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
Infrastructure is one of the main causes of landscape fragmentation, which results in isolation and loss of populations. Although the negative effect of roads on insects is well documented, only a minority of studies has focused on roads in the context of barriers to dispersal. Flying species in particular have been neglected. We investigated the effect of a four-lane motorway as a barrier to the movement of an isolated population of the threatened dragonfly Sympetrum depressiusculum in an agricultural landscape in Central Europe. Generalized additive models were used to assess the motorway's effect on (i) the distribution of adult dragonflies in patches of terrestrial habitat surrounding their natal site, and (ii) individual flight behaviour (i.e. willingness or unwillingness to cross the motorway). Movement patterns of marked adults throughout the landscape were also investigated. During one season, significantly fewer adults were found at patches located on the far side of the motorway, indicating it has a barrier effect. Observations on flight behaviour revealed no apparent effect of the motorway. The possible barrier effect for the species studied was therefore presumed to be a consequence of road mortality. Our results indicate that the motorway may influence the dispersal of this threatened species of dragonfly, which is a habitat specialist with particular requirements for its terrestrial environment. Negative effects on other species with similar behaviour and strategy can be presumed. When establishing new habitats, carrying out reintroductions or translocations, it is necessary to consider that roadways may reduce population size and affect population dynamics by limiting dispersal., Hana Šigutová, Filip Harabiš, Michal Hykel, Aleš Dolný., and Obsahuje bibliografii
This contribution presents butterflies with wings on which scales are partially or fully absent, as well as various forms of their cryptic appearance and mimicry and George O. Krizek.
pro učitelstvo, žactvo středních škol a zvláště sběratele motýlů napsal Karel Exler, S 25 rytinami a 20 tab. obsah. 289 obrazů motýlů a housenek dle přírody vyobrazených, and Converted from MODS to DC version 1.8 (EE patch 2018/05/24)
We studied the demography, movement, behaviour and choice of nectar plants by adults of Aporia crataegi. This study was done in a dense network of different types of habitats (total size of study area 16.26 ha) from open landscape to shrubland, the latter being a result of abandonment of traditional agricultural practices such as extensive mowing and grazing. Total population size was estimated to be approximately 1700 and 2700 for females and males, respectively. Median and maximum distances moved by males were 134 and 3493 m, and by females 138 and 3165 m, respectively. The average lifespan was ca. 7.1 and 7.5 days, with maximum recorded lifespans of 21 and 17 days for males and females, respectively. The greater capture probability recorded for males indicates their high activity, as they spend most of their time in flight patrolling and searching for mates. A parabolic recruitment curve and protandry were also recorded. Both sexes are highly mobile. The spatial distribution of both sexes was roughly similar. The adult behaviour differed in different habitats, with more time spent feeding and resting when nectar plants were plentiful and more time spent flying when they were rare. Although adults utilized nine nectar sources, only two were recorded in over 80% of all the feeding occasions. In order to re-establish open grassland with some shrubland, traditional and mosaic management of the landscape should be revived at least to some extent., Jure Jugovic, Mitja Črne, Martina Lužnik., and Obsahuje bibliografii
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.