نتایج جستجو برای: dragonflies

تعداد نتایج: 552  

2009
Haibo Dong Zongxian Liang

Dragonflies are masters of using the ipsilateral wing-wing interaction for different kinds of flying modes. It has been discovered that the phase difference between ipsilateral forewings and hindwings plays important role on wing aerodynamic performance. In the current study, we continue our research of a modeled dragonfly in slow flight (Liang and Dong (2009)) by varying the phase difference b...

Journal: :Biology letters 2009
Anders Pape Møller Timothy A Mousseau

Effects of low-level radiation on abundance of animals are poorly known. We conducted standardized point counts and line transects of bumble-bees, butterflies, grasshoppers, dragonflies and spider webs at forest sites around Chernobyl differing in background radiation by over four orders of magnitude. Abundance of invertebrates decreased with increasing radiation, even after controlling for fac...

Journal: :Japanese Journal of Applied Entomology and Zoology 2021

Journal: :Annals and Magazine of Natural History 1899

Journal: :Physical review letters 2007
Z Jane Wang David Russell

Dragonflies are four-winged insects that have the ability to control aerodynamic performance by modulating the phase lag (phi) between forewings and hindwings. We film the wing motion of a tethered dragonfly and compute the aerodynamic force and power as a function of the phase. We find that the out-of-phase motion as seen in steady hovering uses nearly minimal power to generate the required fo...

Journal: :BIO web of conferences 2023

Data on the degree of knowledge different groups aquatic invertebrates northern slopes Central Caucasus are given. It is shown that best known mayflies, stoneflies, odonates and caddisflies. Other have been studied to a much smaller degree. The estimated number species in study area several hundreds. Secondary insect groups, such as those order Diptera, most speciose. various presented. dragonf...

2016
Elin Soomets Riinu Rannap Asko Lõhmus

Small freshwater ponds host diverse and vulnerable biotic assemblages but relatively few conspicuous, specially protected taxa. In Europe, the amphibians Triturus cristatus and Pelobates fuscus are among a few species whose populations have been successfully restored using pond restoration and management activities at the landscape scale. In this study, we explored whether the ponds constructed...

Journal: :Anais da Academia Brasileira de Ciencias 2010
Gerson A Müller Fernando T Name Frederico C L Pacheco Carlos B Marcondes

The efficiency of an alternative method of collection (by suction of water) for the study of Culicidae and Chironomidae (Diptera), Scirtidae (Coleoptera) and Coenagrionidae (Odonata) in bromeliads with different foliar architecture in a restinga at Florianópolis, SC, Brazil, was studied. The alternative method was less efficient to collect Culicidae and Chironomidae (Wilcoxon test p < 0.05) and...

2016
Renzo Perissinotto Matthew S. Bird David T. Bilton

Water beetles are one of the dominant macroinvertebrate groups in inland waters and are excellent ecological indicators, reflecting both the diversity and composition of the wider aquatic community. The predaceous water beetles (Hydradephaga) make up around one-third of known aquatic Coleoptera and, as predators, are a key group in the functioning of many aquatic habitats. Despite being relativ...

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