Collective animal behaviour is often modeled by systems of agents that interact via effective social forces, including short-range repulsion and long-range attraction. We search for evidence of such effective forces by studying laboratory swarms of the flying midge Chironomus riparius. Using multi-camera stereoimaging and particle-tracking techniques, we record three-dimensional trajectories fo...

Fluoxetine, a selective serotonin reuptake inhibitor antidepressant and high-prescription-volume drug, is excreted unchanged or as a glucuronide from the human organism. Little is known about its fate in sewage treatment plants. Effects of fluoxetine on life-cycle parameters of the midge Chironomus riparius, especially development (mean emergence time), emergence, sex ratio, and fecundity, were...

Chironomus riparius larvae (3rd-4th instar) were extremely resistant to waterborne Cd with 48h LC50s of 331 mg Cd/L in soft water (10 mg/L Ca CO(3)) and 1106 mg Cd/L in moderately hard (140 mg CaCO(3)/L) water. Unexposed larvae had whole body Ca and Na concentrations of 11.2(0.3) and 84.5(3.0) micromol/g, respectively. The larvae exposed through acute toxicity tests accumulated massive amounts ...

The absence of species in polluted sediments does not necessarily imply exclusion due to toxicity. Other factors, like for instance food availability and oxygen content, could also partly cause their absence. Hence, knowledge of the (combinations of) factors acting on individual organisms is essential in order to understand how populations can persist in polluted sediments. In this study specie...

Field populations of aquatic organisms, particularly those inhabiting flowing waters, likely are exposed to short pulses of pesticides following periods of spray drift, surface runoff, or drain flow. In the present study, we investigated the effect of pulse exposures of a pyrethroid insecticide, esfenvalerate, on survival, development, and reproduction of the midge, Chironomus riparius. The fir...