02320nas a2200145   4500008004100000245006600041210006100107260000800168300001100176490000700187520189300194100001602087700002202103856004902125       2005                        eng d00aThe adipokinetic hormones of Odonata: a phylogenetic approach0 aadipokinetic hormones of Odonata a phylogenetic approach  cMar  a333-410 v513 aAdipokinetic neuropeptides from the corpora cardiaca of the major families of all three suborders of the Odonata were identified by one or more of the following methods: (1) Isolation of the peptides from a methanolic extract of the corpora cardiaca by liquid chromatography, peak monitoring by fluorescence of the Trp residue and comparison of the retention time with those of known synthetic peptides of Odonata. (2) Hyperlipaemic bioassays of the HPLC-generated fractions either in Locusta migratoria or, in a few cases, in Anax imperator or Orthetrum julia. (3) Sequencing of the isolated, bioactive HPLAC fraction by Edman degradation. (4) Mass spectrometric measurement of the isolated, bioactive fraction. Sequence assignment revealed that the investigated Odonata species always contain only one adipokinetic peptide. This is always an octapeptide. The suborder Zygoptera contains the peptide code-named Psein-AKH, the Anisozygoptera and the families Aeshnidae, Cordulegastridae and Macromiidae of the Anisoptera contain Anaim-AKH, whereas Gomphidae, Corduliidae (with the exception of Syncordulia gracilis) and Libellulidae contain Libau-AKH; one species of Libellulidae has Erysi-AKH, a very conservative modification of Libau-AKH (one point mutation). When these structural data are interpreted in conjunction with existing phylogenies of Odonata, they support the following: (1) Zygoptera are monophyletic and not paraphyletic. (2) Anisozygoptera and Anisoptera are sister groups and contain the ancestral Anaim-AKH which is independently and convergently mutated to Libau-AKH in Gomphidae and Libellulidae. (3) The Corduliidae are of special interest. Only Corduliidae sensu stricto appear to contain Libau-AKH, other species placed into this family by most authorities contain the ancestral Anaim-AKH. Possibly, assignments of AKHs can untangle the paraphyly of this family.1 aGäde, Gerd1 aMarco, Heather, G  uhttps://worldodonata.myspecies.info/node/25201921nas a2200145   4500008004100000245017700041210006900218260000800287300001200295490000700307520137000314100001901684700002301703856004901726       2007                        eng d00aFunction of multiple sperm-storage organs in female damselflies (Ischnura senegalensis): difference in amount of ejaculate stored, sperm loss, and priority in fertilization0 aFunction of multiple spermstorage organs in female damselflies I  cOct  a1046-540 v533 aWe studied changes in the number of sperm within two kinds of female sperm-storage organ in the damselfly Ischnura senegalensis (Odonata: Coenagrionidae): the bursa copulatrix and the spermatheca. We counted the number of sperm within each storage organ and tested their viability after a single copulation in female damselflies kept for seven days with and without oviposition. We also counted sperm and tested their viability in females that underwent an interrupted second copulation after the sperm-removal stage, and after subsequent oviposition. Our results showed that the bursa copulatrix and spermatheca have different sperm storage roles. Immediately after copulation, most eggs appear to have been fertilized with bursal sperm, which were positioned near the fertilization point. By seven days after copulation, a greater proportion of spermathecal sperm were used for fertilization, as the number of bursal sperm had decreased. We hypothesize that female damselflies use the spermatheca for long-term storage and the bursa copulatrix for short-term storage: bursal sperm are more likely to be used for fertilization but may have a higher risk of mortality due to sperm removal by a competing male and/or sperm expelling by the female, whereas spermathecal sperm are safer but will be used for fertilization only after their release from the spermatheca.1 aNakahara, Miri1 aTsubaki, Yoshitaka  uhttps://worldodonata.myspecies.info/node/23101602nas a2200169   4500008004100000245007800041210006900119260000800188300001000196490000700206520108700213100002001300700002301320700002401343700001601367856004901383       2007                        eng d00aHygroreceptors in the larva of Libellula depressa (Odonata: Libellulidae)0 aHygroreceptors in the larva of Libellula depressa Odonata Libell  cJun  a550-80 v533 aUltrastructural and electrophysiological (single-cell recordings) investigations were carried out on the coeloconic sensilla borne by the apical antenna of the larvae of Libellula depressa (Odonata: Libellulidae). These sensilla appear as pegs located in pits. One of them is a compound sensillum constituted of two fused pegs in a common pit and the other two are single pegs located in separated pits close to each other. Coeloconic sensilla show position and ultrastructural details very similar to those described in insect hygroreceptors. The electrophysiological recordings on the apical antennae of the last larval instar of L. depressa clearly show the presence of moist and dry cells responding antagonistically to humidity changes. This study gives the first evidence of hygroreceptors in dragonfly larvae and represents the first electrophysiological approach to larval sensilla of aquatic insects. The presence of hygroreceptors in L. depressa larvae is in agreement with the hygropositive response shown by these insects in laboratory and field behavioural experiments.1 aRebora, Manuela1 aPiersanti, Silvana1 aAlmaas, Tor, Jorgen1 aGaino, Elda  uhttps://worldodonata.myspecies.info/node/23602201nas a2200145   4500008004100000245015000041210006900191260000800260520165500268100002001923700002201943700002001965700002101985856004902006       2009                        eng d00aDegrees of polarization of reflected light eliciting polarotaxis in dragonflies (Odonata), mayflies (Ephemeroptera) and tabanid flies (Tabanidae)0 aDegrees of polarization of reflected light eliciting polarotaxis  cAug3 aWith few exceptions insects whose larvae develop in freshwater possess positive polarotaxis, i.e., are attracted to sources of horizontally polarized light, because they detect water by means of the horizontal polarization of light reflected from the water surface. These insects can be deceived by artificial surfaces (e.g., oil lakes, asphalt roads, black plastic sheets, dark-coloured cars, black gravestones, dark glass surfaces, solar panels) reflecting highly and horizontally polarized light. Apart from the surface characteristics, the extent of such a 'polarized light pollution' depends on the illumination conditions, direction of view, and the threshold p* of polarization sensitivity of a given aquatic insect species. p* means the minimum degree of linear polarization p of reflected light that can elicit positive polarotaxis from a given insect species. Earlier there were no quantitative data on p* in aquatic insects. The aim of this work is to provide such data. Using imaging polarimetry in the red, green and blue parts of the spectrum, in multiple-choice field experiments we measured the threshold p* of ventral polarization sensitivity in mayflies, dragonflies and tabanid flies, the positive polarotaxis of which has been shown earlier. In the blue (450nm) spectral range, for example, we obtained the following thresholds: Dragonflies: Enallagma cyathigerum (0% <p*</=17%), Ischnura elegans (17%</=p*</=24%). Mayflies: Baetis rhodani (32%</=p*</=55%), Ephemera danica, Epeorus silvicola, Rhithrogena semicolorata (55%</=p*</=92%). Tabanids: Tabanus bovinus, T. tergestinus (32%</=p*</=55%), T. maculicornis (55%</=p*</=92%).1 aKriska, György1 aBernáth, Balázs1 aFarkas, Róbert1 aHorváth, Gábor  uhttps://worldodonata.myspecies.info/node/207