20 
ideal as regards freedom from fungi, on]} 7 about 1 per cent of the 
changas handled could be even doubtfully classed as killed by this 
fungus. 
Two experiments on a small scale with Micrococcus nigrofaciens, 
a bacterium pathogenic to white grubs and to some Blattids, 1 re- 
sulted negatively as far as the changa was concerned. 
CANNIBALISM. 
Cannibalism among changas is common under laboratory condi- 
tions. When changas were kept in pairs, although provided with 
plenty of vegetable food, one or the other sex was almost certain to 
be killed within a month. Under natural conditions cannibalism is 
probably greatest during the first few days following the hatching 
of an egg cluster. At that time the newly hatched changas remain 
together in their chamber, and a few of the weaklings, as well as 
some of the eggs, serve as food for the stronger or earlier hatched 
members of the brood. Both adult males and females devour the 
eggs when opportunity offers, but in nature they rarely happen upon 
the egg chamber. Imperfectly molted individuals in the breeding 
jars were often killed by other changas. 
ARTIFICIAL CONTROL. 
Control measures for the changa may be divided into preventive 
and remedial. The value of either class depends entirely upon local 
conditions. 
PREVENTIVE MEASURES. 
Mechanical devices. — One of the earliest methods used in combat- 
ing the changa was the wrapping of mamey leaves (Mammea ameri- 
cana) about the roots of seedlings in transplanting. This method 
was in use chiefly among tobacco growers and gardeners. Other 
leaves said to be effective in protecting the roots from the mole 
cricket's ravages are those of pomarrosa (Eugenia jambos) and 
ausubo (two species are included under this common name, Mimusops 
nitida and Sideroxylon foetidissimum). This method of leaf-wrap- 
ping hinders the rooting of the plants and sometimes causes water 
to stand about the roots. Mamey leaves rose in price as they became 
more scarce, and their use practically ceased. Their place was taken 
by cylinders made of tin, heavy paper, or wire. Plants are set within 
these cylinders, and the top of the cylinder allowed to project on 
inch or two above the surface of the ground. These cylinders are 
»Northrup, Zae. Michigan Sta. Tech. Bui. 18 (1914). 
