NOTE ON THE ECONOMY OF HEDYCHRUM. 77 



Art. Vll. — Note on the Economy of Hedychrum. By W. C- 

 Hewitson. 



Dear Sir, — I feel unwilling that the following particulars 

 should remain unknown ; both because I hope they are of 

 sufficient interest to obtain a place in your Magazine, and 

 that they may lead to further inquiry. My knowledge of 

 the Hymenoptera is much too scanty to furnish the names of 

 the two insects, the subject of the following notice. I shall, 

 therefore, feel obliged by your supplying the deficiency ; and 

 should either of them be a desideratum to the cabinet of the 

 Club, please to admit it. 



Mr. G. Waring, of Bristol, had for years been much in- 

 terested by observing the numerous insect inhabitants of 

 an arbour in his garden, in which interest I had, last year, 

 the pleasure of partaking. Its sides are formed of hazel, 

 which is everywhere perforated by the larvre of Ohrkim 

 minutitm. The beetle is in the greatest profusion. The roof, 

 which is thatched with straw, swarms like a large bee- hive 

 with one of the insects I now send you (No. 1). Every straw, 

 and they were many, which I examined in the spring (I do not 

 think there was one exception), contained several of the 

 larvae ; some as many as eleven or twelve ; each in a separate 

 cell, and carefully separated from its next neighbour by a 

 pithy substance; all with their heads towards the open end. 



At the end of June, when the insects were first beginning 

 to come out, I cut open a number of the straws, and in each 

 found individuals which had come to maturity before their 

 turn, and were no doubt anxiously waiting the egress of those 

 which preceded them. I expected to find that they would, in 

 such cases, liberate themselves by gnawing a passage through 

 the straw, but this they had not attempted. 



Some of the straws, perhaps about one in ten, contained one, 

 or rarely two, of the Chrysis-like (No. 2) insect, placed indis- 

 criminately amongst the others. 



In the beginning of August, when the former insect was 

 abroad in thousands (the other being also very numerous), I 

 again opened several of the straws, in and out of which they 

 were continually passing, and found many of then) partly 

 filled with a sweet glutinous substance. 



