1903.] 235 



doubt that a verj close likeness between Vespa rufa and V. austriaca is apparent. 

 The armature in these two species is much more alike than in any other two of our 

 wasps, and it differs from that of the ground-building species (7. vulgaris and V. 

 germanica) more markedly than from that of the tree-building species (F. sylvestris 

 and V. r.orvegica). Indeed, taking all points of structure into consideration, few 

 entomologists would hesitate to arrange our six Irish species of Vespa into three 

 pairs — vulgaris &nA germanica, rufa a.x\A austriaca, sylvestris and norvegica—&r\A. 

 to admit that rufa and austriaca are much more nearly iikin than the two members 

 of either of the other pairs of species. 



Much stress is laid by Eobson on a supposed constant difference between the 

 mouth-organs of Yespa rufa and F. austriaca. " The mandibles [of austriaca'] 

 are," he writes, " smaller and less rugged, .... and the ligula or tongue is 

 very distinctly smaller than in F. rufa." After examination of a number of females 

 of both forms, we can confirm his statement as to a difference in the mandibles 

 (figs. 18, xviii), but the difference is exceedingly slight, the mandibles of F. rufa 

 resembling those of V. austriaca much more closely than those of any other species. 

 F. vulgaris and F. germanica have decidedly larger mandibles than our two forms — 

 F. sylvestris and F. norvegica decidedly smaller. The statement as to the relative 

 length of the tongue is true of some specimens, but in this character a more con- 

 siderable amount of variation than in others is to be noticed. While the tongue of 

 the female F. rufa is, on the average, longer than that of V. austriaca (figs. 16, 

 xvi), some specimens of the former have a tongue no longer than that of some ex- 

 amples of the latter (figs. 17, xvii). Indeed, this character, on which it has been 

 proposed to found a generic distinction, is one of the few in which the two wasps 

 show a complete series of connecting links. 



Our comparison of the structure and markings of these two wasps shows, 

 therefore, that they are distinct forms which do not merge the one into the other. 

 And yet they are more nearly related to each other than either is to any other wasp, 

 while in most of the characters distinguishing them each shows a marked amount 

 of variation towards the other. A close kinship between the two is certain, but the 

 particular conclusion that we are inclined to draw from the facts will be better 

 appreciated after our examination of the nest has been described. 



Early in July, 1902, what was apparently an ordinary rufa nest was discovered 

 at Fenagh. It was at the time so feeble that it was left for a while to develop 

 further. By the beginning of August it was fairly strong, and as the previous 

 year's experience had shown that rufa nests taken on August 18th and 19th all 

 contained young queens and drones, a common balloon fly-trap was placed over the 

 hole on August 7th. Next day 78 workers, all apparently typical rufa, were 

 caught in this trap. 



The next day, by again using tlie trap and by a little thumping on the ground, 

 4 or 5 more rufa workers were extracted, and then all was quiet, so it was decided 

 to dig out the nest. This was soon accomplished, as it was built in exactly the 

 same sort of position as the rufa nests found last year, suspended from the roots of 

 grass, and quite on the surface of the ground. Unfortunately, the covering of the 

 nest came to pieces as we were extracting it, but we got out intact the two layers of 

 comb, of which it consisted ; these were put on the spot with all the inmates into 

 an insect cage, which was ready for their reception. 



