ODONATOLOGICA Journal of the Societas Internationalis Odonatologica

Contents Volume 32, Issue 2 2003

Hornung, J. P. ; Rice, C. L. Odonata and wetland quality in southern Alberta, Canada: A preliminary study. p. 119-129. The relationship between odon. and wetland quality was investigated in Brooks, from May until Sept. 1999. Sixteen study sites were each visited 7 times to survey adult dragonflies and aquatic macroinvertebrates, record environmental parameters, collect water samples, record vegetative characteristics, and assess beef cattle grazing influences. 25 odonate spp. were recorded, of which Ischnura verticalis is new to Alberta. A significant negative correlation was detected between cattle presence (measured as percent stems grazed surrounding the wetland) and odon. species richness (p=0.022; r2=0.322), teneral species richness (p=0.018; r2=0.337), and the Shannon-Weiner diversity indices (p=0.060; r2=0.230) of the study sites. In addition, vegetation species richness and odon. species richness show a positive correlation (p=0.066; r2=0.221). A logistic regression establishes that the absence of Coenagrion angulatum, Enallagma ebrium and Aeshna interrupta is associated with high cattle impacts, or low vegetation species richness. This study outlines the effect that cattle can have on wetland odon. species diversity and recommends that measures are taken to protect wetlands, while offering an incentive and reasonable cost/benefit ratio to both rangeland and wetland mangers.

Samraoui, B.; Weekers, P. H. H.; Dumont, H. J. Two taxa within the north African Lestes virens complex (Zygoptera: Lestidae). p. 131-142. A study of Lestes "virens" in Algeria, based on SEM, size analysis, and molecular analysis of nuclear ribosomal DNA genes (18S, 5.8S) and spacers (ITS1 and 2), reveals the presence of two taxa that can be separated by the length and sequence of their ITS1 and their adult coloration, but not by molecular features in their 18S and 5.8S genes, the ITS2 spacer, and morphology. This contrasts with the Enallagma cyathigerum-group, where geographically defined morphological differences were unaccompanied by differences in ITS1 and ITS2. Previous ecological data had shown the first lestid to be a summer, and the second an autumnal reproducer. The red autumnal species is here named Lestes numidicus sp. n. (holotype male, allotype female: Algeria, Lac des Oiseaux, X-1993; deposited in IRSN, Brussels); the status of the green summer species is discussed. It probably corresponds to L. virens, but this is likely to be a hybrid taxon, resulting from the postglacial introgression of L. numidicus with a taxon invading from the East, via the Iberian Peninsula. L. virens vestalis from France is likely to be introgressed as well. In case this hypothesis is confirmed, the first junior synonym available. L. marikovskii (Belyshev) from Kazakhstan, applies to the taxon extending from Kazakhstan-Tajikistan to Central Europe.

Szallassy, N.; Bardosi, E.; Szabo, Z. D.; Szep, T.; Devai, G. Fluctuating asymmetry, survival and mating success in male Libellula fulva Muller (Anisoptera: Libellulidae). p. 143-151. The studies were conducted at Kutas canal near Artand, Hungary. In order to reveal whether there is any relationship between wing fluctuating asymmetry and mating success in mated (observed at least once in wheel position) and solitary male male (not involved in pairing during the study period), 106 males were marked and their wing length between arculus and pterostigma measured. Mated males had more symmetrical forewings, but in the case of hindwings there were no differences between solitary and mated individuals. The survival rate did not differ between the 2 groups and it was constant over time. The probability of recapture was higher in mated male male and varied with time. The number of hours spent with observation did not explain the variation in the recapture rate.

Abro, A. The composition of sperm bundles in Aeshna juncea (L.) (Anisoptera: Aeshnidae). p. 153-157. Using light and electron microscopy, sperm packing has been studied in the large sperm bundles of an aeshnid dragonfly. Each large bundle is built up of variously-sized smaller bundles which probably reflects the intracyst formation procedure. It is proposed that initially there is a gathering of immature sperm cells into small bundles at several sites within the testicular cyst, and secondly all sperm heads are bundled together. This construction of subunits may be of importance to bundle break-down and release of individual sperm cells after transfer to the female reproductive organs.

Butler, S. G. The larva of Phyllomacromia trifasciata (Rambur, 1842) (Anisoptera: Macromiidae). p. 159-163. A female final instar larva from NW Madagascar is described and illustrated. The generic affinities of Phyllomacromia are briefly discussed.

Malikova, E. I.; Ivanov, P. Yu. The larva of Shaogomphus schmidti (Asahina, 1956) (Anisoptera: Gomphidae). p. 165-169. The final instar (exuviae) from Primorye and the Amur R., Russia is described, illustrated and compared with S. postocularis epophthalmus (Sel.).

Rehn, A. C. Oligoclada teretidentis spec. nov. from eastern Ecuador (Anisoptera: Libellulidae). p. 171-175. The new sp. is described and illustrated (holotype male, allotype female: Ecuador, Orellana prov., forested shore of oxbow lagoon near Rio Tiputini, approximately 1 km. NW of Biological Research Station, Parque Nacional Yasuni, 11-X-2001; deposited in UMMZ, Ann Arbor, MI, USA). Species is peculiar in having a large yellowish patch on the ventral mesepisternum and by discrete lateral bands of pruinosity on synthorax (these bands yellow in females) and, in the male, by the ventral, rounded tooth at 1/2 length of cercus.

Samways, M. J. Conservation of an endemic odonate fauna in the Seychelles archipelago. p. 177-182. The odonate species richness of the granitic islands of Seychelles, a biodiversity hotspot, is significantly correlated to island size. The larger islands also have the highest elevations and hence the most streams from cloud catching as well as from downpours. The Seychelles odon. fauna can be divided into 2 groups: (1) endemic spp., and, (2) geographically-widespread eurytopic, vagile spp. The endemic spp. are elevational fugitives that need high-elevation forest cover, even if secondary. They are remarkably tolerant of temporary drying out of streams. In contrast, the widespread spp. occur at low elevations, are pool spp., and are tolerant of removal of forest cover. They emigrate when the pools dry out. Conservation of the endemic taxa depends on maintaining cloud-catching forest, although evidence suggests that their populations are maintained even where the forest is partly alien invasive trees or secondary regrowth.

	Back to list of issues
	Back to Odonatologica home page