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
In November of 2013, a specimen of Japanese sleeper ray, Narke japonica (Temminck et Schlegel), caught off Nanfang-ao, Taiwan was found to be parasitised by the cestode Anteropora japonica (Yamaguti, 1934). Specimens comprised whole worms and free proglottids, both of varying degrees of maturity. This material allowed for the opportunity to examine in detail the developmental progression of this hyperapolytic lecanicephalidean species with regard to overall size, scolex dimensions, and microthrix pattern. Complete immature worms ranged in size from 2.4 mm to 14 mm. The smallest scoleces were half as wide as larger scoleces and exhibited a much smaller ratio of apical organ width to bothridial width. Proglottids more than quadrupled in length during maturation from terminal attached immature to detached proglottids. In addition, a change in microthrix pattern was observed on the anterior region of the proglottids from immature to gravid proglottids; the anterior region of attached immature proglottids is covered with gladiate to coniform spinitriches with capilliform filitriches only rarely visible, whereas this region in detached proglottids is covered with gladiate to coniform spinitriches and conspicuous capilliform filitriches. This is the first report of A. japonica from outside Japan expanding its distribution south to Taiwan. In addition, a preliminary phylogenetic analysis of the genus is presented that suggests congeners from the same host species are not each other's closest relatives, nor is there an apparent phylogenetic signal for apical organ type or reproductive strategy (apolysis). However, reproductive strategy does seem to be correlated with host group such that euapolytic species parasitise dasyatid stingrays while hyperapolytic species parasitise either torpediniform rays or orectolobiform sharks., Rachel R. Guyer and Kirsten Jensen., and Obsahuje bibliografii
The riparian forests along the Tarim River, habitats for Populus euphratica establishment, are subjected to frequent flooding. To elucidate adaptive strategies that enable this species to occupy the riparian ecosystem subjected to seasonal or permanent water-logging, we examined functional characteristics of plant growth, xylem water relations, leaf gas exchange, chlorophyll (Chl) content and fluorescence, soluble sugar and malondialdehyde (MDA) content in P. euphratica seedlings flooded for 50 d. Although flooded seedlings kept absorbing carbon throughout the experiment, their shoot and root growth rates were lower than in non-flooded seedlings. The reduced leaf gas exchange and quantum efficiency of PSII of flooded seedlings resulted possibly from the reduction in total Chl content. Content of soluble sugar and malondialdehyde in leaves were higher in flooded than in control seedlings. Soil flooding induced hypertrophy of lenticels and increased a stem diameter. These responses were responsible for species survival as well as its success in this seasonally flooded riparian zone. Our results indicate that P. euphratica is relatively flood-tolerant due to a combination of morphological, physiological, and biochemical adjustments, which may support its dominance in the Tarim riparian forest., B. Yu, C. Y. Zhao, J. Li, J. Y. Li, G. Peng., and Obsahuje bibliografii
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.