Personal recollections and anecdotes of a friendship that lasted almost 30 years are given. The full odonatological bibliography of Richard Seidenbusch is appended.

This study describes the fauna of odonates of nine localities in the Zapata peninsula in the South-west of Cuba, sampled in June 2017, January 2018, and September 2019. We failed to find Enallagma truncatum, an endemic species of the area, even though we visited the type locality, Zarabanda, in June and January. We found 37 species in 25 genera and five families, including the first records of 11 taxa for the area: Lestes forficula, L. tenuatus, Leptobasis candelaria, Neoneura maria, Aphylla caraiba, Celithemis eponina, Crocothemis servilia, Erythemis plebeja, Erythrodiplax berenice naeva, Perithemis domitia and Tramea onusta. A dichotomous key for the separation of the four species of females of Cuban Lestes is given.

We used literature data, museum collections, and fieldwork to compile a list of records and produce a distribution map of Sympetrum croceolum in the Russian part of its range from where the species was little known to odonatologists outside of Russia for a long time. A detailed description of the fourth record of the species in Western Siberia (Chernyy Mys village, Kolyvanskiy District, Novosibirsk Province), which is globally the northernmost record of the species, is given. We suppose that the West Siberian S. croceolum populations originate from westward migrations from the eastern core part of the species' range. Morphometric analysis of specimens from different populations showed that variation of the hind wing size is within the individual variability of S. croceolum. By breeding S. croceolum in an aquarium from an egg clutch, information on the period of embryonic development and morphometric characteristics of eggs and larvae of younger instars was obtained. The subspecies Sympetrum croceolum fuscoatrum Belyshev, 1964, is synonymised with the nominotypical subspecies.

Recently Kohli et al. (2018) published a phylogenetic analysis of Somatochlora sahlbergi, including extensive supplementary material listing global distribution records for the species. The compilation of literature data on records of S. sahlbergi in Siberia includes an inacceptable level of false pseudo-data and incorrect statements.

Exposure to plastic litter in ecosystems is increasing globally. Marine and terrestrial ecosystems, as well as freshwater ecosystems, are affected. Despite this, the impact of increased exposure to plastics on the freshwater fauna is largely unexplored. The present work investigates the reactions of 42 Anax imperator larvae to plastics in their habitat. Mesoplastic fibres (ca 8 mm long) were presented with a Chironomus sp. larva that was placed behind the fibre. In the majority of the observations, ejection attempts using the labium and the front legs were observed. When ingestion occurred, macerated plastic fibres (0.5–3.5 mm) appeared in the faeces of several individuals. Consequently, Odonata larvae turned mesoplastics into microplastics. It is assumed that the mechanical comminution was achieved by the action of the gizzard, which contains strong chitinous teeth.

There has been a marked increase in the number of dengue cases reported in Japan. In 2014, 162 people contracted dengue fever from the virus transmitted by Aedes albopictus. The increased prevalence of the disease in Japan implies that climate change and globalization have accelerated the risk of dengue fever spreading to Japan. This study aimed to develop a method for using dragonflies as biocontrol agents for mosquito control. We conducted a field study to determine whether dragonfly larvae could suppress populations of A. albopictus larvae. Eighth instar larvae of Sympetrum frequens were released into an ovitrap in which they preyed upon mosquitos. Compared to the control treatment, mosquito larvae decreased significantly in ovitraps containing S. frequens and S. infuscatum (i.e., experimental treatment). The mean number of mosquito larvae remaining in S. frequens and S. infuscatum ovitraps was 1.5 ± 4.6 (mean ± SD) and 0.6 ± 1.1, respectively. The results showed that S. frequens and S. infuscatum preyed on 410 to 710 and 339 to 592 mosquito larvae per ovitrap at each site. Based on estimates of the number of mosquito eggs laid in ovitraps during the field trial, S. frequens larvae consumed approximately 20.3 to 45.0 % of mosquito eggs in the ovitrap. Suppression effects of S. frequens and S. infuscatum lasted 41 ± 13 and 35 ± 13 days, respectively. The results obtained suggest that S. frequens in ovitraps is effective for regulating larval populations of mosquito vectors.

The reproductive behaviour of the damselfly Disparocypha biedermanni (Chlorocyphidae) was studied in various streams, mainly in the Lake Poso area of Sulawesi. Flight styles of males were analysed in detail for the first time using high speed cinematography. Protracted threatening flights were particularly common between territorial neighbours. Males flew with regular counter-stroking wing beats and the abdomen held horizontally. Occasionally one of the males performed short ascending flights, pausing the wing beat. These threatening flights were interrupted periodically by short bursts of increased intensity with higher stroke frequency where males arched their abdomens. The escalated threat display could be intensified by tremulous horizontal changes in position. Unlike most Chlorocyphidae, mating took place without courtship and oviposition was in vertical mossy structures well above the water. The female was guarded by the male only at the start of oviposition. Possibly the mating system evolved in such a way as to avoid interspecific competition with other Chlorocyphidae but this needs more supporting evidence.

A new Brazilian Protoneurinae damselfly, Forcepsioneura lopii sp. nov. (holotype male deposited in DZUP: Brazil, São Paulo State, Cananéia, Ilha do Cardoso State Park) is described, and diagnosed based on two males and one female. This small dark yellow-orange Forcepsioneura Lencioni, 1999, inhabits typical restinga-like formations in southern Brazil. The coloration and short ventrobasal process of the male cercus of Forcepsioneura lopii sp. nov. make it similar to the larger montane species of the orange-black group, i.e., F. grossiorum Machado, 2005, F. itatiaiae (Santos, 1970), F. janeae Pimenta et al., 2019, F. lucia Machado, 2000, and F. serrabonita Pinto & Kompier, 2018. However it occurs in lowlands and the cercus is slender as in the light blue group, i.e., F. gabriela Pimenta et al., 2019, F. garrisoni Lencioni, 1999, F. haerteli Machado, 2001, F. regua Pinto & Kompier, 2018, and F. sancta (Hagen in Selys, 1860). The very acute, spur-like process on the mediobasal process of male cercus is unique. This is only one of several undescribed species recently discovered in Forcepsioneura, and it reaffirms the necessity for additional investigations to understand the richness and diversification of this genus.

Onychogomphus cazuma Barona, Cardo & Díaz sp. nov. is described from the mountainous inland area of Valencia in central-eastern Spain. The new species presents a combination of morphological characters that distinguishes it from all other species of the genus and can be readily identified by the morphology of the male appendages and the female vulvar scale, and by the shape of the median lobe of the prementum and the labial palps of the exuvia. Molecular analysis of two genetic markers, one nuclear and one mitochondrial (PRMT and COII), supports the full species rank for this new taxon, which is sister to the north-western African endemic O. boudoti. Despite its small known distribution and the vulnerability of its habitat, available data are still insufficient to place this new species into an IUCN Red List of Threatened Species category.

This study provides annotated descriptions of six anisopteran species that were either recently recorded from South Korea or that were subject to taxonomic revision since 2000: (i) Details of Boyeria karubei specimens from South Korea are provided for the first time and they are compared with the congeneric B. maclachlani. The name Boyeria jamjari Jung, 2011, is an unavailable name and the same as B. karubei. (ii) Nihonogomphus minor Doi, 1943, is for the first time designated a junior synonym of N. ruptus (Selys, 1858). (iii) Anal appendages of Stylurus annulatus from Korea are compared with those of the Japanese population. (iv) A slight structural difference between Orthetrum internum from Korean Peninsula and Japan is highlighted. (v) New records of Sarasaeschna pryeri from Jeju Island are detailed and its habitat environment and behavioural ecology are described. (vi) Brachydiplax chalybea, a tropical/subtropical immigrant, has successfully colonised Jeju Island, expanding its range to the south-western region of the mainland.

Agriocnemis lepida sp. nov. is described and figured (holotype ♂: 20-ii-2003, Lao PDR, Khammouan Province, 2.5 km WNW Ban Tathot, Tham Kamouk, 17.6316°N, 105.1250°E, 200 m a.s.l., P. Jäger leg.; deposited at the Forschungsinstitut und Naturmuseum Senckenberg, Frankfurt am Main, Germany). Additionally, illustrations of the male appendages and the posterior lobe of the prothorax of A. clauseni, A. minima, and A. nana as well as photographs and a Selys watercolour of the female holotype of A. carmelita are provided. Agriocnemis carmelita is shortly discussed with references to the genus Mortonagrion.