An associational study of Illinois sand prairie . s are eaten by the Chrysomelidae, lepidopterous larvae, the grasshoppers, the prairie white-footed mouse, and the rabbitThe various floT;ers in the bunch-grass are visited by plant-feedinginsects, v;hich live on the honey and pollen, and which usually aidthe plant by pollenating it. Fruits and berries are eaten by thebox-turtle, by insects, birds, and the prairie mice. The seeds areeaten by Bruohids, certain Carabidae, birds, and rodents. Decayedparts of plant remains are eaten by various scavengers, notably Dip-terous larvae. When more is know
An associational study of Illinois sand prairie . s are eaten by the Chrysomelidae, lepidopterous larvae, the grasshoppers, the prairie white-footed mouse, and the rabbitThe various floT;ers in the bunch-grass are visited by plant-feedinginsects, v;hich live on the honey and pollen, and which usually aidthe plant by pollenating it. Fruits and berries are eaten by thebox-turtle, by insects, birds, and the prairie mice. The seeds areeaten by Bruohids, certain Carabidae, birds, and rodents. Decayedparts of plant remains are eaten by various scavengers, notably Dip-terous larvae. When more is known of the habits of each anima-l speci<^s,we will be able to detennine exactly the function of each animal inthe association, and its ecological relations to other animals andto the This division of labor - the adaption of certain species orgroups to fill a definite place in the association - is carried out to a high degree of specialization in certain forms, and in others the life-needs have a wide range of elasticity. The moderately. 47 specialized forms probably constitute the large raajority of the ani-mals in an association. Theso forms are not restricted to a singlefood plant, although they may be seen to show preference to one par-ticular kind of food. The highly specialized forms are enabled toavail themselves of opportunities denied to the generalized forms:they thus avoid competition, but lose the versatility, if we may callit so - the ability to adapt themselves to changed conditions - thatthe less specialized have. Thoy m^ay thus become abundant attimes, but as they depend wholly upon one variable condition - per-haps the presence of a particular plant vj-hich may be quite rare inthe association - they never can beco^O dominant species. The in-sects which live upon Cacalia - the plant bug Lygaeus bicrucis, andthe stem-borer Languria bicolor are such species; they a re conspicu-ous, but occupy a very insignificant place in the association becauseC
Size: 1332px × 1875px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidassocia, booksubjecttheses
