Subfossil biotic assemblages in surface sediments of lakes have been used to infer ecological conditions across environmental gradients.. Local variables are usually the major drives of assemblage composition, but in remote oceanic islands biogeographic filters may play a significant role. To assess the contribution of local and regional filters in the composition of subfossil diatoms and chiro...

Polytene chromosomes of chironomid larvae (Diptera: Chironomidae), collected on the Wrangel Island are described. Larvae have 2n=8: AB, CD, EF, G (Ch. thummi Keyl, 1962 complex). By karyotype larvae are identical to Chironomus sp. Le1, described from the Sagystyr Island of the Ust-Lena Reserve (Yakutia) (Kiknadze et al., 1996). The insignificant differences include the number of nucleoli and pu...

Aquatic insect secondary production, emergence, and export of adults to the adjacent terrestrial ecosystem were assessed in Sycamore Creek, Arizona, by means of benthic sampling, emergence traps, and catch-nets that passively sampled adults falling into the stream. Annual secondary production was 120.9 ? 18.0 g-m-2 yr-t and emergence was 23.1 g.m-2 yr-t (in dry mass units). The ratio of annual ...

Micropsectra sedna (Oliver, 1976) is a parthenogenetic midge from the Canadian Arctic. The parthenogenetic mechanism is apomictic thelytoky, with a restitutional division during oogenesis, as found in other parthenogenetic Chironomidae. It is triploid, with two similar chromosome sets, and the third is relatively dissimilar, pairing little with the diploid set. Two karyotypes were observed: a s...

Populations of adult chironomids occurring along 5-6 km of waterfront in the city of Sanford facing Lake Monroe, central Florida, were monitored from January 1980 to December 1994 using New Jersey light traps. The annual mean number of total midges per trap per day ranged from 269 (1994) to 8,009 (1980). Among the more than 20 species of midges occurring in the traps, Glyptotendipes paripes was...

The first detailed systematic study on the tanytarsine chironomids recorded in the Eocene amber from the Rovno region (Ukraine) revealed seven new taxa. Archistempellina gen. nov., represented by A. bifurca sp. nov. (type for the genus, male) and A. falcifera sp. nov. (male), displays characters similar to those found in Stempellina Thienemann et Bause, and is recognized as one of probable basa...

We conducted experiments to determine isotope changes in the deposit-feeding chironomid larvae Chironomus acerbiphilus during feeding, starvation and metamorphosis. Isotope changes in chironomid larvae occurred mainly during growth and rarely afterward. This finding indicates that chironomid isotope turnover mainly occurs in conjunction with growth and suggests that chironomid larvae only break...

It has long been assumed that the resistant eggs of many zooplankton are able to survive passage through the gut of migratory waterbirds, thus facilitating their dispersal between isolated aquatic habitats. We present the first evidence that such passive internal transport within birds may be relevant for insect populations. In three out of six faecal samples from black-tailed Godwits on autumn...

Two interrelated aspects of haemoglobin differentiation in vertebrates are tissue specificity (muscle haemoglobin and blood haemoglobin) and time specificity (embryonic, larval or foetal haemoglobin, and adult haemoglobin). Tissue specificity of haemoglobin and of other respiratory proteins has been found in invertebrates and has been shown to be the result of differences in gene activity (Man ...