66 The Irish Naturalist. June. 



DIPTERA AND HYMENOPTERA AT POYNTZPASS 



IN 1921. 



BY REV. W. F. JOHNSON, M.A., F.E.S. 



Though the summer of 192 1 was a very fine one, yet 

 Hymenoptera were anything but abundant ; an apparent 

 anomaly, but really so, for the abundance of these insects 

 in any given year depends on the character of the weather 

 of the preceding year. Now 1920 was most unfavourable 

 to Hymenoptera with the result that they did not appear 

 in their usual numbers in 1921. We will hope that, favoured 

 by the fine summer of 1921, Hymenoptera may prove to 

 be numerous this year. Another factor, which militated 

 against insect life last year, was the very great changes of 

 temperature which occurred in the early season. Thus 

 April nth was a very fine hot day and numerous insects 

 were about, but on 14th and 15th there was snow and 

 severe frost ; this sudden change would kill a number of 

 these early insects and thus interfere with the second 

 broods. 



I particularly wanted to obtain specimens of the Irish 

 varieties of Andrena Jacohi, but only met with a single 

 specimen of each form, a very great disappointment to me. 

 Towards the end of July, Humble Bees [Bomhi) became 

 pretty numerous, crowding on to the flowers of Ragweed, 

 where they were to be found quite late in the evening ; 

 I took some at 9 p.m. They were accompanied by Flies 

 (Diptera) and Ichneumon Flies, but not very many of the 

 latter. Most of the Ichneumon Flies were taken in my 

 fields, the flowers of Hog-weed and Angelica, as usual, 

 yielding a good harvest. Amhlyteles amatorius seems to be 

 rare. I took it as it was crawling among stones on a fence, 

 and from its appearance I think it w^as freshly emerged. 

 It seemed much insulted by my seizing it, and assaulted 

 my finger with its mandibles and terebra, I need hardty 

 say without producing any effect. It is a very handsome 

 insect, the red and black of its abdomen forming a pleasing 



