270 BRITISH ICHNEUMONS. [Ocdemalopsis 



and tibiae infuscate ; hind tibiae slightly intumescent and infuscatc before 

 the base ; basal joint of front tarsi arcuate, their femora not spinose. 

 Wings with radix and tegulae flavous. Length, 5I — 8| mm. 



Bridgman (Entom. 1879, p. 129) gives three 9 9 and two J J slight 

 varieties of this species, which may be tabulated : — 



Spiracles of basal segment not projecting. 



Antennae with joints 14 — 18 white .. No. i, 9- 



Antennae with no joints white above . . No. 2, 9 ''^nd 4> 3- 



Spiracles of basal segment strongly projecting ; 



Antennae of 9 with joints 17 and 18 alone white No. 3, 9 and 5, 3. 



No. I has the basal segment explanate from base to apex, in No. 2 the 

 width is variable. No. 3 has the postpetiole subparallel-sided. In No. 4 

 the second segment is nearly twice longer than broad and in No. 5 only 

 a little longer. No. 3 and 5 ha\e the abdomen and especially the basal 

 segment more coarsel}- punctate and constitute a form perhaps distinct 

 from No. i and 4, the former of which (that figured by van \'ollenhoven) 

 differs from No. 2 only in the lack of a flagellar band. No. 5 is said to 

 be the form described by Gravenhorst. All the forms are common with 

 us, No. 3 perhaps the least so. 



The only other species of this genus, O. limhata, Thoms., is a 9 which 

 agrees with the above in its subglobose head, tumidous cheeks, large 

 epomiae, length of the notauli, elongate mesosternum and areola, short 

 and laterally spinate petiolar area ; but differs in its recurrent nervures, in 

 having all the segments apically stramineous and no flagellar band. It is 

 probably no more than the second of the above varieties. 



The larva of O. uabriciila was first observed by Bridgman, who savs [in 

 lit. to Marshall) " Mr. W. H. B. Fletcher sent me some young larvae, he 

 says no doubt of Tortrix cosfana, with external parasites on them ; each 

 one had a small larva fastened to the Tortrix larva at the neck and laid 

 across the back. In a few days the larvae grew restless and began to 

 spin about, and at length spun an enclosing web between the cork and 

 neck of the bottle. The parasite then cast its skin ; the web was acci- 

 dentally torn and they fell to the bottom of the bottle. I thought they 

 might want to burrow, so I took out the old food and put in some soil. 

 But in opening the half dead leaves of the food, I found one of the larvae 

 which had not been disturbed four times the size of those which had 

 fallen out of the webs, and quite filling the webs. So it seems when the 

 ichneumon lars'a wants to shed its skin. Nature prompts the host to spin 

 a surrounding web ; the ichneumon larva is then able to take hold of the 

 host again and suck it dr}-, the latter half of the process being evidently 

 done in a few days, as after the web is spun the host seems listless and 

 somewhat shrunken, whereas they were very restless just before it. 

 Patiisais and Mesochorus are quite different in their habits." I give the 

 above account verbatim to avoid error and because nothing whatever has 



