ECONOMK^ IMPORTANCK OF SOWBUGS. 17 



females were still alive one hundred and sixty days after the lje«2:in- 

 ning of the exjiei-iment. The cotton leaves. Avhen tender, were ea<Terly 

 eaten. 



Fungous oTowth was favorable only under certain conditions. In 

 the exjjerinients cited above the leaves in contact with the earth de- 

 caj'ed and accumulated a rich growth of mold. Upon these decayed 

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

 dence of feeding on green leaves when such were present. 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 clays. 

 Green 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 nnder these conditions. 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 leaves, and the leaves of 

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

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

 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 l^ondon purple or Paris green with 

 the earth. Deatli always resulted very quickly. AVhen 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 skins w^ere generally devoured. 



Experiments ^yith the cattle tick {BoopJt'ihis (inni/Jafi/s Say) and 

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

 ate the eggs wlieii no other food was j)resent. Thirty-eight sowbugs 

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

 found that in several instances as many as i;^> tick eggs each were 

 eaten per day for a series of days. This, however, was a uiaxinnun. 

 the average dui'ing the conduct of the experinuiit l)eing about ''\ eggs 

 per day each. Kxpei'inients to iind whether the sowbugs fed upon 

 the pupa' of a cutworm {Prodciila ornithogalli (iuen.) ])roved futile. 



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

 what substances miglit be used to attract these crustaceans, and 

 fijially a scries of poison tests to ascertain the most ad\ isnl)lc remedy. 



Bread proved atti'active, but as every piece tried was carried away 

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

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

 the relative value of ditferent insecticides several jioison -tests were 

 conducted with i)yrethrum, I*aris green. London i)uri)le. and arsenic. 

 Few dead sowbues were found, however, and it was noticed that a 



