46 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE, 1952 
Taxonomists associated with the Bureau identified 87,581 lots of 
insects, the largest number ever determined in a single year. These 
identifications assisted in the proper dired ion of research, control, and 
regulatory activities. 
EUROPEAN INSECT PARASITE INTRODUCTIONS 
Several shipments of PerUitus rutffis and Microctonus aetJUops, 
totalling nearly 1,200 cocoons, and 5 shipments of GampogasU r > xigua 
totalling 600 females ready to larviposit, were made from France to 
North Dakota for liberation in fields infested with the sweetclover 
weevil Sitona cylindricollis. 
Investigations of the parasites of the European corn borer were con- 
tinned in Europe during the year. More than 4,300 Lfon/ru Hum alkcu 
cocoons, 2,20o Microgaster tibialis cocoons, and 28,500 corn borer 
larvae containing an estimated 7,100 Apanteles thompsoni larvae were 
shipped to the United States for rearing and colonization in European 
corn borer infested areas. 
Investigations of parasites of the wheat -tern sawfly in Europe were 
started in December 1951 to obtain parasites and ship them to the 
United States for liberation in wheat fields in the Northwest infested 
with the wheat stem sawfly. 
Seven shipments of more than GOO Dexilla rustica females and 5 
shipments of more than 500 Dexilla vacua females were sent from 
Fiance for colonization in fields infested with the European chafer 
Amphimallon majalis in New York State. Experiments in France in- 
dicate that first stage larvae of both of these parasites are capable of 
living from 30 to 40 days in the soil while searching for host grubs. 
and that D. mistica has more than 1 generation a year. 
Small colonies of Horogenes fenestralis Microgaster sp., Apanteles 
sp., Elactertus sp., and Rogas sp.. all parasites of the omnivorous leaf 
tier Cixephasia longana, were sent to Oregon from France during the 
year for release against this pest. 
Several shipments of the elm scales Gossyparia spuria and Lepido- 
saphes uforri were sent from Europe to California for study of the 
issuing parasites. 
Native Parasites Collected for Shipment Abroad 
Assistance was given to the European Plant Protection Organiza- 
tion — an organization closely cooperating with the Food and Agri- 
culture Organization of the United Nations — in collecting parasites of 
the fall webworm in the United States. A limited number of para- 
sites, particularly those attacking the ^tztz stage of this insect, were 
collected in Connecticut and sent to the Commonwealth Institute of 
Biological Control in Canada for further processing before forward- 
ing to Austria and Yugoslavia. 
WIDESPREAD DESTRUCTION OE KLAMATH Will) 
\\\ INSECT PREDATOR 
Biological control of the noxious Klamath weed in Humboldt 
County, California, originally the county most heavily infested with 
this plant, is now an actuality. At the completion of the L951 larval 
feeding period of the insect predators colonized in this county, more 
