ON THE LIFE HISTORY, HABITS, AND ECONOMIC RE- 

 LATIONS OE THE WHITE-GRUBS AND MAY- 

 BEETLES (LACHNOSTBRNA). 



The insects generally known as white-grubs are the young, or 

 larvae, of the large brown beetles commonly called "June-bugs" or 

 May-beetles. For a practical knowledge of these destructive insects 

 it is necessary that we should know the various species of them 

 which do serious injury to agricultural and to horticultural crops; 

 the life histories of all these species ; their relative numbers in dif- 

 ferent parts of the state in different years and in different periods 

 of years ; their food, both as grubs and as adult beetles, including 

 their common preferences where several kinds of food are available 

 to them; their significant habits, especially those of reproduction; 

 their relations to variety of weather and to seasonal change; their 

 modes, times, and places of hibernation; the range of their daily 

 movements and of their movements of migration and dispersal; 

 their enemies, their diseases — especially those of a contagious char- 

 acter, and the other natural checks on their multiplication; their 

 relation to varieties of soil, to its physical condition, its moisture, 

 and its exposure to the sun ; their relation to varieties of the subsoil 

 also ; the effects on their continuance and increase, of various agri- 

 cultural operations and kinds of farm management ;- and their own 

 effects, under varying conditions, on the several kinds of crops sub- 

 ject to injury by them. Finally, the whole field of preventive and 

 remedial measures of a more or less artificial character must be 

 thoroughly explored, including the results of practical experiments 

 on the scale of actual farm management. 



The subject is made especially difficult and complicated by sev- 

 eral facts and circumstances. There are many species of these 

 insects recognizable in the beetle stage but seemingly not distinguish- 

 able as larvae; hence one frequently can not tell what kind of grub 

 he is dealing with until he has reared specimens to the adult. The 

 life history of these insects has a prolonged cycle, probably of three 

 years, but just how many is not definitely known, and life histories 

 can be completed only by keeping specimens alive, under more or 

 less artificial conditions, for this entire time. The various species 

 differ sufficiently in certain parts of their life histories to make it 

 necessary to follow each out separately; and it is not impossible 

 that important differences may be found due to differences in lati- 



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