Spektrum mandelinek rodu Oulema v porostech ozime psenice a jarniho jecmene v okoli Brna

The aim of this PhD Thesis was to study the species spectrum of the chrysomelid genus Oulema in Brno environment. On observed fields the following species of the genus Oulema were found: O. melanopus, O. rufocyanea and O. gallaeciana. O. rufocyanea was recorded from in field conditions in the Czech Republic for the first time. The most numerous was O. gallaeciana, followed by O. melanopus and O. rufocyanea. The sex ratio was in favour of males, only in one case the sex ratio was equal. The beginning of insect invasion into the growths of winter wheat corresponded to TS6 = 110oC. The maximum occurence of Oulema-species was included in TS6 = 149 - 250oC. This results show that in optimal weather conditions the maximal abundance can occur earlier than is cited in the literature (TS6 = 200 - 250oC). On the contrary, the limit TS6 = 400oC for monitoring of larvae was verified. The occurence of each species of the genus Oulema was evaluated by means of analysis of variance, while the Tukey test was used to asses group homogenity. The statistically significant difference (p < 0,01) were proved for feeding plant, species of leaf beetles and the date of sweeping and next for all interactions. Only the interaction of species of leaf beetle x the date of sweeping, was found significantly different (p < 0,05). During the three years period the females of O. melanopus with mature eggs were observed in winter wheat for 16 to 48 days, the females of O. gallaeciana for 40 to 52 days and the females of O. rufocyanea for 14 - 23 days. The same characteristics were observed in the growths of spring barley - the females of O. melanopus for 21 to 37 days, the females of O. gallaeciana for 30 to 47 days and the females of O. rufocyanea for 1 - 25 days. In the first sampling event which corresponded with the first infestation of Oulema species in winter wheat, the females with mature eggs were not found. On the other hand, in growths of spring barley, where the sampling started at the beginning of shotting stage, the females were in the third and the fourth stages of oogenesis. Distinguishing O. melanopus and O. rufocyanea according to external morphological characteristics is considered as uncertain. Totally 469 specimens of O. melanopus and 114 specimens of O. rufocyanea were measured. The ratio of some characteristics was studied: ratio of body length to elytra length, ratio of body length to pronotum length, ratio of elytra length to elytra width, ratio of body length to length of antennae, ratio of pronotum length to pronotum width and ratio of the second to the third antennomeres. Only the ratio of body length to length of antennae and the ratio of the second to the third antennomeres were found to be statistically significantly differenct for both sexes. To separate these two species, the shape of male and female genitalia showed to be the most reliable identification characteristicAvailable from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi