Integrative species delimitation and five new species of lynx spiders (Araneae, Oxyopidae) in Taiwan.

An accurate assessment of species diversity is a cornerstone of biology and conservation. The lynx spiders (Araneae: Oxyopidae) represent one of the most diverse and widespread cursorial spider groups, however their species richness in Asia is highly underestimated. In this study, we revised species diversity with extensive taxon sampling in Taiwan and explored species boundaries based on morphological traits and genetic data using a two-step approach of molecular species delimitation. Firstly, we employed a single COI dataset and applied two genetic distance-based methods: ABGD and ASAP, and two topology-based methods: GMYC and bPTP. Secondly, we further analyzed the lineages that were not consistently delimited, and incorporated H3 to the dataset for a coalescent-based analysis using BPP. A total of eight morphological species were recognized, including five new species, Hamataliwa cordivulva sp. nov., Hamat. leporauris sp. nov., Tapponia auriola sp. nov., T. parva sp. nov. and T. rarobulbus sp. nov., and three newly recorded species, Hamadruas hieroglyphica (Thorell, 1887), Hamat. foveata Tang & Li, 2012 and Peucetia latikae Tikader, 1970. All eight morphological species exhibited reciprocally monophyletic lineages. The results of molecular-based delimitation analyses suggested a variety of species hypotheses that did not fully correspond to the eight morphological species. We found that Hamat. cordivulva sp. nov. and Hamat. foveata showed shallow genetic differentiation in the COI, but they were unequivocally distinguishable according to their genitalia. In contrast, T. parva sp. nov. represented a deep divergent lineage, while differences of genitalia were not detected. This study highlights the need to comprehensively employ multiple evidence and methods to delineate species boundaries and the values of diagnostic morphological characters for taxonomic studies in lynx spiders.

Strong attachment as an adaptation of flightless weevils on windy oceanic islands.

Enhanced attachment ability is common in plants on islands to avoid potential fatal passive dispersal. However, whether island insects also have increased attachment ability remains unclear. Here we measured the attachment of a flightless weevil, Pachyrhynchus sarcitis kotoensis, from tropical islands, and compared it with documented arthropods from the mainland. We examined the morphology and material gradient of its attachment devices to identify the specific adaptive modifications for attachment. We find that the weevil has much stronger attachment force and higher safety factor than previously studied arthropods, regardless of body size and substrate roughness. This probably results from the specific flexible bases of the adhesive setae on the third footpad of the legs. This softer material on the setal base has not been reported hitherto and we suggest that it acts as a flexible hinge to form intimate contact to substrate more effectively. By contrast, no morphological difference in tarsomeres and setae between the weevil and other beetles is observed. Our results show the remarkably strong attachment of an island insect and highlights the potential adaptive benefits of strong attachment in windy island environment. The unique soft bases of the adhesive hairs may inspire the development of strong biomimetic adhesives.

Evolution of horn length and lifting strength in the Japanese rhinoceros beetle Trypoxylus dichotomus.

What limits the size of nature's most extreme structures? For weapons like beetle horns, one possibility is a tradeoff associated with mechanical levers: as the output arm of the lever system-the beetle horn-gets longer, it also gets weaker. This "paradox of the weakening combatant" could offset reproductive advantages of additional increases in weapon size. However, in contemporary populations of most heavily weaponed species, males with the longest weapons also tend to be the strongest, presumably because selection drove the evolution of compensatory changes to these lever systems that ameliorated the force reductions of increased weapon size. Therefore, we test for biomechanical limits by reconstructing the stages of weapon evolution, exploring whether initial increases in weapon length first led to reductions in weapon force generation that were later ameliorated through the evolution of mechanisms of mechanical compensation. We describe phylogeographic relationships among populations of a rhinoceros beetle and show that the "pitchfork" shaped head horn likely increased in length independently in the northern and southern radiations of beetles. Both increases in horn length were associated with dramatic reductions to horn lifting strength-compelling evidence for the paradox of the weakening combatant-and these initial reductions to horn strength were later ameliorated in some populations through reductions to horn length or through increases in head height (the input arm for the horn lever system). Our results reveal an exciting geographic mosaic of weapon size, weapon force, and mechanical compensation, shedding light on larger questions pertaining to the evolution of extreme structures.

Stag beetle Cyclommatus mniszechi employs both mutual- and self-assessment strategies in male-male combat.

Animals may base contest decisions on their fighting ability alone (self-assessment) or also their opponents' (mutual assessment). Many male stag beetles develop disproportionately enlarged mandibles and use them as weapons. Information on their assessment strategy is limited. To investigate their assessment strategy and whether they adopt the same strategy at different stages of contests, we used food to encourage male Cyclommatus mniszechi of different (random pairings) or similar (ML-matched pairings) mandible length (ML) to interact. For the random pairings, losers had shorter mandibles than winners and were faster to feed. Overall contest duration and the tendency to escalate to tussles associated positively with winners' ML and average ML in the random and the ML-matched pairings, respectively, consistent with self-assessment. Non-tussle phase duration associated positively with average ML in the ML-matched pairings, consistent with self-assessment. Tussle phase duration, however, positively associated with losers' ML in the random pairings and had no association with average ML in the ML-matched pairings, consistent with mutual assessment. These results show that (1) the males employ both assessment strategies, (2) winners have more control over contest intensity than losers, and (3) males with shorter mandibles are quicker to feed and also more likely to lose fights.

doublesex Controls Both Hindwing and Abdominal Mimicry Traits in the Female-Limited Batesian Mimicry of Papilio memnon.

Papilio butterflies are known to possess female-limited Batesian mimicry polymorphisms. In Papilio memnon, females have mimetic and non-mimetic forms, whereas males are monomorphic and non-mimetic. Mimetic females are characterized by color patterns and tails in the hindwing and yellow abdomens. Recently, an analysis of whole-genome sequences has shown that an approximately 160 kb region of chromosome 25 is responsible for mimicry and has high diversity between mimetic (A) and non-mimetic (a) alleles (highly diversified region: HDR). The HDR includes three genes, UXT, doublesex (dsx), and Nach-like, but the functions of these genes are unknown. Here, we investigated the function of dsx, a gene involved in sexual differentiation, which is expected to be functionally important for hindwing and abdominal mimetic traits in P. memnon. Expression analysis by reverse transcription quantitative PCR (RT-qPCR) and RNA sequencing showed that mimetic dsx (dsx-A) was highly expressed in the hindwings in the early pupal stage. In the abdomen, both dsx-A and dsx-a were highly expressed during the early pupal stage. When dsx was knocked down using small interfering RNAs (siRNAs) designed in the common region of dsx-A and dsx-a, a male-like pattern appeared on the hindwings of mimetic and non-mimetic females. Similarly, when dsx was knocked down in the abdomen, the yellow scales characteristic of mimetic females changed to black. Furthermore, when dsx-a was specifically knocked down, the color pattern of the hindwings changed, as in the case of dsx knockdown in non-mimetic females but not mimetic females. These results suggest that dsx-a is involved in color pattern formation on the hindwings of non-mimetic females, whereas dsx-A is involved in hindwing and abdominal mimetic traits. dsx was involved in abdominal and hindwing mimetic traits, but dsx expression patterns in the hindwing and abdomen were different, suggesting that different regulatory mechanisms may exist. Our study is the first to show that the same gene (dsx) regulates both the hindwing and abdominal mimetic traits. This is the first functional analysis of abdominal mimicry in butterflies.

Novel wing display and divergent agonistic behaviors of two incipient Psolodesmus damselflies.

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.

Species delimitation and taxonomic revision of Oxyopes (Araneae: Oxyopidae) of Taiwan, with description of two new species.

This study revised the spider genus Oxyopes Latreille, 1804 in Taiwan and delineated the species boundaries based on morphological and molecular characters. A total of seven Oxyopes spiders were recognized, including two newly described species, O. hasta sp. nov. and O. taiwanensis sp. nov. Oxyopes fujianicus Song Zhu 1993 from Yilan County, Nantou County, and Kaohsuing City, and O. striagatus Song 1999 from New Taipei City, Taichung City, Nantou County, and Kaohsiung City were recorded for the first time in Taiwan. An identification key and a distributional map of Taiwanese Oxyopes species were provided. Partial COI sequences were obtained for molecular phylogenetic and species delimitation analyses. Maximum likelihood and Bayesian phylogenies, and DNA barcoding gap analysis supported morphologically defined species. However, molecular species delimitation based on Automatic Barcode Gap Discovery (ABGD), PID (Liberal), and generalized mixed Yule coalescent (GMYC) were incongruent in species assignment. The results showed that the interspecific genetic divergence between O. sertatus and O. taiwanensis was relatively low (1.28 ± 0.43%), and the intraspecific genetic divergence of O. striagatus was relatively high (1.69 ± 0.35%). Ecological data, additional samples and genetic loci are required to further examine the level of reproductive isolation and patterns of population genetic structure in Taiwanese Oxyopes.

Allometry and Fighting Behaviour of a Dimorphic Stag Beetle Cyclommatus mniszechi (Coleoptera: Lucanidae).

Male stag beetles (Coleoptera: Lucanidae) use their mandibles as weapons to compete for resources and reproduction. Mandible size in stag beetles can be associated with different behaviours and the outcome of male contests. We investigated the allometric relationship between mandible and body size in males of the stag beetle Cyclommatus mniszechi to uncover distinct morphs. The results divided male C. mniszechi into majors and minors with the switch point of mandible length at 14.01 mm. The allometric slope of mandibles was positive for both morphs but was steeper for the minors. We also characterised the fighting behaviour of the different morphs in size-matched contests using sequential analyses. Males matched each other's behaviour in contests with many physical contacts, no injury and a progression from low towards high aggression and rare de-escalation. Major and minor males employed the same behavioural elements in contests, but major males were more likely to escalate directly into more aggressive phases and minor males tended to stay within phases. This finding suggests that major males may compete more aggressively than minor males in contests.

Comparative phylogeography of two hemipteran species (Geisha distinctissima and Megacopta cribraria) in the Zhoushan Archipelago of China reveals contrasting genetic structures despite concordant historical demographies.

Continental islands are useful models to explore the roles of shared historical factors in the evolution of sympatric species. However, China's largest continental group of islands, the Zhoushan Archipelago, was neglected by most studies focusing on biodiversity hotspots. Here we investigated the phylogeographic patterns and the historical demography of two sympatric hemipteran insects (Geisha distinctissima and Megacopta cribraria), which shared historical factors in the Zhoushan Archipelago. The results based on mtDNA (COX1, COX2-COX3, and CYTB) and nDNA (28S and ITS2) showed that G. distinctissima diverged into three genetic lineages (L1-L3) ~8.9-13.7 thousand years ago (kya), which coincided with the period of island isolation. However, the three lineages exhibit no clear phylogeographic patterns for frequent asymmetrical gene flow (starting around 5 kya) from the mainland and adjacent islands to other distant islands due to subsequent human activities. In contrast, only one genetic lineage exists for M. cribraria, without any phylogeographic structures. The ancestral range in the mainland as well as in neighboring islands, together with the frequent asymmetrical gene flow of M. cribraria (from the mainland and neighboring islands to more distant islands) within the last 5000 years suggests that human activities may have lead to the colonization of this species in the Zhoushan Archipelago. The contrasting genetic structures indicate shared historical factors but independent evolutionary histories for the two sympatric species in the Zhoushan Archipelago. Our demographic analysis clearly showed that both species underwent population expansion before 5 kya during the post-LGM (Last Glacial Maximum), which indicates that the two species shared concordant historical demographies. This result suggests that the population size of the two species was affected similarly by the climatic oscillations of post-LGM in Eastern China. Together, our findings reveal that the two insect species in the Zhoushan Archipelago exhibit contrasting genetic structures despite concordant historical demographies, which provides an important framework for the exploration of the evolution patterns of sympatric species in the continental island.

Treehoppers (Hemiptera: Aetalionidae and Membracidae) from Madre de Dios region, Peru / Membrácidos (Hemiptera: Aetalionidae y Membracidae) de la región de Madre de Dios, Perú

A list of treehoppers (Aetalionidae and Membracidae) is presented from Madre de Dios region at the southeastern Amazon basin in Peru. The treehopper specimens were collected as by-catch in a survey of the beetles in the Villa Carmen Biological Station and Los Amigos Biological Station. The list comprises 44 species, 31 genera, 16 tribes and 9 subfamilies. Ten genera are new records to Peru. The images of representative specimens of each identified species and genera are provided to facilitate the identification of the local treehopper fauna.

Se presenta una lista de los membrácidos (Aetalionidae y Membracidae) de la región Madre de Dios, en el sureste de la cuenca Amazónica, en Perú. La lista está basada en especímenes recolectados como captura fortuita en un inventario de escarabajos en las estaciones biológicas Villa Carmen y Los Amigos. La lista incluye 44 especies, 31 géneros, 16 tribus y 9 subfamilias. Diez géneros son nuevos registros para Perú. Se presentan las imágenes de especímenes representativos de cada especie y género para facilitar la identifición de la fauna local de los membrácidos.

Endocuticle sclerotisation increases the mechanical stability of cuticle.

The cuticle plays an important role in the evolutionary success of insects. Many studies on insect cuticles have reported a soft, resilin-rich endocuticle. However, a recent study indicated the presence of a sclerotised endocuticle in the weevil Pachyrhynchus sarcitis kotoensis, which contradicts former knowledge. To understand the degree of sclerotisation in the endocuticle of the weevil and its potential function, we first examined the endocuticle by microscopic and staining techniques. We next performed mechanical tests to measure the material properties of the endocuticle, and numerical simulations to predict the structural effect of the sclerotisation. Our results provide the first evidence of the existence of a sclerotised endocuticle and its remarkable function in improving the mechanical stability of the cuticle. This study highlights the finding of a high degree of sclerotisation in the stiff endocuticle of the weevil, especially the matrix surrounding the fibres. This novel case brings new understanding of cuticle properties and gives promising insights into biomaterial design.

A new record of Neoperla obliqua Banks, 1930 (Plecoptera: Perlidae) from Mt. Malindang, Mindanao, Philippines and association of life stages using DNA barcodes.

The nymph of the perlid Neoperla obliqua Banks, 1913 from Mt. Malindang, Mindanao Island, the Philippines is described and associated with the male and female adults using DNA barcodes. Using pairwise CO1, the nymph was associated with 99.9 ± 0.14% interspecific similarity, while comparison between sexes generated a 0.2% intraspecific divergence between males and females of putative conspecifics. Additionally, the mature ova from female adults are described using scanning electron microscopy (SEM). The distinctive chorionic surface is rugose with longitudinal ridge-like pattern with a bare and flat collar.

Biomechanical Strategies Underlying the Robust Body Armour of an Aposematic Weevil.

Robust body armor is one of many anti-predator strategies used among animal taxa. The exoskeleton of insects can serve as the secondary defense mechanism in combination with the primary defense such as warning color. Aposematic Pachyrhynchus weevils advertise their unprofitability and use their robust exoskeleton for effective defense against lizard predators. While the mature weevils survive after the predatory attack, the soft teneral ones can easily be consumed. To reveal how the mature weevils achieve such effective protection, we investigated the ontogenetic changes in the microstructure and material properties of the exoskeleton of the adult weevils. We also tested the functional role of a weevil-specific structure, the fibrous ridge, in the robustness of the elytral cuticle of the mature weevils. The results showed that the mature weevils have thicker, stiffer and more sclerotized cuticle than the teneral ones. The fibrous ridges in the endocuticle considerably increase the overall stiffness of their cuticle. Together these biomechanical strategies enable Pachyrhynchus weevils to achieve robust body armor that efficiently protects them from lizard predation.

Rafting on floating fruit is effective for oceanic dispersal of flightless weevils.

Terrestrial species, especially non-vagile ones (those unable to fly or swim), cannot cross oceans without exploiting other animals or floating objects. However, the colonisation history of flightless Pachyrhynchus weevils, inferred from genetic data, reveals their ability to travel long distances to colonise remote islands. Here, we used captive-bred Pachyrhynchus jitanasaius to analyse (i) the physiological tolerance of weevils (egg, larva and adult stages) to different levels of salinity; (ii) the survival rate of larvae in a simulated ocean environment in the laboratory; and (iii) the survival rate of larvae in a field experiment in the ocean using fruit of the fish poison tree floating on the Kuroshio current in the Pacific Ocean. We found that the survival rate of larvae in seawater was lower than in fresh water, although if the larvae survived 7 days of immersion in seawater, some emerged as adults in the subsequent rearing process. No adults survived for more than 2 days, regardless of salinity level. After floating separately for 6 days in salt water in the laboratory and in the Kuroshio current, two of 18 larvae survived in the fruit. This study provides the first empirical evidence that P. jitanasaius larvae can survive 'rafting' on ocean currents and that the eggs and larvae of these weevils have the highest probability of crossing the oceanic barrier. This ability may facilitate over-the-sea dispersal of these flightless insects and further shape their distribution and speciation pattern in the Western Pacific islands.

Parallel evolution of Batesian mimicry supergene in two Papilio butterflies, P. polytes and P. memnon.

Batesian mimicry protects animals from predators when mimics resemble distasteful models. The female-limited Batesian mimicry in Papilio butterflies is controlled by a supergene locus switching mimetic and nonmimetic forms. In Papilio polytes, recent studies revealed that a highly diversified region (HDR) containing doublesex (dsx-HDR) constitutes the supergene with dimorphic alleles and is likely maintained by a chromosomal inversion. In the closely related Papilio memnon, which exhibits a similar mimicry polymorphism, we performed whole-genome sequence analyses in 11 butterflies, which revealed a nearly identical dsx-HDR containing three genes (dsx, Nach-like, and UXT) with dimorphic sequences strictly associated with the mimetic/nonmimetic phenotypes. In addition, expression of these genes, except that of Nach-like in female hind wings, showed differences correlated with phenotype. The dimorphic dsx-HDR in P. memnon is maintained without a chromosomal inversion, suggesting that a separate mechanism causes and maintains allelic divergence in these genes. More abundant accumulation of transposable elements and repetitive sequences in the dsx-HDR than in other genomic regions may contribute to the suppression of chromosomal recombination. Gene trees for Dsx, Nach-like, and UXT indicated that mimetic alleles evolved independently in the two Papilio species. These results suggest that the genomic region involving the above three genes has repeatedly diverged so that two allelic sequences of this region function as developmental switches for mimicry polymorphism in the two Papilio species. The supergene structures revealed here suggest that independent evolutionary processes with different genetic mechanisms have led to parallel evolution of similar female-limited polymorphisms underlying Batesian mimicry in Papilio butterflies.

You stay, but I Hop: Host shifting near and far co-dominated the evolution of Enchenopa treehoppers.

The importance and prevalence of phylogenetic tracking between hosts and dependent organisms caused by co-evolution and shifting between closely related host species have been debated for decades. Most studies of phylogenetic tracking among phytophagous insects and their host plants have been limited to insects feeding on a narrow range of host species. However, narrow host ranges can confound phylogenetic tracking (phylogenetic tracking hypothesis) with host shifting between hosts of intermediate relationship (intermediate hypothesis). Here, we investigated the evolutionary history of the Enchenopa binotata complex of treehoppers. Each species in this complex has high host fidelity, but the entire complex uses hosts across eight plant orders. The phylogenies of E. binotata were reconstructed to evaluate whether (1) tracking host phylogeny; or (2) shifting between intermediately related host plants better explains the evolutionary history of E. binotata. Our results suggest that E. binotata primarily shifted between both distant and intermediate host plants regardless of host phylogeny and less frequently tracked the phylogeny of their hosts. These findings indicate that phytophagous insects with high host fidelity, such as E. binotata, are capable of adaptation not only to closely related host plants but also to novel hosts, likely with diverse phenology and defense mechanisms.

Do juvenile developmental and adult body characteristics differ among genotypes at the doublesex locus that controls female-limited Batesian mimicry polymorphism in Papilio memnon?: A test for the "cost of mimicry" hypothesis.

Female-limited Batesian mimicry may have evolved because of stronger predation pressure on females than on males, but some physiological costs of mimicry may also hinder the evolution of mimicry in males. In Papilio memnon, which possesses a female-limited Batesian mimicry polymorphism, two alleles at the doublesex (dsx) locus strictly control female phenotypes. To examine whether there are physiological costs associated with mimetic genotypes in the juvenile stage, we compered mortality, juvenile growth and development, and the resultant adult characteristics among three dsx genotypes (HH, Hh, hh) at a constant temperature (25 °C) and two differing day lengths (LD 14:10 and LD 12:12; the latter might induce pupal diapause) by crossing individuals heterozygous (Hh) for the dsx allele. All pupae emerged directly without diapause irrespective of day length. The genotype frequencies of the emerged individuals were consistent with the expected 1:2:1 ratio of HH:Hh:hh. The sex ratio was significantly male-biased in one of two families, but not in the other. We found no effect of genotype on any developmental or adult characteristic, although there were sex differences in most traits. The larval development time was longer and growth rate higher in females than in males; pupal weight, forewing length, and total dry mass of the thorax and abdomen were greater in females, whereas the thoracic mass/abdominal mass ratio was greater in males. We also found that the growth rate was higher and pupal period longer with a short day than with a long day. Overall, we found no evidence for physiological costs associated with the mimetic genotypes. However, it is too early to conclude that no physiological cost of mimicry affects the evolution and maintenance of this female-limited Batesian mimicry polymorphism because we have not studied the adults of different genotypes.

Too hard to swallow: a secret secondary defence of an aposematic insect.

Anti-predator strategies are significant components of adaptation in prey species. Aposematic prey are expected to possess effective defences that have evolved simultaneously with their warning colours. This study tested the hypothesis of the defensive function and ecological significance of the hard body in aposematic Pachyrhynchus weevils pioneered by Alfred Russel Wallace nearly 150 years ago. We used predation trials with Japalura tree lizards to assess the survivorship of 'hard' (mature) versus 'soft' (teneral) and 'clawed' (intact) versus 'clawless' (surgically removed) weevils. The ecological significance of the weevil's hard body was evaluated by assessing the hardness of the weevils, the local prey insects, and the bite forces of the lizard populations. The existence of toxins or deterrents in the weevil was examined by gas chromatography-mass spectrometry (GC-MS). All 'hard' weevils were instantly spat out after being bitten once and survived attacks by the lizards. In contrast, the 'soft' weevils were chewed and subsequently swallowed. The results were the same regardless of the presence or absence of the weevil's tarsal claws. The hardness of 'hard' Pachyrhynchus weevils was significantly higher than the average hardness of other prey insects in the same habitat and the mean bite forces of the local lizards. The four candidate compounds of the weevil identified by GC-MS had no known toxic or repellent functions against vertebrates. These results reveal that the hardness of aposematic prey functions as an effective secondary defence, and they provide a framework for understanding the spatio-temporal interactions between vertebrate predators and aposematic insect prey.

Temporal dynamics of the mimetic allele frequency at the doublesex locus, which controls polymorphic Batesian mimicry in Papilio memnon butterflies.

Tracking allele frequencies is essential for understanding how polymorphisms of adaptive traits are maintained. In Papilio memnon butterflies, which exhibit a female-limited Batesian mimicry polymorphism (wing-pattern polymorphism), two alleles at the doublesex (dsx) locus correspond to mimetic and non-mimetic forms in females; males carry both dsx alleles but display only the non-mimetic form. This polymorphism is thought to be maintained by a negative frequency-dependent selection. By tracking dsx allele frequencies in both sexes at a Taiwanese site over four years, we found that the mimetic allele persists at intermediate frequencies even when the unpalatable model papilionid butterflies (Pachliopta and Atrophaneura species) were very rare or absent. The rates of male mate choice did not differ between the two female forms; neither did insemination number nor age composition, suggesting equivalent reproductive performance of the two forms over time. Our results characterised the temporal dynamics of the mimetic allele frequency in the field for the first time and give insights into underlying processes involved in the persistence of the female-limited Batesian mimicry polymorphism.

Description of a new Oriental stonefly species, Phanoperla constanspina (Plecoptera: Perlidae) from Mindanao, Philippines and association of life stages using DNA barcoding.

A new perlid stonefly, Phanoperla constanspina sp. nov. is described from Mt. Malindang, northern Mindanao, Philippines. The male of the new species is distinguished by lacking lobes on penial sac and large black spines at the penial apex. The female is distinguished by the egg. DNA barcoding was used to associate male, female, and nymphal specimens with 0% divergence. Morphological variation was observed in the shape of the hemitergal anterior processes and the 9th tergal setal patches of male adult and body pigmentation of the nymph. A key to the Philippine Phanoperla species and a checklist of Oriental Phanoperla are also provided.