Zum Fortpflanzungsmodus fossiler Kleinlibellen (Insecta,Odonata, Zygoptera)

Fossil egg-sets of damselflies (Insecta, Odonata, Zygoptera) are recognized from well known localities such as Randecker Maar, Messel (both in Germany) and in an old record about sediments from the Upper Cretaceous of Bohemia (Czech Republic). Such finds bearing witness to the behaviour of certain fossil insects are extremely rare, especially in stratified sediments. Hitherto they have only been recorded from the Upper Oligocene Fossillagerstätte Rott near Bonn (Germany). Two different types of egg-sets could be distinguished; they were described and figured byHellmund &Hellmund (1991, 1993). It is striking that the gap between finds from the Upper Oligocène and those from modern times is mainly due to insufficient observations. The explained strategy of reproduction obviously evolved at least 95 m.a. ago and has been practiced unchanged today.     

A molecular phylogeny of the Odonata (Insecta)

Abstract. We estimated the phylogeny of the order Odonata, based on sequences of the nuclear ribosomal genes 5.8 S, 18S, and ITS1 and 2. An 18S‐only analysis resolved deep relationships well: the order Odonata, as well as suborders Zygoptera and Epiprocta (Anisoptera + Epiophlebia), emerged as monophyletic. Some other deep clades resolved well, but support for more recently diverged clades was generally weak. A second, simultaneous, analysis of the 5.8S and 18S genes with the intergenic spacers ITS1 and 2 resolved some recent branches better, but appeared less reliable for deep clades with, for example, suborder Anisoptera emerging as paraphyletic and Epiophlebia superstes recovered as an Anisopteran, embedded within aeshnoid‐like anisopterans and sister to the cordulegastrids. Most existing family levels in the Anisoptera were confirmed as monophyletic clades in both analyses. However, within the corduliids that form a major monophyletic clade with the Libellulidae, several subclades were recovered, of which at least Macromiidae and Oxygastridae are accepted at the family level. In the Zygoptera, the situation is complex. The lestid‐like family groups (here called Lestomorpha) emerged as sister taxon to all other zygopterans, with Hemiphlebia sister to all other lestomorphs. Platystictidae formed a second monophylum, subordinated to lestomorphs. At the next level, some traditional clades were confirmed, but the tropical families Megapodagrionidae and Amphipterygidae were recovered as strongly polyphyletic, and tended to nest within the clade Caloptera, rendering it polyphyletic. Platycnemididae were also non‐monophyletic, with several representatives of uncertain placement. Coenagrionids were diphyletic. True Platycnemididae and non‐American Protoneurids are closely related, but their relationship to the other zygopterans remains obscure and needs more study. New World protoneurids appeared relatively unrelated to old world + Australian protoneurids. Several recent taxonomic changes at the genus level, based on morphology, were confirmed, but other morphology‐based taxonomies have misclassified taxa considered currently as Megapodagrionidae, Platycnemididae and Amphipterygidae and have underestimated the number of family‐level clades.     

Cytology of the midgut epithelium of Aeshna larvae (Insecta,Odonata)

Summary The midgut epithelium of the larval dragonfly Aeshna cyanea consists of four types of differentiated cells, which all display secretory activity. Pure secretory cells are the mucocytes and two morphologically distinguishable types of endocrine cells, while the enterocytes exert the dual function of secretion and absorption. Both functions can be performed more or less synchronously; however, appropriate feeding and starvation experiments can stress one function over the other. The heaviest accumulation of secretion granules was observed after a few days of starvation following a long period of regular feeding. Then the enterocytes resembled typical protein-secreting exocrine gland cells. It is still unknown whether the two main secretions, namely digestive enzymes and peritrophic membrane material, are jointly or separately distributed in the secretion granules. The morphological findings suggest that the secretory products follow the same cisternal pathway via endoplasmic reticulum, Golgi apparatus, membrane-bound storage granules and exocytotic extrusion that is well established for the exocrine pancreas of vertebrates. The routes of protein secretion and lipid absorption through the enterocytes of Aeshna are discussed in comparison with the enterocytes and mammocytes of vertebrates.Dedicated to Prof. Dr. K.E. Wohlfarth-Bottermann on the occasion of his 65^th birthday     

Junctional structures in the metamorphosing midgut of Aeshna cyanea (Insecta,Odonata)

Summary The metamorphosing midgut of Aeshna cyanea is characterized by the successive development of two tissues: the reticulated tissue and the imaginal epithelium. These tissues supply information concerning contacts between cells diverging in their developmental pathways although arising from the same stem cell population. In addition to small desmosomes, which bind reticulated to imaginal cells, the reticulated cells form invaginations into the apex of imaginai epithelial cells. The projections of the reticulated cells have enlarged tips, and numerous microfilaments run longitudinally along the length of theses processes. It is suggested that the anchoring projections of these cells delay the casting off of the reticulated tissue into the lumen, and thus allow the development of the imaginal microvilli. These project into the dilated intercellular space filled with a glycoprotein material that separates imaginal and reticulated cells (Andries, 1972).     

Dragonflies (Insecta,Odonata) from the Red Sea Hills and the main Nile in Sudan

Twenty-one species of dragonflies are recorded from the Nile and the Red Sea Hills in the Sudan. The majority are species of africotropical origin, but wide-ranging and tolerant of strongly fluctuating environmental conditions. A small but significant fraction is restricted to the Nile Valley, and another fraction, found only in the Red Sea Hills, is composed of Eremian species of Palaearctic origin. Besides adults, the last-instar larvae of Pseudogrion niloticum and of Paragomphus pumilio are described and figured.     

Webspinners in Early Eocene amber from western India (Insecta, Embiodea)

The family Scelembiidae (Neoembiodea: Embiomorpha: Archembioidea) is recorded from Asia for the first time, based on two individuals preserved in Early Eocene amber from the Cambay Basin, western India. Kumarembia hurleyi Engel & Grimaldi, gen. n. et sp. n., is described, figured, and distinguished from other archembioid genera. The genus shares male genitalic features with scelembiids, otherwise known from South America and Africa.     

Hemicycliphora ekrami n.sp. (Criconematina Siddiqi, 1980: Hemicycliophoroidea) from Punjab,India

Summary A new species of Hemicycliphora de Man, 1921 from around the roots of wheat (Triticum aestivum) is described and illustrated from Ludhiana, Punjab, India. Hemicycliophora ekrami n.sp. is close to H. labiata Colbran, 1960, H. mangiferum Misra & Edward, 1971 and H. dhirendri Husain & Khan, 1967 from which it differs in having smooth body annules not interrupted by lateral fields.     

Multiple peptide immunoreactivities in the nervous system of Aeschna cyanea (Insecta,Odonata)

Summary By use of the indirect immunoperoxidase method, the brain, the suboesophageal ganglion and the corpora cardiaca of the dragonfly Aeschna cyanea have been shown to be immunoreactive to proctolin antiserum and to several mammalian peptide antisera including unsulfated cholecystokinin octapeptide (CCK-8 NS) (Andriès et al. 1989), vasoactive intestinal peptide (VIP), human somatoliberin (hGRF) (Andriès et al. 1984) and motilin antisera. Immunohistochemical studies have been performed on material fixed in a solution of picricacid paraformaldehyde or in Bouin Hollande's sublimate solution. Antisera were applied on alternate sections or, according to the elution-restaining method of Tramu et al. (1978), one after another on the same section. Multiple peptide immunoreactivities appear expressed in the brain and the suboesophageal ganglion. Cells reactive to both hGRF and VIP antisera show also gastrin/CCK-like immunoreactivity and some of them are also detected by motilin antiserum. Besides, some cells immunopositive to CCK-8 NS and motilin antisera do not show hGRF or VIP immunoreactivity. At last, two pairs of protocerebral cells appear immunoreactive to both CCK-8 NS and proctolin antisera. Therefore, the present observations support our previously developed idea (Andriès et al. 1989) that the population of CCK-like cells is heterogenous.     

A catalogue of the West Indian dragonflies (Insecta: Odonata)

Summary. Compilation and analysis of the existing literature together with the results of our research carried out since 2000 makes possible an updated catalogue of the West Indian Odonata. Such a catalogue has not previously been available, and dispersed and multilingual literature did not facilitate odonatological studies. The odonate fauna of the Caribbean is currently composed of 108 valid species, of which 36 (32%) are endemic to one or a few islands. The most species-rich families are Libellulidae and Coenagrionidae, together comprising 65% of the total fauna.     

Crevice organs: Sensory structures on the wings of dragonflies (Insecta,Odonata)

Summary Crevice organs are small, elongate, innervated indentations in the hard cuticle of one wing vein of aeshnid dragonflies. There are four groups on each wing. The structure and orientation of crevice organs suggest that they detect strains in the cuticle during wing movements.I wish to thank Mr. R. Whitty and staff for technical assistance with the scanning electron microscope and Dr. E.E. Ball for helpful discussion     

The Level of Toxic Elements in Edible Crops from Seleniferous Area (Punjab,India)

Biological Trace Element Research - The primary objective of the present study was to assess the level of selenium and toxic trace elements in wheat, rice, maize, and mustard from seleniferous...     

Gastrin/cholecystokinin-like immunoreactivity in the nervous system of Aeschna cyanea (Insecta,Odonata)

Summary Gastrin/cholecystokinin (gastrin/CCK)-like immunoreactivity has been detected in the brain, suboesophageal ganglion and corpora cardiaca of the larva of Aeschna cyanea by radioimmunoassay and immunohistochemistry, by use of two antisera raised against the sulfated (CCK-8S) and the unsulfated form (CCK-8NS) of the carboxyl terminal octapeptide. Numerous immunoreactive neurons were demonstrated in the protocerebrum (exclusive of optic lobes) and suboesophageal ganglion where 20 and 15 symmetrical clusters of reactive cells, respectively, were observed. Immunoreactive cells also occurred in the tritocerebrum, the optic lobes and the frontal ganglion. In the corpora cardiaca, gastrin/CCK-like material was found both within intrinsic cells and axon terminals. RIA measurements support the immunohistochemical results in so far as large amounts of gastrin/CCK-like material were detected in the brain, corpora cardiaca and suboesophageal ganglion complex. Both boiling water-acetic acid- and methanol-extraction procedures were performed. Comparisons of the results lead to the conclusion that a large part of the gastrin/CCK-like material occurs as small molecules. Immunohistochemical procedures performed on material fixed in a solution of picric acid-paraformaldehyde demonstrated differences in the immunoreactivity of the tested antisera. First, the immunohistochemical reaction was always more pronounced when the CCK-8NS antiserum was used instead of the CCK-8S antiserum, which may be interpreted by a lower affinity of the latter. In the second place, some neurons strongly stained by the CCK-8NS antiserum were only very faintly if at all stained by the CCK-8S antiserum, which may mean that different peptides or at least distinct forms of the same precursor are detected.     

Simple pond restoration measures increase dragonfly (Insecta: Odonata) diversity

Ponds are home to a diverse community of specialized plants and animals and are hence of great conservation concern. Through land-use changes, ponds have been disappearing rapidly and remaining ponds are often threatened by contamination and eutrophication, with negative consequences for pond-dependent taxa like amphibians or dragonflies (Odonata: Anisoptera and Zygoptera). Increasingly, restoration measures such as removal of shading terrestrial vegetation or submerged organic matter are implemented to counteract current threats, but how these measures affect the target taxa is rarely assessed. We tested if and how simple pond restoration measures affectionate diversity. We propose that pond restoration influences the light regime, which promotes aquatic and riparian vegetation important for different dragonfly life stages, thus increasing their diversity. Additionally, we assume that this changes dragonfly species composition between restored and unrestored ponds. We surveyed exuviae in the riparian and aquatic vegetation along the shore of 29 (12 restored, 17 unrestored) man-made ponds in southwest Germany and assessed environmental variables known to affect dragonfly diversity. We identified the cover of tall sedges and submerged macrophytes as the driving biotic variables for dragonfly diversity and species composition, with restoration measures affecting submerged macrophyte cover directly but tall sedges indirectly via available sunlight. This study demonstrates that simple restoration measures not only have a positive effect on overall dragonfly diversity, but also increase habitat suitability for several species that would otherwise be absent. We therefore propose dragonflies as a suitable flagship group for pond conservation.     

Atbarapur (Hoshiarpur district,Punjab), the Acheulian of the Siwalik Range within the South Asian context

The largest collection of Acheulian artefacts in the Siwalik region is from the site of Atbarapur in north-western India. The artefacts occur in reworked sediments of the Pinjore Formation, starting with the onset of the Pleistocene and continuing at places in this region till 0.6 Ma. The technical study shows two similar “chaînes opératoires”: one based on cobbles for making small flakes and the second based on boulders for large flakes. Both are short and simple: cores are not prepared and each of them produced about seven flakes. Handaxes and cleavers, typical Acheulian tools, are made on the large flakes, often struck from the ventral face of larger flakes (Kombewa method) or from split boulders. The technology compares well with the Lower Pleistocene Acheulian of peninsular India, but with slightly more refined bifaces. It also compares with assemblages from Africa and East Asia: Atbarapur stands as a milestone on the diffusion route(s) of the Acheulian.     

Enigmatic and little known Odonata (Insecta) from the Paleogene of Patagonia and Northwest Argentina

The findings of new specimens of Latibasaliidae and Frengueliidae in Northwest and Patagonia Argentina are noteworthy for the knowledge of these little know families and the explanation of their systematic position. The new findings confirm the phylogenetic position of these families. The morphology of the discoidal cell in both fore and hind wings of Frenguelia corresponds to the most basal epiproctophoran damsel-dragonflies, implying a Triassic age for the particular lineage of this family. The absence of any fossil record between Triassic and Eocene could be related to a highly specialized biology for these animals, maybe related to mountain rainforests as for Epiophlebia, unique surviving damsel-dragonfly. Lastly, the middle Eocene Italian dragonfly family Bolcathemidae Gentilini 2002 is considered as a junior synonym of the Paleocene Argentinean family Palaeomacromiidae Petrulevicius et al. 1999 supporting faunistic contact between Europe and South America during the late Cretaceous.     

Heterogeneity and homologies of the repeating and unique DNA of dragonflies (Odonata, Insecta)

A relative content of unique and reiterated nucleotide sequences in DNA of eleven dragonfly species was estimated. The degree of intra- and intergenomic divergence of these DNA sequences was determined by means of DNA-DNA hybridization. Species from different genera share 40-45% of the repetitive sequences and those from different families--from 11 to 20% only. Data on the thermostability of homo- and heteroduplexes suggest that new families of the repetitive sequences have arisen repeatedly during dragonflies evolution. The quality of homologous unique sequences in the DNA compared (20-97%) correlates with the taxonomic relationships of species. Phylogenesis of some dragonfly families is discussed in view of the results obtained.     

Odonata (Insecta) as a tool for the biomonitoring of environmental quality

Despite the fundamental dependence of human populations on water resources, a range of anthropogenic impacts, in particular the removal of riparian vegetation, threaten freshwater environments. One of the most effective means of evaluating the effects of anthropogenic disturbance in aquatic ecosystems is the use of bioindicators, and the insects of the order Odonata are among the most efficient indicators, due to their enormous sensitivity to environmental changes. In this context, the present study aimed to verify which parameters of the odonate community (species richness, abundance/biomass, composition, taxonomic diversity and taxonomic/phylogenetic distinctness) are most effective for the evaluation of the loss of environmental integrity. The study focused on 50 streams in the northeast of the Brazilian state of Pará. The streams were sampled during the dry season, between June and August 2011. The physical characteristics of each stream were evaluated using a Habitat Integrity Index (HII). The species composition provided the best parameter for the evaluation of ecological integrity, providing a relatively accurate assessment at a lower mean research cost than other parameters. Taxonomic diversity and distinctness also provided relatively reliable results, contributed additional information on the evolutionary relationships among the odonate taxa, and also provided a low-cost approach. Deconstructing communities is necessary to detect impacts, considering the considerable variation in the environmental requirements of the different species. Overall, the parameter that best responded to gradients of disturbance was species composition, followed by diversity and taxonomic distinctness. Given these findings, odonate-based biomonitoring should focus on these parameters to guarantee the optimal detection and evaluation of habitat alterations.