against the glass on the inside of a jar, around the eircuuiference 

 of the bottom, so as to expose the eggs to view. The space was tiUrd 

 in with sifted soil even with the tops of the earth halls, another 

 tier added, and so on until all eggs of a lot were placed. Corn was 

 not planted then until all eggs had hatched, as other^vise the ger- 

 minating roots grew into the egg cavities and smothered the eggs 

 or obscured them from view. Eggs were never put loose into a jar 

 and covered with soil, as they must have room to swell, being laid 

 under natural conditions in small cavities made by the female ovi- 

 positor which allow for swelling. (See Plate V, fig. 9, and Plate VI, 

 fig. 3.) 



A better and simpler method was to place the eggs over damp 

 soil in shallow glass petri dishes. Being tightly closed, and of small 

 size, these dishes maintained the reciuired humidity, and a great many 

 eggs were thus easily attended to and examined in a sliort time. As 

 the eggs hatched, the young gru])s were i-emoved to tin boxes. With 

 this method, care must be taken of two things: one, that the petri 

 dishes remain in a place of little exposure and of uniform tempera- 

 ture; and two, that the soil be sterile, to insure it against mites 

 and nematodes, to both of whose attack iMay-beetle eggs seem to he 

 very susceptible. 



Boxes for grubs just hatched should have thi- soil sifted, quite 

 moist, and packed very gently if at all. Small pits were made in 

 the soil with a match, and the grubs placed into these: if placed 

 on the surface of soil they are often unable to penetrate. No plant- 

 ing of corn was required in the boxes until grubs were nearly ready 

 to molt, as very young grubs were observed to feed almost entirely 

 upon organic matter in the soil, and seldom to touch i-oots. 



PUP^ AND EMERGENCE OF ADTM.TS. 



Before pupating, a May-beetle giiib assumes a soft, flabby condi- 

 tion, during which it lies inertly on its back at the bottom of the 

 tunnel. This is known as the prepupal stage. Prior to changing 

 to the prepupa, the grub shortens and somewhat broadens its tunnel, 

 making it very hard and smooth on the inside. In the cell so formed 

 it undergoes the change to pupa and then to adult. 



Whenever possible, it was found i)referab]e to leave the pupa in 

 its natural pupal cell, simply making an opening in the top of the 

 cell through which it could be viewed. The use of the shallow tin 

 boxes made this possible. When necessary, however, a smooth arti- 

 ficial cell open at the top was made in the soil in a tin box, and 



64 



