153 
E (ECONOMY OF TH. CHRTSIMS PAKASITIC ON OPr^B^S 
spimPES. 
BT T. AlOEENOH CHAPMAN, M.D. 
> 3p.de8 of the genus Ohri/sis are, so far as is Imown, parasitic 
« audTees. tW which are attached (apparently, exclusively) 
r:":^,;. being O. «...o.. and ..*»..... "•^'^ Xrels of 
. . 1 1 n innifa the most abundant species oi 
:^r O svinipes abounds. C. ignita, \iw u u i • j ^f 
;s, ap^ear^ to lay her eggs in the nests of ataost any tad o 
,whici she can obtain access, and occasionally v.s.ts those o^: 
;.,hnt is abundant in the nests of O^P^^r^s ,^un. O. 
has also been recorded (by Mr. J, Sm.th) as attached o O 
;roft::Xrtd:r:p:LTo;::^^ 
----°•T^;:^r1t:r::rt:^^r;:: 
"Z TLaTi: ': rl asa^arasiteof O. »..^«j as 
Tftn to be seen about the burrows of that --t "ea. ^J 
rully as a ..slecta or msntata, out of more «>- ^ J'™'^;^^ 
i. cocoons collected last winter, I found only one <> J- ^»*' 
.is sumu^er I have seen only three of its cocoons m the eel s oi 
ni,e. The destruction caused by CHry.ides -ongst th y°ung 
of O mnipes roughly measured by the cocoons collected tet 
r is inr;roportion of one to three of those of the w.sp ; the 
,rti„„ of 0. n.,U.U to a U.n... ^^^^ :;■,,, „^,„ 
On July 17th, I observed a nest ot O. pa> letum w . ^ . 
°li:inga ;early complete -PI' ^^ "^^'7 anT*- briff 
,et of oviposition. I now regret that ^ '^-''^^J "" /o 
ents of the cell, in order to aseertam the fate of ti^fe ° 
1 Three-quarters of an hour later. 0. panetu,. had closed the 
::thfuL? earthen pellets. Two days "fterwar ' I — d 
cell, when I found a larva of 0. ignita a quarter of an ,nch ong 
,herw.th the ^epi^opterous larv» st^dj be^v.s, ^^^^^^^^^^^^ 
„_ ^ ^f ^.iflifir fiPfr or larva ot the latter. y~>^ 
no trace of either egg or 
no trace ot eituer egy "^ ^"^ . , , , ^ ,_ „ii the 
from the date of oviposition, the 01.ys,. !»"='. ''^^^^f"; 
.„-, „,.s full-fed. I obtained evidence, by findmg the ex„v=e ot 
^:l.. of O. M^e,U^i. I believe ,t had done so four t.mes 
