THE CRANBERRY SPAXWORM. 23 



opposite oxtrcmity. Tlio color varies (o a considerable extent from 

 mottled pale yellowish to brown, often with an olivaceous or greenish 

 tint. Those which have been recently captured in the District of 

 Columbia are reddish brown, mottled, streaked, and lined Avith liirhter 

 yellowish, red, and black. The head is strongly marked with trans- 

 A'erse irregular black bands. The thoracic segments are marked 

 above by a pair of thin median longitudinal lines. The second 

 abdominal segment bears on the dorsal surface a pair of prominent, 

 widely separated, mostly black tubercles, but in some individuals 

 these are wanting. The penultimate segment also bears above a 

 smaller pair of black tubercles. The larva Avhen full grown measures 

 an inch to upward of an inch and a fourth in length (25-3?>'"'") and 

 the greatest diameter is about one-eighth of an inch (S""'). The singu- 

 lar construction of the legs, or rather the lack of the intermediate legs 

 usually present in caterpillars of other families, is the cause of the 

 peculiar motions of the spanAvorms in crawling about in search of 

 food, which have given them their jDopular names. When in motion 

 a larva extends its body to full length, then bi'ings the posterior leg.s 

 close to the anterior ones, causing the body to loop in the center. 

 The body is then stretched out again, these actions i)eing repeated 

 alternately. 



When this spanworm is in repose it attaches itself to the foliage — 

 for example, to the stem of asparagus — by means of its anal pair of 

 legs and stretches out its bodv rigidlv and at an anijle so that its 

 natural colors, harmonize with the foliage or with the landscape. 

 On this head Doctor Smith has remarked that on a section of cran- 

 berry bog on Avhich this species is feeding the observer niaj' stand in 

 the midst of thousands of them and see none until something starts 

 them into motion. Then it appears almost as though the entire bog 

 were alive. As the spawnworms hang somewhat tenaciously to their 

 food plants, they are undoubtedly present frequentl}-^ in numbers 

 without anyone being the wiser. 



The half-grown larva is described by Doctor Forbes." 

 The fiipa^ shown, ventral view, in figure at f/, is of robust form, 

 light greenish brown in color, and a little less than half an inch in 

 length (12"^") and about a third of that (4"^"^) in width. 



DISTRIBUTION. 



The wide distribution of \\\\> insect is shown by the following list 

 of localities, based upon Doctor Packard's list, where the authorities 

 for each locality are given: Maine: Amherst. Cape Cod, Cotuit, 

 Xatick. Mass.; West Farms, Center. Albany, and Brewster, X. Y. ; 

 Philadelphia, Pa.; Lansing, ^lich.: Dayton. Ohio (Pilate); (ilen- 

 coe, Xebr. ; Cadet. Mo.; Centralia and el-ewhere in Illinois; Wash- 

 ington and Brookhmd, D. C. ; Georgia; Calhonn. Dawson, and De- 



