Fylogeografie a ekologie štěnic rodu Cimex (Heteroptera: Cimicidae) v Evropě; evoluce taxonů a hostitelské specializace

The life strategies of parasites and evolutionary mechanisms forming their diversity are particularly various and become frequent objects of study. The Ph.D. thesis deals with one of the obligate ectoparasitic haematophagous groups of insects, the species of the genus Cimex (Heteroptera: Cimicidae). Unlike in most other ectoparasites, the strategy of cimicids consists of remaining hidden in the shelter of their host. They use the host body only to feed and disperse. The advantage of the lower competition with other ectoparasites is counterbalanced by the need for particularly stable blood source, for which the cimicids choose social hosts living in colonies. The most frequent and the original hosts of cimicids are bats. The host range of particular species of Cimicidae is often rather broad. The morphological analysis of the Cimex pipistrelli species group showed, however, differentiation according to host bat species. This suggests a need for adaptation to particular host species within the usual range. The differentiation was not found reflected in the mitochondrial DNA. It is thus possible that cimicids can exhibit phenotype plasticity. The host associated morphological variability likely caused as many as three species of C. pipistrelli group to be described from Europe, from which two were...U parazitických organismů lze pro jejich komplexní vztah s hostitelem nalézt neobvyklé a zajímavé mechanismy diverzifikace a speciace. Štěnice rodu Cimex (Heteroptera: Cimicidae) jsou jedna z obligátně ektoparazitických krevsajících skupin hmyzu. Na rozdíl od většiny ektoparazitů štěnice zaujaly strategii skrytého života v úkrytu hostitele, jehož tělo využívají pouze k potravě a transportu. Výhodu vyhnutí se konkurenci s jinými ektoparazity vyvažuje potřeba zvláště stabilního zdroje potravy, pro nějž si štěnice vybírají sociální hostitele žijící v koloniích. Nejčastějšími a také původními hostiteli štěnic jsou netopýři. Spektrum hostitelů jednotlivých druhů je často spíše široké. Morfologická analýza skupiny druhů Cimex pipistrelli ovšem prokázala rozdíly mezi štěnicemi z různých druhů netopýrů a poukázala tak na potřebu určité míry adaptace na jednotlivé hostitele. Mitochondriální DNA ale rozdíly v morfologii nereflektovala. Takto podmíněná morfologická variabilita zřejmě stála za popisem celkem tří evropských druhů skupiny C. pipistrelli, z nichž dva byly prokázány za neplatné. Štěnice jsou schopné sát na hostitelích značně vzdálených od zástupců jejich obvyklého hostitelské spektra. Dlouhodobé přežití ale vyžaduje velkou míru přizpůsobení, jehož vývoj může být v konfliktu s tokem genů z populací...Department of ZoologyKatedra zoologieFaculty of SciencePřírodovědecká fakult

Reproductive Compatibility among Populations and Host‐Associated Lineages of the Common Bed Bug (\u3cem\u3eCimex lectularius\u3c/em\u3e L.)

As populations differentiate across geographic or host‐association barriers, interpopulation fertility is often a measure of the extent of incipient speciation. The bed bug, Cimex lectularius L., was recently found to form two host‐associated lineages within Europe: one found with humans (human‐associated, HA) and the other found with bats (bat‐associated, BA). No unequivocal evidence of contemporary gene flow between these lineages has been found; however, it is unclear whether this is due to an inability to produce viable “hybrid” offspring. To address this question and determine the extent of compatibility between host‐associated lineages, we set up mating crosses among populations of bed bugs based on both their host association (human—HA vs. bat—BA) and geographic origin (North America vs. Europe). Within‐population fecundity was significantly higher for all HA populations (\u3e 1.7 eggs/day) than for BA populations (\u3c 1 egg/day). However, all within‐population crosses, regardless of host association, had \u3e 92% egg hatch rates. Contrary to previous reports, in all interlineage crosses, successful matings occurred, fertile eggs were oviposited, and the F1 “hybrid” generation was found to be reproductively viable. In addition, we evaluated interpopulation genetic variation in Wolbachia among host‐associated lineages. We did not find any clear patterns related to host association, nor did we observe a homogenization of Wolbachia lineages across populations that might explain a breakdown of reproductive incompatibility. These results indicate that while the HA and BA populations of C. lectularius represent genetically differentiated host‐associated lineages, possibly undergoing sympatric speciation, this is in its incipient stage as they remain reproductively compatible. Other behavioral, physiological, and/or ecological factors likely maintain host‐associated differentiation

Phylogeography and ecology of the Cimex species (Heteroptera: Cimicidae) in Europe; the evolution of taxa and specialization of hosts

The life strategies of parasites and evolutionary mechanisms forming their diversity are particularly various and become frequent objects of study. The Ph.D. thesis deals with one of the obligate ectoparasitic haematophagous groups of insects, the species of the genus Cimex (Heteroptera: Cimicidae). Unlike in most other ectoparasites, the strategy of cimicids consists of remaining hidden in the shelter of their host. They use the host body only to feed and disperse. The advantage of the lower competition with other ectoparasites is counterbalanced by the need for particularly stable blood source, for which the cimicids choose social hosts living in colonies. The most frequent and the original hosts of cimicids are bats. The host range of particular species of Cimicidae is often rather broad. The morphological analysis of the Cimex pipistrelli species group showed, however, differentiation according to host bat species. This suggests a need for adaptation to particular host species within the usual range. The differentiation was not found reflected in the mitochondrial DNA. It is thus possible that cimicids can exhibit phenotype plasticity. The host associated morphological variability likely caused as many as three species of C. pipistrelli group to be described from Europe, from which two were..

Revision of the central European cimex species (Heteroptera: Cimicidae)

Department of ZoologyKatedra zoologiePřírodovědecká fakultaFaculty of Scienc

Posouzení průtokových poměrů jezů a derivačních kanálů na Teplé Vltavě

Hlavním cílem prací je stanovení průtokového režimu na jezu a derivačním kanálu pro zajištění potřebného průtoku pro provoz rybích přechodů. Přesným místem měření je koruna jezu a derivační kanál pro MVE, v místě odbočení derivačního kanálu z hlavního toku. Na základě provedených měření budou následně vypočítány konsumpční křivky, které jsou hlavním výstupem prací. Dále bude stanovena kontrolní úroveň hladiny prostoru nad jezem, za které je zajištěna funkce rybího přechodu. Práce roku 2005 navazují na práce provedené v roce 2004 (viz e4/97/04)

Age-related mating rates among ecologically distinct lineages of bedbugs, Cimex lectularius

Abstract Understanding how many mates an animal has in its lifetime is a critical factor in sexual selection. At the same time, differences in an organism's ecology, such as the quantity and quality of food, could be reflected in different mating rates. Mating rate had a significant effect on female net fitness (i.e., lifetime offspring production), however, laboratory measurements cannot well mirror the situation in wild. The common bedbug (Cimex lectularius) is a well-established model for studying traumatic insemination and sexual conflict. The species comprises two host lineages that feed on bats (BL) or humans (HL). HL can constantly feed on human hosts throughout the year, while BLs feed only during summer months when their bat hosts occupy the roosts. Because mating in female bedbugs is closely linked to foraging, this system provides a valuable model to study mating variation in the field. We established a new method for estimating age-dependent mating rates of females in the wild by relating the fluorescent pigment accumulation in the eyes of females to the number of mating scars that manifest as melanized spots caused by the injection of sperm through the wall of the female abdomen by the male into the spermalege. In addition, using laboratory bedbugs we found that three and a half observed matings on average lead to one observed melanized mating scar. Although young BL and HL females (with low pteridine concentrations) did not differ in the number of matings, the mating rate increased with age only in HL but not in BL females. We sampled on average older BL than HL females. The lack of access to food (bat blood) during winter could explain the lack of increase in the number of scars with age in BL. In species where mating leaves visible marks, using fluorescent pigments to determine female age (applicable to most arthropods) could be an important tool to study sexual selection and mating rate in the wild. The method can help formulate sustainable and biologically lucid approaches for their control

Data from: Host association drives significant genetic divergence in the bed bug, Cimex lectularius

Genetic differentiation may exist among sympatric populations of a species due to long-term associations with alternative hosts (i.e., host-associated differentiation). While host-associated differentiation has been documented in several phytophagus insects, there are far fewer cases known in animal parasites. The bed bug, Cimex lectularius, a wingless insect, represents a potential model organism for elucidating the processes involved in host-associated differentiation in animal parasites with relatively limited mobility. In conjunction with the expansion of modern humans from Africa into Eurasia, it has been speculated that bed bugs extended their host range from bats to humans in their shared cave domiciles throughout Eurasia. C. lectularius that associate with humans have a cosmopolitan distribution, whereas those associated with bats occur across Europe, often in human-built structures. We assessed genetic structure and gene flow within and among populations collected in association with each host using mtDNA, microsatellite loci, and knock-down-resistance gene variants. Both nuclear and mitochondrial data support a lack of significant contemporary gene flow between host-specific populations. Within locations human-associated bed bug populations exhibit limited genetic diversity and elevated levels of inbreeding, likely due to human-mediated movement, infrequent additional introduction events per infestation, and pest control. In contrast, populations within bat roosts exhibit higher genetic diversity and lower levels of relatedness, suggesting populations are stable with temporal fluctuations due to host dispersal and bug mortality. In concert with previously published evidence of morphological and behavioral differentiation, the genetic data presented here suggest C. lectularius is currently undergoing lineage divergence through host-association

Přesné stanovení průtokového režimu na jezu a derivačním kanálu pro provoz rybích přechodů:Posouzení průtokových poměrů jezů a derivačních kanálů na Teplé Vltavě

Cílem studie je přesné proměření a posouzení průtokových poměrů jezů a derivačních kanálů pro zajištění dostatečné funkce rybích přechodů. Pro stanovení měrných křivek jezů a derivačních kanálů bylo provedeno měření v následujících profilech: Františkov, Borová Lada, Zahrádky I, Zahrádky II, Polka, Račí, Zátoň. V roce 2004 byly na cílových objektech získány dvě sady měření. Bylo možné konstatovat, že současný manipulační řád nebo přesněji aktuální průtokové poměry na sledovaných objektech negativně ovlivňují funkci rybích přechodů