Levels of Airborne Sound And Substrate-borne Vibration Calling Are Negatively Related Across Neotropical False-leaf Katydids.

Animals often signal in multiple sensory modalities to attract mates, but the level of signaling investment in each modality can differ dramatically between individuals and across species. When functionally overlapping signals are produced in different modalities, their relative use can be influenced by many factors, including differences in signal active space, energetic costs, and predation risk. Characterizing differences in total signal investment across time can shed light on these factors, but requires long focal recordings of signal production. Neotropical pseudophylline katydids produce mate advertisement signals as airborne sound and substrate-borne vibration. Airborne calls, produced via stridulation, are extremely short, high-frequency, and longer-range signals. Conversely, substrate-borne calls produced via abdominal tremulation are longer, low-frequency, relatively more energetically costly, and shorter-range signals. To examine patterns of stridulation and tremulation across species and test hypotheses about the drivers of signal use in each modality, we recorded multimodal signaling activity over 24 hours for males from ten pseudophylline species from a single Panamanian community. We also collected data on demographic and morphological species characteristics, and acoustic features of airborne calls, such as bandwidth, peak frequency, and duration. Finally, we generated a molecular phylogeny for these species and used phylogenetic generalized least squares models to test for relationships between variables while controlling for evolutionary relationships. We found a negative relationship between sound and vibration calling, indicating that substrate-borne vibrational signaling may compensate for reduced airborne signaling in these species. Sound call bandwidth and the proportion of males collected at lights, a proxy for the amount of male movement, also explained a significant amount of variation in sound calling across species, indicating that the overall relationship between the two types of calling signals may be mediated by the specific characteristics of the signals as well as other species traits.

Notes on the Eneopterinae (Orthoptera, Grylloidea, Gryllidae) from eastern Sabah.

Based on material collected during recent fieldwork in eastern Sabah, the males of Nisitrus danum Robillard & Tan and Cardiodactylus variegatus Gorochov & Robillard are described for the first time, along with their calling songs. New locality records of N. danum, N. vittatus (Haan), Falcerminthus sandakan (Tan et al.), Cardiodactylus borneoe Robillard & Gorochov and C. variegatus are also presented. New material of Nisitrus species-N. danum and N. vittatus-allowed us to compare these syntopic species.

The circadian calling activity of a lebinthine cricket with high-frequency calls is unaffected by cicada choruses in the day.

Background: Many factors can influence circadian rhythms in animals. For acoustically communicating species, both abiotic cues (such as light and temperature) and biotic cues (such as the activity of other animals), can influence the timing of signalling activity. Here we compare the 24-h singing activity of the cricket Lebinthus luae in the laboratory and field to assess whether the presence of other singing insects influences circadian rhythm. Methods: Acoustic monitors were placed in four localities in Singapore and the number of L. luae calls were counted for 10 min of each hour. Individuals from the same localities were captured and recorded in the laboratory in silence but with similar abiotic conditions (temperature and light cycle) as they experience in the field, and the number of calls over 24 h was quantified. Results: The 24-h pattern of L. luae singing was not significantly different between laboratory and field recordings. Singing activity peaked in the morning, with a secondary peak in the afternoon and a smaller peak at night. In the field, L. luae sang in the same locations and at the same time as diurnally singing cicadas, suggesting that the sympatric cicada chorus did not affect the circadian rhythm of communication in this species. Acoustic niche partitioning could potentially explain the ability of this cricket to call alongside cicadas: L. luae sings at higher frequencies than sympatric cicadas, unlike nocturnally singing cricket species that overlap with cicadas in frequency.

Description of one new species of the genus Gymnogryllus (Orthoptera, Gryllidae, Gryllinae) from Cameroon with a key for African species.

During a Gryllidae survey in the Southern Cameroonian Plateau, one new species of the genus Gymnogryllus (Orthoptera, Gryllidae, Gryllinae) was discovered and described, namely Gymnogryllus bilongi Um Nyobe & Kekeunou sp. nov. This finding extends the number of species known of this genus in Cameroon at two and proposes a key for African species.

Taxonomy and bioacoustics of little-known Grylloidea crickets (Orthoptera, Ensifera) from Mindanao, Philippines.

Orthopteran surveys were conducted recently on Mindanao Island of the Philippines. Four species new to science are described here: Mistshenkoana lunotan sp. nov., Mistshenkoana higaonon sp. nov. and Ectatoderus dubius sp. nov. from Misamis Oriental; and Phaloria (Phaloria) rotundata sp. nov. from Agusan del Sur. Based on new collected material, Madasumma fuscoirrorata Chopard, 1925, first described based on a single female from Mindanao, is transferred to Varitrella (Cantotrella) fuscoirrorata (Chopard, 1925) comb. nov. We also describe the male of this species for the first time. Madasumma zamboanga Otte, 2007, first described from Zamboanga del Norte (Mindanao), is also transferred to Mnesibulus (Amnesibulus) and redescribed: Mnesibulus (Amnesibulus) zamboanga (Otte, 2007) comb. nov. We also describe previously unknown calling songs of seven species: Falcerminthus parvus (Baroga-Barbecho & Robillard, 2020), Ajorama balatukanis Otte, 1988, Varitrella (Cantotrella) bakeri (Chopard, 1925), Varitrella (Cantotrella) fuscoirrorata (Chopard, 1925) comb. nov., Phaloria (Phaloria) rotundata sp. nov., Ornebius bioculatus Tan et al., 2019 and Ectatoderus dubius sp. nov.

A review of the genus Monseremus Ingrisch, 2018 (Orthoptera, Stenopelmatoidea, Gryllacrididae) from Borneo.

We review the taxonomy of the gryllacridids from a small genus Monseremus Ingrisch, 2018. Monseremus bellus (Tan Wahab, 2018) comb. nov., previously described from Brunei Darussalam before the description of Monseremus, is now added as a second known species in this genus. From a recent field trip, we also added new locality record for the type species Monseremus appendiculatus Ingrisch, 2018. First described from Mount Kinabalu in western Sabah, this species has now been reported also in Mount Silam in eastern Sabah. Males of the type species were also collected for the first time and are described here. Lastly, we provide a dichotomous key to separate these two species.

New taxa and notes on bark and bush crickets (Orthoptera, Grylloidea, Gryllidae, Landrevinae and Podoscirtinae) from Sabah.

From the eastern parts of Sabah, four new species of crickets are described, two of which are from the subfamily Landrevinae and two from the subfamily Podoscirtinae: Duolandrevus (Duolandrevus) nobilis sp. nov. and Odontogryllodes spinifer sp. nov.; and Brevimunda trilineata sp. nov. and Varitrella (Cantotrella) tabin sp. nov., respectively. We also describe the calling songs for three species: Duolandrevus (Bejorama) lambir Gorochov, 2017, Duolandrevus (Duolandrevus) nobilis sp. nov. and Varitrella (Cantotrella) tabin sp. nov. A new locality record (Sabah, Sepilok) for Duolandrevus (Bejorama) lambir Gorochov, 2017, previously known from western Borneo (Sarawak, Lambir Hill and Brunei Darussalam, Kuala Belalong), was also reported.

Phenotypic plasticity of acoustic traits in high-frequency lebinthine crickets (Orthoptera: Eneopterinae: Lebinthina).

Driven by natural and sexual selection, calling behaviours and call parameters can vary within and between individuals. Phenotypic plasticity can be influenced by environmental conditions (e.g., temperature), size, body condition, and age. Crickets have been classic model organisms for studying the evolution of acoustic communication, but previous studies have focused on field crickets, for which males call at a low frequency, while females exhibit phonotaxis. This study holistically investigated the plasticity of calling behaviours and call parameters across a temperature gradient in a species of lebinthine crickets and examined plasticity between and within individuals. These crickets exhibit a unique communication system, including males calling at a near-ultrasonic frequency while actively searching for females. Ten recording assays at different temperatures were done on males of different sizes and body conditions, half of the assays when the males first became adults and another half 1 month later. Size, body condition, and age group of male crickets, as well as the ambient temperature, had different effects on different calling behaviours (e.g., number of songs produced) and call parameters (e.g., call duration, trill syllable period), even when the acoustic traits were correlated. The crickets also exhibited acclimatisation to the experimental conditions in their calling behaviours and acoustic traits to repeated assays. We also found that calling behaviours were less repeatable than temporal call parameters (e.g., call duration, trill duration), which in turn, were less repeatable than the spectral call parameter (dominant frequency).

Taxonomy and bioacoustics of scaly crickets (Orthoptera, Mogoplistidae, Mogoplistinae) from Borneo and Singapore.

A species of scaly cricket is described here: Ornebius lupus sp. nov. from the mangrove forests in Singapore. Ornebius pullus Ingrisch, 2006 is recorded in eastern Sabah for the first time. The calling songs of Cycloptiloides bimaculatus Tan et al., 2021 and Ornebius pullus from Sabah are described. We also revise the diagnosis of Ectatoderus nigrofasciatus Tan et al., 2021 from Brunei Darussalam.

A new species of Indigryllus (Orthoptera, Gryllidae, Eneopterinae, Xenogryllini) from Kerala, India, with first data on acoustics and natural habitat.

In India, the cricket subfamily Eneopterinae is represented by two known genera, Xenogryllus Bolívar, 1890 and Indigryllus Robillard & Jaiswara, 2019. The latter was recently described and is known from a single species I. kudremu Robillard & Jaiswara, 2019 from Karnataka, India. The species was known exclusively from its morphological features and there existed no information on its biology and acoustic features. The present study is a step ahead in understanding the natural history and acoustic signalling in the genus. Based on a collaboration initiated by citizen science observations on the website iNaturalist, we describe a new species, Indigryllus sagani sp. nov. from Kerala, India, with details on its habitat and acoustic signals.

Daily Signaling Rate and the Duration of Sound per Signal are Negatively Related in Neotropical Forest Katydids.

Researchers have long examined the structure of animal advertisement signals, but comparatively little is known about how often these signals are repeated and what factors predict variation in signaling rate across species. Here, we focus on acoustic advertisement signals to test the hypothesis that calling males experience a tradeoff between investment in the duration or complexity of individual calls and investment in signaling over long time periods. This hypothesis predicts that the number of signals that a male produces per 24 h will negatively correlate with (1) the duration of sound that is produced in each call (the sum of all pulses) and (2) the number of sound pulses per call. To test this hypothesis, we measured call parameters and the number of calls produced per 24 h in 16 species of sympatric phaneropterine katydids from the Panamanian rainforest. This assemblage also provided us with the opportunity to test a second taxonomically specific hypothesis about signaling rates in taxa such as phaneropterine katydids that transition from advertisement calls to mating duets to facilitate mate localization. To establish duets, male phaneropterine katydids call and females produce a short acoustic reply. These duets facilitate searching by males, females, or both sexes, depending on the species. We test the hypothesis that males invest either in calling or in searching for females. This hypothesis predicts a negative relationship between how often males signal over 24 h and how much males move across the landscape relative to females. For the first hypothesis, there was a strong negative relationship between the number of signals and the duration of sound that is produced in each signal, but we find no relationship between the number of signals produced per 24 h and the number of pulses per signal. This result suggests the presence of cross-taxa tradeoffs that limit signal production and duration, but not the structure of individual signals. These tradeoffs could be driven by energetic limitations, predation pressure, signal efficacy, or other signaling costs. For the second hypothesis, we find a negative relationship between the number of signals produced per day and proportion of the light trap catch that is male, likely reflecting males investing either in calling or in searching. These cross-taxa relationships point to the presence of pervasive trade-offs that fundamentally shape the spatial and temporal dynamics of communication.

A new species of Heminicsara (Orthoptera: Tettigoniidae: Agraeciini) from West Papua (New Guinea).

Heminicsara Karny, 1912 is a katydid genus of Agraeciini from the Axylus genus group. It currently comprises 62 species from mainly New Guinea and surrounding archipelagos. Based on recent fieldwork in Lobo in West Papua, Indonesia, a new species of Heminicsara is described here: Heminicsara incrassata sp. nov. It is most readily characterised from congeners and other species of the Axylus genus group by the male tenth abdominal tergite forming a large shield-shaped plate. This represents the first species of Heminicsara described and known from the south-west of New Guinea.

New species of Phaloria (Orthoptera: Phalangopsidae: Phaloriinae) from West Papua (Indonesia).

The genus Phaloria belongs to the monophyletic cricket subfamily Phaloriinae. It is s speciose group comprising 68 species found across Southeast Asia and New Guinea and Australia. The numerical diversity of Phaloria in New Guinea is impressive, but more species still await discovery owing to the large size and remoteness of the island. Based on new material collected from Lobo and Kumawa in West Papua (Indonesia), we describe six new species: Phaloria dischidia Tan Robillard, sp. nov. from Lobo; Phaloria paradischidia Tan Robillard, sp. nov. from Kumawa; Phaloria tukul Tan Robillard, sp. nov. from Lobo; Phaloria brevis Tan Robillard, sp. nov. from Kumawa; Phaloria berbeda Tan Robillard, sp. nov. from Lobo; Phaloria lobulata Tan Robillard, sp. nov. from Kumawa. We also record new localities for a species widespread in Lobo and Kumawa: Phaloria nr. aspersa Gorochov, 1996.

Description and bioecology of two new species of the genus Cryncus (Orthoptera, Gryllidae, Gryllinae) from Cameroon with a key and distribution map of all African species.

The genus Cryncus Gorochov, 1983 composed of African crickets is reported for the first time in Cameroon by the description of two new species collected at Zamakoe, Ongot and Engout'Adjap in the southern Cameroonian plateau during an inventory study of crickets carried out from March 2014 to September 2015. These new species are: Cryncus camerounensis Um Nyobe, Kekeunou Bilong Bilong sp. nov. and Cryncus desutterae Um Nyobe, Kekeunou Ma sp. nov. These descriptions bring the total number of species of this genus to 25. Cryncus camerounensis is distinguished by an irregularly shaped mirror, without a dividing vein, with a short apical field, while Cryncus desutterae is characterized by a divided oval mirror and a long apical field. Cryncus camerounensis was more abundant in the forest environment while Cryncus desutterae would exclusively colonize fallow land. This article is divided into two parts. The first part presents a description of the two new species, followed by a revised diagnosis of the genus Cryncus using both male and female characters and an identification key. The second part presents some bioecological data of these new species and a map of the geographical distribution of all known species of this genus.

A review of the genus Changiola (Orthoptera: Grylloidea: Pteroplistinae) and description of the first species from Borneo.

The taxonomy of the little-known cricket genus Changiola from the subfamily Pteroplistinae is reviewed here. This genus consisted of three species, two from Malay Peninsula and one from Indochina. Here, we describe a new species from Borneo, the first from the island: Changiola sarawakensis n. sp. We also provide a key to the species, although it is likely that more species will be added to this genus with more sampling in the region.

New taxa of the subtribe Lebinthina (Orthoptera: Gryllidae: Eneopterinae: Lebinthini) from New Guinea and nearby islands.

Four new species from three genera of Lebinthina crickets are described here. These include one species of Gnominthus: Gnominthus milneus sp. nov. from Papua New Guinea; two new species of Macrobinthus: Macrobinthus kei sp. nov. and Macrobinthus mamai sp. nov. from Maluka (Indonesia) and Papua New Guinea, respectively; and one species of Microbinthus: Microbinthus elegans sp. nov. from Papua New Guinea.

Taxonomic study of Lebinthus Stål, 1877 (Orthoptera: Gryllidae: Eneopterinae) with description of six new species in the Philippines.

The genus Lebinthus Stål, 1877 (Orthoptera: Gryllidae: Eneopterinae: Lebinthini) in the Philippines is studied. New locality records are provided for L. bitaeniatus Stål, L. sanchezi Bolívar, L. polillensis Baroga, Yap Robillard, L. puyos Robillard, and L. luae Robillard Tan. Six new species are described from Mt. Porras, Sibalom (L. dannybaletei sp. nov.), Mt. Balatukan, Misamis Oriental (L. parvus sp. nov.), Mt. Empagatao, Misamis Oriental (L. palaceus sp. nov.), Tarumpitao, Palawan (L. hamus sp. nov.), Mt. Malinao, Albay (L. magayon sp. nov.), and Boracay, Aklan (L. boracay sp. nov.). A distribution map, a taxonomic key, and an updated checklist of the genus in the Philippines are also provided.

A new species and new records of Pseudolebinthus crickets from Malawi (Orthoptera, Gryllidae, Eneopterinae).

Recent studies have suggested that the diversity of orthopteran insects in the Eastern African region is largely undersampled and understudied, resulting in numerous new species and genera awaiting discovery, while many species are known from only one or few records, preventing precise assessment of the threat to them. In this paper we describe the new species Pseudolebinthus ntchisi sp. nov. from Central Malawi and present new records about two other Pseudolebinthus species from Malawi, with biological information and illustrations of this genus based on field observations.

Pseudolebinthus lunipterus sp. nov.: a striking deaf and mute new cricket from Malawi (Orthoptera, Gryllidae, Eneopterinae).

This article presents an intriguing new cricket species of the tribe Xenogryllini discovered in Northern Malawi. This is the first case of mute and deaf species in the subfamily Eneopterinae; it shows no stridulatory apparatus on short male forewings and no tympana on either side of fore tibiae in both sexes. We introduce the new species and its complete mitogenome and assess phylogenetic relationships based on molecular data obtained from next-generation sequencing genome skimming method. Phylogenetic analyses place the new species within the genus Pseudolebinthus in Xenogryllini, as the sister species of Pseudolebinthus gorochovi Robillard. We describe Pseudolebinthus lunipterus sp. nov., provide illustrations of main morphology, male and female genitalia, photographs of living specimens and information about habitat and update the identification key for species of genus Pseudolebinthus. We discuss the differences between the new species and related taxa and the striking loss of acoustic communication in this cricket.