Abro, A.Structure and function of the male sperm ducts and female sperm-storage organs in Aeshna juncea (L.) (Anisoptera: Aeshnidae).
p. 1-10.

By the use of light and electron microscopy, the micro-anatomy of the male genital ducts and the female reproductive organs have been surveyed. Sperm bundles transmitted from the testis through the vas deferens become embedded in a carrier jelly and also have additional substances bound to them; obviously the sperm cells are undergoing maturation. In the females, sperm bundles in carrier jelly appear to be deposited in the vaginal canal and, particularly, in the receptaculum seminis, the latter serving for long-term conservation. It seems possible that agents emitted from the posterior accessory glands to the vaginal surface near the genital aperture diffuse forwards, reaching the receptacle entrance. Here they presumably induce a liquefaction of the jelly and break-down of sperm bundles, thus releasing individual sperm cells. Free sperm cells are expected to accumulate in the anterior accessory sacs which they leave during fertilization. The morphological changes taking place in the sperm after transfer to the female genital tract appear ambiguous.

Females were observed ovipositing, both alone and in tandem, in Chaves County, New Mexico, United States. The female oviposits by scooping water droplets into the air with the tip of her abdomen. This mode of oviposition is common in many Libellulinae, but this is the first report of a female using it in tandem as well as in solo oviposition. The female L. composita also grips the male abdomen with her legs during post-copulatory oviposition flight, a behavior previously reported only in subfamilies Trameinae and Zygonychinae. Possible functional significance of this flight behavior is discussed based on observations and analyses of the mechanics of the oviposition process that are evident in photographs.

Based on material from the states of Rio de Janeiro and Minas Gerais, A. serrana sp. n. (holotype male: Serra do Subaio, Teresopolis, Rio de Janeiro State) andA. itatiaia sp. n. (holotype male: Brejo da Lapa, Itamonte, Minas Gerais State) are described and illustrated. The type material is to be deposited in the Museu Nacional and in the Instituto de Biologia, UFRJ, Rio de Janeiro. Morphological features of the 2 new spp. are compared in a table and SE Brazilian members of the punctata group (that includes also A. decessus, A. eduardoi and A. punctata) are keyed.

Data were recorded in 1995-1997. An annotated list of species contains a full reference to the specimens collected, notes on biotope preferences, and relative abundance of spp. For some spp., taxonomic notes and data on variation are given. Among the 31 spp., there are the Manchurian Cercion v-nigrum Needh. andAnisogomphus maacki (Sel.), previously thought to range westwards up to Blagoveshchensk only. Anax parthenope Sel. and Pantala flavescens Fabr. proved to occur in Transbaikalia. The Chinese/Mongolian Ophiogomphus spinicornis Sel. enters the Russian territory in southern Transbaikalia, Baikal region and southern Tuva

Aspects of population dynamics were tested against temperature, insolation and moisture. The monthly abundance of H. rosea was estimated utilizing a scan method based on 49 fixed areas in 30-min intervals from 0800 to 1700 h during the day. The daily male activity pattern is characterized by a sharp increase at 0900 h with continuous density until 1430 h, followed by a sharp decrease after 1600 h. A correlation between peak densities was observed during the year and high period of photoperiod and low evapotranspiration suggesting possible ways males can adjust their emergence periods to optimize water loss with longer reproduction periods of activities.

A review of the exclusively South American components of the genus Psaironeura Williamson shows that only 2 spp. are involved, P. bifurcata (Sjostedt), and P. tenuissima (Selys). P. machadoi De Marmels is considered a synonym of P. bifurcata. Illustrations of the variability within the appendages, keys to males, and comments on the taxonomy of the group are included.

Both sexes of the new sp. are described and illustrated. Holotype male: Brazil: Sao Paulo state, Jacarei, Fazenda Santana do Rio Abaixo, alt. 608 m, 07-II-1999, deposited in author’s collection; allotype and paratypes from the same locality. It differs from T. macilentum by the male cerci possessing elongate, ventrally-directed projections, and by being straight in lateral view. 6 Brazilian spp. are keyed.

In this study, a 10-month survey of four aquatic sites in Kibale National Park, Uganda was used to quantify seasonal and spatial variation in both limnological features of the sites and adult damselfly assemblage structure. Of the 4 limnological characters measured dissolved oxygen was the most variable among sites, ranging from an average of 1.01 mg l-1 in the interior of the Rwembaita Swamp (a papyrus-dominated wetland) to 6.71 mg l-1 in an inflowing tributary of the swamp. Species richness was similar among sites and did not correlate with dissolved oxygen concentration. However, site was a significant predictor of occurrence for some spp. This suggests that site effects are important, and that a combination of site-specific environmental characters may underlie the observed distributional parterns. Seasonal fluctuation in rainfall was not a good predictor of Zygoptera activity. Several spp. were active in both the wet and dry seasons. Surprisingly, adult Proischnura subfurcatum were detected year-round in the hypoxic waters of the Rwembaita (papyrus) Swamp and did not occur at any other sites in the larval or adult phase, suggesting that this sp. is a swamp specialist.

Males of calopterygid damselffies appear to court femalefemale of other (related, sympatric) spp. only rarely. Apparently, femalefemale of this group bear species-specific characteristics that release sexual behaviour in conspecific malemale only. Sympatric Calopteryx spp. usually differ conspicuously in pigmentation (colour, transparency, darkness) of their wings.  Female C. haemorrhoidalis differ from all other European spp. by the presence of a dark distal zone in the hindwings. – The relative value of various (manipulated) sets of female wings for elicitation of male courtship was assessed using choice experiments.C haemorrhoidalis males did not court wingless females of their own sp. nor did they court conspecific females with wings of the sympatric C. xanthostoma. However, the presence of a single wing of a conspecific female was sufficient to elicit courtship behaviour. Choices between 2 female models (presented simultaneously to territorial male individuals) revealed that the presence of a contrasting dark zone was an important distinguishing characteristic, whereas too high a transparency (a single wing as opposed to a set of 2 or 4 wings pressed against each other) greatly diminished the value of a model. The need for the presence of a dark zone will be effective in precluding courtship of femalefemale of other sympatric spp. The need for sufficiently low transparency will put a check on courtship attempts of immature females.

The Castel Porziano estate is a well preserved coastal Mediterranean woodland, rich in still bodies of water, where odonatological studies have been taking place since the ’50s. Adult Odon. were recorded for the entire estate in 1997 and 1998 (March-Nov.; 2 checks each month). 1,838 adults (22 spp.) were marked, to assess their movements. The results showed that in 1997-1998 a total of 31 spp. were present. This number is very close to the number (29) recorded up to 1976. Variation in species assemblage in 16 ponds was observed from 1997 to 1998. Although the overall species similarity was preserved, the number of spp. for each pond and the number of ponds inhabited by each sp. significantly increased from 1997 to 1998. In regard to the adult movements, 251 marked individuals of 13 spp. were re-sighted only at the same ponds where they had been marked and 30 individuals of 6 spp. were sighted at different ponds. Among the latter, the majority moved within a range of a few hundred metres, but some individuals were able to fly quite far, e.g. 2.7 km (Coenagrion puella) and 5.8 km (Libellula depressa). It is concluded that the assemblage variation for the entire estate was small, varying more on a decennial than on an annual scale, but for a single pond variation is wider on both time scales. The quick recolonization among ponds, due to the adult’s movements, appears to be the cause of greater stability at mesoscale rather than at local scale.

The mark-and-recapture method was used to study the population parameters of sexually mature adult S. infuscatum in a forest-paddy field complex in the cool temperate zone of Japan. After emergence, they moved into the forest gaps, and they remained and fed exclusively in the forest gaps throughout their lives. Mature males captured outnumbered mature females on each sampling day in the paddy fields, but not in the gaps. However, the estimated daily numbers in both habitats and/or the whole survey area roughly indicated a 1: 1 sex ratio. The estimated daily survival rates and daily immigrations showed that females were apt to stay in the forests, while males sometimes dispersed, though females in the paddy fields tended to have a long-range flight. In the morning, some of the paired couples flew to the paddy fields in tandem and oviposited on the wing; these were so-called flyers. The rest remained in the forests the entire day; these were designated as perchers. The forest gaps were thus important for the life cycle of this species both as feeding and roosting sites.

The ribosomal DNA genes (18S, 5.8S) and internal transcribed spacers (ITS 1, ITS2) of 5 representatives of “Cercion” occurring in East Asia were examined and compared with west-palaearctic “Cercion” lindenii, Erythromma najas (2 populations), E. viridulum, some true Coenagrion species, and with Enallagmaand Ischnura as outgroups. The molecular phylogenetic tree confirms the position of H. Heidemann & R. Seidenbusch (1993, Die Libellenlarven Deutschlands and Frankreichs, Bauer, Keltern) that Cercion lindenii belongs in Erythromma, and consequently, the binomen Erythromma lindenii is accepted. Regarding the “oriental” group for which, under the new situation, the name Cercion is no longer available, the genus name Paracercion gen. n. is introduced. This is supported by molecular evidence and by some morphological traits. A morphological basis for setting apart the new genus from Erythromma is thus achieved, but its delimitation from Coenagrion remains to he defined.

An ultimate male final instar larva from NW Madagascar is described and illustrated. Other, smaller larvae collected at the site are used for both support and comparison. Comparisons with the exuviae of 7 other spp. of the genus Onychogomphus are also provided.

The new sp. is described and illustrated. Holotype male and allotype female (in copula): Bolivia, Cochabamba Department, Chapare prov., lake 2.5 km W of Villa Tunari gate on Hwy 4, 12-XI-2001; both deposited in U.A.G.R.M. in Santa Cruz, Bolivia. males are characterized by the knobbed shaped paraprocts, and the homochromatic females by their black ovipositor. Both can be distinguished from other congeneric spp. by their dark, almost black terminal abdominal segments.

2 larvae from the Yixian Formation are described. One of these has morphological similarities with the ‘ultimate larval instars of Sona nectes’, and the other one is of ”cordulegastrid” -type. The relationships of the ‘ultimate instars of S. nectes’ and its young larvae are outlined and their identity is addressed. The “cordulegastrid”-Iike larva provides new data on the early evolution of the taxa involved.

An analysis of a large series of specimens from Eurasia showed a strong morphological variability. It is of an individual, modificatory, or clinal nature, rather than a geographical one. Thus, 2 continental sspp., S. p. intermedium Belyshev, 1955 and S. p. kurentzovi Belyshev, 1956, should be suppressed as they cannot be defined by any taxonomically significant differences. The insular subspecies, S. p. elatum, inhabiting Sakhalin, the Kurile and the Japanese islands, however, can be separated. It is concluded that S. pedemontanton has only 2 sspp.: continental S. p. pedentontanum and the insular S. p. elatum.

Sperm, transmitted to the female as individual filamentous cells suspended in a liquid medium, are discharged into a thick-walled pouch, the receptaculum seminis, on the dorsum of the vaginal canal. Spermatozoa soon appear concentrated in a single, smaller, pear-shaped accessory sac, the spematheca, attached to the receptaculum-vagina junction. Particular cells in the wall of the accessory sac secrete a material that is thought to be added to the sperm concentrate. The purpose of the accessory sac is to serve as a store ofsperrnatozoa for use in fertilization. A pair of posterior accessory glands has each an efferent duct that opens into the distal region of the vaginal canal; these ducts are provided with an elaborate muscular apparatus probably serving as a pump: in fresh material, efferently directed peristaltic waves have been observed. The glands are presumed to contribute to the investment of the eggs. The apical domains of the glandular epithelial cells contain intraplasmic assemblages of multiplicating bacteroids. They are likely to be transferred to the ooplasm and thereby transmitted to a new generation.

During copulation, C haemorrhoidalis males displace the sperm of rivals stored by the female. During displacement, sperm stored in 2 spermathecae are ejected by the female as a consequence of male genitalic stimulation: the aedeagus distorts 2 vaginal plates in which mechanoreceptive sensilla are embedded. The sensilla control spermathecal sperm release and a wider aedeagus displaces more sperm. There is variation between female female in their sensillum number which might also affect sperm displacement rate. The role of sensillum number and aedeagal width in sperm displacement variation in copulations whose duration was controlled was investigated. Results indicated that only aedeagal width could predict sperm displacement variation. The neural communication between the vaginal plates and both spermathecae was also examined. Previous observations suggested a “lateral” control of sperm ejection between each vaginal plate and its corresponding spermatheca. This was corroborated by stimulating the mechanoreceptive sensilla of females that underwent different surgical treatments: only those females whose vaginal plate nerves were cut, showed no volumetric decline in sperm in the corresponding spermatheca. Finally, the effect of copula duration (number of aedeagal copulatory movements) on sperm ejection was experimentally examined. In natural conditions, males perform approximately 50 aedeagal movements during copulation. There was no difference in sperm volumes between the pairs of females that were subjected to 50 and 80 aedeagal movements of stimulation using the same aedeagus. These results help to understand the nature of the spermathecal sperm displacement mechanism in this sp.

The odon. fauna of Turkish Thrace (52 spp./sspp.) is discussed, based on 40 spp./sspp. gathered during 1997-1999 from 86 localities. Lestes macrostigma(Eversm.), Enallagma cyathigerum (Charp.), Aeshna isosceles antehumeralis (Schmidt), Hemianax ephippiger (Burm.), Onychogomphus f. forcipatus (L.),Cordulegaster i. insignis Schneider, Pantala flavescens (Fabr.) and Sympetrum pedemontanum (Muller) are new to this part of Turkey. Among the taxa discussed in some detail are Calopteryx splendens amasina Bart., Chalcolestes parvidens (Artobol.), Lestes v. virens (Charp.) / L. virens vestalis Ramb.,Ischmura elegans ebneri Schmidt / I. e. pontica Schmidt, Gomphus vulgatissimus (L.) / G. schneiderii Sel., Onychogomphus f. forcipatus (L.) / O. f. albotibialisSchmidt, Somatochlora meridionalis Nielsen, Libellula fulva Mull. / L. pontica Sel., and O. c. coerulescens (Fabr.) / O. c. anceps (Schneider). Some identification errors in earlier publications are corrected.

The behaviour of male Coenagrion puella and Xanthocnemis zealandica towards conspecific andromorph and gynomorph females was studied at breeding ponds in the U.K. and in New Zealand respectively. As expected, male attention directed towards copulation wheels (C. puella) did not depend on whether the wheel contained an andromorph or a gynomorph. Similarly, 6 attention directed towards tandem pairs (C. puella and X. zealandica) did not depend on whether the tandem contained an andromorph or it gynomorph. When individual andromorph and gynomorph females (C. puella and X. zealandica) were released at the water’s edge they experienced similar levels of attention from males. By contrast, males (X. zealandica) formed significantly more tandems with gynomorphs tethered at the water’s edge than with tethered andromorphs. The observations suggest that males readily identify and intercept conspecific females at the water’s edge, particularly when in motion, and that andromorphs and gynomorphs are equally susceptible to male attention. Behaviour of males towards tethered females may be atypical compared to that recorded under more natural conditions.

The last instar larva of D. maya is described and illustrated for the first time, based on reared material from Hidalgo, Morelos and Michoacan States, Mexico. The larva of D. maya is the largest of the genus and is remarkably different from other larvae, mainly by the reduced or wanting dorsal protuberances, and in the short lateral spines on the abdomen. A redescription of the larva of D. sterilis and some notes on other larvae of Dythemis are also provided, and A species are keyed.

In L. virens, the tandem post-copulatory guarding varies from some minutes to more than 4 hours and appears correlated to the time of the day and disturbance by unpaired males. Using a multiple regression analysis, with guarding duration as the dependent variable and time of day, temperature and disturbance as the independent variables, it is shown that only disturbance significantly explains the model. An experimental test, in which early-occurring tandem males were not disturbed, while late-occurring ones were disturbed (a reverse situation of what happens in the field), showed that the latter kept their ovipositing females for significantly longer times than the former. The capability of males of varying guarding duration accordingly to the density of solitary males allows them to invest more or less time for guarding, according to the actual risk of losing sperm precedence.

Shifts between perching sites, the flying behaviour as well as reproductive behaviour of adults were observed. All marked individuals inhabiting the dense reed community floor were followed from sunrise to sunset. Simultaneous observation was carried out by approximately 20 researchers. Every adult, sexually immature and mature, perched at 20 cm above the water surface within the reed community. For immature adults, about 120 flight activities were performed per day. The accumulated length of the movement was 9 m per day. When matured, the number of flight activities increased two-fold and the total length of the movement was 27 m per day. Although this sp. is a percher, showing little movement, increased flight activity by mature individuals caused encounters between individuals, hovering face-to-face. Few tandem flights were observed and females oviposited alone. The behaviour traits of this sp. at low light intensity are discussed.

A larval population was studied (1994-1996) on the Zschopau river, Saxony. Germany. In 325 larvae head widths and wing-sheath lengths were measured, and the abdominal segments that were partly or completely covered by the wing-sheaths were counted. Within the population, there was much size variation throughout the yr. This is interpreted in terms of co-occurrence of the univoltine and semivoltine cohorts. The semivoltine F-0 larvae were larger than the univoltine of the same stage. There are more males than females in the larval population.

The female is described and compared with that of N. cultellatum (Hagen in Selys, 1876). A key to separate the female female of both sp. and notes on the taxonomy, biology and distribution of N. gladiolatum are provided.

Eight species occurring in Japan and continental East Asia are separated by the morphology of their male terminalia and by the structure of the female pronotum and adjacent laminae mesostigmales. Paracercion barbanan is confirmed as a good species, probably restricted to China, where it co-occurs with P. impar and other spp. The continental East Asian P. v-nigrum is suggested to share a common ancestor with the Japanese P. sieboldii. On chorological grounds, the latter should not exist in Taiwan. Both sexes of all spp. are keyed.

Based on literature records and the examination of an extensive Odonata collection made in Fujian in 1930-1940’s (now in RMNH, Leiden), 21 spp. of Caloptera(Calopterygoidea) are recognized as occurring in Fujian province in eastern China. The Fujian Caloptera material (ca 860 specimens of 18 species) in RMNH is enumerated. The following taxonomic decisions are presented: Navas, 1934 is removed from synonymy with Caliphaea nitensBayadera melanoptetyx Ris, 1912 and ranked as a valid species, distinct from C. consimilis McLachlan, 1894. The lectotype of Vestalis smaragdina Selys, 1879 is designated. Vestalis velata Ris, 1912 (syn. V. virens Needham, 1930) is ranked as a good species, while the “hyaline winged form of V. smaragdina velata” (sensu Asahina, 1977) is described as a new sp. Vestalis venusta sp. n. Bayadera continentalis Asahina, 1973 from Fujian and B. ishigakiana Asahina, 1964 from the Ryukyus are treated as full sp. and not as ssp. of Fraser, 1928 from Taiwan. B. brevicaudaBayadera melania Navas, 1934 is synonymized with B. melanopteryx Ris, 1912. Some preliminary taxonomic comments (to be discussed in detail elsewhere) are presented: Calopteryx grandaeva Selys, 1853 is a probable synonym of C atrata Selys, 1853, whereas C. atrocyana (Fraser, 1935) is a good sp. Matrona basilaris Selys, 1853 and M. nigripectus Selys, 1879 appear to be distinct sp. Mnais tenuis Oguma, 1913 and M. andersoni McLachlan in Selys, 1873 are also better treated as separate sp. Faunistic notes include: Libellago lineata (Burmeister, 1839) is recorded from Fujian province for the first time. Old records of Psolodesmus mandarinus McLachlan, 1870 and Euphaea compar McLachlan, 1870 (synonym of E. formosa Hagen in Selys, 1869) from Amoy Island near the Fujian coast are considered doubtful.

Much variation occurs in morphology and colouration among individuals of Japanese Mnais spp. It has been noted that 2 groups of Mnais often cohabit a stream in western Japan. There is, however, no clear morphological difference in male appendages and penis between the 2 groups, and this makes it difficult to determine their taxonomic status. In this study, to clarify the relationships between the sympatric species on both small (along a stream) and large (across Japan) geographic scales, sequences of the internal transcribed spacers 1 and 2 (ITS 1 and 2) of nuclear ribosomal DNA are compared. Base substitutions occurred at 4 sites of 223 bps of the ITS1 region, and by their combinations, the four sequence types could be distinguished among a total of 800 individuals. In the ITS2 region (total 411 bps including 5.8S rRNA region), all examined individuals had the same sequence. The geographical distribution of each ITS1 sequence type and morphological data of wings and a pterostigma suggest that Japanese Mnais includes 2 distinct spp., M. strigata Selys, 1853 and M. costalisSelys, 1869. Their distribution ranges overlap widely in western Japan, where M. strigata is usually found at smaller and upper streams than M. costalis.

Relevant and mainly structural characters of Austrogomphus s. str., Austroepigomphus Fraser, Pleiogomphus Watson, Xerogomphus Watson andZephyrogomphus Watson, all considered by J.A.L. WATSON (1991, Invertebr. Taxon. 5: 289-441) as subgenera of Austrogomphus Selys, are described and illustrated. On the basis of this information it is suggested that Austroepigomphus and Zophyrogomphus should be elevated to generic rank, that Pleiogomphusshould keep its position as a subgenus of Austrogomphus, and that Xerogomphus should be regarded as a subgenus of Austroepigomphus. Some morphological details of the previously undescibed male of what is now Zephyrogomphus longipositor (Watson) are given.

RhinocyPha chaoi sp. n. (holotype male Dadingshan, Guangdong), Megalestes discus sp. n. (holotype male: Mangshan, Hunan). Rhipidolestes chaoi sp. n. (holotype male: Mangshan, Hunan), Calicnemia chaoi sp. n. (holotype male: Pengshan, Guangdong) and Macronlia unca sp. n. (holotype male: Maoping, Guangdong) are described from the Shikengkong area of northern Guangdong province and Southern Hunan ill Southern China.

The new sp. is described, illustrated and compared with the similar H. selysii Fraser. Holotype male: S Vietnam, Laindong prov., 15 km from Bao Lok to Ho-chi-minh, 6-V-1997; deposited in Kanagawa Prefectural Museum of Natural History, Odawara, Japan.

The new gen. and sp. are described and illustrated from the Luohandong Formation of Huating Co., Gansu province, P.R. China, from a single, almost complete specimen. Holotype No. 123518, probably a female, deposited at IGPAS, Nanjing, China.

The long abdominal segment 10 in L. angustus is used as a monopod to support itself while it perches on horizontal steins and twigs in the shade of bushes or trees.