Permission has been granted to the Library of the University of Manitoba to lend or seU copies of this thesis/practicum, to the Nationai Library of Canada to microfilm this thesis and to lend or seil copies of the film, and to University Microfhs Inc. to publisb an abstract of this thesidpracticum.This reproduction or copy of this thesis has been made available by authority of the copyright owner soleiy for the purpose of private stady and research, and may ody be repnidnced and copied as permitted by copyright iaws or with express d e n authorization from the copyright owner.The movement of the adult msty grain beetle, Cyptolestesfërrugineus (Stephens), in 100 cm long columns, filled with wheat of uniform moisture content (m.c.) of 12,1,13.5 and 14.7%.was determined for horizontal and vertical placement of columns at 30°C. Also, the insect movement in columns, filled with hi& moisture content. wheat (above 16.5%) in the middle or top sections, and with uniform rnoisture content wheat (12 or 14.8%) in other sections, was determined. Insect movement was also determined under CO2 gradients (with COz introduced from either top or bottorn) and no CO, gradients (control) in columns filled with either uniform moisture content wheat (12 or 14.6%) or with pockets of high rnoisture content wheat (15.5, 16, 16.6 or 17%) in the middle. bottom or top three sections.Six columns made of polyvinyl chloride (PVC) were tàbricated to hold wheat. Each column (10 cm diameter) was divided into IO equal sections, each 10 cm long. One end of the column \vas closed and the o h -end remained opened to the atmosphere. Each section of the column had one port, except the two end sections, which had two ports each. The second port in the closed end section was for introducing CO, while the port at the open end was used for exit of gases. The first port in each section was used for introducing insects and for taking CO, sarnples. Carbon dioxide gradients were established in the cotumns by maintaining a flow o f 6 mumin fiom a compressed gas cylinder containing a mixture of 10% CO, and 90% air, by voIume. The gas concentration in each section was measured using a gas chromatopph. C~yptolestesfernigineus adults up to 2 rno old were taken fiom laboratoy cultures and 200 adults, 100 each-marked and unmarked, were introduced, either in the middle or at the top. The insect movement was determined in horizontal and vertical columns after 1,3,5, and 7 d, 1 and 5 d or 1 and 7 d.h horizontal columns Eilled with wheat of 13.5% uniform mec., 43% of aduh C. ferrugineus remained in the adjacent sections frorn their point of introduction, but afler 5 d, they exhibited the trend of distributing unifomly in h e columns. in vertical columns filled with 12 or 14.8% unifom moisture content, 63% of the insects moved downward showing positive geotaxism. tn horizontal or vertical coiumns containing pockets of high moisture content wheat, 55% of the beetles aggregated in the region of high moisture content, exhibiting hygrotactic response. Under CO? gradients in co...
