THE 



VOL. 1. 



ST. LOUIS, MO., APRIL, 1869. 



NO. 8. 



Ck l^mtntaii ^ntflmolugbt. 



PliBLISIIKD MOXTIILY BY 



R. F. STXJX)LE-5r <Sc CO., 



104 OLIVE STKEET, ST. LOUIS. 



EDITOKS : 



BEXJ. D. W.VLSII 



' .'HAS. V. RILEY, 2130 Clark Ave. . . . 



' THE .I0INT-W0R5I. 



' a«..v«.'i'i in,n!r!. Harris.) 



Its tlperalions upon small (irain. 

 Ill certain years and in particular Slates the 

 iroiis of wheat, of barley, or of rye are ob- 

 served to be greatly injured by a minute mag- 

 got, popularly known as the " Joint-worm." 

 . Tliis maggot is but little more than one-eijrlith 

 of an inch long, and of a pale yellow color with 

 • the exception of the jaw-s, which are dark \ 

 brown. It inhabits a little coll, whieli is situa- 

 ted in the internal substance of the .stem of 

 .. t lie afiected plant, usually a short distance above 1 

 ;the first or second knot from the root, the outer 

 ..surface of the stem being elevated in a corres- < 

 , londing elongate blister-like swelling; and 

 ( vhen, as i.s generally the case, from three to 

 ten of these cells lie close together in the same 

 spot, the whole forms a woody enlargement ' 

 yioucy-combed by cells, aud is in reality a many- j 

 jcelled or " polythalamous '" gall, analogous in i 

 its nature aud structure to those which we hav(; 

 ' described in a preceding article. (No. 6 of the 

 ^.Vmek. Estom.) In Figure 113, «, will be seen 

 \\ sketch of one of these galls, the little pin- 

 -holes being the oritices through which the tlies 

 n-oduced from the joint-worms have escaped. 

 Vt first sight, these knotty swellings of the 

 ; cm are apP to elude observation, because, ■ 

 I eing almost always situated just above the 

 joint or knot on that stem — whence comes the 

 popular name "Joint-worms'" — they ai-e en- [ 

 wrapped and hidden by the sheath of the blade ; 

 liiit on stripping ofi" the shoath, as is supposed : 



Colors— (o) strinv-y<'ll.«v: (//) lilark 



to have been done in the engraving, they be- 

 come at once very conspicuous objects. AVe 

 have obsy ved that the '• interuodes," as bota- 

 nists call them, or the spaces between the knots, 

 in infested straws are always much I'ontracted 

 in length, none out of a lot of over filly speci- 

 mens examined by us exceeding six inches in 

 length, and many being reduced to only one and 

 a half inches. A similar phenomenon occurs in 

 two "i)oIythalamous ■■ galls formed liy certain 

 Gall-guats {(Jecklomyia) upon the tips of the 

 twigs of certain species of AVillow.* There 

 were only three straws in this lot of over fifty 

 straws, where tw'O Joint-worm galls were found 

 in the same straw ; and in all those three cases 

 they were found in two adjoining interuodes. 

 In a very few instances the galls were situated 

 in the middle of the internode, or even close to 

 the upper knot, instead of being situated as 

 usual immediately above the lower knot. 



Amount of Uamage doue by the Juiiif-wonii. 

 The damage occasioned by the .Joint-worm is. 

 in certain seasons and in certain localities, 

 ruinously great. In the year ISJl. throughout 

 a large part of Virginia, according to the Editor 

 of the Southern Planter. " many crops of wheat 

 were hardly worth cutting on account of its 



•The Willcnv Wlieat-gaU {Salicis trilicoides, Walsh) aiul 

 the Willow BarlfV-gall {Salicia hordeoides, Walsh) , ?rowiii|.' 

 rcspcetiTely on the Heart-Uavcd Willow (S. cordata) and 

 the Humble Willow (S. humili-), and described in Proc. 

 Ent. Soc. Philad. III. pp. iJ98-9. Thoy reoeiTed these n.iincs 

 from their resemblance ivspectivclv to ears of wlieat and 



