Eristalis pertinax varies seasonally, with the spring morph more hairy than the summer morph. We measured the size and the venation of the wings of the seasonal morphs. Wings of the spring morph were significantly larger than those of the summer morph and those of females were larger than those of males. There were also significant differences between the morphs in wing venation and their allometric relationship. The differences between sexes were larger than differences between seasonal morphs. The allometry can account for the sexual dimorphism but not seasonal dimorphism. The differences between seasonal morphs in wing shape were relatively large with very few intermediate individuals. The differences were comparable to those between two related species of Syrphidae. Genetic analyses based on markers in nuclear and mitochondrial genomes unequivocally revealed that spring and summer morphs of E. pertinax form a single population and should not be regarded as separate taxa. Thus seasonal variability in this species is a rare example of polyphenism in Diptera., Lukasz E. Mielczarek, Andrzej Oleksa, Katarzyna Meyza, Adam Tofilski., and Obsahuje bibliografii
The populations of the firebug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae) in Europe exhibit three kinds of host plant associations: feeding on seeds of (1) Tilia spp. (Tiliaceae), (2) Malvaceae (s. str.), and (3) Robinia pseudacacia (Fabaceae). The three host plant taxa often grow in different habitats and localities. We have tested the hypothesis that P. apterus forms on different host plants specialised "trophic populations" which also influence its food preference. We have collected P. apterus from localities with Tilia platyphyllos, Malva neglecta or Robinia pseudacacia as host plants and tested their preferences in a multiple choice test involving seeds of Tilia cordata, T. platyphyllos, Althaea officinalis, Alcea rosea and Robinia pseudacacia. The original host plant of P. apterus population had no influence on food preferences. However, the preferences differed between adults and the third instar larvae. The adults preferred seeds of Robinia pseudacacia followed by Althaea officinalis, while the preferences of larvae were less pronounced and ranked in order Althaea officinalis, Robinia pseudacacia, and Tilia platyphyllos. Existence of trophic populations of P. apterus was not confirmed by our experiment. Durations of feeding were longer on preferred species of seeds in both adults and larvae. and Marta Kristenová, Alice Exnerová, Pavel Štys.
Larvae of the butterfly, Battus polydamas archidamas (Papilionidae: Troidini) feed exclusively on aristolochic acid (AAs)-containing Aristolochia species (Aristolochiaceae). The distribution of sequestrated AAs in the tissues (body, integument and osmeterial secretions) of B. polydamas archidamas larvae during their development, when fed on a meridic diet containing either a higher or lower concentration of AAs (AAI and AAII) than occurs naturally in the aerial tissues of their host plant, was determined. Accumulation of AAs in the body and integument was proportional to the weight of larvae and greater in the larvae that fed on the diet containing the higher concentration of AAs. Phenolic AAs (AAIa and AAIVa) not present in the diets were found in all larval tissues examined. Integument and body extracts had a higher AAI/AAII ratio than in the original diet and also a relatively high AAIa/AAIVa ratio, suggesting a preferred AAII to AAIa transformation in those larval tissues. In the osmeterial secretion, the value of the AAI/AAII ratio was similar to that in the diets and the AAIa/AAIVa ratio close to 1, which suggests that hydroxylation of AAI to AAIVa and of AAII to AAIa occur to similar extents. The higher accumulation of AAs and the relatively higher proportion of AAI, one of the most toxic AAs, in the integument, suggest that their role is to deter attacks by natural enemies. and Carlos F. PINTO, Alejandro URZÚA, Hermann M. NIEMEYER.
Hmyz sající krev svých hostitelů často přenáší i původce různých, více či méně závažných onemocnění, čímž představuje hrozbu, ale současně poskytuje dokonalou ukázku biologické adaptace a evolučního závodu s obranou hostitele i s triky přenášených patogenů. Článek stručně představuje vybrané zástupce krevsajícího hmyzu (např. blechy, vši, ovády, kloše, štěnice, komáry) z území České republiky i vyskytující se v různých částech světa, jejich způsob života a jimi přenášené původce onemocnění., Insects sucking the blood of their hosts often transmit the agents of various serious diseases, which pose a threat, but which at the same time provide a perfect example of biological adaptation and the endless evolutionary race against the host's defences with tricks involving transmitted pathogens. This article briefly presents some selected representatives from these blood-sucking insects (e.g. fleas, lice, horseflies, bedbugs, keds and mosquitoes) in the Czech Republic and occurring elsewhere in various parts of the world, their way of life and the aetiological agents which they transmit., and Jan Votýpka.
Článek přináší ukázku fotografií zástupců čeledi veverkovití (Sciuridae) v Severní Americe. Některé z těchto druhů lze při návštěvách národních parků i jiných míst v Kanadě a Spojených státech amerických pozorovat snadno a někdy i zblízka – představené fotografie vznikly na parkovištích a odpočívadlech, kde se tito hlodavci snaží získat od turistů „pamlsky“., A sample of photographs of representatives of the Sciuridae family in North America is selected. Some of these species can easily be observed on visits to national parks and other locations in Canada and the United States, sometimes from close up – the photos were taken at car parks and lay-bys, where these rodents attempt to obtain “goodies” from the tourists., and George O. Krizek.
Nocturnal pollinators such as moths have received less attention than diurnal insects. To elucidate whether nocturnal moths are important pollinators, we observed both the diurnal and nocturnal visitors to the flowers of Uncaria rhynchophylla (Rubiaceae) in a warm-temperate forest in central Japan. The diurnal visitors included various taxonomic groups (e.g., bees, hoverflies and butterflies). The nocturnal visitors were exclusively moths (Geometridae, Erebidae, Noctuidae and Crambidae). Pollen grains of U. rhynchophylla were attached to both diurnal and nocturnal visitors. Although diurnal flower visitors carried pollen grains of other plant species, nocturnal moths did not carry heterospecific pollen grains. These results suggest that nocturnal moths, as well as diurnal insects, are important pollinators of U. rhynchophylla., Daichi Funamoto, Shinji Sugiura., and Obsahuje bibliografii
The correlation between dorsal wing colours and spectral sensitivity of the compound eyes of 13 species of thecline butterflies, consisting of 8 sexually monomorphic and 5 dimorphic species, was investigated. Spectral reflectance of the dorsal surfaces of the wings was measured using a spectrophotometer and spectral sensitivities using electroretinography. All 13 species examined showed a common basic pattern of spectral sensitivity with a primary peak at a wavelength of 440–460 nm. Detailed analyses of the deviations in sensitivity from the basic pattern revealed a correlation in monomorphic species with conspicuous wing hues, especially in males., Michio Imafuku., and Obsahuje seznam literatury
The expression of sexually dimorphic phenotypes from a shared genome between males and females is a longstanding puzzle in evolutionary biology. Increasingly, research has made use of transcriptomic technology to examine the molecular basis of sexual dimorphism through gene expression studies, but even this level of detail misses the metabolic processes that ultimately link gene expression with the whole organism phenotype. We use metabolic profiling in Drosophila melanogaster to complete this missing step, with a view to examining variation in male and female metabolic profiles, or metabolomes, throughout development. We show that the metabolome varies considerably throughout larval, pupal and adult stages. We also find significant sexual dimorphism in the metabolome, although only in pupae and adults, and the extent of dimorphism increases throughout development. We compare this to transcriptomic data from the same population and find that the general pattern of increasing sex differences throughout development is mirrored in RNA expression. We discuss our results in terms of the usefulness of metabolic profiling in linking genotype and phenotype to more fully understand the basis of sexually dimorphic phenotypes., Fiona C. Ingleby, Edward H. Morrow., and Obsahuje bibliografii
Ants are the most abundant group of soil arthropods in olive groves where they are involved in various trophic relationships of great importance for crops. The system of soil management is one agricultural practice that has a great effect on ants, so the objective of this study was to compare ant populations in organic olive orchards with a ground cover of natural vegetation and others where this natural vegetation is mechanically removed at the beginning of June. Ants were sampled using pitfall traps at 14, 30, 70 and 90 days after the removal of the ground vegetation. Overall, ant biodiversity did not change. However, changes were observed in the abundance of ant species, in particular, in those species that build shallow nests in the soil, both between the rows of trees and under the canopy of olive trees. In contrast, deep nesting species, such as Messor barbarus, were not affected. The response also differed between the various genera: the abundance of Cataglyphis increased, due to there being more of the species C. rosenhaueri, while there was a significant fall in Aphaenogaster, due to the decline in abundance of A. senilis. Thirty days after the removal of vegetation, the response of most of the genera was clearly noticeable, due to the increased activity of workers, and in some cases there were still differences after 90 days. and Mercedes Campos, Luisa Fernández, Francisca Ruano, Belén Cotes, Manuel Cárdenas, Juan Castro.
Galleria mellonella larvae spin protective tubes, which they use until they finish feeding, when they spin cocoons. A feeding choice experiment showed that some of the silk produced by feeding larvae was consumed in addition to the standard diet (STD). To determine the effect of feeding on silk, last instar larvae were fed for 24 h on foods based on STD but modified by replacing the dry milk component (10% of the diet) with equal amounts of different kinds of silk. While each control larva consumed 21 ± 0.5 mg of the STD and produced 4.5 ± 0.1 mg of silk, larvae that ate the food that contained larval silk consumed 10 ± 0.4 mg of food and produced 6.1 ± 0.1 mg silk; the percentage ratio of silk produced to diet consumed was 21% and 61%, respectively. A more pronounced reduction in food consumption occurred when larvae were supplied with Galleria "cocoon" silk or the sericin fraction of such silk, and only 3.8 mg/larva was ingested of the diet containing Bombyx mori cocoon silk or its sericin fraction. Silk production expressed in terms of percentage of diet consumed was always higher than that recorded for larvae fed STD. We conclude that G. mellonella larvae recycle part of the silk that they produce during feeding. Presence of silk in the diet reduces food intake but increases the ratio of silk production to diet consumption. Sericin fraction of the cocoon silk seems to deter feeding., Haq Abdul Shaik, Archana Mishra, František Sehnal., and Obsahuje bibliografii