282 Kansas Academy of Science. 



made with the same regularity, and sometimes included two 

 days without the need of a fresh change to maintain a degree 

 of enticement. 



Despite these ample provisions, the female ladybird repeat- 

 edly ate her own eggs, and the male in a few instances was also 

 observed in the same act. If the insects were free in nature 

 such cannibalistic tendencies might be obviated in a great 

 measure on account of the insects being at liberty to rove, but 

 otherwise the quantity of prey consumed would very probably 

 in most cases be considerably less than what the experimental 

 deductions show. Only during extreme infestation of fields 

 could prey be found as available and constant in volume as 

 would compare on an equal basis with the supply furnished for 

 the experimental tests, with the difference, of course, of no ex- 

 penditure of energy being required on the part of the ladybirds 

 for hunting in small imprisoned spaces. In restricted confine- 

 ment the beetles could not fail to find the supply of food pro- 

 vided for them, whereas in freedom they would be apt to meet 

 with uncertain or irregular provision, owing to the variable oc- 

 currence of prey. Even in time of abundant spoil the roving 

 disposition of the ladybird may possibly lead many individuals 

 far astray from the areas of infestation. The prospect of 

 decimation appeared most perilous during midsummer, which 

 may be regarded as the prevailing period of seasonal adversity, 

 for in this interval the natural restriction of prey subsequent 

 to the maturity of the small grain crops certainly reacted with 

 disastrous effect on the spotted ladybird. 



One serious fault to be found with the spotted ladybird, if not 

 also applicable to many of its relatives, as was learned from 

 observations regarding its attention to aphid prey in the fields 

 as well as in confinement, is the evident fact that it is a vacil- 

 lating hunter. Its movements are decidedly erratic and there- 

 fore too variable from any proper course to be fully effective in 

 overtaking prey to the best advantage or wherever the latter 

 might occur most numerously. Hunting in a random sort of 

 way, the beetle seems to miss the greater share of prey in any 

 general path which the individual pursues, and one may even 

 brush past a particularly infested plant without showing the 

 least concern. 



Still effective work by it may be possible in case that a suf- 

 ficient number of beetles abounds so one might chance upon 

 what prey another has failed to find. Its faculties for de- 



