Influence of biotope on the distribution and peak activity of questing ixodid ticks in Hungary

Abstract In order to update the occurrence of hard tick species in Hungary, 3442 questing ticks were collected from the vegetation by the dragging/flagging method in 37 different places in the country, between March and June of 2007. Ixodes ricinus (L.) turned out to be ubiquitous. Dermacentor marginatus (Schulzer) was absent from sampling sites in the southwestern part of the country, but in most places was concomitant and contemporaneous with Dermacentor reticulatus (Fabricius). These two species, as well as I. ricinus, occurred up to an altitude of 900–1000 m a.s.l. Haemaphysalis inermis (Birula) and Haemaphysalis concinna (Koch) were not confined to any parts of the country, unlike Haemaphysalis punctata (Canestrini & Fanzago) which was found in only one region. The local prevalence of the latter species was also significantly lower than those of the former two in the same habitat (fringes of meadows, paths in forests). Dermacentor spp. and H. inermis were represented only by adults. In most species females were collected more frequently than males, except in H. concinna and H. punctata. Temporal differences between the peak activity of I. ricinus and Dermacentor spp. on dry pastures appeared to equalize on meadows in mountain forests, and a similar phenomenon was observed for the three Haemaphysalis spp. when collected along forest paths with fresh, green vegetation.     

Multiple mating in wild Drosophila melanogaster revisited by microsatellite analysis

The occurrence of multiple mating in Drosophila melanogaster is of particular interest to evolutionary biologists, as seminal fluid has some toxic effects for females. Thus, it has been predicted that the number of matings per females should be low. We have tested this prediction with seven highly polymorphic microsatellite loci in inseminated females from a Viennese D. melanogaster population. In contrast to the predicted low number of matings and previous studies in natural populations, we identified the genotypes of four to six different males fertilizing the offspring of each female tested. Potential causes and consequences are discussed.     

The Cell Cycle in Crithidia fasciculata. Temporal Relationships between Synthesis of Deoxyribonucleic Acid in the Nucleus and in the Kinetoplast1, 2

SYNOPSIS. Autoradiographic technics with tritium-labeled thymidine have been used to determine G1, S, G2 and D for the kinetoplast and the nucleus of Crithidia fasciculata at 15, 25 and 32 C. The kinetoplast completes division before the nucleus at all 3 temperatures. The S phases of both organelles occur in approximate synchrony and are approximately equal in length but the nucleus begins and completes S before the kinetoplast at the 2 lower temperatures. This relationship is reversed at 32 C. Most of the effect of temperature on generation time is due to its effect on the length of S. The results are compared with similar studies on C. luciliae, Trypanosoma mega, other protozoa and tissue cells in culture. The role of the approximate synchrony of nuclear and kinetoplastic cycles in maintenance of the kinetoplastic condition is discussed and the hypothesis is proposed that this synchrony results from the sharing by nucleus and kinetoplast of the same mechanism for the production of the deoxyribonucleotides used in replication of their respective DNAs.     

Extracellular release of photosynthetic products by freshwater phytoplankton populations, with special reference to the algal species involved

SUMMARY. Over three successive years, depth profiles of C-fixation and excretion, chlorophyll- a concentrations, phytoplankton species composition and bacterial numbers were determined in Lake Vechten, a slightly eutrophic lake in The Netherlands. Special attention was given to the method used to measure extracellular release.
Excretion of dissolved organic ¹⁴C depended largely upon the photo-synthetic activity of the phytoplankton, ranging from 0–2.5 mg m^-1 h^-1, representing a percentage extracellular release (PER) of 0–25%.
During a period in August, however, a subsurface chlorophyll- a maximum at 5–7 m depth coincided with high excretion rates of up to 10 mg Cm^-3 h^-1 (PER = 55%). Phytoplankton analysis revealed a stratification in numbers of Mallomonas caudata with a maximum at 5–7 m depth.
The results suggest that in these water layers bacterial populations grew at the expense of the dissolved organic carbon compounds excreted by Mallomonas caudata. This means that extracellular release can temporarily function as an important nutrient source for the heterotrophie community in addition to the more or less constant dissolved organic carbon pool.     

The Papuan tortricine genus Heterochorista and the systematic position of the Sparganothini (Lepidoptera, Tortricidae)

ABSTRACT .
The previously monotypic Papuan genus Heterochorista Diakonoff, 1952 is revised and twenty-one species are recognized. Nikolaia Diakonoff, 1953 is synonymized, syn.n. with Heterochorista. The following six species are placed in new combination in Heterochorista: Nikolaia melanopsygma Diakonoff, N.inumbrata Diakonoff, N.aperta Diakonoff, Isochorista papuana Diakonoff, I.polysperma Diakonoff and Dicellitis chrysonetha Diakonoff. Thirteen new species are added to Heterochorista: acomata sp.n., rostrata sp.n., trivialis sp.n., ornata sp.n., prisca sp.n., punctulata sp.n., rufulimaculata sp.n., classeyiana sp.n., spinosa sp.n., signata sp.n., fulgens sp.n., nitida sp.n. and aura sp.n. A checklist and a key to species are provided, and adults and male and female genitalia are described and illustrated. The phylogeny of Heterochorista is outlined on the basis of a cladistic character analysis and the genus is referred to the base of the Sparganothini. The apomorphies characterizing this tribe are reviewed with regard to their phylogenetic significance and the relationship between Sparganothini, Archipini and Atterini is briefly discussed.     

Developmental Capacity of Aneuploid Xenopus Species Hybrids

Diploid as well as triploid Xenopus interspecific hybrids generate aneuploid eggs because of the presence, at meiosis, of univalent chromosomes which are presumably distributed at random. Zygotes obtained from such eggs, fertilized by either normal or UV-irradiated sperm, were analysed for their developmental capacities. All monosomics die in the course of embryogenesis, whereby optimum capacities correspond closely with those observed in monosomic mammalian embryos, especially in mice. In contrast, hyperdiploid Xenopus are relatively viable: although many die exhibiting the'haploid syndrome'or various other abnormalities, 8% of them reach metamorphosis, and 1–2% become adults. Of the latter, the karyotype was established in 13 individuals. Among them, 8–16 supernumerary chromosomes were found to be present.     

The Native Dialectica aemula (Meyrick) and the Introduced Dialectica scalariella (Zeller) (Lepidoptera: Gracillariidae) in Australia: Characterisation of Two Closely Related Species on Boraginaceae

Two gracillariid leaf miners of the genus Dialectica Walsingham are present in Australia on plants belonging to the family Boraginaceae, one a native species here identified as Dialectica aemula (Meyrick) which was originally described from India, and the Palaearctic Dialectica scalariella (Zeller) or Echium leaf miner, deliberately introduced as a biological control agent for Echium plantagineum L. or Paterson's Curse. Differential diagnoses are given for the two species, and they are comprehensively illustrated to enable identification. In contrast to the externally indistinguishable adults, the cocoons of the two species differ significantly in shape and colour and a colour plate allows easy identification.     

A preliminary assessment of the conservation status of Cypripedium species in the wild

The conservation of few plants produces such an emotive response as that of hardy slipper orchids of the genus Cypripedium. The genus, comprising 45 species and two varieties, is holarctic in distribution with the centre of diversity in China. Much is known about the status of some species and their populations in Europe and North America, but little information is available on the Asiatic and Mexican species. Most cypripediums are showy orchids and are well represented in herbaria, allowing an estimate of the present distribution, frequency and conservation status of the known species to be made. The authors conclude that having considered the number of herbarium specimens, nearly half of the genus may be considered threatened and in need of some legal protection if the plants are to survive in the wild. They identify a need to examine the conservation status of the taxa in in this genus more closely, and outline two important conservation tools that may help efforts to this end: the IUCN Red List Categories and Criteria for the Amendment of the Appendices of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora).