ECONOMIC IMPORTANCE OF SOWBUGS, 17 



females were still alive one hundred and sixty days after the iK'^iii- 

 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 leaves in contact with the earth de- 

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

 leaves the sowbugs seemed to thrive, although there Avas always evi- 

 dence of feeding on green leaves when such were i)resent. Fungous 

 growths on dry leaves, on decaying fruit, and on moist dead wood 

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

 served. Fungus found on earth moistened with molasses sustained 

 9 sowbugs thirty-six days, and 2 survived as long as seventy-five days, 

 (jreen cotton leaves alone will sustain the life of these crustaceans 

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

 the longest any remained alive under these conditi(ms. The other 

 vegetation j^rovided 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 leaves, and the leaves of 

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

 These leaves did not retain their moisture long after picking. When 

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

 life eighteen days. Additional proof that nourishment is sought in 

 the soil was obtained by mixing London jjurple or Paris green with 

 the earth. Death always resulted very quickh\ '\Mien other condi- 

 tions were unfavorable it was often found that some Avere svistained 

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

 pletely devoured. The molted skins were generally devoured. 



Experiments with the cattle tick {Boophilus anmtlatus Say) and 

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

 ate the eggs Avhen no other food was present. Thirty-eight sowbugs 

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

 found that in several instances as many as 18 tick eggs each were 

 eaten per day foi- a series of days. This, however, was a maximum, 

 the average duiMug the conduct of the experiment being about 8 eggs 

 per day each. Exjjeriments to find whether the sowbugs fed upon 

 the pupa^ of a cutworm {Prodenia ornithogalli Guen.) proved futile. 



A series of outdoor tests was also conducted with baits to find 

 what substances might be used to attract these crustaceans, and 

 finally a series of poison tests to ascertain the most advisable remedi'. 



Bread proved attractive, but as every piece tried was carried away 

 by some mannrud or bird its use seemed inadvisable. Flour, bacon, 

 jDotatoes. radishes, and sugar i)roved to be good baits. To ascertain 

 the relative value of diti'erent insecticides several poison tests were 

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

 Few dead sowbuii's were found, however, and it was noticed that a 



