Albert G. Orr

The final stadium larva of Platysticta apicalis Kirby is described, based principally on a female exuvia collected in the wild, from near Deniyaya, southern Sri Lanka. Identification was by supposition, based on the proximity a teneral adult evidently recently emerged from the exuvia. Other exuviae of both sexes from the same site were also examined, judged to be of the same species, and used to augment the description. This is the first description of the larva of a member of the subfamily Platystictinae, and also describes the larval stage of the type genus of the family. In general form the larva of P. apicalis closely resembles all known members of the subfamilies Protostictinae and Palaemnematinae with a broad roughly heart shaped head, well tracheated saccoid gills and a flat prementum with convex lateral margins. In some details, such as the palmate molar crest of the left mandible, the moderately projected ligula and the longish well-spaced coronate setae on the margin of the ligula it most closely resembles species of the New World Palaemnema Selys, but despite the extreme conservatism in larval morphology exhibited by the family, it has several characters not seen elsewhere. This is in agreement with some, but not all, studies of relationships within the family based on analysis of adult DNA, which recognise Platystictinae and Palaemnematinae as sister groups.

The states of several characters relating to the legs and mouthparts in the larva of a Bornean protostictine larvae, described previously as Platystictidae sp. A, are corrected and augmented to facilitate accurate comparison with descriptions of other members of the family available in the literature.

We present an updated classification for extant dragonflies and damselflies (Odonata) and summarize new insights gained over the past two decades. Our focus is on taxa of family-level and higher and we indicate subfamilies only when their monophyly is currently undisputed and well-supported by phylogenetic analyses. The superfamily Calopterygoidea was known to be polyphyletic and based on recent phylogenomic data is divided into nine superfamilies, of which eight are recognized for the first time (Amphipterygoidea stat. nov., Euphaeoidea stat. nov., Megapodagrionoidea stat. nov., Mesopod­agrionoidea stat. nov., Philogangoidea stat. nov., Polythoroidea stat. nov., Priscagrionoidea stat. nov., Tatocnemidoidea stat. nov.). At present, midway through 2025, odonates are divided into three suborders, 17 superfamilies, 55 families and 687 genera containing 6447 species (May 1, 2025). We give an overview of the distribution of the families across major biogeographical realms. Except for Amanipodagrionidae, nymphs of at least some of the species of all families are known. Our understanding of the classification of dragonflies and damselflies has greatly improved in the past two decades largely due to phylogenetic inferences based on molecular studies. We expect that in the next few years the last remaining issues regarding the higher-level phylogeny and classification, including the position of the South American genus Sciotropis and the division into subfamilies of families such as Coenagrionidae, Aeshnidae, Gomphidae and Libellulidae, will be better refined by the acquisition of additional morphological and genomic data.

Literature on larvae of Calopterygoidea occurring in the Oriental Realm is comprehensively reviewed and assessed with a view to enabling workers in the region to identify larvae to genus level, and to navigate and interpret existing literature, which is scattered and uneven in quality. A family key and, where necessary and possible, generic keys for each family are provided, with the most significant gaps in our knowledge identified. Larvae of all 11 families except Priscagrionidae (2 genera) are known but larvae of many genera remain unknown and a few known genera cannot be determined with confidence by morphological characters. In total, larvae of 28 of 50 genera occurring in the region are known but apart from monotypic or ditypic families these are variably known: ratios of ‘genera with larva known’ to ‘total known genera’ are Calopterygidae (11/12), with confident generic determination of most specimens; Euphaeidae (6/8) with fair confidence of determination; Chlorocyphidae (6/16) with genera usually not clearly identifiable, hence no generic level key is provided for this family, although known intergeneric and interspecific variation is discussed.

The final stadium larvae of the following four species of south-east Asian Chlorocyphidae are described and compared: Aristocypha fenestrella (Rambur), Heliocypha biseriata (Selys), Libellago hyalina (Selys) and Sundacypha petiolata (Selys), including both sexes for the latter two species. Excepting one L. hyalina specimen from Brunei, identified by supposition based on habitat, all specimens were identified by comparing and matching the mitochondrial marker COI with that of known adult specimens from Sarawak, Brunei and several localities throughout tropical Asia. The specimens presented close matches with all adults in this gene. An assessment of the efficacy of this method of identification is provided, noting that in some cases close species cannot be separated by bar-code matching and ultimate determination is partially based on known distributions of adults. Some aspects of the relationships among genera revealed by the genetic analyses are also discussed. In addition, an exuvia of Libellago lineata (Burmeister) from northern Thailand, identified by supposition, is partially described for the purpose of comparison with L. hyalina. For the morphological analysis the unique features of chlorocyphid anatomy are discussed, and some new terminology is introduced. Overall, the morphological analysis revealed numerous clear differences between the four species studied, and comparisons with available literature suggest that some of these may be characteristic of their genera. It is also evident that in some cases clear interspecific differences occur within genera. It is however concluded that a generic level larval key for the Oriental region Chlorocyphidae based on morphology may never be attainable, although local generic or even species level keys addressing the fauna of limited geographic areas may be possible in many places, especially as the larvae of more species come to be known and described in detail.

The final instar larva of the large, spectacular Philippine and Luzon endemic euphaeid damselfly Heterophaea barbata (Martin, 1902) is described and illustrated for the first time, based on field collected exuviae of both sexes. Identification is by supposition, but larvae of the only other euphaeid on the island, Euphaea refulgens Hagen in Selys 1853, have been previously described and illustrated and can be confidently ruled out. The specimens are exceptionally large for the family and present several novel structural features not recorded in other euphaeid genera. The antennae of the principal specimen studied were asymmetric in length and numbers of segments, suggestive of a possible teratological event caused by genetic load or environmental factors during development. This and other specimens exhibited up to 14 antennomeres, more than hitherto recorded for any odonate larvae.

A late instar larva of an unknown calopterygid species, here termed ‘species Q’, was collected at Godawari, Nepal, in 1992 by SGB. It resembles, but appears to differ fundamentally from a larva described erroneously as Caliphaea confusa by F.C. Fraser from Meghalaya, Assam, in 1943. Fraser’s description seems to contain impossible discrepancies but the original specimen may pertain to Echo margarita, which occurs in the same locality. However, there are no records of this genus from Nepal, from where just three species of the family, Caliphaea confusa, Neurobasis chinensis and Vestalis gracilis, are known. None of these three genera have larvae matching that of ‘species Q’. The mystery larva is described and compared with that described by Fraser. Fraser’s description is analysed and critiqued. The larva is concluded to be related to the genera Mnais, Echo and Psolodesmus but its specific identity and that of the larva described by Fraser remain uncertain, with the possibility of ‘species Q’ representing a new species or even a new genus with an unknown adult being suggested.

The final stadium larva of Anisopleura furcata Selys, 1891 is described and illustrated. The larva can be separated from all known Anisopleura Selys, 1853 larvae by the following characters: the profusion of elongated tubercles on the labrum and antefrons, the presence of a long bifid spur on the outer margin of the mandibles, presence of a row of claviform setae on dorsal apex of tarsus, and antennae 8-segmented. The inner lobe of the labial palps forms a tiny truncate tooth broadly similar to the condition in all other known members of the genus. Diagnostic features that separate this species from potentially syntopic euphaeid genera are discussed.

The final instar of Bayadera strigata Davies & Yang, 1996, from Yunnan Province, China, is described and illustrated for the first time. This study confirms several characters as being typical of, or unique to, the genus Bayadera and discusses them in comparison to other genera. The larva of B. strigata is distinguished from its congeners by the presence of numerous distinct short spines on the genae, but no long spines. The gonapophyses are unusually long in both sexes. Notes on this species’ habitat and behaviour are provided. The material examined will be stored at the Bioscience Museum of Dali University, Dali, Yunnan, China.

The tropical and subtropical rainforests of eastern Australia are a major component of the Forests of East Australia global hotspot. Australian rainforests are maintained orographically and are embedded within vast tracts of pyrogenic open forest and woodland. Australian tropical and subtropical forests stretch over 24° of latitude from Cape York, Queensland, to south of Sydney, New South Wales. Since European colonization in 1788 these rainforests have been reduced in extent by about 30%. The most abundant and functionally significant animal species within these forests are arthropods. These have attracted the attention of western science since before formal colonization. Through the twentieth century this focus increased and comparative biogeographic studies began to emerge. Some taxa have received much more attention than others. Selected butterflies and beetles plus economically important species stand out in this respect. From the late 1980s mass sampling approaches developed. Recent research foci have included tropical and subtropical elevational transects, latitudinally diverse multi-method one-hectare surveys, and use of canopy knockdown as a way of sampling the canopy. Important and distinct patterns reflecting latitude, altitude and vertical position have emerged. A focus on moths in remnant and elevational studies has led to the identification of indicator sets of species which may be most useful for tracking the impacts of environmental degradation and global warming. Arthropods are increasingly being nominated on lists of rare, threatened and endangered species; a range of species of insects, particularly butterflies, have been so identified in Australia but few of these are rainforest species. The vulnerable Richmond Birdwing butterfly, a species of subtropical rainforests, has become an icon of how recovery methods can be applied to invertebrate species. Regarding the entire rainforest community—microbiota, plants, vertebrates and invertebrates—as the ‘object’ to be conserved is an essential and much more realistic mindset for future conservation efforts. Most of Australia’s tropical and subtropical rainforests are held in National Parks and they are defining features of two of Australia’s largest World Heritage Areas. Growing impacts of global warming means they cannot be regarded as ‘safe’ from a conservation point of view. Increasing frequency of wildfires impinging upon rainforest areas is having a devastating effect on some of these fire-sensitive forests. Implications for insect conservation: Most of Australia’s tropical and subtropical rainforests are held in National Parks and they are defining features of two of Australia’s largest World Heritage Areas. Nevertheless the growing impacts of global warming means they cannot be regarded as ‘safe’ from a conservation point of view. Increasing frequency of wildfires impinging upon rainforest areas is having a devastating effect on these fire-sensitive forests. Regarding the entire rainforest community—microbiota, plants, vertebrates and invertebrates—as the ‘object’ to be conserved is an essential and much more realistic mindset for future conservation efforts.