ECONOMIC IMPORTANCE OF SOWBUGS. 17 



females were -till alive one hundred and sixty days after the begin- 

 ning of the experiment. The cotton leaves, when tender, were eagerly 

 eaten. 



Fungous growth was favorable only under certain conditions. In 



the experiments cited above the leave- in contact with the earth de- 

 cayed and accumulated a rich growth of mold. Upon these decayed 

 leave- the sowbugs seemed to thrive, although there was always evi- 

 dence of feeding on green leave- when such were present. Fungous 

 growths on dry leave-, on decaying fruit, and on moist dead wood 

 were only capable of sustaining them a- long a- the moisture was con- 

 served. Fungus found on earth moistened with molasses sustained 

 9 sowbug> thirty-six days, and 2 survived as long a- seventy-five day-. 

 Green cotton leaves alone will sustain the life of these crustac 

 longer than any other simple condition tried — thirty-two day- being 

 the longe>t any remained alive under these condition-. The other 

 vegetation provided was not favorable, and the sowbugs seemed 

 rather to keep alive on the moisture from the blotter or on the fungus- 

 covered decayed leaves; thus, rose buds and leave-, and the leaves of 

 violet, mint, and chrysanthemum were untouched by the sowbugs. 

 The>e leaves did not retain their moisture long after picking. When 

 moist earth alone was provided, some found sufficient food to sustain 

 life eighteen day-. Additional proof that nourishment i- sought in 

 the soil was obtained by mixing London purple or Pari- green with 

 the earth. Death always resulted very quickly. When other condi- 

 tions were unfavorable it was often found that some were sustained 

 by feeding upon the bodies of their dead associates, which were com- 

 pletely devoured. The molted -kin- were generally devoured. 



Experiments with the cattle tick (Boophilus annulatus Say) and 

 its egos evidenced the fact that the sowbugs fed on the dead ticks and 

 ate the eggs when no other food wa- present. Thirty-eight sowbugs 

 were furnished with a large number of eggs of the tick, and it was 

 found that in several instances a- many a- 13 tick eggs each were 

 eaten per day for a -eric- of day-. This, however, was a maximum, 

 the average during the conduct of the experiment being about •'« 

 per day (Mich. Experiments to find whether the sowbugs fed upon 

 the pupa' of a cutworm (Prodenia omithogaUi Guen.) proved futile. 



A -eric- of outdoor tests was also conducted with bait- to find 

 what substances might be wx\\ to attract these crustaceans, and 

 finally a -eric- of poison tests to ascertain the most advisable remedy. 



Bread proved attractive, but a- every piece tried wa- carried away 

 by some mammal or bird it- use seemed inadvisable. Flour, bacon, 

 potatoes, radishes, and sugar proved to be good bait-. To ascertain 

 the relative value of different insecticides several poison tests were 

 conducted with pyrethrum. Paris green. London purple, and arsenic 

 Few dead sowbugs were found, however, and it wa- noticed that a 



