Population Dynamics of Chironomid Larvae (Diptera: Chironomidae) in Earthen Fish Ponds in South-eastern Australia

The chironomid community of ephemeral earthen ponds used to rear juvenile percichthyid fish in southeastern Australia was described for the first time. Seventeen chironomid taxa were collected with genera Chironomus, Polypedilum and Procladius the most common. Chironomid densities reached a maximum of 27,450 ind. m^-2. Polypedilum was most abundant, followed by Chironomus and then Procladius. Polypedilum and Procladius appeared to prefer the shallower sections of the ponds. Approximately 33% of specimens from the “Orthocladiinae spp.” taxal group were encased in a “cocoon” constructed of sand grains. Marked variations in the abundance of chironomid taxa were observed between months and seasons. In the first half of the season (November-December), Chironomus was most abundant and common, whereas in the latter half of the season (January-February) Polypedilum was most abundant. Both Polypedilum and Procladius were more abundant in the first year than in the second year of the study.