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Smoky rubyspot damselflies (Hetaerina titia Drury, 1773) are one of the most commonly encountered odonates along streams and rivers on both slopes of Central America and the Atlantic drainages in the United States and southern Canada. Owing to their highly variable wing pigmentation, they have become a model system for studying sexual selection and interspecific behavioral interference. Here, we sequence and assemble the genome of a female smoky rubyspot. Of the primary assembly (i.e. the principle pseudohaplotype), 98.8% is made up of 12 chromosomal pseudomolecules (2N = 22A + X). There are 75 scaffolds in total, an N50 of 120 Mb, a contig-N50 of 0.64 Mb, and a high arthropod BUSCO score [C: 97.6% (S: 97.3%, D: 0.3%), F: 0.8%, M: 1.6%]. We then compare our assembly to that of the blue-tailed damselfly genome (Ischnura elegans), the most complete damselfly assembly to date, and a recently published assembly for an American rubyspot damselfly (Hetaerina americana). Collectively, these resources make Hetaerina a genome-enabled genus for further studies of the ecological and evolutionary forces shaping biological diversity.

Damselflies and dragonflies (Order: Odonata) play important roles in both aquatic and terrestrial food webs and can serve as sentinels of ecosystem health and predictors of population trends in other taxa. The habitat requirements and limited dispersal of lotic damselflies make them especially sensitive to habitat loss and fragmentation. As such, landscape genomic studies of these taxa can help focus conservation efforts on watersheds with high levels of genetic diversity, local adaptation, and even cryptic endemism. Here, as part of the California Conservation Genomics Project (CCGP), we report the first reference genome for the American rubyspot damselfly, Hetaerina americana, a species associated with springs, streams and rivers throughout California. Following the CCGP assembly pipeline, we produced two de novo genome assemblies. The primary assembly includes 1,630,044,487 base pairs, with a contig N50 of 5.4 Mb, a scaffold N50 of 86.2 Mb, and a BUSCO completeness score of 97.6%. This is the seventh Odonata genome to be made publicly available and the first for the subfamily Hetaerininae. This reference genome fills an important phylogenetic gap in our understanding of Odonata genome evolution, and provides a genomic resource for a host of interesting ecological, evolutionary, and conservation questions for which the rubyspot damselfly genus Hetaerina is an important model system.

Dragonflies and damselflies are excellent bioindicators of the quality of both aquatic and terrestrial ecosystems. In our study, we assessed the usefulness of metric and meristic morphological traits as environmentally friendly and cost‐effective indicators of the integrative ecological quality of watercourses. Our study species of choice was the damselfly banded demoiselle, Calopteryx splendens (Harris) (Odonata: Calopterygidae). Adult C. splendens specimens were collected at three study sites along the trophic gradient of the Tisza River in Hungary and Ukraine. Body and abdomen length, head width, and distances between wing landmarks were assessed as metric traits, and the number of wing cells as meristic traits. The concentration of chlorophyll‐a was used to classify the three study sites into having a low, intermediate, and high trophic condition based on earlier studies. Significant differences were found along the trophic gradient based on the measured metric and meristic traits. Especially, insects from the site with the highest trophic condition had the largest body length, head width, and distances between wing landmarks, as well as the highest number of cells in the fore wings. There were also differences between males and females, but we did not find differences in fluctuating asymmetry (FA), i.e., differences between the left and the right wings. These results indicated that the morphological traits of adult banded demoiselles could be indicative of the environmental quality of a watercourse. [ABSTRACT FROM AUTHOR]

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AbstractFemale polymorphism is visible in some populations of Odonata species for unknown reasons. In general, one of the female forms which is more or less similar to males is called andromorph. Andromorph females show similar color patterns and sometimes, even some structural and behavioral aspects to the conspecific males, whereas gynochrome females are different from males. One mentioned reason for the existence and survival of this phenomenon in the odonates is the avoidance of male harassment toward females during the breeding season. Males and females of Calopteryx intermedia have sexual dimorphism in the wing shape. It represents differences in flight dynamic models of the two sexes. Therefore, the decrease of harassment of females by males needs mimicry of male’s flight dynamic, but this could be possible with the same wing shape as males but not gynomorph females. The results of the present study revealed that the shape of fore and hindwing of andromorph females were significantly different from males but not gynomorph females. As a result, it seems that andromorph females are not able to mimic the males’ flight and it seems that the andromorph females with a wing spot, approximately the same as that of conspecific males, cannot mislead the males. Thus, we have to seek other places for their existential reason(s) and survival.

Sexual selection via male competition is a strong evolutionary force that can drive rapid changes in competitive traits and subsequently lead to population divergence and speciation. Territorial males of many odonates are known to use their colorful wings as visual signals and to perform agonistic displays toward intruders. Psolodesmus mandarinus dorothea and Psolodesmus mandarinus mandarinus are two parapatrically distributed sister damselflies that share similar ecological characteristics but differ markedly in wing coloration. The wings of P. m. dorothea are mostly clear, whereas those of P. m. mandarinus have a large area of black pigmentation and a central white patch. We investigated whether territorial males of the two damselflies at breeding sites display distinct agonistic behaviors associated with their respective wing colors. Behavioral interactions between territorial and intruder males and their wing kinematics were filmed and analyzed for P. m. dorothea in Lienhuachih of central Taiwan, and P. m. mandarinus in Tianxiyuan and Fusan of northern Taiwan. We observed that the P. m. mandarinus males exhibited a novel set of perched wing displays, which was not only absent in its sister P. m. dorothea but also previously unknown in Odonata. At breeding sites, perched rival males of P. m. mandarinus with pigmented wings exhibited escalating agonistic wing-flapping and wing-hitting displays toward each other. In contrast, territorial males of P. m. dorothea with clear wings engaged only in aerial chase or face-to-face hovering when intruder males approached from the air. These results indicate that the two sister P. mandarinus damselflies diverged behaviorally in territorial contests and support the hypothesis of coadaptation on the basis of wing colors and types of wing movement in Odonata. Our findings further suggest that divergent agonistic wing displays may play a pivotal role in the speciation mechanism of P. mandarinus damselflies. The sequential analyses of behavioral characteristics and progression suggest that P. m. mandarinus damselflies likely use mutual assessment of rivals in territorial contests. [ABSTRACT FROM AUTHOR]

For ectothermic insects, their colour and size are important determinants of body temperature: larger bodies require more heat to reach a certain temperature, and dark colours absorb heat more efficiently. These dark colours are expressed using melanin, which has been intimately linked with the thermoregulatory capabilities of insects. Melanin is also linked with immune defence and is often used as a secondary sexual character in insects. There is a potential trade-off situation between thermoregulatory capabilities, immune defence and secondary sexual characters, all of which use melanin. Some Calopteryx damselflies, such as Calopteryx splendens , have melanin-based wing pigmentation that is sexually selected and drives intra- and interspecific territorial aggression. Our goal was to study experimentally how the wing pigmentation and body size of C. splendens males affect their thermoregulation and, especially, their ability to become active (hereafter, 'activate') after being cooled down. Our results were in line with our hypotheses, showing that individuals with larger wing spots had significantly faster activation times than those with smaller wing spots, and that individuals with larger body size had significantly slower activation times than those with smaller body size. Both variables showed an interaction and are therefore important in damselfly warm-up and activation. We discuss the role of wing pigmentation and thermoregulation in the behavioural patterns observed in Calopteryx species. [ABSTRACT FROM AUTHOR]

The article focuses on the 2022 Spring Raptor Migration at Fort Smallwood Park in Maryland, detailing the count numbers, species variations, and their deviations from average counts. Topics include the significant increase in Turkey Vulture numbers, declines in Red-shouldered, Broad-winged, and Red-tailed Hawks, and the observations of various bird species beyond raptors during the migration period.

Female polymorphism is visible in some populations of Odonata species for unknown reasons. In general, one of the female forms which is more or less similar to males is called andromorph. Andromorph females show similar color patterns and sometimes, even some structural and behavioral aspects to the conspecific males, whereas gynochrome females are different from males. One mentioned reason for the existence and survival of this phenomenon in the odonates is the avoidance of male harassment toward females during the breeding season. Males and females of Calopteryx intermedia have sexual dimorphism in the wing shape. It represents differences in flight dynamic models of the two sexes. Therefore, the decrease of harassment of females by males needs mimicry of male’s flight dynamic, but this could be possible with the same wing shape as males but not gynomorph females. The results of the present study revealed that the shape of fore and hindwing of andromorph females were significantly different from males but not gynomorph females. As a result, it seems that andromorph females are not able to mimic the males’ flight and it seems that the andromorph females with a wing spot, approximately the same as that of conspecific males, cannot mislead the males. Thus, we have to seek other places for their existential reason(s) and survival. [ABSTRACT FROM AUTHOR]

We sequenced and assembled the complete mitochondrial genome of Mnais tenuis from Darshi, Taoyuan County, Taiwan. The complete mitogenome of M. tenuis is 15,131 bp long, and contains 13 protein-coding, 22 tRNA, and two rDNA genes. Nucleotide compositions of the mitogenome of the M. tenuis are A: 40.08%, T: 25.47%, C: 20.38%, and G: 14.07%. The AT and GC skewness of the mitogenome sequence was 0.2228 and −0.183, showing the A-skew and C-skew. The clade including M. tenuis and all the other Odonata species received absolute support (100%). The phylogenetic position of Anisozygoptera is sister to Anisoptera. Mnais is phylogenetically close to Psolodesmus. Mitogenomic data from this study will provide useful information for further studies for the population genetics, speciation and conservation of M. tenuis in the future.

A new species, Noguchiphaea laotica, is described based on specimens from Lon San, Saysomboun Province, Laos. The holotype male and a paratype female are deposited in the National Museum of Nature and Science, Tokyo. This new species is allied to N. yoshikoae from northern Thailand, but differs from it in the morphology of the male cercus which is depressed centrally apically in dorsal view, and with a more robust dorsal spine at about one-third from its base. In addition, DNA analyses confirm that there are genetic differences between N. laotica and N. yoshikoae. Some observations on the ecology and behavior of N. laotica are briefly reported. http://www.zoobank.org/urn:lsid:zoobank.org:pub:44D39DC5-40A5-4F33-B951-D3AD0B5247B7 [ABSTRACT FROM AUTHOR]

Adaptation of life-history traits is an important factor for the success of insects. Voltinism is a feature that descends from several life-history traits and, given that the latter depend on the specific environment of growth, voltinism can vary between populations across latitudes or habitats. In addition, some insects, like many odonates, have developed different patterns of voltinism within the same population, due to mechanisms of cohort splitting. Calopteryx splendens (Odonata: Calopterygidae) is a widespread damselfly in Europe that has been extensively studied regarding its evolutionary ecology, but detailed studies about its voltinism are relatively scarce and confined to the central and northern areas of Europe. So we investigated the voltinism and larval development of a population of C. splendens both by captive rearing and in the field in Northern Italy, the southernmost area in which its voltinism has been studied so far. We found an earlier start of larval growth, with respect to previous studies. Additionally, the head-width of larvae of the same instar decreased with the cohort ageing. Finally, the results are consistent with a two-groups emerging pattern that may support partial semivoltinism or partial bivoltinism of C. splendens in Northern Italy. [ABSTRACT FROM AUTHOR]

We applied geometric morphometric techniques to explore the morphological variation of forewings between 10 Asian Calopteryx splendens populations including Azerbaijan, Russia, Turkey, Uzbekistan, Iran, Turkmenistan, Tajikistan, Kazakhstan, and Kyrgyzstan countries. We focused on the study of the phenetic relationships among the populations in central Asia. The results showed that the northern and western populations of Iran had the largest and smallest centroid size of the wings, respectively. In addition, differences among wing shape of the 10 studied populations of C. splendens were significant. Our results indicated that Tajikistan population has quite distinct divergence and also Turkmenistan and northern part of Iran populations both were very close each other and located in a separate clade. The Azerbaijan, Russia, Turkey, Uzbekistan, west Iran, Kazakhstan and Kyrgyzstan populations were revealed to be more interrelated to each other, although Kazakhstan and Kyrgyzstan populations seems to be more closer than the other.

This study examined the effects of seasonal and annual variations on wing shape and wing size of eight damselfly species in central Texas. Comparisons included i) populations collected early in the flight season versus those collected late in the flight season, and ii) populations collected from the same locations during several annual flight seasons. We found widespread differences in both wing shape and body size in males and females among most species examined. Wing shape of male and female damselflies collected early varied significantly from those collected late in the flight season for all locations and years sampled. Damselflies emerging early in the flight season were significantly larger than those emerging late, except for Enallagma civile showing opposite results. Populations of six species sampled in different years at the same location were compared, and significant differences in wing shape and size occurred in no females and in males of only two species. Our results suggest that differences in seasonal and year-to-year environmental conditions frequently influence wing shape and body size in multiple damselfly species. [ABSTRACT FROM AUTHOR]

A list of the Odonata of North America, including all of its tropical regions south through Panama and the West Indies, is presented here. Common names in English are included for all of the species. [ABSTRACT FROM AUTHOR]

Coloration is associated with male quality in various animal species. These secondary sexual characters are a result of selective pressures that favor males able to cope with the physiological costs of production and maintenance of the ornament. Males of the Neotropical damselfly Hetaerina longipes exhibit red wing pigmentation, which is considered a sexual ornament. We tested the hypothesis that territorial males assess the quality of sexual ornamentation of rival males and respond with aggressive or neutral behaviors according to the quality of the opponent. Since wing pigmentation is an indicator of male quality, influencing contest outcome and territory acquisition, we expected that territorial males would decrease their aggressiveness when facing opponents with experimentally enhanced wing pigmentation, assuming that males should avoid conflicts with stronger males. The results suggest that territorial males are in fact more aggressive against rivals with increased pigmentation, contrary to our initial hypothesis. We discuss the cognitive ability of odonates in the assessment of opponents and suggest three hypotheses to explain the observed patterns. [ABSTRACT FROM AUTHOR]

We used geometric morphometrics to determine variation in the morphology of the forewings of individuals in 20 populations of Calopteryx splendens s.l. in Eurasia and related these to the circum-specific taxonomy of this taxon. We found differences in shape, with the largest and smallest centroid size of the wings in adjacent northern (orientalis) and western (intermedia) populations in Iran, respectively, so isolation and relationship are not necessarily determined by distance, but often associated with the stream basin inhabited. The variation in wing shape, however, was much greater. with Populations at the eastern edge of the range (Tajikistan, Kyrgyzstan and East Kazakhstan) uniquely different. Oddly, no taxonomic name is associated with them, although they may be among the oldest representatives of the splendens complex. The European and Asian populations are in two separate clades. One of these includes insects with no to a medium-sized wing spot, which does not reach the tip of the wing (waterstoni-group), while the other includes insects with very broad wing spots, or, when short, it extends to the very tip of the wings and most females are androchrome (ancilla or intermedia group). Turkmenistan and northern Iranian population form a separate line inside this clade, which we equate with Calopteryx orientalis. South Albanian and Greek populations are in a separate branch corresponding to ssp. balcanica; two populations from Ireland and Italy form a branch that has no equivalent in traditional taxonomy, while Calopteryx xanthostoma was not identified by its wing shape. Understanding this multitude of phenotypes and the enormous amount of variation within certain populations but not in others becomes easy if one assumes there were two probable late Pleistocene waves of migration, the first of insects lacking spots that migrated east and westwards from the South Black Sea basin, the second, perhaps from the west Caspian, composed of heavily spotted insects with androchromic females. The hybridization between these two waves resulted in the current plethora of colour forms and accounts for why similar phenotypes may turn up independently in widely distant locations.

Colour-based traits are widespread in flying species due to the importance of visual perception in their communication. Ontogenetic colour changes and reversible physiological colours occur in some species and are used as communication signals to conspecifics. The genusMnais(Zygoptera: Calopterygidae) shows both genetic colour polymorphism and age-related colour changes, making challenging even the identification of species. Here we study three Chinese populations ofMnais andersoniduring one month by mark-resighting methods. We describe the ontogenetic body and wing colour changes of male morphs (orange-winged and hyaline-winged) and females. With maturity, thoracic colour changes from metallic green to copper. The initially transparent wings of the hyaline winged males and females became light amber with age, while the orange-winged males show this colour since emergence to maturity. Whitish pruinosity covered all thorax in orange-winged males, while it remained limited to the ventral part of the thorax in hyaline-winged males and females. Hyaline-winged males presented less abdominal pruinosity than the rest of individuals. Our observations suggest that male morphs ofM. andersoniare analogous to other species of the genus. [ABSTRACT FROM AUTHOR]

In this note, the occurrence of phoresy between larvae of Rheotanitarsus sp. (Diptera: Chironomidae) and larvae of Heteragrion sp. (Odonata: Megapodagrionidae) and of unidentified genera of Calopterygidae (Odonata) collected in a first-order stream in an area of Atlantic Forest in southeastern Brazil is reported. During the dry season of 2007 and the rainy season of 2008, with the aid of a Surber sampler, 15 samples of each of the following mesohabitats were collected: litter from riffle areas, litter from pool areas and sediment in pool areas. Eighty-five Odonata larvae were obtained, 10 (11.76%) with cases of phoresy by Rheotanytarsus sp.. These chironomids were associated with only one specimen of Megapodagrionidae, whereas the other larvae were recorded in association with Calopterygidae. Most of the Odonata with cases of phoresy by Rheotanytarsus sp. were recorded in the dry season. In the present study, the absence of the phoretic association with other potential hosts for Rheotanytarsus sp. found in the samples indicates a possible preference of these larvae for Odonata, which accounted for only 2.42% of the collected macroinvertebrates in litter and sediment.

Males of the damselfly Hetaerina rosea may defend mating sites along river margins (resident males) or, alternatively, wander among different areas presumably searching for mates (nonterritorial males). Although the occurrence of territorial and nonterritorial males of H. rosea is very common in Brazil, studies examining which factors may be responsible for the adoption of alternative mate-locating tactics in this species are inexistent. We investigated the relationship between the adoption of these alternative mate-locating tactics by males of H. rosea and two possible causes: body weight and male abundance. We carried the study in three areas: sites 1, 2 and 3. Samples were monthly undertaken in sites 1 and 2 between September/2001 and August/2002 and in site 3 between May/1999 and January/2001. Using the scan method with fixed areas and mark-resighting techniques, we did not find any relationship between the proportion of nonterritorial males and male abundance per month on sites 2 (n=6) and 3 (n=7), indicating that the adoption of alternative mate-locating tactics is not affected by competition for territories. In the same way, nonterritorial and resident males showed similar body and thoracic weight measures (n=30 and n=27 for sites 2 and 3 respectively). Maybe the nonterritorial tactic is adopted by individuals searching for better territories or males that were evicted from their defended sites. The absence of relationship between weight and male territorial status is in accordance with other Hetaerina species. However, other traits not investigated here such as parasitic load, fat content and age may influence the adoption of different mate-acquisition tactics in H. rosea males. Rev. Biol. Trop. 57 (1-2): 361-370. Epub 2009 June 30.Los machos de la libélula Hetaerina rosea pueden defender sus sitios de apareamiento a lo largo de márgenes de ríos (machos residentes) o, alternativamente, deambulan entre diferentes áreas presumiblemente buscando pareja (machos no territoriales). Aunque la existencia de machos territoriales y no territoriales de H. rosea es muy común en Brasil, no hay estudios que examinen cuáles factores pueden ser responsables para la adopción de tácticas alternativas para localizar pareja en esta especie. Investigamos la relación entre la adopción de estas tácticas alternativas para localizar pareja por machos de H. rosea, y dos posibles causas: peso del cuerpo y abundancia de machos. Realizamos el estudio en tres áreas: sitios 1, 2 y 3. Las muestras se tomaron mensualmente en sitios 1 y 2 entre setiembre 2001 y agosto 2002, y en sitio 3 entre mayo 1999 y enero 2001. La adopción de tácticas alternativas de localización de machos no se ve afectada por competencia por territorios. La ausencia de relación entre peso y estatus del macho territorial coincide con otras especies de Hetaerina. No obstante, otros rasgos que no fueron estudiados aquí, como la carga de parásitos, contenido de grasa y edad, pueden influenciar la adopción de diferentes tácticas de adquisición de pareja en machos de H. rosea.

A geographical survey of two Mnais damselfly species in the Kinki area of Japan showed evidence for character displacements when the two species were found in sympatry. Mnais costalis, a species that has polymorphic male mating types of orange-winged territorial and clear-winged non-territorial morphs (hereafter abbreviated to orange and clear morphs respectively) in allopatry often shifted to having monomorphic orange morphs in sympatry. The mean body size of orange morphs was consistently larger than that of clear morph in allopatry. The mean body size of the sympatric orange morphs was even larger than that of allopatric orange morphs. By contrast, Mnais pruinosa, a species that also has two morphs of large orange and small clear morphs in allopatry, shifted to having monomorphic clear morphs in sympatry. The mean body size of the sympatric clear morphs was smaller than that of allopatric clear morphs. Divergence was also detected in the preference for habitat insolation conditions between sympatric Mnais damselflies. Both species in allopatric regions prefer half-light forest habitats, while in sympatric regions they showed diversified habitat preference: M. costalis preferred sunny habitats while M. pruinosa preferred shady habitats. Multiple character displacements in signal traits and habitat preference emerged in heterogeneous forest light environments are likely to have synergistic effects on the reproductive isolation of the two species. [ABSTRACT FROM AUTHOR]

Insects adapt commonly to seasonally changing habitats and reproductive contexts. Individuals that mature at different times during the year can show patterns of life cycle or morphological variation, possibly associated with changes in reproductive behaviour. Concerning mating strategies of flying insects, wing morphology may be related both to the outcome of male-male contests and to the ability in acquiring females. Therefore, different mating strategies (territorial vs. non-territorial) may have different flight morphology optima that increase fitness in their context. Males of Calopteryx splendens are mainly territorial early in the season, but with the advancing season and with increasing competition, more and more males adopt a non-territorial pursuing strategy. Given that different mating tactics have different wing morphologies, here we test whether the wing shape of males shifts from a 'territorial' to a 'non-territorial morphology' during the season. So, early in the season males show highly sexually dimorphic wings, which allow for high manoeuvrability and larger spots, while late in the season wing shapes of males become less sexually dimorphic and more suitable when pursuing females. Additionally, we studied the seasonal variation of other flight related traits, specifically wing lengths, abdomen length and weight. We found that these latter traits decreased along the season in both sexes without altering sexual dimorphism. However, wing shape, which resulted sexually dimorphic, showed a seasonal variation, decreasing the level of sexual dimorphism. The most probable determinant of this change is phenotypic plasticity triggered by environmental cues, but other explications of the observed pattern are discussed. [ABSTRACT FROM AUTHOR]

It has been proposed that wing pigmented spots function in temperature control in male calopterygids. Using two rubyspot species Hetaerina americana Fabricius and Hetaerina vulnerata Hagen in Selys, the present study investigated whether (i) wing spot size and colour-modified aspect can predict temperature gain after a cooling event; (ii) wing spot size is related to the temperature needed to fly and how long it takes to initiate flight; and (iii) wing spot size is related to seasonality and altitude. The results obtained do not support any of these relationships. The results also indicate that H. vulnerata can achieve flight at 8 °C less than H. americana. The present study further investigates whether the species differ in their latitudinal and geographical distribution, and respond differently to bioclimatic variables. The results obtained provide support for this particular hypothesis, showing that H. vulnerata inhabits higher altitudes, and is able to tolerate colder environments compared with H. americana. Wing spots in the two Hetaerina species do not help in thermoregulation, although both species show different temperature control abilities. This difference in thermoregulatory ability may enable the species to colonize different environments and reduce interspecific competition. [ABSTRACT FROM AUTHOR]

Two mutually-excluding hypotheses explain the intensity of aggression between neighbors and their non-neighbors in territorial animals. On one hand, the 'dear enemy' hypothesis predicts that territorial animals should be more tolerant towards their neighbors than towards non-neighbors. Conversely, the 'nasty neighbor' hypothesis predicts increased aggression towards neighbors than non-neighbors. These different situations depend on who is more likely to be a real competitor, either a neighbor or a non-neighbor, and the intensity of resource competition. Male damselfly of Hetaerina vulnerata defend riverine, mating territories that is the main way to have access to females. These territories are not fixed and so males continuously defend them especially against neighbors. Given this, we tested whether the nasty neighbor principle operates in this species. We monitored a population during an entire mating season, and recorded duration of aggressive behaviors. As a key prediction of the nasty neighbor hypothesis, we expected that such behaviors last for longer when encountering a conspecific neighbor than a conspecific non-neighbor. We also predicted that such duration should be date-dependent as territorial competition could increase in the middle of the season when male density is at its highest. Our results corroborated that aggressive behaviors lasted longer against a neighbor male than a non-neighbor male but there was not effect of date. Thus, neighbors may pose a greater risk and may be a strong selective force than non-neighbors in terms of resource competition. Since neighbor males are continuously trying to widen their territory boundaries (a situation that has been also found in other study systems), an owner male may not even need to recognize his neighbors to fight back. [ABSTRACT FROM AUTHOR]

Odonate larvae are commonly considered opportunistic general predators in freshwater ecosystems. However, the dietary breadth of most odonate larvae in forest streams is still poorly documented. We characterized the prey species and estimated the level of dietary niche overlap of two damselflies, Euphaea formosa Hagen 1869 and Matrona cyanoptera H€am€al€ainen and Yeh, 2000 in a forest stream of central Taiwan on the basis of DNA barcoding of larval feces. A collection of 23 successfully identified cytochrome c oxidase 1 (CO1) barcoding sequences suggested that the mayflies (Ephemeroptera), caddisflies (Trichoptera), and midges (Diptera) comprise the majority (43%, 6/14) of prey species consumed by E. formosa larvae, whereas the identified prey for M. cyanoptera were mainly zooplankton (56%, 5/9). Statistical analysis of dietary overlap indicated that these two species occupy different dietary niches (Pianka's index¼0.219). DNA barcoding analysis of damselfly larval feces was effective in detecting less sclerotized prey such as vertebrates (fish and frog) and small zooplankton. However, a moderately successful rate (<70%) of PCR amplification by universal CO1 primers and a low percentage (<60%) of identifiable sequences in public databases indicate the limitations of naive DNA barcoding in fecal analysis. [ABSTRACT FROM AUTHOR]