232 DRY AND MESOPHYTIC FOREST COMMUNITIES 
sure on the back of the neck. In this state it can be handled as if dead, 
laid in any position, or tied into a knot. The only movement it persists 
in making is that of turning its ventral side uppermost. Ant-lions (Fig. 
203) are very rarely found at the south end of Lake Michigan, except 
in the oak belt. They make cylindrical conical pits in the sand (177, 
179). The most characteristic species under the bark of fallen oaks is 
the flatbug (Fig. 209). 
b) The field stratum.—This stratum is dominated by many flowering 
plants, such as Monarda, etc. The addition of a host of insects and 
spiders not present in the earlier conditions is noticeable. Of the grass- 
hoppers we add six species (Scudderia texensis, Xiphidium strictum, 
Chloealtis cons persa, 
Schistocerca rubiginosa, 
Oecanthus fasciatus, and 
Conocephalus ensiger) 
(40). 
The andrenid bees 
(Agapostemon splendens) 
and various robber-flies 
are numerous. On the 
Monarda the honey-bees, 
bee-flies (Fig. 210), bum- 
blebees, and spiders (Mis- 
umessus asperatus [Figs. 
207, 208], Dictyna foliacea, 
Fic. 210.—A bee-fly (Bombylius major Linn.) A griope trifasciata, and 
(from Williston after Lugger). Epeira sp.) are common. 
The blueberry is com- 
monly one of the small herbs of the field stratum and upon it we find 
several characteristic galls. 
c) Shrub stratum.—This stratum is made up of the choke-cherry, 
young oaks, rose, etc. The shrub which has been given most attention 
is the choke-cherry. On this the lacebugs (Fig. 211) are often numerous; 
the puss caterpillar (Cerura sp.) (163) sometimes occurs. This cater- 
pillar has a pair of long projections at the posterior end. When disturbed 
it extends and waves these projections and thus makes of itself one of 
the most fantastic of our caterpillars. 
Grapevines are not uncommon on the dunes and we often find a 
curious red petiole gall on them, which is not common elsewhere. The 
large fleshy larvae of the achemon sphinx (163) are sometimes taken. 
