36 Journal New York Entomological Society. [Voi. ix. 



rows which extend from 1 8 to 28 inches down. Males may be taken 

 about these burrows, as well as females. Late in March cells are 

 formed and stored with pollen and honey in the form of a pasty mix- 

 ture filling less than half the cell. Eggs may be first noted at the be- 

 ginning of April and none hatch before the end of that month — the 

 majority not until the middle of May or later. At least a month may 

 be counted for this stage. Larvae are nearly full grown July ist and 

 probably ready to pupate by the middle of that month ; which gives 

 a growing period of from six to eight weeks. Beyond this all positive 

 knowledge ends. Adult males have been taken up to June ist ; females 

 have not been observed after the beginning of May. The bee begins 

 making cells from the bottom of the burrow and works up, never mak- 

 ing more than four and rarely more than two cell-bearing laterals from 

 one upright. How many such burrows an individual female may make, 

 is yet indetermined; certainly more than one unless most of the eggs 

 in the ovaries were intended to remain undeveloped. 



On this point I examined a number of examples that came in early 

 in the season ; I found only a small number of ova indicated ; but 

 there are four ovarian tubes on each side, with at least two developing 

 eggs in each tube. There is a third egg cell in each tube, but at the 

 slow rate in which these individual eggs can be placed it is not likely 

 that more than sixteen, perhaps not more than eight ova ever come to 

 maturity. From the specimens examined it appears as if a single egg 

 only developed at one time ; at any rate it is certain that there always 

 was only one large egg in one of the tubes, while all the rest were 

 very much smaller. It is probable that the scattering of brood cells 

 is a measure of protection as is also the filling up of the burrows. The 

 honey paste must be tempting to many insects, especially ants, and 

 if six or eight or more cells were grouped around each burrow, the dis- 

 covery of one series by an ant hill would mean the rifling of every 

 cell in it and the consequent destruction of the entire progeny of a 

 single bee at one time. So the filling up of the burrow makes the 

 discovery of the cells more difficult, the one first planted being pro- 

 tected by the time the lateral for the second is completed. 



In the course of the observations on CoIIetes which began earlier 

 than any other form was seen to be on the wing, a few other species 

 were noted incidentally and a few plaster casts of their borings were 

 made. None were followed out as was the Colletes, but as the results 

 are additions, though small, to positive knowledge, it is deemed not 

 unnecessary to record them here. 



