Diamesa mendotae Muttkowski is commonly observed emerging during winter at low air temperatures from Minnesota streams, but little is known about the winter dynamics of this and other winter-emerging aquatic insects. Biweekly collections of surface-floating pupal exuviae indicated that this species emerged from October through May, when water temperatures were less than ≈10C. Emergence occurred continuously through winter, with a lull during January and February. Development of larvae from in situ growth enclosures supported emergence data and indicated that the reduction and halt of emergence in the spring was related to increasing water temperatures (>10°C), which were unsuitable for the growth or survival of the larvae. Development continued through January when water temperatures were at their lowest for the study stream and therefore did not explain the mid-winter lull in emergence. Growth rates of D. mendotae were not greater than other chironomid taxa at similar temperatures, indicating that lower critical thermal limits for growth allow this species to dominate ground-water influenced streams during the winter in Minnesota. The results of this study show that D. mendotae is well suited for growth and development at low temperatures and provides an assessment of important factors that regulate this species at low water and air temperatures.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.