ~rotectin_g s~ru~ where the warm rays of the sun can not effect any m1sch1ef. Th1s s1te d · ,doubtless well selected for the reasons above adduced. There are usually two broods of this species in a season; a summer brood, which makes its appearance early in July, and a spring brood ': which has survived the winter in its double cell of earth and leaves. It, is possible that the larva, after having exhausted i~s stock of h?~ey and pollen, its natural food early in the fall, ~asses mto the con~it1on of: pupa, and thus remains until awakened from 1ts sleep by the genial wann . of spring. · , In the cells designed for the winter accommodation of the species, thi -double arrangement of the inner cells will not materially affect the original Pose since both insects will have passed through the cycle of trant-pur , • r h • f mations and when the suitable time shall have amved 1or t cir or , d · departure , the one occupying the upper cell will have ma e 1ts way CM . and thus left a clear passage for the one below. The absence of a line of separation between the two cells appears ~ . indicate that the food had been deposited in the lower cell, and two egp · instead of one had been left in mistake. \Vhere it is the custom of the insect to dej)osit but one egg, instinct teaches it to collect just eno• THE CANADIAN ENTOMOLOGIST 175 íood to provi~e for the sustenance of the larva to which it gives birth ; the two eggs m the present cases were deposited through sorne inadvert--ence upon the part of the insect, and it <loes not seem wise to conclude that a similar inadvertency had led to an accumulation of a double portion -OÍ food. If this double brood had been the result of mistake it is not ~ossible that severa! mistakes of a similar. kind would have occ~rred, since 1t was my good fortune to meet with unoccupied cells that showed -cvidence of being once occupied. If two eggs are deposited within the same cell, there must be collected .a double quantity of pollen and honey for the nourishment of the larvre. The one which attained to full growth first would, no doubt seek a clear 1pace in which to spin its covering, and this would be afforded by the up~e: part of the tube or upper cell. The other, after having made a suffic'.e~t space for this essential operation by the consumption of the rcmammg food, would accomplish the task therein. Sorne cells, which it was my privilege to examin~, exhibited faint tr:lci?g_s of a partition-like arrangement between them. A portion of the clcbns m the lower cell, to w_hic~ reference has been previously made, may have been due to the comnunutwn of the lea ves forming the separating layers, through sorne cause or other. But this I am unable to substantiate . If such should prove to be the case by future observations there is no doubt that therc will be found to exist a separate accum~lation of pollen and honey in each cell. · · After a little reflection, there seems to be an offset to a portion oí this -'. MgUment. May it not be possible that after the two larvre had matured · foto perfect insects, the more powerful one overcame the weaker and that lhe fra~men~s of win?s' le~s, body segments, &c., are the sad tr~phies of IUC_h a confüct? . Thts pomt would be worthy of acceptance if every cell 'Wh1ch was exammed had betrayed similar evidences. But it was not the .ase. lt only remains, then, to assume one of two opm1ons eithert riat ihe two ova were cleposited upon a double allowance of food, so that the larvre, when hatched, should find ample sustenance to reach maturity, and 111b~~quentl~ had . ~onstru~ted their silken cocoons in their respective . pos1t1ons, sa1d pos1llons bemg determined upon by priorily of growth . ~• that a double ce_ll was ~uilt, one on the top of the other, each properl; · '1Ctualled and prov1ded w1th an ovum. 

Notes on Megachile centuncularis

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Notes on Megachile centuncularis

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