Publication Date


Document Type


First Advisor

Zar, Jerrold H., 1941-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Taeniopteryx nivalis; Stone-flies; Insects--Development


The emergence biology of the winter stonefly, Taeniopteryx nivalis (Fitch) (Plecoptera: Taeniopterygide), was studied at Ferson Creek, a small stream in eastern Kane County, Illinois (Geneva Quadrangle, Sec. 20, T40N, R8E) during the winter of 1977-1978. The study included investigations of the naiadal growth pattern, adult emergence in the field, and laboratory experiments on the effects of temperature and photoperiod as factors influencing adult emergence. In the field, naiadal growth was described by measurements of head capsule width, total length, forewing pad length, dry weight, and total lipid expressed as a percentage of the body weight. Growth was rapid from late October when the first post-diapause specimens were collected, until mid-January when maximum values for most of the variables measured were obtained. The percent lipid decreased throughout the study period, reaching a minimum value in mid-February and remaining at this level until emergence in mid-March. Greater than 80 percent of the emerging population had emerged by the mid-point of the 12 day emergence period. This pattern is described as being between that of a synchronous and extended type. In the laboratory, emergence was initiated first from the experimental treatment of warm (5°C) water temperature EGH long (L:D = 14:10 hr) photoperiod. This was followed by the emergence from the warm-short (L:D = 8:16 hr) treatment. Emergences from the cold (l°C)-long and cold-short treatments were similar and occurred later than the other two treatments. The emergence periods from treatments with the long photoperiod were of shorter duration than those from treatments with the short photoperiod. It was also noted that the emergence periods shortened as the time spent in the mature naiad stage (the period from minimum percent total lipid values until emergence) was increased because of the delay in the initiation of emergence due to the maintenance of cold temperatures. It is suggested that, after naiadal maturity is reached, the adult emergence of this species will be initiated by an increase in temperature. The photoperiod at the time of emergence and the length of time from naiadal maturity to emergence are factors influencing the length of the emergence period of this species.


Includes bibliographical references.||Includes illustrations and map.


vi, 67 pages




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