Laboratory conditions in our study (temperature ca 27~ r.h. 95%, shade 70%) were optimal for infection, and more so than possible in the field. Nevertheless, none of the plants tested
(except waterlettuce, another problematic weed in Mexico) was infected by C. piaropi or A. zonaturn. Therefore, based on this host specificity test, the use of C. piaropi and A. zonatum lot
biological control of waterhyacinth would not be expected to affect plants of economic and ecological importance in Mexico.