II 6 HYMENOPTERA 



CHAP. 



sufficiently distinct from Ampulicides, although the pronotum is 

 much shorter, but Handlirsch has recently observed that the 

 European species attacks Blattidae as do the normal Ampulicides ; 

 and Ferton has recorded that D. haemorrhous lives at the expense 

 of Loboptera decipiens, the wasp depositing its egg on the left 

 intermediate femur of the prey. This is placed in a solitary 

 cell, and is entirely consumed by the larva, life being preserved 

 till within a few hours of the end of the repast, which occupies 

 altogether eight days. 



Sub-Fam. 3. Larrides. Hind lody not pedicellate, or with 

 only a short pedicel ; one spur on the middle tibia ; labrum 

 inconspicuous. Marginal cell of the front wings appendi- 

 culale, 1 or mandibles excised externally, or loth. 



This group is by some writers called Tachytides instead of 

 Larrides, as owing to a change of nomenclature Tachytes may now 

 be considered its principal genus. It is in connection with 

 this and the neighbouring sub -families of Sphegidae that some 

 of the greatest taxonomical difficulties exist. We include in 

 Larrides the " Miscophus group " of Kohl. 



The species of the genus Tachytes seem to have habits very 

 similar to those of the genus Sphex ; they form shafts in the 

 earth and provision them with Orthoptera ; like the Sphex and 

 other Fossores, they have the habit, when they fly to their tunnel 

 with a victim, of depositing it for a short time on the ground 

 close to the mouth of the burrow while they turn round and 

 enter backwards; and, after doing this they again seize their 

 prey and drag it into the burrow. Fabre availed himself of an 

 opportunity to remove the prey while the Hymenopteron was 

 entering the hole alone ; as a result it had to come out again to 

 seek the object ; this it soon found, and carried to the hole, 

 relinquishing it again as usual while it turned round ; Fabre 

 repeated the operation several times, and always with the same 

 result ; the wasp, though it might have kept hold of the victim 

 while it turned, and thus have saved itself from losing the 

 precious object, never did so. 



1 When a second cell is more or less perfectly marked out, the cell with which 

 it is connected is said to be appendiculate. The nervures frequently extend beyond 

 the complete cells towards the outer margin, forming "incomplete" cells; only 

 complete cells are counted, except when "incomplete" is mentioned. 



