Dragonflies of the Golfo Dulce Region,

Piedras Blancas National Park “Regenwald der Österreicher”

Printed with generous support from the Austrian Federal Ministry of Agriculture, Forestry, Environment and Water Management

1 Authors

Stefan Schneeweihs

Department of Population Ecology University of Vienna

Rennweg 14, 1030 Vienna, Austria

[email protected]

Roland Albert Werner Huber Anton Weissenhofer

Department of Chemical Ecology Department of Ultrastructure Department of Ultrastructure and Ecosystem Research Research and Palynology Research and Palynology University of Vienna University of Vienna University of Vienna

Rennweg 14, 1030, Vienna, Rennweg 14, 1030, Vienna, Rennweg 14, 1030, Vienna, Austria Austria Austria

[email protected] [email protected] [email protected]

2 Contents

The “Tropical Research Station La Gamba” ...... 4

The rainforests of the Golfo Dulce region ...... 6

Introduction ...... 8

History and diversity of ...... 8

Adults and larvae ...... 8

Life cycle ...... 9

Morphology of the adult ...... 10

Identification ...... 11

Tropical dragonflies ...... 11

Odonatological field trips around La Gamba ...... 12

Forests ...... 12

Cultivated landscapes ...... 13

Forest margins ...... 13

Zygoptera ...... 14

Polythoridae ...... 14

Calopterygidae ...... 16

Megapodagrionidae ...... 18

Pseudostigmatidae ...... 20

Protoneuridae ...... 21

Coenagrionidae ...... 23

Anisoptera ...... 28

Gomphidae ...... 28

Libellulidae ...... 29

Diversity of dragonflies in La Gamba ...... 50

Acknowledgements ...... 50

References ...... 51

Dragonflies on the web ...... 51

Picture credits ...... 52

3 The „Tropical Research Station La Gamba“ Roland Albert Secretary General of the „Society for the Preservation of the Tropical Research Station La Gamba“ Department of Chemical Ecology and Ecosystem Research, University of Vienna

The main building of the Tropical Research Station

In 1991, Michael Schnitzler, a distinguished Station La Gamba" flourished and grew. It now musician and former professor at the University comprises several buildings and includes com - of Music and Performing Arts in Vienna, found - fortable living and research facilities for more ed the "Association Rainforest of the Austrians" than 30 visitors as well as a botanical garden. In (Verein Regenwald der Österreicher ). Over many 2008 an air-conditioned laboratory was construct - years, he collected contributions in Austria and ed with the support of the Faculty of Life Sciences forwarded the funds to the Costa Rican govern - of the University of Vienna. With its infrastruc - ment. With the money, the government pur - ture, the field station is currently on the threshold chased large tracts of forest from landowners and of becoming an internationally established placed it under the control of the “Parque research institution and education centre, Nacional Piedras Blancas”, thereby preserving focussing on the exploration and conservation of the Esquinas Rainforest in southwestern Costa Neotropical rainforests. Since its foundation, Rica. It soon became apparent that this protected many scientists have carried out field research in area also provided ideal conditions for promoting the Esquinas rainforest and many visitors have Austrian research and teaching programmes in admired its beautiful surroundings. rainforests. As well as supporting research and teaching To make the area more accessible, the activities, the station helps the inhabitants of La "Association Rainforest of the Austrians" bought Gamba by means of a series of applied projects to an old farmhouse (a finca ) in 1993. This formed improve their living conditions. These projects the nucleus for a tropical field station, located are partly run in collaboration with the nearby directly on the border of the National Park near "Esquinas Rainforest Lodge", another brainchild the small village of La Gamba. With the support of Michael Schnitzler, which represents an of the "Association Rainforest of the Austrians", Austrian example of sustainable ecotourism. the Ministry of Science and Research and the Indeed, the lodge was recently awarded the offi - University of Vienna, the "Tropical Research cial Costa Rican “Three-Leaf Certificate of Sustainable Tourism”. We are particularly proud that the former European Commissioner for Agriculture, Dr. Franz Fischler, has been a patron of the “Society for the Preservation of the Tropical Station La Gamba” ( Verein zur Förderung der Tropenstation La Gamba ) since 2006. Numerous scientific publications have result - ed from research performed at the Tropical Research Station La Gamba, including about 60 doctoral and diploma theses. The scientific work initially focussed on the flora and vegetation of Students crossing the Rio Bonito during a field course the Esquinas forest but it has now broadened to

4 include a wide range of other topics, such as ani - We are now proud to offer a further colourful mal-plant interactions, herpetology, ornithology, issue dealing with a group of - the drag - entomology (especially studies of butterflies), lim - onflies – that may at first sight appear less obvious nology, chemical eco-physiology, bio-geochem - than the region’s birds, amphibians or reptiles. istry, geography and sociology. About 50 field However, due to its high precipitation the region courses and excursions have been organized, of La Gamba, with its numerous ponds, runoffs enabling students and scientists from universities and brooks, harbours a huge diversity of these all over the world to visit the Piedras Blancas beautiful animals. We owe the appearance of this National Park. booklet to Stefan Schneeweihs, who has enthusi - Our Society is particularly interested in pro - astically carefully gathered information and pho - viding all our visitors, and beyond that the many tographic records from the ecologically diverse friends and admirers of the tropics, with informa - surroundings of La Gamba, where primary and tion on the biology and ecology of the local and secondary rainforests are closely associated with regional rainforests and of the adjacent cultural cultivated land. A booklet on “Corbiculate bees of land. Following the publication of an internation - the Golfo Dulce region, Costa Rica” is being pub - ally acclaimed "Field Guide of Flowering Plants lished simultaneously. of the Golfo Dulce Rainforests" in 2001, five It is our hope that this booklet – as our former colourful brochures have to date been published: brochures and books - will be a source of informa - "Amphibians and Reptiles of the Golfo Dulce tion and joy to lovers of tropical life, to scholars Region", “The Birds of the Golfo Dulce Region, und students, to teachers and researchers at the Costa Rica”, “Das Leben hier und dort – La vida University and – finally - to all the friends of the aquí y allá”, “Ecosystem diversity in the Piedras "Rainforest of the Austrians" and the “Tropical Blancas National Park and adjacent areas (Costa Research Station La Gamba”. Rica)” and “Fruits in Costa Rican Markets”, as well as a scientific monograph “Natural and For further information see: Cultural History of the Golfo Dulce Region, Costa www.lagamba.at Rica”,. www.regenwald.at

The “Comedor” Scientists in the air-conditioned laboratory

The pond in the garden of the station

5 The rainforests of the Golfo Dulce region Werner Huber & Anton Weissenhofer Department of Ultrastructure Research and Palynology, University of Vienna

The Golfo Dulce region is located in the southern corner of the Pacific coast of Costa Rica, near the border with . Within this region are the Corcovado and Piedras Blancas national parks. The forests of the region are the only moist or wet evergreen lowland forests that still exist on the Pacific coast of Central America. The elevations range from sea level to 745 m on the Cerro Rincón, Peninsula de Osa; the annual precipi - tation is up to 6,000 mm with a short or almost nonexistent dry season from December until March; the relief is strongly structured at the

Climatic diagram, La Gamba

landscape level and contains many microhab - itats and niches; and the soil types are diverse and the vegetation highly dynamic. All of these factors, coupled with the biogeographi - cal position of the Golfo Dulce, have led to a very -rich forest: about 2,700 species of higher plant have been recorded from the area. The tallest in the moist and wet ever - Morning clouds above the forest green lowland forests grow up to 60 m high

Waterfall on the Quebrada Chorro

6 Students with a huge with buttress roots in the forest

(e.g. Anacardium excelsum , Parkia pendula , grove ( Rhizophora mangle ) and mangle pinuela Carapa guianensis , Brosimum utile and Caryocar (Pelliciera rhizophorae ). In addition to the vari - costaricense ). Most trees retain their foliage ous types of primary and secondary forest, throughout the year. Palms (about 45 species) the area also features other types of habitat such as Socratea exorrhiza , Iriartea deltoidea , such as pastures, pools, rivers, cultivated land Welfia regia and Asterogyne martiana are typical and various kinds of plantation (e.g. oil palm, features of the forest. Heliconia herbs are obvi - teak and manioc). Bees are very abundant and ous near streams and in gaps. Lianas (e.g. are found in all habitats. Bauhinia and Entada ), vines and epiphytes Costa Rica’s geographic location on the (, Orchidaceae) are found on ‘bridge’ between North and South America many trees. About 100 species of orchid (e.g. and the fact that the country formed a kind of vanilla) and 40 species of bromeliad are dis - refuge for tropical animals and plants during tributed in the region. the last ice age has led to remarkable biogeo - Hemi-epiphytic plants of the Clusia graphical patterns. Restricted-range plants are abundant in the very wet parts of the for - and animals are abundant and many reach est while fig trees ( Ficus ) are more frequent in their northern limits in southern Costa Rica. the drier regions (on the Corcovado plains). The region is an excellent place for naturalists On the coast, the coconut palm ( Cocos nucifera ) to enjoy tropical nature. An extensive system and the “tropical almond tree” ( Terminalia cat - of trails in the Corcovado and Piedras Blancas appa ) are the most conspicuous plants; in the national parks (La Gamba) offers wonderful mangroves this position is taken by red man - insights into tropical rainforests.

Interior of the forest of the NP Piedras Blancas

7 Introduction

Visitors to the La Gamba Research ecosystem. Today the order (drag - Station will find a rich array of tropical life. onflies) is divided into three suborders, the As well as an overwhelming diversity of most common being the smaller Zygoptera plants, they will see birds and butterflies, (also known as ) and the larger two of the most popular and conspicuous Anisoptera. A third suborder, the groups of animals. Hummingbirds, noisy Anisozygoptera, which combines character - toucans, and brilliant butterflies like the iri - istics of the other two groups, is represented descent Morpho or the spectacular Heliconius by two species in Nepal and Japan. are well known throughout the world. But Approximately 5700 species have been there are many other groups which are just described so far, with almost equal numbers as recognisable yet not as widely known. in Zygoptera and Anisoptera. Because larval Unfortunately there is often a dearth of growth responds positively to temperature, knowledge about such organisms, and access dragonflies are assumed to have developed to the relevant literature is difficult. in a warm climate. Today the greatest diver - Sometimes, however, we just need a little sity is found in tropical regions, declining help to find them. Dragonflies are skilled towards higher latitudes. Areas of the high - fliers, fearless predators, and passionate est diversty are found in South America and lovers, and once you notice them, you will South East Asia, especially in montane find them fascinating. regions where examples of previously The ecology and behaviour of the Central unknown species are often reported. American fauna has been laid out in detail in the specialist literature (see refer - Adults and larvae ences), and more interested readers are invit - Zygoptera and Anisoptera can be easily ed to consult these sources. This booklet is identified as adults and larvae. Adult designed as a pocket guide to the identifica - Zygoptera are usually finely built tion of the most frequently observed species with slender abdomens. The eyes are sepa - around La Gamba. The descriptions of char - rated and situated laterally on the head. acteristics and differences between the Their fore wings and hind wings are fairly species are limited to essential information. similar in shape and venation, and are held Although identification can be difficult, and over the abdomen when resting. In flight for some species beyond the scope of this they are less acrobatic than Anisoptera, and booklet, it should be possible to recognise are often found patrolling in dense vegeta - most of the common species present in the tion near the water’s edge. The larvae of region. For the interested observer, this Zygoptera are small and slender, this shape booklet will serve as an introduction to the often appearing pronounced by the presence diversity of a fascinating group of animals. of three flattened, elongated and highly tra - We hope it will raise awareness of the diver - cheate caudal appendages that serve as res - sity of dragonflies, but also of how urgently piratory organs. Three tropical families form we need to work for their conservation. the exception, showing either lateral gills on the abdomen (Euphaeidae and History and diversity of dragonflies ), or gill tufts at the end of the The first fossil records of a group called abdomen (Amphipterygidae). Protodonata, closely resembling today’s Adult Anisoptera are built robustly, with dragonflies and thought to represent their a long or stout abdomen. Their large eyes ancestral form, date from the Upper cover almost the whole head and meet on Carboniferous period 325 million years ago. top of the head, or they can be slightly sepa - With a wingspan of 70 cm, Meganeura monyi rated as in the family Gomphidae. The wings was one of the largest insects ever to have differ in shape and venation and are held lived on the planet. Today’s dragonflies are open when resting. Anisoptera can be considerably smaller, but these ancient observed perching on exposed structures insects still have a valuable place in the along banks, or patrolling for hours over the

8 water surface. The larvae are stout and have ronmental factors like the reflection of the three strong spines instead of lamellate aquatic surface, and the vegetation structure. appendages. They breathe by ‘rectal ventila - After one or more weeks the embryo will tion’, pumping water through the rectum, have completely developed, and the first where a tracheate organ serves for gas larva (prolarva) will be ready to hatch from exchange. Water can be expelled from the the egg. Subsequently, having reached the rectum very forcefully, so that the larva water (in the case of endophytic eggs), the swims forward. This ‘jet propulsion’ is also prolarva starts to moult (i.e. to leave the old used to escape predators. cuticula), in a process called ‘ecdysis’. Larvae and adults are predators and fair - During the larval phase, which can last from ly opportunistic in their choice for prey, a few weeks up to several years, up to 15 although specialisation does occur (see ecdyses are completed, separated by periods ). Both developmental of foraging behaviour and growth. In tem - stages are perfectly adapted to this lifestyle. perate regions, eggs or larvae can display a Larvae actively search out or ambush their diapause, a reduction of metabolism and prey, detecting it visually or by touch, and growth during winter. capture it by the rapid protraction of the The final larval stage, at which an adult modified lower lip (or ‘labium’) which forms is contained within the larval skin, sees the the so-called ‘mask’. Adults detect prey with larva leaving the water for emergence. This their large eyes. In flight, they can turn spectacular scene usually takes place shortly quickly, hover, and even backwards, before dawn. The larva climbs up a suitable since the flight muscles insert directly on the structure, often a piece of aquatic vegetation, wing base, allowing them to move each pair and searches for a firm grip with its legs. The of wings independently. Even fast-flying larval skin then bursts at pre-formed points, prey such as other dragonflies can be cap - and the young adult leaves the skin. After a tured by their acrobatic manoeuvres, held by short rest the adult unfolds its wings and their legs, and then manipulated with their abdomen by pumping in haemolymph. After sharp mandibles. emergence, the smooth and shimmering skin first has to harden. Then the dragonfly sets Life cycle off on its maiden flight, leaving the site of Dragonflies are hemimetabolic insects, emergence. exhibiting incomplete metamorphosis and Young adults spend their first days on lacking a pupal stage like that in butterflies; the side of the water in order to build up fat the adult develops during the last larval reserves, and to avoid interference from stage. Their life cycle comprises three phases: mature and territorial dragonflies. The sexu - egg, several larval stages, and adult. The lar - al organs are not yet fully developed, and vae live predominantly in fresh water, inhab - they start to mature during this period. In iting lakes, streams, bogs, and ephemeral some tropical species, when breeding habi - water bodies. Only a handful of species are tats have dried out, this pre-reproductive known to develop in the brackish water of time can be prolonged for months until the marine marshes, or to have terrestrial larvae. beginning of the next wet season. When the Many species are generalists, capable of sexual organs have fully developed, the inhabiting a wide spectrum of freshwater adults turn to suitable water bodies for systems. Some species, however, have nar - reproduction. row breeding site requirements and are thus Males spend many days at reproductive sensitive to disturbances and habitat destruc - sites, where they establish temporary territo - tion. Many of these specialists are rare, but ries that are defended against other males. they can be used for the assessment of eco - Females are often dispersed around other logical freshwater status. habitats and only visit the water bodies for After mating, the female lays fertilised copulation and oviposition. When a female eggs either on the water (exophytic), or into enters a territory, the male up and tries (sometimes submerged) plants (endophytic). to grasp her with the caudal appendages, on Before oviposition, suitable habitats for the female’s thorax in the case of Zygoptera, development are selected by the adults. and on her head in Anisoptera. The male During this selection they orientate on envi - then bends its abdomen forward to transfer

9 sperm from its sexual organs to its copula - Morphology of the adult tion organ. Finally, the female bends her The body of a dragonfly is separated into abdomen forward to bring her genitals into head, thorax and abdomen. The head bears contact with the copulation organ of the two large compound eyes, three median male, forming the ‘wheel of love’ (see ocelli, and two short antennae. Between the herculea ). With its copulation organ, eyes, the ‘frons’ forms the frontal part of the the male is able to remove sperm from previ - head. Below the frons, the labrum covers the ous copulations with other males and trans - mouthparts, which handle prey. The fer its own sperm into the female. Copulation colouration of eyes, frons, and labrum can be can take place while airborne or resting, and important characteristics for identification. may take anything from a few seconds to The thorax consists of three segments, each many minutes. The female can start to lay with a pair of legs. The first segment (protho - eggs immediately after copulation. Males rax) is short. The second and third segments often guard the female during oviposition, are fused and dorsally inclined backwards, either still attached or hovering next to her, and each has a pair of wings. The wings have to avoid other males attempting to copulate. five major veins and numerous crossveins. The front margin of the wing is formed by a vein called the ‘costa’. Details of venation are variable, but two conspicuous structures are present in all species. The ‘nodus’ is a strong crossvein, inserted at the front edge of the wing approximately half way along its length. The ‘pterostigma’ is a dark cell at the distal part of the wing on the costal side. The base of the wing can be narrow for the length of several cells (petiolate), extended, or nei - ther. The colouration and markings on the wings can be helpful characteristics for iden - tification. The abdomen consists of ten segments of Front view of the head of an Anisoptera ( sp. variable length. The first two segments are ) short, segments 3–7 are long, and segments

Body regions of a male Zygoptera ( Acanthagrion inexpectum )

10 8–10 become shorter again. In males, seg - The most frequently observed forms of ments 2 and 3 bear the copulation organ ven - different species are illustrated in this book - trally. Females have ovipositors at the ven - let. If an observed individual does not fit any tral side of segment 8, sometimes extending of the photographs, this may be for one of to the tip of the abdomen, or a small vulvar two reasons. Either the species is not includ - lamina. At the end of the abdomen are the ed in the booklet, or the individual is of a dif - appendages, two upper and two lower in ferent sex or age. The following caveats have Zygoptera males, and two upper and one to be kept in mind during identification: lower in Anisoptera. species of the same genus may be similarly coloured; colouration may differ between Identification males and females of the same species; pre- Characteristics for unambiguous identifi - reproductive males often resemble females cation include wing venation and the struc - and usually become darker before entering ture of the male copulation organ or the the reproductive period; the shallow ovipositor. Examination of these structures colouration of recently emerged adults turns requires specialist knowledge and the ability into their characteristic pattern after several to capture individuals. Colouration, howev - hours, but wing markings may need longer er, can also be useful for identification, to become fully developed. Descriptions of although species–level determination is not immature and mature forms, and males and always possible. Any individuals observed females, are given in the text wherever they should be compared with the photographs, are available. Species closely resembling sizes, and descriptions of details in this book - each other are also mentioned in the text. let. The availability of aquatic habitats for Males can be recognised by the presence larval development constrains reproduction of a secondary copulation organ at the ven - in dragonflies, and consequently the rainy tral side of segments 2 and 3 of the abdomen, season marks the climax of the reproductive which forms a small but prominent structure period for many species. Adults of some absent in females. Females may have a con - species may be absent during the dry season, spicuous ovipositor on the ventral side at the either not yet emerged from their larval end of the abdomen. In Anisoptera, the stage, or occupying alternative habitats. It is ovipositor may be reduced to a small lami - therefore possible that not all species present nate structure arising from the end of seg - in the region may be observable during a ment 8, and projecting towards segment 9. short visit. Males are usually brightly coloured and often have conspicuous markings on the Tropical dragonflies wings. Females are usually dark or brownish In both their ecology and behaviour, yellow and less colourful. tropical dragonflies deviate in some ways Body and wing measurements may help from temperate species. In montane regions to distinguish between similarly coloured isolation processes have favoured speciation, species of different sizes. The body and and diversity in the tropics by far exceeds the abdomen sizes given in this booklet include number of species in temperate regions. In the caudal appendages. Values given are the tropics, manifold niches have enabled the either means of several individuals, or meas - development of specialised life strategies. urements of single individuals. Individual The larvae of Neotropical Pseudostigmatidae variation in body proportions can be up to and some other families, for example, inhab - several millimetres, and this should be borne it ‘phytotelmata’ - water-filled cavities like in mind when comparing observed dragon - tree holes or plant tanks. The long abdomen flies with the values given in the description. of Pseudostigmatidae females is useful for Measures of size and body parts account for oviposition into such deep structures. The both sexes if not indicated otherwise. strategy of migrating species such as Pantala The abundances of species are given for the flavescens may be linked to the unstable and region around La Gamba, and do not apply unpredictable availability of breeding waters to their frequencies in Costa Rica or Central in drier regions. This circumtropical species America. often forms swarms of hundreds of thou -

11 sands of individuals migrating over long dis - Austria (77 species) and Europe (125 tances in front of rain fronts. The eggs are species), Costa Rica is very rich in dragon - laid in bodies of water that sometimes persist flies, with 268 currently described species. no longer than a month. This becomes possi - Many of these dragonflies are part of the ble due to the speed of embryonic and larval North and South American fauna, but a development. In tropical montane forests, small but significant proportion of Costa turbulent and shaded streams harbour a rich Rican dragonflies are endemic to the region, dragonfly fauna. In temperate regions, in which includes and Panama. contrast, relatively few species are adapted semiopaca , a species present in La Gamba, is to these special conditions. endemic to Costa Rica. The Caribbean slope The dragonfly fauna of Costa Rica is one of the Cordillera seems to harbour more of the best-studied in Central America, yet it species. is still not fully explored. In comparison with Odonatological field trips around La Gamba

Although dragonflies are often seen fly - Forests ing or resting on vegetation beside water, the Forests may originally have been the pri - easiest way to observe them is at their breed - mary habitat of dragonflies in Costa Rica, ing sites, usually streams or ponds. and the prevailing conditions may have Odonatological field trips therefore concen - influenced the mixture of species living in trate on aquatic habitats, but these habitats them. Swamps and smaller streams can be are embedded in a matrix of landscapes that completely shaded and flow can be very tur - heavily influence the quality of breeding bulent, which provides well oxygenated sites. Dragonfly distribution is greatly affect - water, but with an increased risk of being ed by the drastic difference between undis - carried away by the water. Polythoridae like turbed forests and intensively used agricul - Cora semiopaca prefer these conditions. The tural areas and their respective water bodies. forest interior, where modesta

A shaded stream in the forest interior

12 and Megaloprepus cerulatus can be found, is landscapes including plantations, crop fields dark, and temperatures are lower than in and pastures, narrow strips of gallery forest open habitats, constraining the thermal often form the last remnants of primary veg - requirements of adults. Many species living etation. In this dramatically altered land - in the forest are shade–loving and are there - scape, the dragonfly fauna is different, and fore not found in open areas. For a species generalist species like many Libellulidae, like Philogenia zeteki , the dense understorey which are able to live under a wide range of may additionally provide protection from environmental conditions, prevail. On a predators. Such forest species are specialised small spatial scale, species richness can to these circumstances, whereas many other increase in cultivated areas through the species would not be able to survive. Forests colonisation of these habitats by generalists. have been hit hard by human activity, and Mostly, however, generalist species like the remaining islets surrounded by open fusca are widespread and com - landscape may be too small or isolated to mon and therefore, on a broader scale, over - sustain populations of forest dragonflies. In all richness may be reduced. forests, on the other hand, degraded and open patches like those caused by tree falls Forest margins or logging, as well as roads, resemble open Aquatic habitats at forest margins can landscapes and are often used by species like either resemble forests or open landscapes imbuta which are usually found in depending on the type and density of gallery open habitats. vegetation. Running water along forest mar - gins may be suitable for shade–loving Cultivated landscapes species such as erythrogastrum . Cultivated landscapes are those artifi - Artificial ponds can be exposed to the sun cially shaped by human land use. Bodies of and may be colonised by generalist species water in these environments are usually like Orthemis ferruginea . In the garden of the exposed to the sun, leading to higher temper - Research Station, several small ponds and atures and lower oxygen levels. Pollution by rivulets provide habitats for generalists, and the inflow of agrochemicals or domestic some common species can frequently be sewage can influence water quality. observed there. Embedded in a matrix of relatively uniform

Stream with open canopy surrounded by cultivated areas

13 Zygoptera

Family Polythoridae the wings in Polythoridae are petiolate, the (polythorids, polytóridos) wings are relatively narrow, and males lack red colouration at the base. Females are light They are medium–sized Zygoptera species to dark brown. Polythoridae are shade–lov - with dense wing venation, many antenodal ing dragonflies that live beside streams in crossveins, and short legs. In contrast to undisturbed forests. The larvae have lateral members of the Calopterygidae, the bases of gills on the abdomen.

Cora notoxantha common in Central America, but in that size: 39 mm, abdomen: 31 mm, fore wing: 25 mm species the abdomen is almost blue dorsally. The eyes are dark and the face is white. This The thorax of the male is bright yellow or species is known from Costa Rica and blue, with a thin black mid-dorsal line in Panama. some individuals. Blue coloured individuals We found this rare species beside a forest may be confused with Cora marina , a species stream

Cora notoxantha male

14 Cora semiopaca lar. This stream–dwelling species may be size: 35 mm, abdomen: 27 mm, fore wing: 27 mm threatened by disturbance due to its small range size. This stream–dwelling species is endemic to We found this rare species beside a stream Costa Rica. The male has characteristic running through a shaded ravine. reflective zones on the wings, and dark bands on the distal parts of the wings. In the dark forest undestorey, the shimmering blue reflections may attract fe- males that are searching for mat - ing partners and suitable sites for oviposition. The face is white. The female in this photograph was not identified to the species level but is likely to be a female of Cora semiopaca ; most females in the genus look simi - Cora semiopaca male

Cora sp. female

15 Family Calopterygidae abdomen. Females are either similarly (rubyspots, calopterígidos, Prachtlibellen) coloured, or metallic green with yellow lines on the thorax. Many species look similar and Calopterygidae are large Zygoptera with identification usually requires examination long legs, dense wing venation and many of the caudal appendages. Calopterygidae antenodal crossveins (crossveins inserting at perch on vegetation overhanging the water. the costa between the wing base and the They are common along rivers in forests and nodus). In contrast to species of the family open landscapes, but it is not clear how Polythoridae, the base of wings is not petio - many species of this family live around La late. Males of the Costa Rican species have Gamba. There are probably more than five basal red markings on their wings, a metallic species. copper sheen on the thorax and a dark

Hetaerina fuscoguttata by the extent of the red markings on the size: male 51 mm, female 41 mm, wing, which usually reach the level of the fore wing: male 28 mm, female 28 mm nodus in H. fuscoguttata . The marking at the wing tip is diffuse. Females are dark metallic Males are dark red with yellow stripes on in colour, with yellow stripes on the thorax. the thorax. They resemble males of Hetaerina Both sexes can be observed along streams occisa , from which they can be distinguished where they perch on the riparian vegetation in large num - Hetaerina fuscoguttata male bers. The species’ dis - tribution ranges from Costa Rica to Columbia and . We found this common species be- side streams in all habi - tats.

Hetaerina fuscoguttata female

16 Hetaerina occisa vegetation. Males display in short patrol size: male 44 mm, female: 37 mm flights and attack intruders or the owners of fore wing: 25 mm neighbouring territories. This species is dis - tributed from to . Males have a metallic copper colour with We found this common species beside yellow stripes on the thorax. They are char - streams in forests, along the forest margin acterised by their long lower appendages, and in open areas. widened distally. They may be con - Hetaerina occisa male fused with Hetaerina fusco- guttata , but the red wing marking does not usually reach the level of the nodus and the dark spot on the tip is discrete. Females are metallic green with pale areas on the thorax. They usually have a small white pterostig - ma, which is absent in some females of the genus. Like H. fuscoguttata , this species can be abundant, perch - ing on the bank

Hetaerina occisa female

17 Family Although some species may be abundant at (megapodagrionids, megapodagriónidos) suitable sites, Megapodagrionidae are not often seen and the ecology of many species is Megapodagrionidae are medium–sized to poorly known. They live beside streams in large Zygoptera with much diversity in size relatively undisturbed areas, or dispersed in and colouration. Many species are uniformly the forest. The species of both genera usually dark while others are brightly coloured. perch with their wings open.

Heteragrion erythrogastrum family and the family Lestidae. This species size: male 46 mm, fore wing: 23 mm can be found from to Ecuador. We found this common species beside sever - A Large Zygoptera with eyes dark above. al streams in forests and along forest mar - The thorax has pale brown sides and a dark gins. colouration dorsally. Males have a red abdomen, females are light brown col-oured. H. erythrogastrum can be distinguished from other species of the genus by its dark labrum. This species prefers shaded sections of running waters. Males have a red coloured abdomen, however, they may be difficult to detect perch - ing on shaded vegeta - tion. In its typical resting position the male clinch - es to a leaf and the abdomen hangs beyond the leaf’s tip. The wings are held open when rest - ing, a behaviour known for some species of this

Heteragrion erythrogastrum male

18 Philogenia zeteki size: 54 mm, fore wing: 34 mm

A large, dark species with a white labrum and a contrasting white spot at the end of the abdomen. This species can be found some distance from watercourses, along forest trails, where it is difficult to see when resting motionless. Both sexes look alike. It is distrib - uted in Costa Rica and Panama. We found this rare species along forest trails.

Philogenia zeteki male

19 Family Pseudostigmatidae to show facultative specialisation to prey. (helicopter damselflies, pseudostigmáti - Adults prey on , hovering in front of dos) the web and striking the in a rapid attack. Light effects created by the marked Species of this predominantly Neotropical wing tips give their flight a special aspect, family are characterised by their large size: and for this reason they are known as ‘heli - Megaloprepus caerulatus has the largest copter dragonflies’. Pseudostigmatidae are wingspan of any dragonfly or . The found within the forest where they can abdomen is long and slender. Larvae inhabit sometimes be seen in natural clearings. phytotelmata and it is the only family known

Mecistogaster modesta which also has white wing tips, but the size: 65 mm, abdomen: 56 mm, fore wing: 40 mm abdomen of the latter species is longer. Another species in the region, Megaloprepus This is a very large Zygoptera species with caerulatus , is even larger, with black and an elongated abdomen and white markings white markings on the wing tips. on the wing tips. The basic colouration is ranges from Mexico to dark, with three yellow lines on the sides of Venezuela. thorax and two yellow spots on the rear of We found this rare species at light gaps in the the head. Both sexes look alike. This species forest. can be confused with ,

Mecistogaster modesta female

20 Family open when resting. They can be found beside (threadtails, protonéuridos) streams in slightly disturbed areas. The colouration is different in other genera of the The species of this family are small, with a family. Psaironeura , which was found beside slender and often long abdomen. Some a stream along the forest margin, is a very males are red in colour, but they are smaller small species with red eyes and a slender, than Heteragrion and do not hold their wings dark, metallic–coloured abdomen.

Neoneura esthera and black pattern behind the eyes. The size: 50 mm, abdomen: 40 mm, fore wing: 30 mm abdomen is shorter in relation to the wings than in . Females are less brightly This is a slender, medium–sized Zygoptera coloured, and large areas of the abdomen are species. The male’s thorax is red with a thin black. Neoneura esthera is found from Costa black mid-dorsal line, and paler sides that Rica to Venezuela. can become greenish. The abdomen is red or We found this rare species beside a stream in orange with small black areas on the last seg - a cultivated area. ments. This species has dark eyes, and a red

Neoneura esthera male

21 Protoneura amatoria a duller orange. The abdomen is longer in size: 37 mm relation to the folded wings than in Neoneura . Tandems of this delicate species are incon - This is a small Zygoptera species. Males spicuous as they fly close to the water sur - have a bright red to orange abdomen with face. Protoneura amatoria is distributed from small black markings. The thorax is red with to Venezuela. broad black stripes. The eyes are red above We found this rare species beside a stream in and the rear of the head is black. Females are a cultivated area

Protoneura amatoria male

22 Family otherwise dark. In contrast to the males, (pond damselflies, coenagriónidos, which can often be identified to species level Schlanklibellen) by the characteristic blue and black patterns on the abdomen, females look very alike The small and medium–sized species of the across most of the Coenagrionidae, and are family Coenagrionidae, the largest family in best identified when seen in tandem with a the Zygoptera, occupy all types of aquatic male during mating. Many species look very habitats. Males are often blue with a black similar and are difficult to identify. They rest pattern on the thorax and abdomen. Some on or patrol along the riparian vegetation. species are a metallic copper colour on the Females are often seen laying their eggs into thorax. Females are pale rather than blue, plants while still engaged with the male in and have larger black areas on their the tandem position. abdomen. Other species are mostly red or

Acanthagrion inexpectum of segments 7, 8 and 9 are blue, while the rest size: 32 mm, abdomen: 26 mm, fore wing: 18 mm of the abdomen is black. Females have a black abdomen except for the last two seg - This is a medium–sized Zygoptera species. ments, which are pale. The thorax is pale Males are blue with a black pattern, and look with broad black stripes. very similar to Argia . The male has a black We found this moderately abundant species mid-dorsal line or stripe on segment 3, which beside streams in open areas. does not reach segment 2. The distal halves

Acanthagrion inexpectum male

23 Argia sp. stripes on the thorax and a black pattern on size: 33 mm, fore wing: 20 mm the abdomen of varying extent. Females are pale green, with black stripes on the thorax This genus is very rich in species, and unfor - and an almost entirely black abdomen. tunately, the systematics of this group is Species of the genus Argia can be found in chaotic. Many species have very similar forests and open habitats. They are very colouration and are difficult to identify. common and reproduce along streams and Males of the genus are blue, with black beside ponds.

Argia sp. male

Argia sp. female

24 Argia cupraurea abdomen with a pale basal ring on each seg - size: 38 mm, abdomen: 30 mm, fore wing: 22 mm ment. The thorax is greenish with two metal - lic copper stripes dorsally. In the habitats This is a medium–sized Zygoptera species. where this species occurs, it is quite easy to In contrast to other species of this genus, detect due to its relatively large size and the males of Argia cupraurea are easily identified male’s red eyes. It is distributed from by their red eyes; the other species in the Honduras to Venezuela. genus with red eyes are distinctly smaller. We found this common species beside The dorsum of the thorax is a brilliant metal - streams in cultivated areas and along the for - lic copper colour. Females have a black est margin.

Argia cupraurea female

Argia cupraurea male

25 novaehispaniae is metallic blue and violet, with three black size: 31 mm, fore wing: 20 mm lines dorsally. Females are similar but less brightly coloured, and lack the bright blue This is a small species. Males have pale blue area on segment 3. The abdomen is entirely colouration on abdominal segments 1, 2 and black except for a proximal blue spot on seg - 3 except the distal part of segment 3, which is ment 8. This species is widely distributed black. Segments 8 and 9 are similarly blue from North to South America. except for a distal black ring on segment 8. We found this rare species beside streams in The rest of the abdomen is black. The thorax cultivated areas.

Enallagma novaehispaniae male Enallagma novaehispaniae male

Enallagma novaehispaniae female

26 Ischnura capreolus ments. Older females have broad black lines size: 22 mm, fore wing: 20 mm on the dorsum of the thorax. Abdominal seg - ment 9 is blue, while the rest are black. The This is one of the smallest dragonflies and is species’ range extends from Mexico deep therefore easily overlooked. The male’s tho - into South America. rax is greenish with broad black stripes. The We found this moderately abundant species abdomen is black, except for segment 8 and a beside a stream in a cultivated area and small distal blue area on segment 7. Young beside ponds between the station and the females are bright greenish or yellow on the lodge. thorax and on the first two abdominal seg -

Ischnura capreolus male

Ischnura capreolus young female

27 Telebasis sp. size: male 32 mm

This is a medium–sized Zygoptera species. The eyes are red above and green below, while the labrum is red. The greenish thorax is darker dorsally, and the abdomen is uni - formly red in both sexes. Telebasis is more robustly built than Protoneuridae. Both sexes look very similar. We found this rare species at a pond in the garden of the station. Telebasis sp. male Anisoptera

Family Gomphidae abdomen are broad in the males of all Costa (clubtails, gónfidos, Keiljungfern) Rican Gomphidae. Though not uncommon, species of this family are seldom seen. Males These are typically large Anisoptera which spend most of their time perching on open live in undisturbed habitats. Gomphidae dif - banks or vegetation, and rarely patrol on the fer from other Anisoptera in having widely wing. An encounter with one of these species separated eyes. The last segments of the is a rare and fascinating event.

Aphylla obscura (= A. tenuis ) with a slight red tint. The thorax is greenish size: approximately 65 mm with broad, contrasting black stripes. The eyes are green. Females look similar to This is a large Anisoptera species with a males. Aphylla obscura occurs in Costa Rica, robust thorax and a long, slender abdomen. Panama and Venezuela. The end of the abdomen is expanded and We found this rare species beside a stream bears large, hook–shaped upper along the forest margin appendages. The male’s abdomen is dark

Aphylla obscura male

28 Family Libellulidae (skimmers, libélulidos, Segellibellen) reproductive period is very long, and young (pre-reproductive) males are coloured less This is the largest family in the Anisoptera conspicuously and often resemble females. and its members are very diverse in their Reproductive males become darker and morphology. Species range from very small often develop pruinosity (a blue or violet to large in size. The abdomen is relatively waxy colouration). Libellulidae use many short compared to other Anisoptera, and can types of habitats and the majority of species be cylindrical or flattened in shape; some are generalists. Some species, however, can species have a thin abdomen with the last be stenotopic forest denizens. segments swollen. In some species the pre-

Cannaphila insularis half of the abdomen (segments 3–5), the rest size: 40 mm being black. The colour of the eyes turns bright bluish- green. The frons is metallic This is a medium-sized Libellulidae species, blue. The base of the hind wings is narrow. with a flattened abdomen that tapers Females resemble young males. towards the end. Young males have a dark insularis is distributed in North and Central orange abdomen with a black pattern, America. becoming larger distally. The thorax is We found this rare species in light gaps brown with yellow lines. Mature males are along a forest stream. dark with blue pruinosity on the proximal

Cannaphila insularis young male

29 Cannaphila vibex bright mid-dorsal line on the thorax is still size: 41 mm present in mature males, while the eyes turn bright blue. The frons is quite a metallic This is a medium-sized Libellulidae species, green. The base of the hind wings is narrow. with a flattened, tapering abdomen. Young Females resemble young males, but become males have yellow lines on the thorax. The darker with age. This dragonfly can be found abdomen is more orange than in Cannaphila from Mexico to and . insularis . Mature males are dark, with blue We found this rare species patrolling natural pruinosity on the abdomen extending basal - light gaps along a forest stream. ly to segment 7. Segments 8–10 are black. The

Cannaphila vibex young male

30 Dythemis multipunctata colouration, but the abdomen of females is size: 37 mm, abdomen: 25 mm stouter and somewhat shorter. Males may be confused with Micrathyria or Nephepeltia , but This is a medium–sized Libellulidae species this species is distinctly larger and the with a long, slender, cylindrical abdomen. abdomen is not widened at the end. This The eyes are bright blue. The frons is dark species is less abundant than its congener and the rest of the face is white. There are Dythemis sterilis . It is widely distributed in pale greenish stripes on the thorax. The Mexico, and Central and South America. abdomen is black with proximal, pale paired We found this common species beside lines on the first segments and two large streams along the forest margin and at a spots on segment 7. The sexes are similar in pond between the station and the lodge.

Dythemis multipunctata male

Dythemis multipunctata female

31 Dythemis sterilis stouter and slightly shorter. This species size: 38 mm, fore wing: 30 mm often displays the ‘obelisk position’, holding the abdomen upright against the sun. This This is a medium–sized Libellulidae species minimises the surface exposed to the sun and with a long, slender, cylindrical abdomen. is a strategy to regulate body temperature. D. The body is brown with yellow stripes on the sterilis can be found from Mexico to South abdomen. The eyes are light brown above America. and greenish below. The wings have a deli - We found this common species beside cate light brown colouration on the base, and streams along the forest margin and in culti - a brown tint on the tip. Both sexes are simi - vated areas, and at ponds between the sta - larly coloured but the abdomen of females is tion and the lodge.

Dythemis sterilis male

Dythemis sterilis male in ‘obelisk position’

32 peruviana can be distinguished by its smaller body and size: 43 mm, fore wing: 31 mm the absence of a pale mid-dorsal stripe and pale sides to the thorax. The species occurs in This is a medium–sized Libellulidae species Mexico and Central America. with a long, strongly flattened abdomen. The We found this moderately abundant species male closely resembles Libellula herculea but at ponds between the station and the lodge.

Erythemis peruviana male

33 Erythemis plebeja that has become very dark. Males resemble size: 46 mm, fore wing: 31 mm females but they have a dark thorax. The dark spot at the base of the hind wing is larg - This is a medium–sized Libellulidae species er, and the abdomen is slightly longer. The with a long, slender, cylindrical abdomen. upper appendages are white above. In this The first three abdominal segments are genus, species can be of very different gener - strongly swollen. Females have a light al appearance. Erythemis plebeja is widely dis - brown thorax. The abdomen is predominant - tributed in the Americas. ly black with pale yellow markings. A small We found this moderately abundant species area on the base of each hind wing is dark. beside ponds between the station and the The figure below shows an old individual lodge.

Erythemis plebeja female

34 yellow, darkening with age, with a contrast - size: 35 mm ing black pattern on the abdomen and a dark tint on the wing tips. The females of the This is a medium–sized Libellulidae species genus generally look very similar to the with a flattened abdomen. Males are red and males, and are difficult to distinguish. E. fer - have conspicuous deep red markings at the vida is widely distributed in Mexico, Central base of each wing. The face is red and the America and the Caribbean. eyes are red to brown above. The thorax is We found this common species beside red on the sides, quite brown dorsally, and streams in the forest, in open areas, and lacking dark markings. The abdomen is beside ponds between the station and the shortened and the tip is black. Females are lodge.

Erythrodiplax fervida male

Erythrodiplax fervida female

35 extending from the base of the wing to size: 42 mm, fore wing: 30 mm beyond the nodus. Mature males have a dark body with blue pruinosity, and the eyes are This is a large Libellulidae species with a dark brown above. Females resemble young long and slightly flattened abdomen. Young males. E. funerea is found from North males have eyes that are brown above and America to Ecuador. grey below, and a yellow face. The body is We found this moderately abundant species yellow with a dark pattern. The characteris - in the garden of the station and along the tic wing pattern is less developed in young road to the lodge. males and becomes dark in mature males,

Erythrodiplax funerea mature male

Erythrodiplax funerea young male

36 on the wing base also become dark. Females , size: 30 mm, fore wing: 24 mm like all females of this genus, are yellow with a dark pattern on the abdomen, and are best This is a medium–sized Libellulidae species identified by their small size compared to with a shortened, flattened abdomen. In their congeners. males , the sides and dorsum of the thorax This species is widely distributed in North are red. The face is also red. They are gener - and South America and can be very abun - ally smaller than Erythrodiplax fervida , and dant in secondary habitats. the basal spot on the wings is smaller and We found this very abundant species beside less intense. Young males resemble females. ponds between the station and the lodge, Mature males first become bright red, than beside streams in open areas, and also along dark with blue pruinosity on the abdomen. roads and in the garden of the station. The thorax turns dark brown and the spots

Erythrodiplax fusca male

Erythrodiplax fusca female

37 Erythrodiplax kimminsi has dark final segments. The sides of the tho - size: 33 mm, fore wing: 24 mm rax are whitish without dark markings. The frons is metallic blue and the eyes are dark This is a medium–sized Libellulidae species brown above. The species lives in Costa Rica, with a long, flattened abdomen. Mature Panama and South America. males are unmistakable due to their dark We found this moderately abundant species basal wing spots surrounded by white opal beside streams and roads in open areas and bands. The abdomen is blue, pruinose, and in the garden of the station.

Erythrodiplax kimminsi male

38 Libellula herculea side of the thorax. The eyes are dark brown size: 53 mm above. This species is larger than Erythemis peruviana . Both sexes look very similar. It can This is a large Libellulidae species with a be found from Mexico to South America. long, flattened and very broad abdomen. The We found this moderately abundant species sides of the male’s thorax are grey and pru - beside ponds between the station and the inose, and a white stripe crosses the dorsal lodge and in the garden of the station.

Libellula herculea , male (above) and female (below) during copulation

39 Macrothemis sp. abdomen can be variable in young and old size: 34 mm, abdomen: 25 mm, fore wing: 28 mm males. In pre-reproductive males, some seg - ments may already be swollen. Species of This is a medium–sized Libellulidae species this family can be very similar in general with a long, slender abdomen. In males of appearance. this and other species, segments 6–9 are We found different species of this genus widened and bear bright spots dorsally. beside a stream in the forest along clearings, Species with widened segments may be mis - but also in cultivated areas in moderate taken for Micrathyria , but the latter species is abundance. smaller. The position of pale spots on the

Macrothemis sp. young male

40 the dark thorax, two large pale spots are sit - size: 38 mm, fore wing: 28 mm uated dorsally and a broad pale stripe later - ally. Females are brown with a bright stripe This is a medium–sized Libellulidae species on each side of the thorax. The range of this with a long, slender abdomen, with seg - species extends from North to South ments 6-9 widened in males. The species of America. this genus all look very similar. Young males We found this moderately abundant species have paired pale stripes on the abdomen. On beside streams in open areas

Macrothemis imitans young male

Macrothemis imitans female

41 Micrathyria pseudeximia and blue below. Females have a brown tho - size: 25 mm, abdomen: 16 mm, fore wing: 22 mm rax and a dark abdomen. This species is smaller than Macrothemis . Micrathyria This is a small Libellulidae species with a pseudeximia occurs in Central and South short and basally slender abdomen. America. Segments 6–9 are widened in males with two We found this moderately abundant species bright spots on segment 7. The upper part of beside ponds between the station and the the frons is metallic blue, while the rest of the lodge and in the garden of the station. face is white. The eyes are bright green above

Micrathyria pseudeximia male

Micrathyria pseudeximia male

42 Nephepeltia phryne when the dragonfly is held in the hand. size: 20mm, abdomen: 14 mm, fore wing: 19 mm Females are yellow with a black pattern. The base of the wings is flavescent. This species This is a very small Anisoptera species with resembles Micrathyria but is smaller and a a short, slender abdomen. Segments 6–9 are faster flier. It is widely distributed from widened in both sexes and bear two bright North to South America. spots. Males have a black abdomen and a We found this species beside ponds between greenish-blue thorax, lacking the dark lines the station and the lodge and at a stream in seen in Micrathyria . They have a spike an open area. between their legs, which can only be seen

Nephepeltia phryne male

Nephepeltia phryne female

43 Orthemis ferruginea mid-dorsal line on the thorax. Males defend size: 50 mm, fore wing: 41 mm territories beside ponds and at small puddles on roads after rain. Females can even be This is a large species. Males are unmistak - observed laying their eggs in these puddles. able by their purple colouration. The The species is widely distributed in the abdomen is long and slightly flattened. They Americas. can be confused with Rhodopygia , but the lat - We found this very common species beside ter species is bright red and a faster flier. ponds between the station and the lodge, by Orthemis ferruginea is the more abundant large streams in cultivated areas, and along species. Females are brown and have a pale roads.

Orthemis ferruginea male

44 Pantala flavescens a dark mid-dorsal line. The superior size: 49 mm, fore wing: 43 mm appendages are long. Both sexes look alike. This species often forms large migrating This is a large Libellulidae species with a swarms, as does another migratory species, long, slightly flattened abdomen. The frons is Tramea binotata . Pantala flavescens occurs in yellow, and the base of the hind wings is tropical and subtropical regions all over the expanded and often flavescent, sometimes world. with dark wing tips. The colouration of the We found this moderately abundant species abdomen varies from orange to yellow, with along roads in cultivated areas.

Pantala flavescens female

45 Perithemis mooma male’s territory may be a small sunny patch size: 22 mm, abdomen: 14 mm, fore wing: 19 mm beside a pond or a slow–flowing stream. It rests on perches near the water, from which This species is a small but skilled flier. The it makes short patrol flights. The species is abdomen is short and flattened. Males are distributed from Mexico to South America. very conspicuous due to their yellow and We found this moderately abundant species black colouration and their orange wings. at streams along the forest margin, in culti - Females are dark and the wings are hyaline vated areas, and by ponds between the sta - with two large, yellow or dark spots. The tion and the lodge.

Perithemis mooma male

46 Rhodopygia sp. males, although they are slightly less bright - size: 48 mm, fore wing: 39 mm ly coloured. Males patrol very quickly along habitat structures and even attack Orthemis This is a large Libellulidae species with a ferruginea males, probably mistaking them long, slightly flattened abdomen. Males are for conspecific rivals. an intensely bright red in colour (see We found this common species beside ponds Orthemis ferruginea ). The thorax is red on the between the station and the lodge, beside sides and greenish dorsally. The face is red large streams in cultivated areas, and along and the eyes dark brown above. The base of roads. the wings is flavescent. Females resemble

Rhodopygia sp. male

47 Tramea binotata long. Mature males are blue and pruinose; size: 47mm, fore wing: 42 mm females are brown. Like Pantala flavescens , this species forms swarms of many individu - This is a large Libellulidae species with a als migrating over long distances, and is long, slightly flattened abdomen. The base of therefore widely distributed. the hind wings is expanded, and bears dark We found this moderately abundant species spots. The superior appendages are very along roads in cultivated areas.

Tramea binotata male

48 females become blue and pruinose, the eyes size: 33 mm, abdomen: 23 mm, fore wing: 28 mm becoming dark brown above and blue below. The face is blue but not metallic in colour. This is a medium–sized Libellulidae species Females and young males are found in great with a long, slightly flattened abdomen. abundance along forest margins and in clear - Males of this species have a long pre-repro - ings in the forest. The species occurs from ductive period. Young males resemble North to South America. females in colouration, being brown with We found this very common species at clear - black bars on the abdomen. The eyes are ings in the forest and in open areas brown above. Reproductive males and older

Uracis imbuta mature male

Uracis imbuta female

49 Diversity of dragonflies at La Gamba genus Hetaerina , it is possible that three addi - tional species are among those Hetaerina The list of dragonflies identified with suffi - that live along streams around La Gamba. In cient certainty in La Gamba comprises 33 total, this increases the number of species species so far, all of them described in this potentially occurring and reproducing in the text. A further 11 species have been caught region to 50. The absence of whole families and examined, or photographed, but these like Lestidae in the surveys carried out so far have not be identified, although they could is unlikely to be the result of a true absence of be clearly separated into different species by such groups in the region. This supports our morphological attributes or colouration. estimate that the total number of species is These include three species of Argia , two somewhere around 65, indicating that there species of Macrothemis , two species of is still much to discover. The author will Erythrodiplax , one species of Psaironeura and appreciate any information on new records one gomphid (Gomphidae). Of the latter, or interesting observations of dragonflies in Telebasis sp. and Rhodopygia sp. are described La Gamba. Further investigations into drag - in the text. The large Mecistogaster modesta is onflies will almost certainly increase the known to live in the forest near La Gamba. number of species recorded in the region and Individuals of a further two species of the contribute to a complete list of the dragon - family Aeshnidae, both large dragonflies, flies of La Gamba. We hope that this booklet have been seen by the author patrolling over will stimulate interest and so help to increase ponds near the station. Due to difficulties in our knowledge. the identification of species forming the

Acknowledgements Special thanks go to Carlos Esquivel (Universidad Nacional Costa Rica, Heredia) My thanks are due to the following people for his support and for the identification of who collected and photographed the species difficult species. The Costa Rican Ministerio and contributed information about their del Ambiente y Energía kindly granted morphology, behaviour and abundance: research permits. I also thank the team at the Florian Hofhansl, Alexander Kainz, Barbara La Gamba Research Station. Post, Valentin Wagner, Nikolaus Wagner.

50 References

CORBET, P.S. (1999): Dragonflies: Behavior and Ecology of Odonata. Harley Books, Cornell University Press, 829 pp.

ESQUIVEL, C. (2006): Dragonflies and Damselflies of Middle America and the Caribbean. Primera edición. Instituto Nacional de Biodiversidad (INBio), 320 pp.

FÖRSTER, S. (1999): The Dragonflies of Central America exclusive of Mexico and the West Indies. A guide to their identification. G. Rehfeldt, Wolfenbüttel, 141 pp.

HOFHANSL, F.P. & SCHNEEWEIHS, S. (2008): Banderillas: Effects of deforestation on dragonflies (Insecta, Odonata) in the Pacific lowland of Costa Rica. Stapfia, 88, 237-247. In: Weissenhofer A., Huber W., Mayer V., Pamperl S., Weber A. & Aubrecht G. (editors) 2008. Natural and Cultural History of the Golfo Dulce Region, Costa Rica. Stapfia, 88, 768 pp.

RAMÍREZ, A., PAULSON, D.R. & ESQUIVEL, C. (2000): Odonata of Costa Rica: Diversity and checklist of species. Revista De Biologia Tropical, 48, 247-254.

Dragonflies on the web http://ghostmoth.eeb.uconn.edu/laselvadragons/ Pictures of dragonflies of La Selva, Costa Rica. http://www.ups.edu/slatermuseum.xml Information about South American dragonflies including photographs of many species. http://gallery.cs.umb.edu/gallery/main.php?g2_itemId=381112 Pictures of dragonflies from the Monteverde region, Costa Rica. http://www.aeshna.com/default.htm John Abbot’s web site with photographs of Central American dragonflies.

51 Picture credits*

The „Tropical Reseach Station La Gamba“

Werner Huber: Waterfall on the Quebrada Chorro

Peter Weish: Morning clouds above the forest, Interior of the forest of the NP Piedras Blancas

Damiel Schenz: Students with a huge tree with buttress roots in the forest The rainforests of the Golfo Dulce region

Werner Huber: The main building of the Tropical Research Station, Students crossing the Rio

Bonito during a field course, The ‘comedor’, The pond in the garden of the station

Florian Etl: Scientists in the air-conditioned laboratory Introduction

Alexander Kainz: Body of a Zygoptera

Barbara Post: Front view of an Ansioptera

Stefan Schneeweihs: A shaded stream in the forest interior, Stream with open canopy sur - rounded by cultivated areas Zygoptera

Alexander Kainz: Acanthagrion inexpectum , Argia sp., Cora sp., Hetaerina fuscoguttata male

Stefan Schneeweihs: Argia cupraurea , Cora notoxantha , Cora semiopaca , Enallagma novaehispani - ae , Hetaerina fuscoguttata female, Hetaerina occisa , Heteragrion erythrogastrum , Ischnura capreolus male, Mecistogaster modesta , Neoneura esthera , Philogenia zeteki , Protoneura amatoria , Telebasis sp.

Nikolaus & Valentin Wagner: Ischnura capreolus female Anisoptera

Alexander Kainz: Dythemis sterilis , Erythrodiplax fusca male, Libellula herculea , Micrathyria pseudeximia male #1, Nephepeltia phryne female, Tramea binotata

Stefan Schneeweihs: Aphylla obscura , Cannaphila insularis , Cannaphila vibex , Dythemis multi - punctata , Dythemis sterilis ‘obelisk position’, Erythemis peruviana , Erythemis plebeja , Erythro- diplax fervida , Erythrodiplax kimminsi , Libellula herculea (cover) , Macrothemis imitans male, Macrothemis sp., Micrathyria pseudeximia male #2, Nephepeltia phryne male, Orthemis ferruginea , Pantala flavescens , Perithemis mooma , Rhodopygia sp., Uracis imbuta

Nikolaus & Valentin Wagner: Erythrodiplax funerea , Erythrodiplax fusca female, Macrothemis imitans female, Uracis imbuta male

*The copyright of the pictures remains with the photographers.

52