Contents

Preface vii

Natural History and in the natural world 1 Habitats of damselflies and dragonflies 4 Endemics and more recent arrivals 9 Biology and behaviour 12 Conservation 51 Photographing damselflies and dragonflies 54 Damselflies, dragonflies and communities 56

Species Accounts Blue colensonis 60 Gossamer damselfly Ischnura aurora 66 Chatham redcoat damselfly Xanthocnemis tuanuii 72 Redcoat damselfly Xanthocnemis zealandica 78 Bush giant carovei 84 Mountain giant dragonfly Uropetala chiltoni 90 Lancer dragonfly Aeshna brevistyla 96 Baron dragonfly Anax papuensis 102 Dusk dragonfly Antipodochlora braueri 108 Sentry dragonfly Hemicordulia australiae 114 Yellow spotted dragonfly ‘Procordulia’ grayi 120 Ranger dragonfly Procordulia smithii 126 Red percher dragonfly bipunctata 132 Common glider dragonfly Tramea loewii 138

Species Likely to Establish 144 Bibliography 148 Acknowledgements 151

 A teneral sentry dragonfly clings to its exuvia while hardening through the night. Preface

Dragonflies – if a name should reflect The New Zealand damselfly and character, then dragonflies could not have dragonfly fauna comprises 14 species been better named. Dragons in legends, currently known to breed in the North and mythologies and fairy tales are often South Islands, Stewart Island/Rakiura and pictured as strong, fearsome, merciless the Chatham Islands. Additional species rulers of the air, but are sometimes have been recorded on the Kermadec portrayed as full of wisdom. Dragonflies Islands and others still have arrived have it all: they are strong, dynamic fliers occasionally on New Zealand’s main islands showing no mercy towards mosquitoes but have failed to establish permanent or many other small . What about populations. Some tropical Pacific odonates wisdom? Well, one could argue that by are gradually expanding their ranges with surviving the many major extinction events increasing global temperatures and may since the first dragonfly-like ancestor find their way to New Zealand in the near appeared on our planet – more than 325 future. This book includes all those species, million years ago – this group of insects has but local New Zealand residents are our indeed earned the label ‘wise’. Regardless, main focus because most of them are today’s dragonflies are superbly adapted to endemic, meaning that they are found only their environment. on these four main islands and nowhere Damselflies, on the other hand, look else in the world. We pay special attention completely opposite to their relatives – to what we need to know and do in order to delicate wings; slim, elongate abdomens; protect them from introduced pest large, wide-set eyes that track the minutiae and plants, which may deplete or smother of the world around them; subtle nuances dragonfly natural habitats and replace our of colours on their bodies in a combination unique treasures forever. that is very often pleasing, even entrancing, New Zealand’s eight endemic species to a human observer. No wonder that their sit in five genera (spread over four common name associates them with a families), three of which – Xanthocnemis, young girl. Uropetala and Antipodochlora – are entirely However, both dragonflies and damsel- endemic (the other two genera have flies have similar life histories and the species found outside of New Zealand). same general organisation of their bodies. The evidence suggests that some of our Therefore, they are combined in one endemics developed from ancestors that group – the order . Since there is were isolated from the rest of the world not a general common name for the whole more than 80 million years ago, after the group, people often refer to them all as break-up of the supercontinent Gondwana. ‘odonates’. Likewise, for convenience, that Subsequent generations persisted, surviving

 A male yellow spotted dragonfly illustrating the approach is used in this book dedicated to through New Zealand’s geomorphological association of this group of insects with flying dragons. New Zealand species of Odonata. history, which included subsidence of the

vii land, earthquakes and volcanic activities, is enacted in or around the open wetlands, the formation of mountains and glaciation. rivers or temporary puddles in which So, today’s odonates are messengers, they breed. Almost all you have ever read time capsules containing encoded genetic in nature books or watched in natural information from ancient times when their history documentaries about the lives of ancestors were flying together with the mammals or birds – such as establishing predecessors of species that we now find and defending territories, finding mates on distant continents such as Australia and food, or the general struggle for and South America. existence – is easily observable from the Odonates may not possess human bank of an overgrown pond. Just book intelligence but they can certainly help your seat by bringing a chair and watch us to exercise our brains more effectively. the odonates dance over the water. Observe and remember what you see, Wetland, river, puddle, pond – the link and refer to this guide. You can go one or between odonates and freshwater is more more steps further by taking notes in the than just opportunistic. These insects field and/or recording encounters with a depend on freshwater, and many species camera or sketchbook. There is no better are quite sensitive to its quality, so the way to connect with nature. The more cleaner the waterway, the more diverse you watch odonates, the more you will be and abundant is its odonate fauna. Record enchanted. The more carefully you observe the presence of adults of each species them, the richer will be your experience. throughout the year, noting this on a In fact, damselflies and dragonflies are calendar. Keep doing this year after year. easy to observe. The life of adult odonates Do not stop. You will come to expect each

 Damselflies and dragonflies are easy to observe from the bank of a pond.

 Male gossamer damselflies are dainty and extremely pretty insects.

PREFACE • ix Natural History

This book includes those odonates so the New Zealand species have unique far established on New Zealand’s four features that distinguish them to some main islands as permanent or accidental extent from their overseas counterparts. residents. To date, 14 species are To make sense of New Zealand’s recognised as breeding in the North and odonates, we begin with a broad look at South Islands, Stewart Island/Rakiura and what these insects are and where they fit the Chatham Islands. There are 11 genera, in the global classification of organisms which are in turn grouped into six families. living on our planet. Eight of these species are endemic – , Xanthocnemis DAMSELFLIES AND DRAGONFLIES tuanuii, X. zealandica, , IN THE NATURAL WORLD U. chiltoni, Antipodochlora braueri, The branch of science called ‘Procordulia’ grayi and P. smithii. Four deals with the naming and classification species (Ischnura aurora, Anax papuensis, of living organisms. Scientists working Hemicordulia australiae and Tramea loewii) in this field are taxonomists. They place established breeding populations in organisms into hierarchically ranked New Zealand less than a hundred years groups or taxa (singular ‘taxon’). At the ago. The remaining two (Aeshna brevistyla lowest level, similar individuals that are  A female redcoat damselfly greets us at a pond’s edge in Christchurch, New Zealand. Odonates are and ) are also found capable of interbreeding and producing excellent indicators of water quality and they can ‘teach’ us how to manage our freshwater resources. on other Pacific islands and in Australia; fertile offspring are categorised as however, preliminary studies indicate that being of the same species. Closely species to appear at a particular time of for ideas for future studies; for guidelines the year and to fly for a specific period. on conservation activities; and as an album Suborder Family Species Species common name When there are changes in your local of nature photos. For quick reference Zygoptera Austrolestes colensonis Blue damselfly water habitats, damselflies and dragonflies in the field, you can use the separate Ischnura aurora Gossamer damselfly will be among the first to ‘tell’ you – you’ll identification chart in this book. We like to Xanthocnemis tuanuii Chatham redcoat damselfly notice fewer species, lower numbers than think that we are giving you a guide to last Xanthocnemis zealandica Redcoat damselfly usual or even different species. These your lifetime. At least, that’s how we feel Anisoptera Uropetala carovei Bush giant dragonfly alarm bells can prompt you to check with about these insects, which have guided Uropetala chiltoni Mountain giant dragonfly your neighbours to find out what may have our lives for more than 30 years. For us, happened and how it can be fixed. odonates have been a never-ending source Aeshnidae Aeshna brevistyla Lancer dragonfly Anax papuensis Baron dragonfly This book aims to be a broad guide of joy, wonder and intellectual stimulus. to New Zealand Odonata. Use it: as an We hope we have managed to convey the Antipodochlora braueri Dusk dragonfly identification manual; as a source of pleasure that we have experienced during Hemicordulia australiae Sentry dragonfly ‘Procordulia’ grayi Yellow spotted dragonfly information on damselfly and dragonfly years of study and that you, the reader, Procordulia smithii Ranger dragonfly biology; for instructions on how to take will enjoy your time with New Zealand close-up photos of insects in nature; for damselflies and dragonflies as much as Diplacodes bipunctata Red percher dragonfly directions on where to observe odonates; we have! Tramea loewii Common glider dragonfly x • PREFACE 1 Similar-looking species pose problems Insecta. Collectively, insects represent the Kingdom Animalia even for 21st-century taxonomists. most successful lineage of multicellular Phylum Arthropoda Historically, species were classified using organisms on the planet, both in numbers Class Insecta only morphological traits and they remain of individuals and diversity (numbers of Order Odonata very important for identification and in species). In fact, the number of insect Suborder Zygoptera describing new species. However, where species greatly surpasses that of all other Family Coenagrionidae Genus Xanthocnemis morphological features are ambiguous, , plant and fungi species combined. Species zealandica scientists use additional features based Insects are grouped into more than on the specimens’ geographic distribution, 30 orders. This book deals with just one,

 Taxonomic classification of the redcoat damselfly behaviour and ecology. In recent years, the order Odonata. The name of the order (showing main taxonomic categories only). taxonomists also compare the molecular means ‘toothed’ and originates from the structure of sections of the specimens’ powerful serrated jaws (or ‘mandibles’) related species of common evolutionary author’s name and date are placed in DNA. This has proved especially valuable that are typical of all members of the group. origin that cannot interbreed form a parentheses. Although all scientific names in revealing higher-level relationships Although Odonata is a comparatively genus. Similar genera are combined in are nominally in Latin, they are frequently between groups, such as where a family small order of the Insecta (with just over a family, and the hierarchy continues as based on Latinised classical Greek or other should be placed, but it can also reveal 6000 extant species), the group has a increasingly inclusive groups: order, class, languages (as in the chiltoni example, ‘cryptic’ species – species that are almost very long evolutionary history. The oldest phylum, kingdom and domain. which is based on an English name). impossible to differentiate by their fossil record of a dragonfly dates back Since 1758, scientific names follow Another advantage of an organism’s outward appearance. more than 250 million years and odonates’ the binomial (‘two-name’) system of scientific name being a unique combination Turning specifically to the taxonomy giant relatives – the Griffenflies – date nomenclature devised by the Swedish of genus plus species is that it provides of odonates, they belong to the kingdom back 325 million years. Unfortunately, naturalist Carolus Linnaeus. Every species worldwide consistency, which is especially Animalia, phylum Arthropoda, class no fossil odonates have been found in is identified uniquely by its genus followed important for communication between by its species name, as well as the name of scientists. Although common names may  A pair of mandibles of the ranger dragonfly, showing the teeth from dorsal (left) the scientist who described the species and be easy to use, they can often cause confu- and ventral (right) views. BORIS MARINOV the year that description was published. sion even among the native users. The term The need for this is easy to see. There are, ‘sandflies’ illustrates this well. The annoying for example, many species named chiltoni, midges that New Zealanders call ‘sandflies’ honouring the distinguished New Zealand are ‘black flies’ if you live in Britain or North zoologist Charles Chilton. These include America, but they all belong to the same worms, a fish, a snail, a crab and several family, Simuliidae. On the other hand, insects. But the dragonfly Uropetala chiltoni in Australia, ‘sandflies’ is the common Tillyard, 1921 is uniquely identified as a name for equally annoying insects of a dragonfly of the family Petaluridae by different family, Ceratopogonidae. its associated genus, as well as the fact It bears pointing out, however, that that the description was published by non-scientific names have often been the Australian entomologist Robert John used to successfully distinguish between Tillyard in 1921. The author and date are closely related species. Members of a needed to establish priority in case another tribe in Papua New Guinea recognise 137 author should later publish the same name out of the currently known 138 species referring to a different species. If new of birds found in their area. The only two information comes to hand and the species species they did not differentiate were is later moved to another genus, the original very closely related.

2 • NATURAL HISTORY NATURAL HISTORY • 3  Fossil of Tupus gallicus from the Middle Permian (265 million years ago), from France. ANDRÉ NEL

New Zealand yet. This is a significant gap in with laterally expanded abdomens, and our knowledge as fossils would tell us much they lack lamellae. Instead, their internal about our past fauna and provide clues to gills line the walls of the rectum, which understanding the present-day distribution can be sealed by closing small, spine-like of our species. projections on their abdomen. All New Zealand Odonata are Although Odonata comprises both divided into two suborders: Zygoptera damselflies and dragonflies, in recent  Adult and naiad Odonata are very convenient subjects for studying general insect body and Anisoptera, which correspond to years, ‘odonates’ or ‘dragonflies’ have been morphology. Clockwise from top left: Adult blue damselfly; Naiad of the blue damselfly; the common names ‘damselflies’ and used widely when referring to all members Adult yellow spotted dragonfly; Naiad of the yellow spotted dragonfly. ‘dragonflies’. All our Zygoptera are small of the order. In this book, whenever we and light in build, and they rest with their speak of odonates, we mean the entire Running and standing waters each provide present fauna. The islands that form wings folded together above the body, order Odonata. In some specific instances, a host of distinct habitats, supporting New Zealand today are the elevated whereas our Anisoptera are larger, more we refer to the two suborders by their unique communities of naiads preferring remnants of a now mostly submerged heavily built and rest with their wings scientific names: Zygoptera and Anisoptera. different freshwater conditions. In the continent, Zealandia. This large block open. The two suborders differ in several Northern Hemisphere, some species are of continental crust extends from the other ways. In Zygoptera, the fore- and HABITATS OF NEW ZEALAND especially adapted to live only in very harsh Subantarctic Islands to New Caledonia. hindwings are almost identical, narrow and DAMSELFLIES AND DRAGONFLIES conditions, such as occur in bogs within the About 84 million years ago, Zealandia often stalked; Anisoptera have dissimilar New Zealand has a unique odonate fauna. Arctic Circle where temperatures are very began to separate from the Australian wings that are broad at the base, especially Given the size of the two largest islands cold even during the summer, or in fast- portion of the supercontinent Gondwana. the hindwing. They also differ in the and the availability of good damselfly running, shaded mountain streams passing Apart from Zealandia, Gondwana included terminal appendages of the male and in and dragonfly habitat (sites with poor through cool temperate forests. what are now Australia, Antarctica, India, their naiads (this term, sometimes called drainage that can accumulate freshwater), By contrast, New Zealand rivers and Africa, South America and some larger a larva or nymph, refers to the period of New Zealand has surprisingly few streams are almost devoid of odonates, islands such as Sri Lanka and Madagascar. life between egg and adult). Zygoptera species, all of which occur at relatively a phenomenon that has never been With the break-up of Gondwana, naiads have slender and nearly parallel- low abundance. In other parts of the world fully explained. The geological and its odonate fauna became fragmented and sided bodies with three long, paddle-like with a similar climate, most freshwater climatological history of the land isolated on the separating land masses. gills (also known as ‘lamellae’ because habitats sustain rich odonate communities, undoubtedly had a significant impact We do not have fossil evidence to judge of their thin, flat and often transparent although there are progressively fewer on the evolution of local damselflies and what share of species New Zealand layer). Anisoptera naiads are stouter, species as one approaches the poles. dragonflies and the composition of the received from the probably rich

4 • NATURAL HISTORY NATURAL HISTORY • 5 Gondwanan fauna. We can, however, colonise very shallow and temporary pools, assume that during the millennia of isola- ponds and ditches. Freshwater lakes near tion, New Zealand’s species were exposed the coast are good areas to find lancer and to dramatic geological and climatic events. baron dragonflies. The freshwater allows New Zealand travelled further south, the growth of a dense fringe of emergent taking warm-adapted species to a colder vegetation and also supports floating climatic zone. During the subsequent tens plants, both of which provide perches for of millions of years, Zealandia’s surface dragonflies and sites for egg-laying and area was reduced to a few islands owing to emergence. Like the blue damselfly and the the subsidence of a large part of the land.  Waihihi Stream by Puriri Grove Track, Hunua red percher dragonfly, the lancer dragonfly Most probably glaciation also took its toll, Ranges. MILEN MARINOV can breed in very shallow water. q Mountain tarn in the Canterbury high country. reducing further an already impoverished Inland lakes (such as Rotoaira and odonate fauna. The southern latitudes Rotopounamu, near Taupo) with large areas may have been more favourable for of open surface water are attractive sites, cold-tolerant insects such as stoneflies especially for the yellow spotted dragonfly. (order Plecoptera) and some mayflies The naiads live among submerged (order Ephemeroptera), which develop aquatic plants or on the lake bottom. Bank predominantly in mountain streams. vegetation is also important to them for

However, damselflies and dragonflies  Sandy Creek, Waiparere Farm, Wairoa, successful emergence. However, naiads that occupy such habitats are mainly Hawke’s Bay region. do not depend on this entirely as adults restricted to the tropics. Odonates found in temperate-zone mountains typically differentiating from populations in the rest of the ranger dragonfly have been found inhabit lakes and ponds. of the country. Unfortunately, with the lack occasionally in running water in the South In New Zealand, volcanic and tectonic of any fossils of dragonflies or dragonfly-like Island, but usually close to larger still-water activity raised some of the low-lying lakes organisms, and no detailed comparisons basins from which they had most probably (several of the present-day tarns), isolating between New Zealand species and those been flushed. That species also survives the species in and around them from their from the rest of the world, every theory in North Island streams, but prefers lowland counterparts. Streams and rivers is speculative at this stage. An integrated sunnier sections than the dusk dragonfly that originated on the newly raised slopes study involving several scientific disciplines and the redcoat damselfly. Unfortunately, offered a wealth of new habitats. However, is needed before we can begin to explain our beautiful braided rivers do not support the species specialised to life in standing the paucity of odonates throughout any viable odonate populations, as their water probably were unable to occupy their New Zealand, especially in running water ever-changing shape and rocky bottoms are  Brooklands Lagoon in Spencer Park, near Christchurch. unclaimed niches. It has been suggested and in the South Island. not suitable for any of our present species. q Lake Rotopounamu, near Taupo. that some populations of redcoat In fact, in running water habitats of the Although both the redcoat damselfly and damselflies in the North Island may have South Island, there are scarcely any species the ranger dragonfly can breed in running invaded streams in shady forested areas at all. The dusk dragonfly is the only water, they are clearly far more abundant and, over time, the descendants acquired New Zealand species with an affinity for at ponds, lakes and other standing-water morphological features which more than flowing water and its distribution is limited habitats. These species can even be found a hundred years ago were considered to shady forest streams in the North Island. in lakes with slightly increased salinity, such sufficient for them to be described as The redcoat damselfly may survive in slow- as Brooklands Lagoon near Spencer Park, a separate species. Similarly, redcoat flowing rivers of the South Island, especially north of Christchurch. Coastal wetlands damselflies in the mountain tarns of in areas where the water backs into small are also occupied by the blue damselfly the South Island are probably gradually eddies along vegetated banks. Naiads and the red percher dragonfly, which may

6 • NATURAL HISTORY NATURAL HISTORY • 7 sometimes emerge directly on rocks or Similarly, the bush giant dragonfly is also places. The aptly named wandering glider fallen tree trunks near a bank. The yellow seen along walking tracks that pass through or globe skimmer () spotted dragonfly is also a common species forested areas. Adults of this species tend has been found in the Himalayas at in city gardens and at pools in recreational to avoid open areas and prefer the shade altitudes above 6000 m a.s.l. The same parks such as Otipua Wetlands, south of the trees. They may fly across forested species is the only known dragonfly from of Timaru, and The Groynes Recreation clearings, but are rarely seen perching on Easter Island and it is also reported as Reserve, near Christchurch. completely exposed, sunlit vegetation. regularly appearing in huge numbers over Some North Island ponds are dominated Clearly, New Zealand odonates have the Maldives. The latter entirely lack open by the sentry dragonfly, which is gradually survived the many cataclysms over time freshwater, making it impossible for any occupying larger territories in the South that have shaped their natural habitats. dragonfly species to breed and establish Island. Currently known as far south as  Burrow entrance of a bush giant dragonfly, Some species are continuing to adapt to a permanent colony there. The species’ Christchurch, this species may soon be Tanekaha Tracks, Brynderwyn Range, today’s constantly changing environmental nearest known breeding habitat is in India Mangawhai. Diameter of ring is about 2 cm. recorded further south, especially with MILEN MARINOV conditions – changes wrought mostly and some researchers believe the Maldives the present global trend of increasing through human modification of habitats are just a staging post in a more than annual temperatures. However, given usually occupied by the redcoat damselfly, and introduction (unwitting or deliberate) 3000 km migration from India to the east its preference for warm habitats (adults the blue damselfly and the ranger dragonfly. of exotic species. Understanding the coast of Africa. have been observed patrolling over Areas of open tussock grasslands with species’ needs for natural space is crucial Scientists are still searching for thermal streams near Rotorua, which tiny water trickles flowing downhill are the in our attempt to preserve the unique plausible explanations for this and similar were quite hot to touch), it is unlikely that habitat of the mountain giant dragonfly. assemblage of New Zealand damselflies discoveries. An often-cited hypothesis is the sentry dragonfly will ever establish at Giant dragonflies are exceptional in that and dragonflies that we have inherited. wind-assisted flight across the ocean. Some high elevations in South Island mountain their naiads live in burrows dug into wet studies even suggest that certain species tarns and peaty lakes. These areas are soils, usually densely overgrown with ENDEMICS AND MORE RECENT of Odonata evolved wings that enable mosses and often far from any surface ARRIVALS them to glide, which would make journeys water. The size of the burrow depends on Nowadays, with so much interest in between oceanic islands energetically the naiad’s stage of development, but they odonates, species new to science are possible. These conclusions are supported can be as deep as 70 cm. They may end in being discovered regularly and well-known by some curious observations, such as blind chambers or be U-shaped, thereby species are turning up in the most unusual the astonishing migration of the green providing an alternate exit to escape a potential threat. The burrows are always partially inundated but are usually dry at the entrance, although in particularly wet soils the water level may reach almost to  The Groynes Recreation Reserve, near the burrow’s opening. The naiads always Christchurch. q Boggy area above Lake Sarah, near Cass. keep the burrow clean – doing ‘home maintenance’ each night. Growing roots are nipped off, and collapsed soil is removed to a small pile at the entrance using the broad, flat mouthparts as shovels. Vacated burrows very soon became obliterated by growing roots and collapsing soil. Adults of the mountain giant dragonfly

are often encountered on some of  Wandering glider New Zealand’s more common alpine walks. (Pantala flavescens).

8 • NATURAL HISTORY NATURAL HISTORY • 9 Indonesia, New Guinea, New Caledonia, ability to fly long distances or was their surveying the transoceanic movement of Norfolk Island and the Kermadec Islands, introduction due to human influence? insects on board ships in the mid-20th was first captured in New Zealand in 1918. The above-mentioned migration of century argued that the physical conditions The sentry dragonfly, native to Australia the wandering glider from India (to the of the insects caught within the storm were and also found in the lesser Sundas, Maldives and then) to Africa is still a not necessarily fatal and often some of Norfolk Island and the Kermadec Islands, hypothesis, which has not yet been proven. them were still active even when tossed on was originally reported as an occasional The green darner, on the other hand, does the ship by the wind. After a 10-year study immigrant to New Zealand in the 1920s. migrate long distances; however, in the open ocean, the Museum scientists The common glider dragonfly, found in the dragonflies are always flying over land inferred that insects’ own, natural power  Green darner (Anax junius). Australia, Timor, New Guinea and New or have it at a distance as visual stimuli. of dispersal had been overestimated. Their Caledonia, established breeding colonies Since green darners have stored fats for conclusion was that, at the time, humankind darner (Anax junius). Using various on the northern part of the North Island only a maximum of 8.3 hours of flight, they was the primary agent transporting insects methods, including attaching micro-radio around 2005–7. must stop regularly to feed while flying from one location to another. transmitters to the insects, scientists The establishment of these four over the land. Obviously, this isn’t possible This brings us back to the four dragonfly tracked a journey of nearly 3000 km widespread species in the last hundred while flying over large expanses of open species that were recorded as ‘new’ across the North American continent. years raises an interesting question: water, so long ocean crossings would surely in New Zealand in the last hundred years. It seems probable that if odonates can Why did it not happen earlier? Well, require wind assistance. Furthermore, It is quite possible that humans played migrate such long distances, they could perhaps it did and warm-adapted species it can’t be conventional oceanic winds a key role in their establishment here. also travel successfully from eastern had been arriving from the tropics regularly, that carry insects between oceanic islands The time of first arrival of those species Australia to New Zealand, a mere but found the New Zealand environment because such winds weaken close to the coincides with the return of the ANZAC 2000 km approximately. too harsh and quickly died out. On the other shore. Instead, violent storms are proposed troopships after World War I, which mostly Indeed, some odonate species must hand, perhaps they arrived and survived as the most likely agent to translocate docked in Australia before their final have accomplished this in the past given for a time but were not noticed by the insects between islands. Researchers from journey to New Zealand. We cannot say the species composition of contemporary scientific community. Around the turn of Bernice Pauahi Bishop Museum in Honolulu for certain if ships brought back any alien New Zealand and that of our neighbours. the 20th centuries, there were only a few Nowadays, the New Zealand fauna local entomologists monitoring the whole  A sentry dragonfly. comprises almost equal numbers of country, so some of the species mentioned endemic species and those with a wide above may have arrived even earlier than distribution in Australia and various Pacific recorded. We owe our knowledge of the islands. However, at the beginning of the arrival of baron and sentry dragonflies and 20th century, the fauna of our four main the gossamer damselfly to the medical islands consisted of endemic genera, practitioner (and entomologist) John endemic species and just two Australian Armstrong, who collected intensively species (which possibly may have been mainly around Lake Taupo. Dr Armstrong distinct subspecies). Other Australasian presented good evidence for the rapid or Indo-Australian species reached spread of the newcomers, which were New Zealand less than a hundred years ago. already quite well established around The gossamer damselfly – which is very the lake by the 1940s and 1950s. He also often cited as an example of a wind-borne commented that a local species (the yellow insect, passively carried on air currents and spotted dragonfly) might be replaced by an transported to new territories – was first invader (the sentry dragonfly). recorded here in the mid-1920s. The baron An even more important question is: dragonfly, otherwise known from Australia, Did the new species arrive using their

10 • NATURAL HISTORY NATURAL HISTORY • 11 insects, but the possibility cannot be ruled globe skimmer has reached the North grasshoppers in the field, you will find some out. What we do know is that dragonflies Island as an occasional vagrant but has so disproportionally enlarged body parts that often travel aboard large vessels cruising far failed to establish breeding populations. may obscure other less obvious features the oceans. Night-time illumination of There are several other widespread tropical and their wings may completely cover ships attracts many insects, including species that could very well reach the the abdomen or, conversely, be reduced dragonflies and especially those hardy, Kermadecs or even the North Island in the or missing altogether. On the other hand, widespread species that can be found near future. They are all beautiful insects, wasps and flies have certain body parts near ports and towns. and no doubt would be an attractive fused or underdeveloped. These examples New Zealand’s most prominent Odonata addition to the depauperate New Zealand make it challenging indeed for an observer researcher Dr Richard Rowe considers Odonata fauna. However, according to to assess all of the features of an insect’s two additional, human-related factors to recent ecological studies, they are likely to body plan. be increasingly significant in facilitating compete with locally established species. The large size and well-defined structure the colonisation of new locations by These potential new arrivals are presented of damselflies and dragonflies makes it dragonflies: global warming and habitat on pages 144–47. relatively easy to see their main body parts modification. The northward movement with the naked eye. In addition, odonates of dragonflies associated with rising are generally highly conspicuous in their BIOLOGY AND BEHAVIOUR temperatures has been well documented environment, either perching prominently in Europe, with new species records almost Body structure or staying on the wing for long periods. a yearly occurrence in Fennoscandia Dragonflies are members of the huge Furthermore, they often have colourful (the large peninsula comprising the phylum Arthropoda, which includes bodies, which can be easily differentiated Scandinavian Peninsula, Finland, Karelia all other insects, the commonly seen into the main parts typical of all insects: and the Kola Peninsula (part of Russia)), myriapods (millipedes and centipedes), head, thorax and abdomen. Understanding and elsewhere. New Zealand has been less arachnids (including spiders and mites) this basic structure is a good starting affected than most places, but slight rises and crustaceans (including crabs, lobsters, point from which to appreciate the various in temperature over the last 20 years may shrimps and barnacles). are distinguishing features of odonates detailed have tipped the balance, allowing species invertebrate (lacking a backbone) animals, in the Species Accounts in this book. such as the common glider dragonfly with a segmented body. They have one to establish breeding populations. distinctive feature – an exoskeleton  Examples of New Zealand species of non-insect Arthropoda. Top to bottom: Green orbweb spider Deforestation and farming activities have (external skeleton) with jointed legs, from (Colaranea viriditas); Freshwater crayfish (Paranephrops planifrons); Common millipede (Eumastigonus sp.). q The body parts of an odonate: head, thorax and abdomen. probably created many new habitats which the name of the phylum is derived. for opportunistic breeders to settle in ‘’ is Greek for ‘jointed foot’. New Zealand. The newly arrived species Among insects, there is an astounding are known to be relatively unfussy about diversity of body types, which all have where they lay their eggs and where the arisen from a basic hexapod (six-legged) naiads develop, although they do favour body plan over evolutionary time. Text open and often disturbed habitats. books, websites and other resources Therefore, should (when?) tropical use various schemes to demonstrate and/or subtropical species somehow the general body structure of an insect, find their way to New Zealand’s main with the most commonly used examples islands, the continuing increase in annual being grasshoppers, wasps and flies. abdomen head temperatures and expanding agricultural However, all of them have drawbacks thorax sector will mean conditions are more when presented as the archetypal insect favourable for them to settle. Already the body plan. For example, when observing

12 • NATURAL HISTORY NATURAL HISTORY • 13 Blue damselfly Austrolestes colensonis (White, 1846) endemic

Mature male. ADULT IDENTIFICATION but many lose their grip, fall into the This is New Zealand’s only blue odonate, water and need another attempt before and the largest of the Zygoptera species they emerge. Immature adults disperse found here. Mature males are normally blue quickly from the water, often flying with metallic black markings. Young males kilometres away. They feed very actively and females may appear predominantly (cannibalism is quite common) because greenish due to the iridescent sheen they do not store much fat as naiads. Their given off from the dark areas of the body. colouration changes with the temperature: The sexes are also easily distinguished on cold mornings, both sexes are dull in by their body shape: females are stouter colour, but with rising temperatures, their compared with males, which also have long colouring lightens and, in males, the blue thin appendages at the tip of the abdomen. becomes more vivid. Females that are sufficiently warmed may also look bluish.  Immature female. MEASUREMENTS Mature males set up territories along the males tbl 43–45 mm, hw 24–25 mm; rushes and sedges. Intruders are chased females tbl 40–41 mm, hw 25–27 mm away by swift, aggressive attack flights.

GENERAL BEHAVIOUR BREEDING HABIT AND HABITATS without any courtship display, and The long, thin naiads are most common Breeding pairs show a strong preference copulation takes place mainly in the early in the shallow waters of ponds, pools and for rushes and sedges. Breeding can occur afternoon. The copulatory wheel lasts lakes. Underwater, they are constantly in in minute trickles and tiny pockets of about 10 minutes, during which time the motion and do not appear to be territorial. marginally permanent water, usually at couple perches on vegetation. Females Naiads usually emerge on bank vegetation sunlit sites. Males seize passing females oviposit predominantly in rushes, selecting stems deep within a cluster, and insert  Mature female. the eggs into the plant tissues above water level. The male typically guards the  Naiad. female by holding her in tandem during oviposition. The newly hatched pronaiad wriggles down the stem following the track left by the female while ovipositing. If it falls on dry ground, the pronaiad ‘flicks’ its body in little jumps until it reaches water.

WHERE TO OBSERVE IN NEW ZEALAND Very common all over the country. It is one of the dominant species in mountain tarns and is thought, therefore, to be adapted to colder environments. The blue damselfly is also present on Stewart Island/Rakiura and Chatham Island (Rēkohu).  Naiad raising its caudal lamellae in a threat display.

62 • LANCER DAMSELFLY BLUE DAMSELFLY • 63 FLYING PERIOD It has been observed year-round throughout the country. It is unclear if records of late-flying individuals from June and July are of overwintering adults. The best period to see adults is from the beginning of November to late April.

FUTURE STUDIES Studies have shown that the Chatham Island population differs at a molecular level from the populations on New Zealand’s main islands. For the moment, these differences are not considered sufficient to separate them into two distinct species, especially as no consistent morphological differences have been found.

q Male guarding a female during oviposition.

p Adult female blue damselfly from Chatham Island (Rēkohu) with a notable interrupted blue stripe on the thorax. This is a common feature t Male cleaning its body. for most of the individuals on the island. DAVID BOYLE

64 • BLUE DAMSELFLY BLUE DAMSELFLY • 65 DRAGONFLIES AND DAMSELFLIES OF NEW ZEALAND

 Superb flyers with extraordinary vision and startling colours, dragonflies and damselflies are exquisite examples of evolutionary adaptation and a favourite of nature lovers around the world. This book is a beautifully illustrated natural history and field guide to New Zealand’s 14 species of dragonflies and damselflies.

• Expert and up-to-date information on the 14 species breeding in New Zealand. • Natural history of the group including an introduction to evolution, habitats, biology, behaviour, photography and conservation. • More than 200 new photographs and hand-drawn illustrations of dragonflies and damselflies at all life stages in their environment. • Authoritative text on each species covering identification, measurement, behaviour, breeding, flying period and where to observe the species. • Range maps for all species.

DRAGONFLIES & DAMSELFLIES OF NEW ZEALAND

MILEN MARINOV & MIKE ASHBEE