Dimorphism in wing length is well known in many insect species. It is generally believed that a trade-off between dispersal and reproduction exists, with the long-winged (LW) morph being a better disperser due to its superior flight capability. The short-winged (SW) morph is less mobile and it is hypothesised that females of this morph invest more of their energy reserves in producing offspring. We determined the variation in body and wing size in the pygmy grasshopper Tetrix subulata (Orthoptera: Tetrigidae). The results of the morphological study support the occurrence of two clearly distinct wing morphs in both sexes. SW individuals, especially males, were smaller and in accord with proposed developmental instability showed greater variability in body size than LW individuals. Using data for 700 wild-caught individuals from 10 populations, we demonstrate a variable frequency in the percentage of LW individuals, ranging from all-LW to all-SW populations, even if the LW morph is by far the most common morph in an area. The male-biased percentage of LW individuals recorded in intermediate populations supports a difference in the dispersal reproduction trade-off between the sexes., Anja Steenman, Arne W. Lehmann, Gerlind U. Lehmann., and Obsahuje seznam literatury
Body size is a standard criterion of quality control in insect rearing and often assumed to correlate with fitness in parasitoid wasps, but various metrics of body size can be used. The purpose of this study was to determine which morphological feature provides the best correlation with body size and egg load in a thelytokous population of the parasitoid wasp, Lysiphlebus fabarum (Marshall), when reared on Aphis fabae Scopoli under standardized conditions in a growth chamber (21 ± 1°C, 60–70% RH, and 16L : 8D). Candidate metrics included head width, length and width of the pronotum, length and width of the right forewing, and length of the right hind tibia. In the first experiment, correlations were determined between these measurements and overall wasp body length. As head width and hind tibia length emerged as the most suitable proxies for total body length, the next experiment these two variables as proxies for egg load in females reared from different nymphal instars of the host aphid. There was a non-linear relationship between body size and egg load of wasps emerging from hosts parasitized in different nymphal instars. Egg load increased linearly with body size across all host growth stages, but the second nymphal instar was the most suitable stage for parasitism when speed of development was factored in. The results suggest that head width is a suitable morphometric for monitoring quality control in mass-reared cultures of this wasp., Mohammad Ameri ... [et al.]., and Obsahuje seznam literatury
Mravenec lužní (Liometopum microcephalum) dosahuje na jižní Moravě (v jihovýchodních Čechách) severozápadní hranice svého rozšíření, a druhu se tak dostávalo velké pozornosti mezi českými přírodovědci. Mnohé informace publikované v literatuře nebo na internetu však jsou spíše mýty než fakta. O areálu druhu se často uvádí, že se rozkládá od Iberského poloostrova do východní Evropy a nejzápadnější části Asie, někdy dokonce až na ruský Dálný východ. Ve skutečnosti neexistují žádné doklady o historickém ani současném výskytu mravence lužního na západ od Alp (severní Itálie). Populace na Dálném východě byla již před dlouhou dobou odlišena jako samostatný druh. Článek detailně popisuje historické a současné rozšíření tohoto mravence na jižní Moravě. Ačkoli jde o nejsevernější populaci druhu, populace na Ukrajině a v Rusku dosahují téměř stejné zeměpisné šířky. Mravenec lužní kolonizuje staré, ale živé stromy s dutinami, zpravidla duby, v lesích i mimo les. Na severní hranici svého areálu dává jednoznačně přednost lužním stanovištím, na jihu je preferuje mnohem méně. Jasné doklady uváděné ochrany hnízdních stromů mravenčími koloniemi scházejí. Přes protichůdné názory publikované v literatuře tvoří trofobióza významnou součást potravní strategie druhu, ale stanovení důležitosti jednotlivých složek potravy stále chybí. Druh se vyznačuje jasným polymorfismem dělnic, ale stupeň polymorfismu se liší mezi koloniemi, mění se v průběhu roku a také závisí na podmínkách prostředí, jako je přítomnost silných kompetitorů. Mnohé otázky týkající se biologie a ekologie mravence lužního zatím zůstávají nezodpovězeny., The arboricolous ant Liometopum microcephalum, which reaches the north-western edge of its range in South Moravia (south-eastern Czechia), has been receiving substantial attention by Czech naturalists. However, many pieces of information presented in the literature or on the internet are more myth then fact. Its range is often reported to reach from the Iberian Peninsula to Eastern Europe and western-most Asia, sometimes even to the Russian Far East. In fact, there is no evidence of its historic or present occurrence west of the Alps (northern Italy). The Far Eastern population has been recognized as a separate species a long time ago. The historic and current range in South Moravia is described in detail. Although being indeed the northern-most population of the species, populations in the Ukraine and Russia reach almost the same latitude. Old but living trees with cavities, mostly oaks, are colonized both in and outside of forests. There is a clear preference for alluvial habitats in the northern part of its range, much less so in the south. There is hardly any evidence for the reported protection of nest trees by its ant colonies. Despite contrary opinions published, trophobiosis is an important part of the species’ foraging behaviour, but an assessment of the importance of different components of its diet is still lacking. Worker polymorphism is apparent but its degree varies among colonies and changes in the course of the year and also mirrors environmental variables such as the presence of strong competitors. Many questions regarding the species’ biology and ecology remain open., and Jiří Schlaghamerský, Lenka Petráková.
Muchničky jsou známy v mnoha oblastech jako trapiči člověka i dobytka, ale také jako přenášeči parazitárních onemocnění, z nichž nejvýznamnější je říční slepota. Muchnička Simulium colombaschense byla v minulosti považována za jeden z nejnebezpečnějších druhů v rámci čeledi, protože na následky napádaní samičkami tohoto druhu uhynuly na Balkánském polostrově desetitisíce kusů dobytka. V současnosti se však zdá, že může být považována za ohrožený druh, především v důsledku regulace velkých řek. Podle předběžných výsledků analýzy polytenních chromozomů představuje S. colombaschense komplex druhů s menšími areály. Typová lokalita druhu S. colombaschesne byla zničena po přehrazení Dunaje v oblasti Železných vrat a následně z této oblasti postupně zmizelo i S. colombaschense. Podobný osud může v blízké době postihnout, nebo už postihl také další blízce příbuzné druhy z tohoto komplexu., Black flies (Simuliidae) are known in several areas as pests to humans and cattle, but also as transmitters of parasitic diseases, among which river blindness is the most important. In the past, the black fly Simulium colombaschense was considered to be one of the most dangerous species of the family, because it caused the death of tens of thousands of cattle in the Balkan peninsula. However, at present it seems that it can be considered an endangered species, especially due to large river regulation. Moreover, according to preliminary analysis of polytene chromosomes S. colombaschense is a complex of species with smaller distribution areas. The type locality of S. colombaschense was destroyed after the Danube was dammed in the Iron Gate region and subsequently S. colombaschense disappeared from this area. In the near future the same might possibly happen, or has already happened as to other species from this complex., and Tatiana Brúderová, Matúš Kúdela.
Muga silkworm (Antheraea assamensis Helfer) is endemic to Assam and adjoining areas in North-Eastern India, and naturally produces golden silk. From time immemorial, many ethnic and tribal groups have produced muga silk. Muga silkworms are mostly wild unlike the mulberry silkworm, which is completely domesticated. The muga silkworm is a single species with little genetic variation among populations, survives harsh climatic conditions and is subject to various diseases, pests and predators. Due to the high incidence of disease and natural enemies, and variations in climatic conditions, the production of muga silk has recently declined dramatically. In order to improve the productivity of this silkworm it is important to have a better knowledge of both its host plants and biology. Lack of knowledge of its genetics and host plants is a major bottleneck. This paper reviews various aspects of muga silkworm culture, including the availability of different populations, and methods used to select for improvement in survival, cocoon yield, disease resistance, conservation and egg production., Amelendu Tikader, Kunjupillai Vijayan, Beera Saratchandra., and Obsahuje seznam literatury
In social insects, the high variability in the number of queens per colony raises fundamental questions about the evolution of altruism. It is hypothesized, for instance, that nestmate recognition should be less efficient in polygynous than in monogynous colonies because the presence of several breeders increases the diversity of genetically determined recognition cues, leading to a less specific colonial signature. Recent studies, however, have shown that the link between the number of queens in a colony and the recognition abilities of its members is more complex than previously suggested. Here, we studied intraspecific aggression, diversity of potential recognition cues and genetic structure of colonies in the highly polygynous ant Crematogaster pygmaea. Our results reveal that workers of this species are clearly aggressive towards non-nestmates in field experiments but not in more artificial bioassays conducted in Petri dishes, underscoring the importance of context-dependent aspects of the assessment of nestmate recognition. Behavioural, genetic and chemical data show that C. pygmaea is a multicolonial species, forming spatially restricted and well-defined entities. Therefore, the postulated negative correlation between recognition ability of workers and queen number in a colony is not supported by the results of this study., Rachid Hamidi ... [et al.]., and Obsahuje seznam literatury
Můrovití (Noctuidae) představují po obalečovitých (Tortricidae) druhou největší čeleď motýlů v České republice. Dosud bylo na našem území zaznamenáno kolem 430 druhů, ale mnohé z nich se zde nevyskytují trvale. Můrovití jsou obvykle velmi dobří a pohybliví letci, často mají tendenci kolonizovat nová území. Řada druhů žijících v jiných částech Evropy byla zaznamenána pouze v jednom nebo omezeném počtu exemplářů (zhruba 20 druhů), jiné jsou pravidelnými migranty (13 druhů), někteří zástupci se v současnosti šíří (asi 10 druhů), zatímco jiní jsou na ústupu (5–6 druhů), nebo mají proměnlivou hranici areálu. V článku naleznete příklady druhů z uvedených skupin, s diskuzí současného nebo historického stavu., Owlet moths (Noctuidae) are after leafrollers (Tortricidae) the second largest family of butterflies and moths in the Czech Republic. So far, about 430 species have been recorded, but many of them do not occur permanently in the area. Owlet moths are usually very good and highly mobile fliers, often with a tendency to colonize new territories. Some species living in other parts of Europe have been registered in only one or a limited number of individuals (about 20 species), others are regular migrants (13 species). While some species are currently spreading (about 10 species), others are retreating (5–6 species), or the boundaries of their ranges are unstable. Examples of these groups are given and discussed., and Zdeněk Laštůvka, Aleš Laštůvka.
The mechanism of sex determination is common for all honeybee species (Apis spp.) by the complementary sex determination (csd) gene. The csd gene has been studied in the Western honey bee (Apis mellifera L.), the Eastern honey bee (Apis cerana F.) and the giant honey bee (Apis dorsata F.), whereas no studies had been conducted on the high altitude Himalayan or black giant honey bee, Apis laboriosa Smith. In the present study, we cloned the genomic exon 6 to exon 9 region of the A. laboriosa csd gene, and identified 13 csd haplotypes. The data was analyzed and compared with the other aforementioned three honeybee species. The results showed that, as with the other three Apis species, region 3 of the csd gene contains an RS domain at the N terminal, a proline-rich domain at the C terminal, and a hypervariable region in the middle. A phylogenetic tree showed that the csd haplotypes from A. laboriosa fell into one clade with those from A. dorsata, and were separated from those from the other two species, A. mellifera and A. cerana. The network map also showed that the csd haplotypes from A. laboriosa and A. dorsata are well mixed among each other, and do not form two separate branches. Pairwise Fst analysis revealed that the value between A. laboriosa and A. dorsata was very low (0.098), confirming a close relationship to exist between them., Huan Wang ... [et al.]., and Obsahuje seznam literatury
Endosymbiotic organisms are known to manipulate the reproductive biology of their hosts. Incomplete prevalence of endosymbiont inducing thelytokous parthenogenesis results in the coexistence of sexual and asexual individuals, and could account for the maintenance of sexual reproduction in certain populations or species. In the parasitoid Venturia canescens, arrhenotokous ("sexual") and thelytokous ("asexual") individuals occur sympatrically. We aimed to determine whether endosymbionts are implicated in the thelytoky of V. canescens. After screening females of the two reproductive modes for several reproductive parasites: bacteria (Wolbachia, Rickettsia, Bacteroidetes, Spiroplasma, Arsenophonus) and Microsporidia, we concluded that thelytoky in V. canescens is not induced by any of these parasites and confirmed its suitability as a biological model for solving the evolutionary enigma of the maintenance of sexual reproduction., Vincent Foray ... [et al.]., and Obsahuje seznam literatury