much of the infested area. Even higher percentages are recorded in browntail and 
satin moth infestations (1/73, 269, 328, 1262). 
Blepharipa pratensis (Meigen) (fig. 218), a parasite of the gypsy moth, was 
imported and became established by 1911. In most of the areas where it occurs, it 
parasitizes from 5 to 25 percent of the gypsy moth population. As far as known, it 
confines its attack to the gypsy moth in this country, whereas in Europe it has 
several lepidopterous hosts. Its life history and habits are discussed (/73). 
Courtesy P. Godwin, Hamden, Conn. 
Figure 218.—Adult of Blepharipa pratensis, a parasite of 
the gypsy moth and other defoliators. 
Parasetigena silvestris (Robineau-Desvoidy) and Exorista larvarum (L.) were 
imported against the gypsy moth from 1924 to 1933. P. silvestris, a single-brooded 
species, 1S probably the most important parasite of the nun moth in Europe. E. 
larvarum, a multibrooded species, attacks about 45 different hosts in Europe. Both 
species are now important parasites of the gypsy moth through the generally 
infested area in the United States. EF. /arvarum is also a parasite of the satin moth 
and browntail moth in this country. 
Two species, Zownsendiellomyia nidicola (Townsend) and Carcelia laxifrons 
Villeneuve, were imported against the browntail moth early in this century. 7. 
nidicola quickly spread throughout the infested area. It has frequently parasitized 
an average of 17 percent of overwintering browntail moth larvae. C. laxifrons also 
occurs throughout the infested area. Unfortunately, it parasitizes a very low per- 
centage of the population. 
Chaetexorista javana Brauer & Bergenstamm, a native of Japan, was imported 
against the oriental moth in 1929 and 1930. As early as 1933, parasitism in the 
infested area around Boston, Mass., averaged 60 percent. Erynniopsis antennata 
Rondani, a native of Europe, has been successfully introduced into California 
against the European elm leaf beetle. Colonies have also been liberated against the 
beetle along the Atlantic Seaboard but without success. Palexorista bohemica 
(Mesnil), a native of Europe, was successfully introduced into Canada against the 
European spruce sawfly during the thirties and forties. This is probably the same 
species that was introduced into the United States around 1906 as P. inconspicua 
453 
