AMERICAN ELM. 511 



and more or less shaded with black. The length of his body varies from three- 

 quarters of an inch to one inch and a quarter; and his wings expand from one 

 inch and a quarter to two inches, or more. ***** The female, when 

 about to lay her eggs, draws her borer out of its sheath, till it stands perpendicu- 

 larly under the middle of the body, when she plunges it, by repeated wriggling 

 motions, through the bark into the wood. When the hole is made deep enough, 

 she then drops an egg therein, conducting it to the place by means of the two fur- 

 rowed pieces of the sheath. The borer often pierces the bark and wood to the depth 

 of half an inch, or more, and is sometimes driven in so tightly, tiiat the insect 

 cannot draw it out again, but remains fastened to the tree till she dies. The eggs 

 are oblong-oval, pointed at each end, and rather less than one-twentieth of an 

 inch in length. The larva or grub, is ycUowish-whitc, of a cylindrical shape, 

 rounded behind, with a conical, horny joint, on the upper part of the iiindcr 

 extremity, and it grows to the length of about an inch and a half. It is often 

 destroyed by the maggots of two kinds of ichneumon-flies {P(m/)la utr<tta^ and 

 lunator^ of Fabricius.) These flies may frequently be seen thrusting their slen- 

 der borers, measuring from three to four inches in length, into the trunks of trees 

 injiabited by the grubs of the tremex, and by other wood-eating insects; and, 

 like the female tremex, they sometimes become fastened to the trees, and die, 

 without being able to draw their borers out again."* Among the lepidopterous 

 larvae that attack the elm, are those of the four-horned ceratomia, {Ceratomia quad- 

 ricornis, of Harris,) and those of several species of Geometridaj, such as span- 

 worms, loopers, measurers, etc., including those of the lime-tree winter-moth, 

 (^Hybernla tiliaria, of Harris,) and the common canker-worm {Phaloifia vernataj 

 of Peck.) The leaves of this tree are also preyed upon by a coleopterous beetle, 

 and its larvse, {Chrysomela scalaris, of Le Conte,) and likewise by the larvas of 

 a species of saw-fly {^C'unhex ulmi, of Peck, or C. americana, of Leach.) These 

 insects, according to Dr. Harris, appear from tlie latter part of May to the middle 

 of June, during which period the female lays her eggs upon the trees. The larvee, 

 which come to their growth in August, measure from an inch to an inch and a 

 half in length, are rather thick and cylindrical in their form, and have twenty- 

 two legs, or a pair to every ring, except the fourth. They have a firm, rough 

 skin, of a pale, greenish-yellow colour, covered with numerous transverse wrin- 

 kles, with a black stripe, consisting of two narrow black lines, along the top of 

 the back, from the head to the tail; and their spiracles, or breathing-iioles, are 

 also black. When at rest, they lie on their sides, curled up in a spiral form, and, 

 in this position, look not much unlike some kinds of cockle or snail shells. Like 

 all the false caterpillars of the genus cimbex, this insect, when handled or dis- 

 turbed, betrays its fears or its displeasure by si)irting out a watery tlnid from cer- 

 tain little pores, situated on the sides of its body, just above its spiracles. At^er 

 its feeding state is over, it crawls down from the tree to the ground, and conceals 

 itself under fallen leaves or other rubbish, and there makes an oblong-oval, brown 

 cocoon, very closely woven, as tough as parchment, and about an inch in length. 

 In this, the false caterpillar remains unchanged throughout the winter, and is not 

 transformed to a chrysalis till the following spring. At length the insect bursts 

 its chrysalis skin, and, by pushing against the end of its cocoon, forces ofl' a little 

 circular piece, like a lid, and, through the opening thus made, it comes forth in a 

 winged form.f 



Properties and Uses. The wood of the Ulmus americana, like that of the 

 European elm, is of a dark-brown colour, and is liable to decay when exposed to 

 the alternations of moisture and dryness ; and, when cut transversely or obliquely 

 to the longitudinal fibres, it exhibits the same numerous and fine undulations : 



Report on the Insects of Massachusetts, pp. 389, 390, et 391. t Ibidem, p. 375. 



