76 



Hibernation may occur in two stages of the larva and occasionally 

 in a third, as well as in the beetle state, and some variation as regards 

 the insect's life economy is to be expected in the higher temperature 

 of a greenhouse. 



White grubs are preyed upon by a host of natural enemies, includ- 

 ing other insects, parasitic and rapacious, birds, mammals, and 

 Batrachians. In the last class toads are the most efficient, and they 

 are sometimes utilized for the purpose of destroying insects in 

 greenhouses. 



REMEDIES. 



The habit of white grubs of passing the greater part of their exist- 

 ence underground and at a considerable depth renders it a matter of 

 difficulty to reach them with insecticides. Against some forrus bisul- 

 phide of carbon, kerosene emulsion, and poisoned baits have been used 

 with some success. For use in greenhouses the best remedy, ever}'- 

 thing considered, is the poisoned baits. Of these, one of the best is 

 the bran-arsenic mash, which has been mentioned in connection with 

 remedies used against cutworms. In addition to the use of this mash, 

 it is always advisalile to pursue the cleanest of cultural methods, the 

 same as has been advised against cutworms, which includes the avoid- 

 ance of fresh soil which might contain these creatures, the keep- 

 ing down of all grasses in the immediate vicinity of greenhouses, and 

 particularly in the soil in the greenhouse itself. The use of fertilizers 

 is also advisalde, as it enables plants to resist insect attack at the roots. 



Sterilizing the soil by means of heat or steam is also of value. 



As manures are frequently infested by white grubs, and some of 

 these are at tmies troublesome, it is well to exclude such forms as 

 experience has shown contain an excess of these creatures — as, for 

 example, horse manui'c. They can be identified readily by disinte- 

 grating the material, and chickens and other fowls could be utilized 

 in destroying them before the manure is used in the greenhouses. 



WHITE GRUB OF THE GREEN JUNE BEETLE. 



{AUorhiiia nithhi Liiin.) 



Complaints are frequently recei\'ed from correspondents of injur}'- 

 by the larva? of this species, but in most cases there tire reasons to 

 believe that the damage is reall}^ done ]>v cutworms or some other 

 insects, and the white grubs, on account of their large size and their 

 habit of crawling about on the surface of the ground, are blamed 

 for the misdemeanors of the other species. 



An instance which was probably of this character was reported to 

 this office Noveml)er 21, 1898, l)y Mr. W. E. Pray, Kiidvora, N. J., who 

 sent specimens Avith I'eport that this "grub-worm""' was troublesome 



