Population Growth Curves of Adults of Hippodamia Convergens And Olla V-Nigrum (Coleoptera: Coccinellidae)

Abstract

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: Y₁(T, PP)=1.058e+02-1.300e+01* T-7.817e-01^* PP+4.058e-01* T²+1.037e-02* PP²+3.922e-02*T PP-5.360e-04*T PP² Y₂(T, PP) = 1.246e + 02-1.761e+01*T - 8.349e-01* PP+6.359e - 01*T² + 6.767e-02* PP² - 1.166e-02*T PP-2.865e-04*TPP² where T is the average monthly standard temperature, PP is the average monthly accumulated rainfall and Y₁ and Y₂ 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 (θ= 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° 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.