272 BRITISH ICHNEUMONS. [Oedema topsis. 



It would appear, then, that the parasite mouUed when still only some 2 or 

 2.5 mm. long and completed the destruction of the larva by attacking it 

 in a fresh place and sucking it dry, the greater part of its growth now 

 taking place. It could not well have another moult, as the time seems 

 too short for a moult, feeding up, spinning a cocoon, changing to pupa 

 and — as the brown eyes suggest — already making some further develop- 

 ment. The empty skins still attached to the remains of the larvae are 

 not shrivelled but stand out in some degree in natural position. On 

 soaking larva and mounting, the remains of Tortrix lana are found to be 

 complete as regards skin, etc., so that feeding has only been done by 

 suction. The larva of parasite appears to have been free, or nearly so, in 

 its last instar. I'he cast skin mounted shows a series of heads, the final 

 — really penultimate — of this series at one end is still attached to the 

 larval skin and three others, at fairly regular distances, along the concave 

 margin of the skin, against the Tortrix lar\a. The fourth — earliest and 

 smallest — close to what may be really the eggshell ; the latter, if so, is 

 quite transparent. All these heads seemed to be attached to the dead 

 larva ; the process of moulting was obviously for the larva to leave the 

 old skin where it was, advance the front segments so that the new head 

 could take a fresh hold, the later segments still occupying the old skin, 

 but of course advanced forwards within it, as the larva was lengthened 

 and the old skin as it was cast (not as described by Newport, etc.) shoved 

 back, but simply maintaining its place and the grown larva extended for- 

 wards. The skins are very puzzling at first, with a great excess of spira- 

 cles of various sizes and ages, viz. those of all the four skins. This method 

 of growing accounts for the larva being at first lateral and finally with its 

 head ventral ; it perhaps also accounts for the number of larvae in excess 

 dying, probably being seized and sucked by their brethren, whose posi- 

 tions imply their doing so. On March 15th, 1907, two 9 9 emerged;" 

 they were six millimetres in length, both had broadly white banded an- 

 tennae and the abdomen of one is slightly distorted ; both lived in con- 

 finement till 22nd March. 



On 15th March, 1907, Mr. Sich found larvae of Capua angtistiorana feed- 

 ing on box in Kew Gardens ; two of these had external parasites ; in one 

 case the parasitic larva was lying across the cater- 

 pillar's back between the meso- and meta-thoraces 

 and in the other it was between the 2nd and 3rd 

 abdominal segments. The hosts did not attempt to 

 dislodge them. Neither attained full growth and 

 were reduced to little more than emptv skins before the parasites spun 

 silken cocoons which produced this species, a 9 on 13th May and a J 

 a day or two later, 



