Bulletin ov Tiir. Illinois State Laboratory OF Natural History Ukbana, Illinois, U. S. A. STEPHEN A. FOKBES, Ph.D.. L,I..D. DiRBCTOR Vol. IX. October, 1910 Articles I-II. ART. r. ON THE COMMON SHRRW-MOL,E IN ILLINOIS BY FRANK ELMER WOOD, A. 15. ART. II. A STUDY OF THE POOD OP MOLES IN ILLINOIS BY JAMES A. WEST, A. M. NATI/fiAl iuSlOii :m^ S^P 1969 ERRATA AND ADDENDA Page 54, lines 3 and 2 from bottom, and elsewhere in Article III. for Cassia chainaechrista read Cassia chamaccrista. Page 62, between lines 4 and 5 from bottom of table insert Erigeron annuus. Page loi, table, after Croloii glandulosus read var. septentrionalis: and for Eijuisettim laeinyatum read Eqnisetum bycmale var. inlermedium. Page 131. line 3, for coerulea read caerulca. Page 138, last line, for Zi::a read Zizia. Page 141, line 21 from bottom, dele Diodia teres. Page l6g. between lines 3 and 4, insert as follows : Erigeron annuus (L.) Pers. An interstitial in the liunch-grass association in the Hanover area. Page 177, line 5, for casti^'ard read iveslzvard. Page 209. line 3 from bottom, for copalina read copallina. Page 210, line 13 from bottom, for Diospyrus read Diospyro'i. Page 211, line 5, for Foresteria read Foresticra. Page 256, line 3 of table, for Dr. H. M. Pepoon read H. 5". Pepoon. Page 278, line 16, the fifth word should be in Roman type. Page 286, line 6 (second column), page 295, list of secondary species (second column), and page 353. line 8 from bottom, for hiematis or hiemale read hye- mnte. Page 313, line 4 from bottom (first column), for pedicularis read pcdicularia. Page 315, line 10, second column, for Apoeynum read Apocynum. Page 323, line 3 from bottom, for Cyperus read Scirpus. Page 330, line 14, for virginianum read inrginicum. Page 336. lines 3 and 2 from bottom, for virginicum read virginianum. Page 337. line 2 from bottom, for philadelphicum read philadelphicns. Page 339» in first list of invading species, for Rhus hiria read Rhus typhiua. Page 351. line 4 from bottom, for .verophtic read .verophytic. Page 355, above line 6 from bottom, insert Scirpus heterochaetus Chase. Page 356, line 14 from bottom, for Symlocarpus read Symplocarpus. Page 360, line 14, for Pirus read Pyrus. Page 362, after line 7, insert Acer saccharinum L. Page 363, line 2 from bottom, for quadiflorum read quadriflorum. Page 365, line 14, for Ihapus read thapsus. Page 369, last line, for Tanecelum read Tanaceium. Page 417, line i. dele the. Page 497, line 9 from bottom, for neglible read negligible, and in foot-note, for Auslall read Anstalt. Page 498, line 4 from bottom, for Lockport read Chillicothe. Page 500, line 13 from bottom, after up insert in. Page 5or, line 2 from bottom, for dissolving read dissolved. Page 504, line 23, for gryina read gyrina : line 17, for dentata read knickerbockeri. Page 506, line 11, for vernata read ternala. Page 507, line 3 from bottom, for Macon read tt'asoi. Page 513, line 19, for Nepa read Zaitha; line 18, and page 517, line 13 from bot- tom, page 520, line 12 from bottom, and page 532, line 4, read naid or naids for naiid or naiids. Page 517, line 6 from bottom, for pondiveed read pickcrel-iveed. Page 519. for first sentence of last paragraph read as follows: We have no exactly comparable chemical data for July; but analyses for August give percentages of saturation for Morris and Marseilles as follows : 20.4 per cent, at Morris on the nth and 11 per cent, at Marseilles on the 12th; 16.35 P<^r cent, at Morris on the 22d and 23d and 7.4 per cent, at Marseilles on the 24th and 25th. Page 521, line 6 from bottom, and page 529, line g, for chrysoleucas read cryso- leticas. Page 525, line 22, and page 536, lines 21 and 24, for Ekmann read Ekmnn. Page 532, line i, for Ancyclus read Ancylus. Page 551, line 7, for 00 read 572. Page 615, second line above foot-note, for 106 read 94. Page 616, line I, for the second Biindeln read Bilndel; line 2, for Biindeln read Biindcls; line 3, for ausscrn read ausscren; line 6, for sweierlie read sweierlei. Page 629, line 12, for kciii read kcincn. Page 634, line 9, for untcrnommcn read untcninntincnen; and in line 14 from bottom, after ;;/$ insert is fig. Plate III, Fig. i, after the word mixed in legend insert consocies of the. Plate IX, Fig. 2, dele the legend and read instead ; Root-system of Tephrosia virgiiiiana, exposed by blowing of the sand. Plate X, Fig. 2, dele the legend and read instead ; A blowout almost stabilized by bunch-grasses, especially Leptoloma cognatum. Plate XXXIX. for Calainogrostis read Calamagrostis. Plate LIV. exchange places of cuts, but not the legends. Plate LXXXV, for 7 read ye. 14 Article II.- — A Study of the Food of Moles in Illijtois. By James A. West. The moles wliicli furnished the basis for this discussion were in part specimens collected in central Illinois at various times, whose stomaclis had been preserved with the material of the State Labora- tory of Natural History without definite data as to the special situa- tion in which the moles were found, but chiefly specimens recently collected, nearly all trapped in 1907 and 1908 by Mr. F. E. Wood, assistant in the State Laboratory of Natural History. In April, 1907, special interest in the subject of the feeding habits of the mole was stimulated by a letter from C. A. Rowe, of Jackson- ville, Illinois, to Dr. S. A. Forbes, Director of the State Laboratoiy, under whose direction this investigation was undertaken. Mr. Rowe reported that moles had been very abundant in that locality for sev- eral seasons, and that they had been seriously destructive to seed-corn in recently planted fields. His letter was accom]5anied by the contents of a mole's stomach, which proved to be about 65 per cent. corn. On account of the subterranean life of the mole its feeding habits are but little known. In captivity it is a voracious feeder, incapable of enduring any considerable period of starvation. The only accurate way, however, of determining the character of its natural food is to examine the material which it has actually eaten. METHOD OF EXAMINATION In studying the food of the mole we must examine and classify in detail the entire stomach contents of each specimen, and must esti- mate the amount of each of the food materials, taking account also of any undetermined residue. For this purpose sheets of filter-paper, twenty by twenty inches, were ruled into one-inch squares and placed on a sheet of glass. A stomach was then opened and the contents, put into a dish with alcohol, were broken up by agitation and thrown upon the filter-paper in a way to distribute the particles of food well over it. The material on each square was then examined and esti- mated separately. If the entire stomach content, or the greater part of it, was comiX)sed of one material—earthwomis, for example—it was often possible to determine its character by simple inspection. 15 The contents of the stomachs examined were mainly earthworms, insects—either achiUs, lar\-tT, or pup;e—vegetation, and a miscellane- ous remainder. The mole had commonly chewed its food so fine as to make it impossible to recognize the species of insects and their larv?e; nevertheless, the number specifically determined was sufficient to give a fair idea of the dominant character of the insect food. GENERAL RESULTS OF THE EXAMINATION The following table shows the per cent, of the various kinds of food in each stomach. There is no "miscellaneous" column, since stomach contents not otherwise assignable were rare, and may con- venientlv be mentioned later. u s 16 X) S 17 u E 18 The preceding table shows that 31 moles had eaten earthworms, which formed 26 per cent, of the total food of the 56 specimens; 53 had eaten insects, amounting to 62 per cent, of the total food, of which 36 per cent, was insect larvje (contained in 47 stomachs), and 26 per cent, was adult insects (in 42 stomachs). The 3 moles which had eaten no insect food had taken earthworms, and one of tliem n little grass. Vegetable matter was present in 28, to the amount of 1 1 per cent, of the total food. Al>out i per cent, of the stomach con- tents are classed as miscellaneous. This includes spiders, myriajxids, needles from a spruce tree, mole hair, and feathers, these various items each occurring but once, except spiders, which were found twice. Before entering into further details it seems desirable to add a table gi\'ing a sunimar\- exhibit of the situations where the tiftv-six moles were taken, the number from each situation, and the number of occurrences of the different kinds of food, classified in relation to situation. The table, page 19, although very imperfect, may ser\e a useful purpose to those pursuing the subject later. ni'T.XTI.S OF TIIK Foon. Such kinds of their food as are ciuite generally distributed — earthv^rorms, some insect lan-as, and adult insects, for example—are ver}' frequentl}' and freely eaten by moles. This is evident in the case of earthworms, white-grubs (larxK oV Laclinosfcnia and Cyclo- ccpliala), cutworms, wireworms, ground-beetles and their larvae, and the common brown ant. Fragnnents of at least 9 white-grubs were present in one stomach ; and the bronzed, the W-marked, the glassy, and the dingy cutworms were all identified. Among Carabidcc, the following genera were distinguished : P'te'ro^tkhits, Agonodcnts, Bcinbidiiim, Harpaliis, Phiiyiius, and Gcnpiniis. Gcopinus incras- satits had been eaten by a mole in the sand region near Havana, Illi- nois, where this insect is quite abundant. Other larvae prominent in the food were sod web-worms and larvee of the banded Ips, each oc- curring twice. One mole had eaten at least 18 sod web-worms, and another at least 85 larvc-e of Ips quadriguttatus. May-beetles had been eaten only by moles living in sod in the months of May and June. Whenever present they formed a large part of the contents, and one stomach contained nothing else. The common corn-field ant, Lasiiis niger americanus, was present in several stomachs in large numbers. The single mole taken in winter (January) had eaten no less 19 o 20 than 150 specimens of this ant. The carpenter-ant, Caiiiponotus penn- sylvanicjis, which usually nests in logs and stumps in shady woods, was found in the stomachs of all moles taken in woodlands and in one from a garden. Two more species of ants were recognized : Solen- opsis debilis, present in two moles taken in plowed ground; and a Myrmica, probably scabrinodis, which was found in a single mole captured in a corn field. The click-beetles shown in the table formed but a small part of the total food, and but one buprestid was found. The abdomen of a wasp very much like that of Tiphia was found in a mole from a com field, and a hymenopterous puparia had been eaten by one from an alfalfa field. Two noctuid pupse occurred in the stomach of a mole from a corn field. It is unfortunate that an im- portant jjart of the insect food must remain unclassified. Corn was present in the stomachs of eleven moles, making 8 of the II per cent, of vegetable matter eaten by them. Five of these specimens were trapped in corn fields in spring, shortly after corn had been planted, and three of the five had burrowed along the planter track. Two were taken from fields in which the corn was cut and shocked, two were from lawns, and one was from a garden, corn being near at hand in each case. Indeed, corn had been carried into the run of one of the moles trapped in the lawn. Corn in some cases formed the principal part of the stomach content, in one instance 90 per cent. Six moles which probably had access to corn, had eaten none. Some observations made in the spring of 1908 on the work of moles in corn fields illustrate the nature of the damage they may do. In one instance the writer saw a mole-run which followed the track made by a planter wheel for a distance of seventeen hills. Occasion- ally the mole had turned slightly out of its course ; but it had im- mediately worked back into the packed soil. The corn had sprouted and was showing above ground. Fourteen hills in this strip were dead or dying, the kernel having been eaten away and the sprout left untouched. A similar instance is reported of eighteen hills, not all in the same row, destroyed, apparently by a single mole, after the corn had sprouted. In another case one or more moles, entering a corn field from a pasture adjoining, formed a network of burrows in an area ten hills wide by nineteen long. Eighty-nine corn hills were missing in this plot. Grass, grass-roots, seeds, etc., were fre- quently found in the mole stomachs, usually in small quantities, but 21 amounting- in three cases to 30 per cent., and in one to 35 per cent, of the food. The known dates of capture of the moles were as follows : Janu- ary I, March i, April 5, May 17, June 19, July i, August i, and October 4. Seven of the fifty-six specimens were preserved without dates. Twenty-eight of the stomachs were well filled with food, 21 were moderately filled, and in 7 there was but a small anmunt. CONCLUSIONS OF OTHER WRITERS In the Seventh Report of the Kentucky Agricultural Experiment Station (1894) H. Garman reports the examination of fourteen mole stomachs. He found some fragments of dead parts of grasses and other plants, taken, as he believes, by accident while animal food was being devoured, but no traces of fresh plant structures. He says : "I am disposed to acquit the mole of the charge of intentionally eat- ing vegetation. I do not offer this as a final conclusion, however; more material should be studied." Fifty stomachs containing food were examined by L. L. Dyche, as reported in Volume XVHI of the Transactions of the Kansas Academy of Science. He says that vegetable food, almost all of it com, amounted to 3.7 per cent, of the whole. Corn was found in 4 stomachs, in the ratios of 10, 30, 60, and 65 per cent, of the food of these animals, respectively. The last two were taken in January and October. "It is evident," he says, "that the damage done to lawns, gardens, and fields by moles is due chiefly, not to the food the animals eat, but rather to their manner of securing it." Another paper on this subject is published in Bulletin No. 31 of the Pennsylvania Department of Agriculture. Of 36 stomachs, ex- amined by Hariy Wilson, only one contained green tissue of grain, but this had been bitten ofif in pieces by the teeth of the mole. One mole, killed in the ground under a corn shock, contained corn about equivalent to a single kernel. Wilson believes that all the damage done by the eating of grains, seeds, and fibrous roots, and by the gnawing of tubers, which is attributed to moles is due to mice, for it is a fact, he says, that the runways of the mole are often occupied dur- ing the latter part of the summer by the common brown field- or meadow-mouse. 22 CONCIvUSION The contents of the stomachs here reported, have shown perhaps a greater amount of insect food and somewhat smaller ratios of earth- womis than those examined hy other writers, but there is a sub- stantial agreement to the effect that half or more of the food of the mole consists of insects and their larvse, most of them noxious. So far as its food is concerned, the mole is thus beneficial, on the whole. There is no direct evidence that it will eat potatoes or other tubers, but circumstantial evidence on this point is so strong that the mole must remain under suspicion, even admitting that mice of herbiv- orous habit may occupy mole-runs in fall. In this paper it is shown, for the first time, that corn may form an important item of the food of moles ; that recently planted corn is sometimes destroyed by them ; and that if numerous in corn fields in spring, they are capable of doing considerable damage there. October, 1910.