PARASITIC FUNGI AND MOULDS. 49 
have given rise to a surmise that if we could discover 
the parasitic fungus of the phylloxera, we might 
transform it into a powerful auxiliary of agriculture, 
since by its aid the parasitic insect which 
now ravages our vineyards might be 
destroyed. 
From this point of view Giard 
has observed several of these parasites 
of insects, which he ealls Entomo- 
phthorec, from the name of their prin- 
cipal genus, Entomophthora. Such is 
E. rimosa, which attacks grasshop- 
pers and the diptera of the genus 
Chironomus, enveloping them in a thick 
feltwork formed by the winter spores, Fig. 23—Butterny- 
and speedily killing them. In the Cordiceps. = 
same manner Isaria pulveracea attacks Pyrrhocoris 
apterus, an insect which is often injurious to our 
kitchen gardens. 
It has been asked whether Lntomophthora Plun- 
choni, the parasite of the aphis, might not also prey 
upon the phylloxera, but the experiments made in 
this direction have not hitherto been so successful as 
to allow us to count on this means of averting the 
scourge. With the same object, Hagen has suggested 
the use of beer-yeast, which seems to have a destruc- 
tive effect on insects, as it is developed in their tissues. 
