CORIXIDS (HEMIPTERA) IN LA GOLETA RESERVOIR, ESTADO DE MEXICO AND THEIR RELATIONSHIPS WITH SOME ENVIROMENTAL PARAMETERS

The Corixidae family is analyzed at La Goleta reservoir, Estado de Mexico and their relationships with some environmental parameters during May 2007 and April 2008, locating three littoral stations of sampling, taking in each one, original and five replica at intervals of one hour. Were determined: depth, transparency, temperature, oxygen, pH, conductivity, hardness and alkalinity. The corixids were captured with network of spoon. Were evaluated diversity, maximum diversity, evenness and dissimilarity. Four corixids species were registered in 2007: Trichocorixella mexicana, Graptocorixa abdominalis, Krizousacorixa femorata and Trichocorixa parvula, being the one last a new registry for the zone. In 2008 two species only were registered: T mexicana and G. adominalis. The greater diversity values and maximum diversity appeared in 2007 (0.7108 and 1.9997, respectively); whereas evenness was smaller in this period (0.3354). The second period registered smaller values of diversity and maximum diversity (0.6025 and 0.9998, respectively) and evenness was greater (0.6026). The dissimilarity analysis showed differences in both periods due to the fluctuations in the abundance of this familiy. We concluded that the conditions in the reservoir have been modified remarkably making descend the diversity values and the abundance from these organisms.