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[Vol. 89 
pula arctica (Rohwer), have large and highly curved sting shafts in 
comparison with those of nonparasitic queens such as V. acadica 
(Fig. 2). However, a facultative social parasite, V squamosa 
(Drury), does not have a recurved sting shaft, but has a large abrupt 
curve at the distal end (Fig. 2E). V. austriaca and D. arctica stylets 
have a similar configuration, except only the extreme tip of the 
stylet is abruptly hooked (Fig. 2C). However, this condition is 
entirely lacking in the V. acadica queen (Fig. 2D). Both parasite and 
host have barbs on the sting lancets. 
In conjunction with the curved sting, the distal tip of the seventh 
abdominal sternum of V. austriaca turns down more sharply than 
does the same sternum of the V. acadica queen. In addition, this 
sternum has prominent lateral carinae on the ectal surface, whereas, 
this ridge is less developed in the host queen. The seventh sternum in 
V austriaca is a ca 0.40 mm longer along the midline than that of V. 
acadica. 
The exocrine glands of four late summer and two spring foun- 
dresses, and one fall V acadica queen were examined and measured. 
Thirteen of the 14 known glands in Vespula were present, and their 
size and development fell within the ranges reported by Landolt and 
Akre (1979). The endostipal gland was lacking. In contrast, only 12 
glands were located in two aged and 17 preusurpation, summer 
parasites since the sixth sternal and endostipal glands were absent. 
The head glands, except for the hypopharyngeal, were comparable 
in size to those of V acadica and other vespines (Landolt and Akre 
1979). The two distinct clusters of cells of the hypopharyngeal gland 
were nearly in contact with each other in the center of the suboral 
plate of the labrum-epipharynx (see Fig. 5, Landolt and Akre 1979). 
The clusters were on the average larger than those in V acadica, but 
were usually within the size range found in V pensylvanica (Saus- 
sure) (0.03 0.8 mm 3 ). However, two parasites had clusters about 
0.12 mm 3 . The thoracic or salivary glands were also present in V 
austriaca and were similar in size to those in nonparasitic queens. 
Although the seventh sternal gland, eighth tergal gland, and poi- 
son gland reservoir are similar in size and development to those of 
other vespines, evident differences exist between the two species in 
the other gastral glands. The sixth sternal gland and the associated 
sternal brush (i.e., tuft of hairs) are absent in V. austriaca. This 
gland (but not the brush) is present in V. acadica, other members of 
