Dispersion of Epiphytic Chironomid Larvae and the Probability of Random Colonization

Dispersion of chironomid larvae between and within stands of the aquatic macrophyte Ranunculus penicillatus var. calcareus was studied by sampling individual leaves of Ranunculus. Two of the six common species exhibited no variation in density between sites, while others had significant variations. A new probability density function was applied to the data and it was revealed that random colonization was not uncommon among these epiphytic larvae. It was suggested that stochastic factors are of some importance in the system under study.