109 



Upon remnants of prairie vegetation growing at Urbana, Illinois, 

 I have found several kinds of insects centered about a wild lettuce, 

 Lactuca canadensis. Upon the upper, tender parts of this plant, the 

 plant-louse Macrosiphum riidheckicc Fitch, thrives late in the fall, in 

 very large numbers. Some seasons nearly every plant is infested. The 

 lice become so abundant upon these tender parts that the entire stem 

 for a distance of a few inches is completely covered. They migrate 

 upward with the growth of the stem and keep on the fresh, tender 

 parts. Among the plant-lice, and running about on the stem of the 

 plant, attending ants abound; eggs, larvae, and adults of lace-wing flies 

 (Chrysopa) also abound; and several species of coccinellids, syrphid 

 larvae, and a variety of small parasitic Hymenoptera are present. 



5. Upland Prairie Association 



The w^ell-drained prairie, a degree removed from the permanently 

 moist prairie, is fairly well represented by the physical and biological 

 conditions in which Bnphorbia corollata, Apocynum mediuin, and 

 Lactuca canadensis, are the representative plants. The plant ecologist 

 would consider the conditions favorable to mesophytic plants. In the 

 Charleston region these conditions are approximated at Station II, 

 where drainage has doubtless changed the area from a somewhat 

 moist, to its present well-drained, condition. 



Representative animals of this community are as follows : Argiopc 

 aitrantia, Misumena aleatoria, BncoptolopJius sordidus, Melanopliis 

 hivittatus, M. dijferentialis, Orchelininni vidgare, Xiphidimn strictum, 

 Biischistus variolarius, Phyniata fasciata, Chaidiognathiis pennsylvan- 

 icus, Bpicauta niarginata and B. pcnnsylranica, RhipipJwrus diniidia- 

 tns and R. linibatus, Anunalo, Bxoprosopa fasciata, Fromachns verte- 

 hratus, Bonihus pennsylvanicns, and Myzine sexcincta. 



On dry prairie at Mayview, 111., September 26, I found the plant- 

 louse Aphis asclepiadis Fitch on the leaves and stems of the dogbane 

 (Apocynum) and the lice attended by the ant Formica fusca L. A 

 beetle, Languria mozardi Latr., whose larva is a stem-borer, inhabits 

 Lactuca canadensis. Its life history and habits have been discussed 

 by Folsom ('09, pp. 178-184). 



6. The Solidago Community 



A common community in the late summer and early fall is centered 

 about the goldenrod (Solidago). This plant was not abundant or in 

 blossom at any of the stations studied in detail, but it grew in small 

 widely scattered colonies or clumps. Observations were made in two 



