Population growth curves of adults of Hippodamia convergens and Olla v-nigrum (Coleoptera: Coccinellidae)

Population growth curves in two predator species in the region of Irapuato, Guanajuato, Mexico, were estimated using multivariate multiple regression techniques through third-degree polynomials functions defined by: Y-1(T,PP) = 1.058e+02 - 1.300e+01*T - 7.817e-01*PP + 4.058e-01*T-2 + 1.037e-02*PP2 + 3.922e-02*T*PP - 5.360e-04*T*PP2 Y-2(T,PP) = 1.246e+02 - 1.761e+01*T - 8.349e-01*PP + 6.359e-01*T-2 + 6.767e-02*PP2 - 1.166e-02*T*PP - 2.865e-04*T*PP2 where T is the average monthly standard temperature, PP is the average monthly accumulated rainfall and Y-1 and Y-2 are the numbers of Hippodamia convergens and Olla v-nigrum adults, respectively. The Roy criterion was used in the multivariate analysis of variance of the multivariate multiple regression, which statistical test value was 80.379 with a probability for its corresponding approximation F of 0.0001295, consequently, the estimated polynomials for the population growth curves were adequate. Multivariate association measures Wilks (ALH = 0.987978) and Roy (theta = 0.9877118) were calculated, allowing estimation of growth curves as prediction tools. These models of polynomial growth curves were compared to each other through the statistic W = 1978.3, which yielded a probability value P = 0**, concluding that the growth curves were different. The critical point for temperature and rainfall in both species coincided with the point (13.7 degrees C, 2.0 mm), in which the maximum numbers of individuals were obtained, resulting 3.4 to H. convergens and 2.2 for O. v-nigrum.