of the larval stage of the female parasite. There may be three to 
five generations per year. 
The genus Tetrastichus contains a large number of important 
parasites of important forest insect pests. Descriptions of most 
North American species and information on their distribution 
and hosts were published by Burks (125). 
Tetrastichus turionum (Htg.) was imported during the thirties 
and released in New England, New York, and New Jersey against 
the European pine shoot moth. Several years later it was also 
released in Ontario. It is known to occur in Massachusetts, New 
Jersey, on Long Island, and in southern Ontario. The adult is a 
tiny, iridescent, blue-green insect. The antennae are brown and 
the apices of the femora and the tarsi are light yellow or white. 
This is a pupal parasite and it has one generation per year. So 
far, it has been of no consequence in control of the shoot moth in 
this country. 
Tetrastichus brevistigma Gahan is a pupal parasite of the elm 
leaf beetle. Adults are black with a slight, metallic, greenish tinge 
and are only about .5 to 1.5 mm. long. An average of 12 parasite 
larvae develop in each pupa and there are three or four genera- 
tions per year. Parasitization as high as 50 to 80 percent occurs 
commonly in the vicinity of Boston, Massachusetts, where it was 
introduced from California. T. holbeini Gir. and T. rugglest Roh. 
attack several species of Chrysobothris and Agrilus, respectively. 
Dimmockia incongrus (Ashm.) parasitizes the gypsy moth and 
many other species of Lepidoptera. Elachertus cocoeciae (How.) 
parasitizes various species of Lepidoptera. Members of the genus 
Hyssopus Gir. parasitize several species of shoot and tip moths 
and seed and cone infesting insects. 
FAMILY ELASMIDAE 
This family is represented in North America by one genus and 
17 species, all of which occur in eastern United States. They are 
parasitic on lepidopterous larvae or hyperparasitic on ichneu- 
monid or braconid parasites of lepidopterous larvae. 
FAMILY THYSANIDAE 
This family is also represented by one genus and 17 species in 
the United States and Canada. As far as known, they either at- 
tack various species of scale insects, whiteflies, and other Homop- 
tera, or they attack other chalcid parasites of Homoptera. 
FAMILY ENCYRTIDAE 
This is a large family of parasites. Insect hosts are widely dis- 
tributed among the various orders, but the majority of species are 
parasitic on aphids, scales, and whiteflies. Adults are 1 to 2 mm. 
long. 
Ooencyrtus kuwanai (Howard), a parasite of gypsy moth eggs, 
was introduced into the United States in 1908 and 1909 from 
Japan (175). The adult is black and about 1 mm. long. Winter is 
spent in the adult stage, during which mortality may be severe. 
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