Reduced oviposition by ladybirds in the presence of tracks of fourth instar larvae owing to the presence of oviposition deterring pheromones is well established across many genera. However, deterrence, if any, by other life stages has not been well investigated, in particular the effect of conspecific presence. The present study investigates the effects of conspecific presence and semiochemicals of conspecific life stages (eggs, fourth instar larvae, pupae, adult males and females) on oviposition by five ladybird (Coleoptera: Coccinellidae) species, viz. Coccinella septempunctata, Coccinella transversalis, Cheilomenes sexmaculata, Propylea dissecta and Anegleis cardoni. Results reveal that the presence of life stages inhibits oviposition and the inhibition is density-dependent, although the degree of inhibition is species-specific. Surface semiochemicals of eggs and larval and adult tracks also show density-dependent inhibitory effects. Moreover, the semiochemicals in tracks (oviposition deterring pheromones) and egg surface semiochemicals are not similar, indicating semiochemical parsimony. Of all species tested, C. transversalis and C. septempunctata were the most and the least responsive to both conspecific presence and semiochemicals, respectively., Geetanjali Mishra ... [et al.]., and Obsahuje seznam literatury
An interference between a thermosensitive (ts) mutant and the wild-type (wt) of tick-borne encephalitis (TBE) virus in Ixodes ricinus L, and Rhipicephalus appendicuiatus (Neumann) ticks is reported. /. ricinus females were dually infected by a parenteral inoculation of ts and wt strains at 10-day interval. Interference was demonstrated by the lowered ability of wt virus to replicate in ticks previously infected by ts virus. The wt virus was demonstrated in only 30% of the ticks; the average virus titre was lowered by 2.1 log|0 compared with the control group, which was infected with the wt virus only. The oral infection of R. appendicuiatus ticks with the same viruses also revealed an interference with the growth of the superinfecting wt virus. While in the control group all the ticks became infected, in the dually infected group the wt virus was found in only 50% of the ticks. However, when the ticks were infected orally with is virus and superinfected parenterally with the wt virus, no interference was observed. In a R. appendicuiatus-derived cell line persistently infected with the ts virus (100% of the cells), a partial inhibition of the growth of the superinfecting wt virus was observed. The ts virus retained its thermosensitive phenotype throughout the persistent infection of both the ticks and the tick cell line.
The endemic large carpenter bee, Xylocopa (Koptortosoma) ogasawarensis Matsumura (Hymenoptera: Apidae), on the oceanic Ogasawara (Bonin) Islands, located in the northwestern Pacific Ocean, approximately 1000 km south of the Japanese mainland, is a generalist flower visitor. Although the flower-visiting behaviour of X. ogasawarensis females has been frequently recorded, the behaviour of the males in this species has rarely been studied. I observed the territorial behaviour of males on flowers of the native plant species Scaevola sericea Vahl (Campanulales: Goodeniaceae) in a coastal area of Hahajima in early July 2007. Each male chose a particular inflorescence, hovered near it (mean distance, 239 mm from the inflorescence) and patrolled around it for several minutes (mean time, 331 s). Therefore, X. ogasawarensis males exhibit resource-based (i.e., flowers) territoriality. Males frequently attacked other males when defending their territories. However, males did not defend their territories against flower visitors of other species (i.e., introduced honeybees). Therefore, male territorial behaviour in X. ogasawarensis may be related to intrasexual competition for sites visited by females. This is the first report describing the male territorial behaviour of X. ogasawarensis.
The surface topography persists for a long time in the forefront interest of many research and development organisations due to the perpetual quest for more precise and perfect measurement methods. So far used contact methods cannot be applied in many cases where their application can damage the measured surface and therefore waste the measured element, for instance lens surface or silicon plates etc. The great effort is therefore devoted to the development of contactless methods that employ various physical principles. In this article the brief description of light interference is presented including some algorithms for evaluation of the interference field and potentials of actual measuring instruments manufactured by prestigious producers and examples of model which are available at the today market. and Problematika topografie ploch je již dlouhou dobu v popředí zájmu řady výzkumných a vývojových pracovišť, neboť oblast vědy a techniky vyžaduje stale přesnější a dokonalejší metody měření. Dosud využívané kontaktní metody jsou v řadě případů zcela nepoužitelné vzhledem k tomu, že při jejich aplikaci dochází k poškození měřeného povrchu a tím ke znehodnocení měřeného prvku (např. plochy čočky, křemíkových desek apod.). Velké úsilí je proto věnováno právě vývoji bezkontaktních metod, pracujících na různých fyzikálních principech. V článku je stručně popsána interference světla a některé algoritmy pro vyhodnocování interferenčního pole se současným uvedením aktuálních možností měřicích přístrojů renomovaných světových výrobců a příklady modelů, které jsou v dnešní době na trhu k dispozici.
In this article, evaluating system for measuring of near electromagnetic field is described. The field is radiated by a cell phone. Results from proposed software are presented here. It can help find positions with raised emissivity and give some indication for engineering interventions leading to elimination of interference of electronic systems. and V článku je popsán vyhodnocovací systém pro měření blízkého elektromagnetického pole vyzařovaného mobilním telefonem. Jsou zde prezentovány výsledky z navrženého vizualizačního programu, pomocí kterého lze nalézt místa se zvýšenou vyzařovací schopností a tím naznačit cestu pro konstrukční zásahy k omezení vzájemného rušení elektronických systémů.