286 The Irish NahcralUt. [Nov., 



Our foremost authority on the Order, Mr. Edward Saunders 

 in a letter to Mr. Carpenter in 1893, stated that V. arborea, 

 Sm., will be most probably found to be merely a modified 

 female or queen of some of the social wasps ; but in his 

 ** Hymenoptera-Aculeata of the British Islands," since pub- 

 lished, he adopts M. Andre's view as to its identity with 

 V, aush'iaca, Panz. 



The social species it most closely resembles is Vespa rufa, 

 Linn., from which it differs principally in the shape of the 

 black marks upon the yellow clypeus, or portion of the face 

 between the jaws and antennae, the yellow line on the first 

 antennal joint, and some other minor, but not always constant, 

 particulars. 



The plate, drawn from one of my specimens taken last July, 

 shows the typical markings of the insect, and the clypeal 

 differences w^hich distinguish it, in the main, from V. rufa. 



That there may be something more than accidental 

 resemblance between these two species I am led to surmise 

 from the fact that this year (1897), I have almost always taken 

 both together. V. rufa, although it has been taken in the 

 North, appears to be a somewhat southern species in Ireland, 

 and makes its nest in the ground, like our two commonest 

 social wasps, V. vulgaris and V. ge7ma7iica. Smith first 

 named the insect which supplies the title of this paper, 

 arborea, because he took it, as he believed, in the act of build- 

 ing a nest in a fir-tree, but no subsequent collector or student 

 of the Order, since that date, 1836, has confirmed his 

 observations. 



The question of the true identity of V. arborea, as it stands, 

 is a very pretty entomological puzzle, which can only be 

 properly solved by a careful examination of the nests of the 

 various species. 



Bearing in view Smith's statement in the Zoologist^ I have 

 during the past three years thoroughly examined every nest 

 of our tree-building wasps, Vespa sylvcstris and V. 7iorvegiaa, 

 that I could obtain, but without finding anything unusual. 



Nests of V. vulgaris and V. germa^iica, ground-nesting 

 species, have also yielded no results ; but I have unfortunately 

 never had an opportunity of finding the nest of V. rufa, which 



