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Reactions of avian predators to automimicry in milkweed bugs (Heteroptera: Lygaeidae):
Stránská, Anna ; Exnerová, Alice (advisor) ; Baňař, Petr (referee)
Automimicry, or intraspecific variation in defence mechanisms in aposematic prey, is very common in nature. Especially in chemically protected prey. This study contains two experiments. The first experiment investigated the reaction of naive predators, which were Great tits (Parus major), to automimetic prey. The prey was the black-and-red-bug (Lygaeus equestris). The tits were divided into three experimental groups and each group was presented with three bugs that were fed on an artificial diet with different amounts of cardenolides. The control group was presented with prey that had no cardenolides in the diet. The group tested with the low concentration received bugs that fed on a diet with a low concentration of cardenolides and the group tested with the high concentration received bugs that fed on a diet with a high concentration of cardenolides. In a generalization test, all groups were then offered a single firebug (Pyrrhocoris apterus). It was found that the group tested with the high concentration experienced a higher rate of aversive learning. This group also killed and consumed fewer firebugs than the other two groups. The group tested with high concentration generalized most to novel red-and-black prey because they were least likely to attack the firebug. The second experiment tested...
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Reactions of predators towards species of red-and-black mimetic complex
Kotlíková, Lucie ; Exnerová, Alice (advisor) ; Baňař, Petr (referee)
The red-black mimetic complex in the Western Palaearctic region includes a large number of arthropod species. These species differ in the degree of their mimetic resemblance, as well as in defensive mechanisms and their effectiveness against various predators. This study is based on two experiments. The first experiment was carried out with adult great tits (Parus major) and artificial prey (photographs). The birds were divided into two experimental groups and were trained to discriminate between palatable and unpalatable prey. One group was trained with higher diversity in the coloration of unpalatable prey (ten species of subfamily Lygaeinae), while the other was trained with low diversity in the coloration of palatable prey (ten individuals of the same species, Lygaeus equestris). After ten learning blocks, two generalization blocks followed, in which both groups received the same prey that was completely different from the prey during learning phase. The rate of learning was not significantly different between the two groups. However, more effective generalization was observed in the group trained with higher prey diversity. However, this trend was only observed in the first generalization block. On the second day, both groups achieved similar generalization success. The second experiment was...
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Review of present knowledge of the external male and female genitalia in Pyrrhocoroidea (Heteroptera)
Mazáčková, Nikola ; Kment, Petr (advisor) ; Baňař, Petr (referee)
Superfamily Pyrrhocoroidea with its about 670 species in 71 genera is one of the smaller groups within the true bugs (Hemiptera: Heteroptera: Pentatomomorpha). The common characteristics for these bugs are aposematic coloration and absence of ocelli. Most of the species are phytophagous and some are of economic importance as cotton stainers. The superfamily is further subdivided into two families, Pyrrhocoridae and Largidae, whose phylogenetic relatioships have been a subject of only few studies so far. To help resolve this problem, both molecular and morphological phylogenetic studies are needed. Among the morphological characters of importance are external genitalia of both sexes. This thesis gives a short overview of the current phylogeny of Pyrrhocoroidea. Its main focus is on the morphology of external male and female genitalia, which is summarized and characterized for each genus, and points out some essential differences between the taxa. A table uniting terms used for the particular structures of genitalia by different authors is included.
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Mechanisms and effectiveness of antipredatory defences within red-and-black mimetic complex
Kotlíková, Lucie ; Exnerová, Alice (advisor) ; Baňař, Petr (referee)
Strikingly coloured species can form mimetic complexes. One of them is an extensive black-and-red mimetic complex in the Palearctic region. It consists of representatives across arthropod taxa with different levels of defense and investment in it. To describe individual mimetic relationships in this complex, it is necessary to know the effectiveness of these defense mechanisms against predators. Reactions of individual predators vary considerably. Differences in reactions primarily depend on the ability to perceive some components of defense, using sensory and cognitive abilities. Mechanisms and effectiveness of antipredatory defence are the subject of numerous studies, but there is still a lack of description of some mechanisms among many representatives forming this mimetic complex. For this reason, further studies are needed to allow the derivation of mimetic relationships prevailing in this mimetic complex in the future. Keywords: mimicry, aposematism, antipredatory defense, colouration, mimetic complex
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Taxonomy of Oriental Enicocephalidae (Heteroptera: Enicocephalomorpha) and morphological novelties of new taxa.
Baňař, Petr
The infraorder Enicocephalomorpha represents the basalmost group of Heteroptera, the sister group of all remaining Heteroptera (= Euheteroptera) (ŠTYS 1989). The infraorder, whose unique phylogenetic position was recognized by most modern authors (ŠTYS & KERZHNER 1975), is currently divided into two families, Aenictopecheidae and Enicocephalidae. Some new taxa are described (Results: Parts A-H) and special attention is paid to newly discovered or overlooked morphological characters of the group, some of them important for all the Heteroptera. In Part A is described first member of worldwide distributed genus Systelloderes from the Oriental region, S. loebli Štys & Baňař, 2007 and the term neopatella is established for for sclerites within the femoro-tibial intersegmental membrane. Xenicocephalus josifovi Štys & Baňař, 2008 is described in Part B, representing first known complete adult of this peculiar genus. Unique type of raptorial foreleg among all Enicocephalomorpha is described and illustrated and its function by predation is assumed. In Part C is described new genus Phaenicocleus Štys & Baňař, 2009 from northern Borneo, based on males of three species. New diagnostic characters in Enicocephalomorpha are used. Phaenicocleus granulosus Baňař & Štys, 2011 is described in Part D, based on the...
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Taxonomy of Oriental Enicocephalidae (Heteroptera: Enicocephalomorpha) and morphological novelties of new taxa.
Baňař, Petr ; Štys, Pavel (advisor) ; Papáček, Miroslav (referee) ; Heiss, Ernst (referee)
The infraorder Enicocephalomorpha represents the basalmost group of Heteroptera, the sister group of all remaining Heteroptera (= Euheteroptera) (ŠTYS 1989). The infraorder, whose unique phylogenetic position was recognized by most modern authors (ŠTYS & KERZHNER 1975), is currently divided into two families, Aenictopecheidae and Enicocephalidae. Some new taxa are described (Results: Parts A-H) and special attention is paid to newly discovered or overlooked morphological characters of the group, some of them important for all the Heteroptera. In Part A is described first member of worldwide distributed genus Systelloderes from the Oriental region, S. loebli Štys & Baňař, 2007 and the term neopatella is established for for sclerites within the femoro-tibial intersegmental membrane. Xenicocephalus josifovi Štys & Baňař, 2008 is described in Part B, representing first known complete adult of this peculiar genus. Unique type of raptorial foreleg among all Enicocephalomorpha is described and illustrated and its function by predation is assumed. In Part C is described new genus Phaenicocleus Štys & Baňař, 2009 from northern Borneo, based on males of three species. New diagnostic characters in Enicocephalomorpha are used. Phaenicocleus granulosus Baňař & Štys, 2011 is described in Part D, based on the...
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Taxonomy of Oriental Enicocephalidae (Heteroptera: Enicocephalomorpha) and morphological novelties of new taxa.
Baňař, Petr
The infraorder Enicocephalomorpha represents the basalmost group of Heteroptera, the sister group of all remaining Heteroptera (= Euheteroptera) (ŠTYS 1989). The infraorder, whose unique phylogenetic position was recognized by most modern authors (ŠTYS & KERZHNER 1975), is currently divided into two families, Aenictopecheidae and Enicocephalidae. Some new taxa are described (Results: Parts A-H) and special attention is paid to newly discovered or overlooked morphological characters of the group, some of them important for all the Heteroptera. In Part A is described first member of worldwide distributed genus Systelloderes from the Oriental region, S. loebli Štys & Baňař, 2007 and the term neopatella is established for for sclerites within the femoro-tibial intersegmental membrane. Xenicocephalus josifovi Štys & Baňař, 2008 is described in Part B, representing first known complete adult of this peculiar genus. Unique type of raptorial foreleg among all Enicocephalomorpha is described and illustrated and its function by predation is assumed. In Part C is described new genus Phaenicocleus Štys & Baňař, 2009 from northern Borneo, based on males of three species. New diagnostic characters in Enicocephalomorpha are used. Phaenicocleus granulosus Baňař & Štys, 2011 is described in Part D, based on the...
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