Ecological Study of Hemiptera of Cranlerry Lake Region 17 



these amphibians. The fishes of course consume many aquatic 

 insects and forms that happen to fall into the water, but they 

 have very little relation to the forest Hemiptera. 



The predaceous Hemiptera play an important role in the control 

 of plant-feeding Hemiptera and other phytophagus insects. Such 

 ravenous forms as Nabis limbatus, N. roseipennis, N. rufusculus, 

 Podisus serieventris, P. modesties, P. placidus, P. maculiventris, 

 Anthocoris horealis, Tetraphleps oshorni, Triphleps insidiosus, 

 Deraeocoris (Camptohrochys) horealis and the like are very con- 

 spicuous in the region studied. The aquatics are mostly predatory, 

 but they sustain themselves upon aquatic insects and other aquatic 

 animals and also upon insects that happen to fall in the water, 

 Hymenopterous egg parasites were bred from the eggs of several 

 of the Heteroptera and numerous Jassids were parasitized by 

 dryinids. Tachinid eggs were observed on the backs of some of 

 the Pentatomidae. Predaceous insects in other orders also destroy 

 many Hemiptera. 



Of the invertebrate groups associated with Hemiptera the 

 spiders are of special interest and while the species are not 

 numerous and individuals have not been observed as specially 

 abundant they are probably the most important of the natural 

 enemies. 



Collections of these have been made incidentally while sweeping 

 or beating for Hemiptera and specimens have been submitted to 

 Dr. W. M. Barrows of the Ohio State University for identification. 

 The following list should not be considered as representing the 

 spider fauna of the region, but simply as indicating the most 

 common species associated with the Hemiptera and from the 

 known food habits * as constituting a natural check for this group 

 as well as other associated insects. 



Common Spiders of Cranberry Lake Region 



Epei/ra insularis Hentz. Barber Point, no special habitat noted. 



Epeira trifolium Hentz. Barber Point, collected in the Beaver Meadow, 

 July 30, 1920. 



Epeira trivittata Kej'S. Barber Point: mars>li, July 5 and 28; willow, 

 Aug. 5; tote road along Sucker Brook, July 2,8; virgin forest, July 28; 

 Aug. 11; Plains, Aug. 3, 1920. 



Epeira thaddens Hentz. Virgin forest, Aug. 11, 1920. 



Fellenes lioyi Peckliam. Barber Point — no sii^ecial habitat noted but accord- 

 ing to Dr. Barrows this is a meadow sipecie;?. 



Tibelliis duttoni Hentz. Barter Point, taken in the marsh and Beaver 

 meadow, July 5, 28; tote road, July 28; on willows, July 2'8, "burn," July 

 28, 1920. 



Tihellus ohlongus (^Yalck). Barber Point, taken near the tote road leading 

 to Forsaith's Bog, July 28, 19120. 



Dendrjiphantes militaris (Hentz). Marsh and meadow tote road, July 28; 

 burn July 27; on willows Aus:. 5, 1920. 



Dendryphantes capitatvs (Hentz). Taken on willow, July 28, in dense 

 virgin forest; Barber Point, July 29. 



* Bilsing. S. W. Quantitative Studies in the Food of Spiders. Ohio Journal of 

 Science, Vol. XX, 1920, p. 215-260. 



