the (Economy of several Species of Hymenoptera. 1 7 



10. Pemphredon lugubris, Fab. 



I have watched this insect burrow into the wood and throw 

 out the saw-dust. It appears to prefer decayed wood for 

 making its cells, in which it deposits aphides. 

 11. Pemphredon Morio, Van L. 



I am not quite certain whether I took this insect at the 

 summer-house or not, but 1 think I did. 



12. Pemphredon unicolor'*, Lat. 



The ceconomy of P. unicolor is, I believe, well known. I 

 have taken it carrying an aphis, but have not examined its 

 cells. 



13. Psen atratumf, Pz. 



This insect has been exceedingly numerous this year, using 

 the straws in the thatch to deposit its prey in, in some of 

 which I have counted as many as a hundred aphide. The 

 partitions appear to be made of the scrapings of the inside of 

 the straw cemented together. The egg is wliiteand semitrans- 

 parent, and is attached to the abdomen of an aphis near the 

 bottom of the cell. The males first appeared the beginning 

 of July, flying about the thatch and the neighbouring shrubs 

 in thousands. They disappeared about the end of the month. 

 The females did not become numerous until the 10th. 



14. Odynerus quadratusX, Don. 



This insect entombs small green caterpillars having sixteen 

 feet; six pectoral, eight abdominal, and two anal. On cutting 

 open a post where I saw the female enter with its prey, I 

 found a tunnel of about four inches in length running parallel 

 with the sides of the post, and divided into three or four cells 

 by partitions of clay. In each of these cells were about ten 

 caterpillars closely packed, and a long white egg attached to 

 the side of the cell near the bottom. 



I first noticed this insect the beginning of June, and it was 

 abundant during the whole of that month. 



15. Odynerus bidens, Linn. 

 I observed a female of Odynerus bidens burrowing into a 

 post the beginning of July, and a day or two afterwards I cap- 

 tured her while conveying her prey, which appeared to be the 

 larva of a Chrysomela, On opening the post the end of July 

 I found a tunnel two inches in depth, divided into three 

 cells by partitions of clay. In the first cell the Odyneius was 

 in the pupa state, and in the two lower ones in that of larva. 

 Each of the cells contained the remains of larvae, and in one 

 of them was a small dipterous insect quite perfect. 



• Curt. Brit. Ent., pi. 632. f Ilnd., fol. 25. J Ibid., fol. 137. 



PhiU Mag, S. 3. Vol. 1?. No. 71. Jan, 1838. D 



