The larvae of Cora inca Selys, 1873 and Polythore gigantea (Selys, 1853) from Colombia (Odonata: Polythoridae), with a larval diagnoses of some genera in the family.

The larvae of Cora inca Selys, 1873 and Polythore gigantea (Selys, 1853) were found in first and second order forested streams at the Tatamá Natural National Park in the Colombian Western Andes. Their final larval stadia are here described and figured. Cora inca differs from the larvae of C. cyane Selys, 1853 and C. marina Selys, 1868 by a combination of features including presence of an irregular patch of minute, gray scales to each side of the ventral midline on the ventral pad of hypopharynx, paraprocts with five projections, and the position of epiproct and paraproct projections. On the other hand, the larva of P. gigantea differs from the larva of P. spaeteri Burmeister & Börzsöny, 2003 by antennal scape slightly shorter than 3rd antennomere, prementum 0.10x longer than its widest part, and the position of epiproct and paraproct projections. Although most of the larvae in the family Polythoridae are still unknown, here we discuss the main morphological characteristics that help to diagnose some of the genera in this family, presenting a regional taxonomic key that includes the genera Cora Selys, 1853, Euthore Selys, 1859, Miocora Calvert, 1917, and Polythore Calvert, 1917.

The rediscovery of Heteragrion azulum Dunkle, 1989 with additional notes on the female (Odonata: Heteragrionidae).

Some details of the morphology of the female of Heteragrion azulum Dunkle, 1989 are described for the first time such as the intersternite, and illustrated with high quality photographs, based upon two specimens collected in the tropical rain forest at the region of Los Tuxtlas, in the state of Veracruz, Mexico. A comparison with females of the other three species of Heteragrion Selys, 1862 occurring in Mexico is also provided. Additional data of males of H. azulum collected together with the females are also given, including some illustrations.

Two new species of Archaeopodagrion (Odonata, Philogeniidae) from the western foothills of the Tropical Andes, with biological observations and distributional records.

Two new species of the damselfly genus Archaeopodagrion, A. recurvatum sp. nov. and A. mayi sp. nov., are described from the confluence of the Tropical Andes and the Tumbes-Chocó-Magdalena biodiversity hotspots. Adults differ from the other known species in the shape of female posterior lobe of pronotum and male structures of cerci and paraprocts; the larva differs from other Archaeopodagrion species in the caudal lamellae structure and in the mandibular formula. The two new species are diagnosed, a morphological key to all known males and females in the genus is provided, and geographical distributions are updated. Finally, observations on habitat preferences for each newly described species are provided.

Description of the larva of the genus Archaeopodagrion Kennedy, 1939 (Zygoptera: Philogeniidae).

The larva of Archaeopodagrion fernandoi Bota-Sierra, 2017, is described and illustrated in detail, being the first larva described for the genus Archaeopodagrion. The description is based on F-0 larvae collected from the type locality. The larva of A. fernandoi shows great resemblance to larvae of Philogenia spp., which adds support to the hypothesis of the monophyletic family Philogeniidae which groups together Archaeopodagrion and Philogenia. However, both genera differ each other by the presence of basal, spiny, fleshy tubercles on caudal lamellae of Archaeopodagrion.

Redescription of the larva of Neoerythromma cultellatum (Hagen in Selys, 1876) (Odonata: Coenagrionidae: Coenagrioninae).

The final instar of Neoerythromma cultellatum (Hagen in Selys, 1876) is redescribed and illustrated based upon reared specimens from Turrialba, Cartago, Costa Rica. This is a detailed complement of the original description provided by García-Díaz (1938) and illustrated with high quality photos of the larval morphology. The larva of N. cultellatum is characterized by a slender, spinulose, and yellow to yellowish-brown body, premental setae 3+1, five palpal setae, male cerci long, and caudal lamella lanceolate, with obvious node, spotted, and markedly tracheate.

Two new species of Colombian Epigomphus (Odonata: Gomphidae).

The Neotropical genus Epigomphus Hagen in Selys, 1854 groups 31 species distributed from Mexico to northern Argentina. Only two species have been recorded so far from Colombia. Here we present two new species found in the north of the Andean Colombian Cordillera Central, Epigomphus rufus sp. nov. and Epigomphus brillantina sp. nov. Full descriptions of adult male and female and adult male respectively, plus diagnoses, pictures of the diagnostic characteristics, natural history notes, and a distribution map are provided.

The larva of Phyllogomphoides pugnifer Donnelly, 1979 (Odonata: Gomphidae).

The larva of Phyllogomphoides pugnifer Donnelly, 1979 is described for the first time based on reared specimens to emergence, and several F-0 larvae collected in Chiapas and Veracruz states, Mexico. The larva of P. pugnifer can be separated from other larvae of the genus by the length/width proportion of structures such as prementum, ligula, and abdominal segment 10, as well as length of cercus relative to epiproct.

Descriptions of the larvae of Acanthagrion speculum and A. trilobatum from Costa Rica (Odonata: Coenagrionidae).

Description of the final instar of Acanthagrion trilobatum Leonard, 1977 and A. speculum Garrison, 1985 is based on associated specimens from San José, Turrialba and Sarapiquí Provinces, Costa Rica. Illustrations of these two species and a comparative table summarizing the main features of all larvae of Acanthagrion described to date are provided. The larva of A. trilobatum is distinguished from that of A. speculum by shorter lateral caudal lamellae (length 7 mm vs. 8.2 mm), lateral carina of abdominal segments 2-8 with spiniform setae on posterior 1/3 (lateral carinae of only S6-8 with spiniform setae in A. speculum), and male gonapophyses incurved (straight in A. speculum).

The probable larva of Anotogaster gregoryi Fraser, 1923, with new distributional records of the genus from northern Thailand (Odonata: Cordulegastridae).

The probable larva of Anotogaster gregoryi Fraser, 1923 is described for the first time by supposition based upon four F-0 larvae collected in the provinces of Loei and Phitsanulok, which are new province records for Anotogaster in Thailand.

A synopsis of Phyllogomphoides Belle, 1970 (Odonata: Gomphidae) of Mexico: taxonomy and distribution.

A synopsis of the 13 species of Phyllogomphoides Belle, 1970 known to occur within Mexico is presented. Taxonomic keys for males are based primarily on morphology of anterior and posterior hamules, caudal appendages and of the vulvar lamina in females and includes full descriptions for each species accompanied by high-resolution photographs, drawings, comparative diagnostic notes, natural history and distribution maps. Females of P. danieli González Novelo, 1990 and P. nayaritensis Belle, 1987 are described for the first time. Moreover, new records for P. albrighti (Needham, 1950) for the states of Guerrero; P. danieli González Novelo, 1990 for Colima, Guerrero and San Luis Potosí; P. duodentatus Donnelly, 1979 for Oaxaca; P. luisi González Novelo, 1990 for Nayarit, and P. pugnifer Donnelly, 1979 for San Luis Potosí, are also provided.

The larva of Amphigomphus somnuki Hämäläinen, 1996 and the first records of the genus Stylogomphus Fraser, 1922 for Thailand (Odonata: Gomphidae).

The larva of Amphigomphus somnuki Hämäläinen, 1996 is described for the first time based on an emerged male specimen from Chiang Mai Province, and several F-0 larvae collected in other provinces of Thailand. The larva of A. somnuki is the smallest and differs from A. nakamurai Karube, 2001 by the caudal appendages densely covered with minute spiniform setae, and from A. hansoni Chao, 1954 by the male epiproct with the dorsal tubercles at 0.65 the length of the epiproct. New province records for A. somnuki and the first records of Stylogomphus Fraser, 1922 for Thailand are provided.

The larvae of Phaenandrogomphus Lieftinck, 1964 in Thailand, including the description of P. tonkinicus (Fraser, 1926) with a larval diagnosis and new province records of P. asthenes Lieftinck, 1964 (Odonata: Gomphidae).

The larva of Phaenandrogomphus tonkinicus (Fraser, 1926) is described for the first time based on several F-0 larvae collected in Chiang Mai and Nan provinces of Thailand. The larva of P. tonkinicus differs from that of P. asthenes Lieftinck, 1964 by having the 3rd antennomere mesal margin strongly convex, 4th antennomere vestigial and dome-like, postclypeus thick and shelf-like, S8 lacking a posterolateral spine, and cerci usually shorter than the epiproct. New Thailand province records of P. asthenes also are provided.

Description of the larva of Orthemis ferruginea (Fabricius, 1775) (Odonata: Libellulidae).

The last larval stadium of Orthemis ferruginea (Fabricius, 1775) is described and illustrated in detail based on reared material collected in the municipality of Paso de Ovejas, Veracruz, Mexico. It is compared with larvae of other species of the genus previously described. The main structural features are the number of setae on palp, prementum and palp crenations, the size proportion of cerci respect to epi- and paraprocts, and the number of sclerites on abdominal sternum 5.

The larva and female of Perigomphus basicornis Amaya-Vallejo, Novelo-Gutiérrez & Realpe, 2017, and the first record of Perigomphus pallidistylus (Belle, 1972) for Colombia (Insecta: Odonata: Gomphidae).

The larva and female of Perigomphus basicornis are described and illustrated, and compared with the larva and female of P. pallidistylus. The larva of P. basicornis differs from that of P. pallidistylus in having sternum 8 divided in five sclerites, abdominal segments 8 and 9 with small, low protuberances on the tergites and male's epiproct as long as its basal width, mainly. The female of P. basicornis differs from that of P. pallidistylus in having the apical lobes of vulvar lamina wider, with divergent tips. P. pallidistylus is recorded for Colombia for the first time.

Cordulegaster virginiae sp. nov. from Mexico, including a comparison with C. diadema Selys, 1868, and a redescription of its larva (Odonata: Cordulegastridae).

Cordulegaster virginiae sp. nov. is described based on eight adults (7 males, 1 female) collected in cloud forest in municipalities of Banderilla and Xalapa, Veracruz, Mexico. The new species is compared with adults of C. diadema Selys, 1868. All the structural differences between both species are located on the abdomen. Cordulegaster godmani McLachlan, 1876 is considered a junior synonym of C. diadema. The larva of C. diadema is redescribed and illustrated in detail based on reared material.

The genus Heteragrion (Odonata: Zygoptera) in Northwestern Colombia, with the description of Heteragrion tatama sp. nov.

The Neotropical forest specialist genus Heteragrion counts with 54 species and one subspecies described to date, eight of which have been recorded from Colombia. Here, information on Heteragrion species resulting from ten years of exploration of northwestern Colombia and examination of museum collections, including types and species from Central America, is presented. A new species endemic to the Tatamá National Park in the western Andes, Heteragrion tatama sp. nov. is described, as well as the female of Heteragrion aequatoriale Selys, 1886. Heteragrion calendulum Williamson, 1919 was rediscovered, a century after its first collection, which allowed us to compare it with Heteragrion atrolineatum Donnelly, 1992, and to conclude that the latter species is its junior synonym. We present pictures of female prothoracic intersternite, which offer valuable taxonomic information. The variation in coloration patterns for H. aequatoriale and Heteragrion mitratum Williamson, 1919 is discussed, and maps with new distributional data, a taxonomic key, natural history notes and photographs of the Heteragrion species distributed west of the Magdalena valley in Colombia, are also provided.

The larvae of Epigomphus jannyae Belle, 1993 and E. tumefactus Calvert, 1903 (Insecta: Odonata: Gomphidae).

The taxonomic knowledge about immature stages of the insect order Odonata (dragonflies and damselflies) is rather limited in tropical America. Here, the larvae of Epigomphus jannyae Belle, 1993 and E. tumefactus Calvert, 1903 are described, figured, and compared with other described congeners. E. jannyae larva is characterized by 3rd antennomere 1.6 times longer than its widest part; ligula very poorly developed, with ten short, truncate teeth on middle; apical lobe of labial palp rounded and smooth. Lateral margins on abdominal segments (S5-9) serrated, lateral spines on S6-9 small and divergent; male epiproct with a pair of dorsal tubercles at basal 0.66; tips of cerci and paraprocts strongly divergent. The larva of E. tumefactus is characterized by 3rd antennomere 2.3 times longer than its widest part, ligula with 6-7 truncate teeth, apical lobe of labial palp acute and finely serrate. Lateral margins of S6-9 serrate, lateral spines on S7-9; male epiproct with a pair of dorsal tubercles at basal 0.50. Differences with other species were found in 3rd antennomere, lateral spines of S7-9, and the caudal appendages. Epigomphus larvae inhabit small, shallow creeks (1st order streams) where they live in fine benthic sediments. When mature, the larva leaves the water in shady places, climbing small rocks at the water's edge and metamorphosing horizontally on flat rocks. These new descriptions bring the total number of Epigomphus species with known larval stages to eight; only 28% of the species in this genus are known as larva.

The Ambrysus Stål (Heteroptera: Naucoridae: Cryphocricinae) of Mexico: Revision of the subgenus Syncollus La Rivers.

The subgenus Ambrysus (Syncollus) La Rivers is mostly Neotropical and includes nine described species. Features uniting species in this subgenus are related to the position of the propleura with respect to the prosternum in males and females, as well as characteristics of tergum V and the genitalia of males. Three species of Syncollus are known from Mexico including Ambrysus baeus Polhemus & Polhemus, A. circumcinctus Montandon, and A. pygmaeus La Rivers. The remaining six species in the subgenus are distributed in Central and South America. Herein we review Syncollus and revise the Mexican fauna. More specifically, three new species from Mexico are described: A. chiapanecus n. sp., A. totonacus n. sp., and A. xico n. sp. The subspecies A. circumcinctus caliginosus Usinger, A. c. concavus La Rivers, and A. c. extremus La Rivers are proposed as junior synonyms of A. c. circumcinctus Montandon. Ambrysus partridgei De Carlo is transferred from Syncollus to the subgenus Ambrysus.