122 HYMENOPTERA. 



probably alarm tlicm and cause them to become restive ; 

 but the tail filament is not a stinging organ but an 

 ovipositor, of curious structure, by means of which the 

 female drills a hole in the wood, usually fir, into which 

 she deposits her eggs, from which are developed blind 

 grubs with six true legs, all the abdominal ones being 

 absent. These larvse often cause great damage in pine 

 forests — the wood of which they intersect by their 

 burrows — but they are also found on other trees, as on 

 the hornbeam and willow. It is supposed that British 

 specimens have been introduced in the larva or pupa 

 state in foreign timber. Another large species of Strex 

 — or Urocerus (Horn-tail) as the genus is now often 

 called — the S. juvencus is sometimes found in this 

 country. The male is yellow and black, but the 

 female is dark black with a violet tinge. On one or 

 two occasions this species has been sent to me. 



The sub-section, Entomojjhaga, contains the Ichneu- 

 mons, Ruby-tails, and Gall-flies ; though these latter 

 are not insect eaters — for they feed on the juices of the 

 gall — they, are generally placed in this division, because 

 in other respects they have their affinities with the 

 other insects of the sub-section. All the insects of the 

 insect-eating Borers, excepting some of the Gall-flies, 

 are parasitic, some depositing their eggs within the 

 bodies of other insects or insect-larviTe, where they hatch, 

 develope, and feed on the fat or juices of their doomed 

 hosts, others placing their eggs in the nests of other 

 insects, where the larvae either consume provisions 

 destined for others, or where food has already been 

 stored by the parent insect. This sub-section, Entomo- 

 phaga, contains two divisions, viz., the Dart-bearers. 



