LOW PRAIRIE 285 
sawfly (Fig. 287), which is very abundant in early June. Associated 
with this are many caterpillars (174). The greasy cutworm (A grotis 
ypsilon Rott.) feeds upon the strawberry. The army worm (Lucania 
untpuncta Haw.) feeds upon a variety of plants, and several of its near 
relatives occur. The larvae of the salt-marsh caterpillar (Estigmene 
acraea) (Figs. 290, 291), the yellow bear (Diacrisia virginica Fab.) (Fig. 
292), hedgehog caterpillar (sia isabella S. and A.), and A pantesis 
phalterta Harr. are common. 
Of the Ortho ptera, Xiphidium fasciatum and the 2-lined locust (Melano- 
plus bivittatus), the red-legged locust (Melanoplus femur-rubrum), and 
the short-winged brown locust (Stenobothrus curtipennts) (Fig. 293) 
are most characteristic. 
Fic. 292.—The yellow bear: a, larva; 
b, adult (Diacrisia virginica Fabr.); nat- 
ural size (after Forbes). 
Fic. 293.—The short-winged brown 
locust (Stenobothrus curtipennis) (after 
Lugger). 
On the flowers are many flower-frequenting flies, viz., Sparnopolius 
flavius Wied., Asilus sp., Syritta pipiens Linn., Coenosia spinosa Walk., 
Paragus angustifrons Loew., Pachryrhina ferruginea, and Helophilus 
conostoma Will. Preying upon the various insects are the mud-dauber 
wasp (Scelipron cementarius) and the digger-wasp (Ammophila nigricans). 
Parasites, such as Ichneumon zebratus, Paniscus gemminatus, Epeolus 
cressonii, etc., occur upon the plants, and certain of them are often 
found engaged in depositing eggs in or on caterpillars. The onion-fly 
(Tritoxa flexa) (190) is striking because of its black body and black 
wings, obliquely marked with white. 
Spiders, especially crab spiders, are abundant. The white Misumena 
vatia occurs on the milkweed and the flowers of the mint. Lpevra 
trivittata and the long-bodied spider (Tetragnatha laboriosa) occur on the 
blossoms and stems of various plants. 
