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Role of wings in reproduction of cockroach Eublaberus distanti (Blattodea: Blaberidae)
Kotyk, Michael ; Kotyková Varadínová, Zuzana (advisor) ; Štys, Pavel (referee)
Regardless the wings and active flight are recognized as one of the most iconic innovations in insects, a great number of their representatives exhibit wing reduction. In many cases only females lose the wings while males not. It is usually believed that lower investments into wings and wing muscles save energy for reproductive gain in females. Cockroaches are the insect order with one of the highest occurrence of forms with reduced wings andspecies exhibiting sexual wing dimorphism, and thus are a good model group for testing the hypotheses concerning the wing reduction. For our experiments we chose macropterous cockroach Eublaberus distanti and manipulated with the length of its wings.Contrary to common assumption, we did not find any significant difference in fecundity between apterous and macropterous females. So we conclude that wing presence or absence has no effect on reproduction success of cockroach females. Surprisingly, we have found out that male wings play a substantial role in the courtship ritual of E. distanti. Our results reveal that partial or complete loss of wings severely decreases reproductive success of E. distanti males compared to macropterous conspecifics. We thus conclude that the reason why cockroach males keep their wings while females not is because of their fundamental role in...
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Minor insect groups as pollinators and flower visitors
Jůna, František ; Kotyková Varadínová, Zuzana (advisor) ; Tropek, Robert (referee)
The aim of my bachelor thesis is to review flower-insect interactions in those insect orders which are traditionally recognized as minor groups of insect pollinators. This means Coleoptera, Diptera, Hymenoptera and Lepidoptera orders are excluded. The emphasis is on the occurrence of pollination relationship, but palynivory, nectarivory, flower herbivory and flowers as hunting-site are discussed too. Much of the research is just listing the species which were found on flowers without any deeper study of their relationship with the flower. These non-specified interactions are recognised as flower visitors. Most of this bachelor thesis is about the order of Thrips (Thysanoptera), because of the large number of pollinators in this order. On the other hand many other orders are only mentioned or they even are missing. There is little interaction by some orders, or the interactions are missing or they are unknown. Also fossil flower-insect interactions are mentioned too. Key words Pollination, Thrips, Cockroaches, Lacewings, True bugs, Scorpionflies, Earwigs, Orthoptera, Caddisflies
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Wing reduction in cockroaches (Blattaria)
Kotyk, Michael ; Kotyková Varadínová, Zuzana (advisor) ; Nedvěd, Oldřich (referee)
My bachelor thesis deals with the wing reduction in cockroaches and the causes of its appearance. Order Blattaria is the insect order with the third highest occurrence of apterous and brachypterous species. Yet still only a minimum of publications were performed to cover this topic. Therefore, I analyse in several chapters both the types of wing reduction as well as generally accepted theories explaining the reasons of its evolution in insects. Then I discuss their relevance in the case of order Blattaria. Namely, ecological theories, regarding interactions of insect and its habitat, and physiological theories, describing life history trade- offs and constrains related to wings. I present examples of species to every theory which are probably concerned. There are also examples of species which maintain the macropterous state, although no longer capable of flight and theories that explain the retention of macroptery. As a part of the thesis I have also included a phylogenetic tree of cockroaches with marked wing condition for each sex, which outlines evolutionary trends of individual groups within the order. Keywords: Blattaria, reduction, macroptery, brachyptery, aptery, habitat, life history trade-offs
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Aggregation behaviour of cockroaches (Blattaria: Blaberidae): intraspecific and interspecific preference
Varadínová, Zuzana ; Frynta, Daniel (advisor) ; Janda, Milan (referee)
Cockroaches (Blattaria) are considered to be nearly universally gregarious insect order. In spite of this fact most of the research effort has been devoted to the behaviour of domiciliary species. It is thus not surprising we still do not have comparable information about aggregation behaviour in common laboratory blaberid species. We have investigated aggregation behaviour of adult males and females in six blaberid species: four South American species (Blaberinae: Eublaberus posticus, Eublaberus distanti, Blaberus discoidalis, Blaberus craniifer) and two Madagascar species (Oxyhaloinae: Gromphadorhina portentosa, Princisia vanwaerebeki). Intraspecific aggregation behaviour was determined using two approaches: the binary choice tests arena and free interaction arena tests. Results obtained with both methods were largely consistent. We have found that blaberid clades clearly differed in their aggregation patterns. (1) Females of Eublaberus species aggregated while only a slight and less consistent aggregation tendency was recorded in conspecific males. (2) Both sexes of Blaberus species aggregated, especially when tested in the arena. (3) The Madagascar hissing cockroaches of the Gromphadorhina-Princisia clade are not gregarious, the aggregation tendency was entirely absent in the males of both species and...
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