THE GREEN JUNE BEETLE. 43 



(PL VIII, B). Earh T every morning the boards were turned over, 

 and the larvae which had worked close to the surface during the 

 night were collected in cans or pails. Several dozen larvae were 

 usually found under every board thus turned, and after several days 

 the boards were shifted to new areas. Since this method necessitates 

 a large amount of hand labor it is somewhat expensive. 



THE FLOWERPOT METHOD. 



A severely infested field was selected in which parsley was 

 growing in beds 6 to 7 feet wide and 200 feet long, with the plants 

 in rows 6 inches apart. Three-inch floAverpots with the bottoms 

 stopped with corks were set between the rows of parsley 2 to 3 feet 

 apart in the rows, with the top of the flowerpot about a half inch 

 below the surface of the ground, the soil being packed around the pot 

 in a sloping fashion (PL IX, B). 



The habit of the grubs of coming to the surface at night and 

 crawling on their backs proved to be their doom. In passing a 

 flowerpot the larvae invariably fall in, and owing to the smooth sur- 

 face and steepness of the sides they are unable to crawl out. Two 

 to three dozen larvae were usually caught in one of these small 

 pots. A bed containing approximately 150 pots would in the course 

 of several days trap from 2.000 to 3,000 grubs. 



The redeeming feature in the use of this method is that the pots 

 act as a permanent trap, and after a bed has been thoroughly rid of 

 the grub the pots can easily be shifted to other infested fields. More- 

 over, the pots need not be emptied oftener than two or three times 

 a week, or until they become two-thirds filled with grubs. In most 

 instances observed, when larvae are thus confined they destroy each 

 other, thus preventing the pots becoming filled or affording the larvae 

 a means of escape. 



In fallow fields or in spaces between beds, larger pots may be 

 used. Experiments were conducted by using 7-inch flowerpots in the 

 ground in the same manner as described for the small pots (PL IX, 

 A). The advantage in the use of the larger pots is that the contents 

 need not be emptied. Sometimes, when rains occur, the pots become 

 filled with water, which drowns the larvae. 



This method is the only one now known that can be safely used in 

 saving a crop that is planted in an infested field. Except for the 

 outlay in obtaining the pots and the labor required in setting them 

 in the ground, there is no expense attached to this method. 



THE V-SHAPED TROUGH METHOD. 



Trapping the grubs by constructing V-shaped troughs proved 

 quite successful. (PL X ; text fig. 7.) Owing to their size they can be 



