Water boatman (Hemiptera: Corixidae) faunas in the playa lakes of the southern high plains of Texas
Eleven collection dates were used to sample the population density of corixids in three lake types found on the Southern High Plains of Texas from June 1990 to August 1991. Lakes were designated feedlot, saline, and vegetated according to visual categorization. Abiotic and biotic environmental parameters were sampled in each lake to determine if correlations exist between these parameters and the corixid species population density observed. The parameters measured were turbidity, nitrogen, salinity, and number of plant stems. Seven species of corixids were found during the study. Corisella edulis, Corisella tarsalis and Sigara alternata were well-established in feedlot and vegetated lakes, whereas Trichocorixa reticulata and Trichocorixa verticalis were found in great abundance in saline lakes. Few significant differences were found between the parameters measured and the density of any of the corixid species found in these lakes. Cluster analysis showed that the feedlot lakes were most similar to each other both in species density and the correlation of these species with the measured parameters.