Taxonomic Study of the Genus Conocephalus Thunberg in Korea (Orthoptera: Tettigoniidae: Conocephalinae)

ABSTRACT The genus Conocephalus Thunberg in Korea was taxonomically studied. As the result, five species were confirmed to Korean fauna including a newly recorded species, Conocephalus bambusanus Ingrisch. The key to species, distributional data and comparative figures for identification are given.     

Decisions during Phonotaxis in the Bushcricket Requena verticalis (Orthoptera: Tettigoniidae): Do Females Change Direction to Alternative Male Calls?

Female bushcrickets (Requena verticalis, Listroscelidinae, Tettigoniidae) show a preference between male calls that differ in three parameters, temporal structure, frequency and intensity. In a two-choice speaker situation they prefer louder calls, songs in which the upper part of the frequency spectrum occupies higher frequencies and calls with short chirps rather than those with longer chirps. In an experiment females were offered an alternative call while orienting to a model of their conspecific song. The alternative call was demonstrably preferred by females when presented in a paired-speaker trial. Two motivational states were identified where females moved slowly or quickly to a sound source. Movement patterns were associated with the form of stimulus and slow females were discriminatory of male calls while fast females were not. Slow females changed speaker preference when the alternate speaker broadcast a call model with the higher frequency peak or the song model with the shorter chirps. By comparison fast moving females only changed course when the alternative sound source was louder.     

Coercive Copulation in the Alpine Bushcricket Anonconotus alpinus Yersin (Tettigoniidae: Tettigoniinae: Platycleidini)

Sexual coercion in the form of forced copulation is widespread in the animal kingdom and has been documented in several insect taxa. In crickets and bushcrickets (sub‐order Ensifera), however, mating typically involves luring acts as opposed to forcing acts. The mating behaviour of the tettigoniid Anonconotus alpinus Yersin, which is described in this paper, appears to be unique amongst the Tettigoniidae (and possibly amongst the Ensifera) in that it is coercive, involving forced matings. Males did not stridulate immediately prior to mating but instead leapt on passing females, using their anal cerci as pincers to maintain a hold on the female's abdomen (which was sometimes damaged in the process). Males appeared to lack a sexual refractory period and attempted to copulate again as little as 18 s following the previous mating.     

Male Agonistic Behaviour of the Bushcricket Mygalopsis marki Bailey in Response to Conspecific Song (Orthoptera: Tettigoniidae)

Experiments were conducted on Mygalopsis marki Bailey to determine the response of calling males to singing intruders. By increasing the density of natural aggregations of singing males we were able to observe the behavioural responses of individuals. In high density situations, males sang from lower perches in their plant and this effect was correlated with each male's proximity to other calling males. Furthermore, to examine if resident males were affected by conspecific song, a playback technique was employed using tape recordings of M. marki song. The design of the experiment was such that when confronted with an intruder, steadily increasing the intensity of its song, resident males moved to a lower position in the plant and ceased singing.     

The Phlesirtes complex (Orthoptera,Tettigoniidae, Conocephalinae,Conocephalini) reviewed: integrating morphological,molecular, chromosomal and bioacoustic data

The tettigoniid genus Phlesirtes Bolivar and its allies are reviewed. Morphological, ecological and molecular data prompt the erection of the new genus Chortoscirtes gen.n. with type species Xiphidion meruense Sjöstedt. The genera Phlesirtes, Chortoscirtes, Karniella and Naskreckiella are characterized by morphological characters supported by molecular, acoustic, ecological and chromosomal data. Four species, Chortoscirtes pseudomeruensis sp.n. , C. masaicus sp.n. , C. puguensis sp.n. and C. serengeti sp.n. , are described from localities in northern and coastal Tanzania and one Karniella, K. crassicerca sp.n. , is described from Uganda. The following comb n. are proposed: Phlesirtes kibonotensis (Sjöstedt) and Phlesirtes kilimandjaricus (Sjöstedt). Subtribal status is proposed for the four investigated African genera. A key to the Chortoscirtes species is provided.     

A new genus of African Karniellina (Orthoptera,Tettigoniidae, Conocephalinae,Conocephalini): integrating morphological,molecular and bioacoustical data

Melanoscirtes gen.n. is established within Karniellina. The members of this subtribe are small conocephaline bush crickets, confined to Africa. Melanoscirtes is erected on Phlesirtes kibonotensis, a species restricted to forest clearings and forest edge in the submontane and montane zones of Mt. Kilimanjaro. A subspecies, M. kibonotensis uguenoensis, is described from the North Pare mountains, a mountain range of the Eastern Arc adjacent to Mt. Kilimanjaro. Further species of Melanoscirtes occur on other mountain ranges of the northern branch of the Eastern Arc mountains of northern Tanzania and southern Kenya. The South Pare mountains harbour M. shengenae; the West Usambaras, M. usambarensis, and the Taita Hills, M. taitensis. All species and subspecies of Melanoscirtes exhibit a similar morphology and occupy analogous habitats on the respective mountains. The song patterns for all species found within this genus are very similar, and this, together with evidence from molecular data, suggests that allopatric speciation is the reason for the biogeographic pattern found in this genus. A key for the subspecies and species of Melanoscirtes is provided.     

Phonotaxis in the painted reed frog (Hyperolius marmoratus)

Summary A detailed study was conducted of the three-dimensional accuracy of phonotaxis by femaleHyperolius marmoratus. This analysis involved videotape recordings of phonotactic approaches to an elevated loudspeaker through a three-dimensional grid. Females readily resolved the sound source elevation, but the jump error angles describing the precision of approach were considerably greater in this three-dimensional analysis than in the more conventional two-dimensional ground approach analysis. Extensive use was made of visual cues in elevated phonotactic approach and lateral head scanning prior to jumps, often accompanied by vertical changes in head orientation, was frequent. The ability of such small anurans to localize a sound source in both the horizontal and vertical plane is remarkable.On leave from the Section of Neurobiology and Behavior, Cornell University, Ithaca, New York 14853, USA     

Structure of the stridulation ofOrchelimum (Orthoptera: Tettigoniidae)

Summary The structure of the stridulation was investigated by re-playing tape-recordings at very slow speed. The findings were corrobrated by sonograms and mingograms.The central part of the song is the ripple, a fast succession of syllables around which isolated syllables (clicks) are distributed according to species and circumstances. The rate of syllables in the ripple is a linear function of temperature.A quantitative expression for the stridulatory activity is the actual number of syllables per time unit, including pauses. By changes in the combination of elements, at leastO. agile is able to increase the output of syllables four to six times.This work was made possible by a grant from the Carlsberg Foundation to whom my most sincere thanks are due. —As I do not have advanced equipment for sound analysis, I am very much indebted to Dr. Bondesen and cand. sci. Poul Hansen, Bioakustisk Laboratorium, Naturhistorisk Museum, Aarhus, Denmark, and Mr. W.B. Broughton and Dr. M. Samways, Animal Acoustic Unit, City of London Polytechnic, London, for analysing part of the material by sonograms and mingograms. The very valuable help of Dr. Th.J. Walker, University of Florida, Gainesville, Florida, in identifying the species is gratefully acknowledged. For friendly discussions and linguistic corrections my best thanks are due to H.T. Evans and F.D.S. Evans.     

Ultrastructural Studies of Spermiogenesis of Conocephalus saltator (Saussure)

The acrosome of the spermatozoa is the organelle involved in its penetration through the ova membranes during the fertilization process. Several features of this process are considered to be related to the fertilization events e.g. some substance coats outside the membrane. During the maturation process the spermatozoa of Conocephalus saltator develop a coat of tubules and filaments which overly some membrane regions in a specific array. The mature spermatozoa are seen to adhere in these regions and form threads of 20 cells long and five to six wide. It is suggested that the external coat plays a role in this 'sticking' phenomenon.     

Ecological adaptations of grassland‐inhabiting flightless Orthoptera: Fulvoscirtes and Acanthoscirtes,two new genera of African Karniellina (Orthoptera,Tettigoniidae, Conocephalinae,Conocephalini)

Two new genera, Fulvoscirtes n.gen. and Acanthoscirtes n.gen. , are established within the subtribe Karniellina of Conocephalini. Fulvoscirtes is based on Xiphidion kilimandjaricum Sjöstedt, 1909 and Acanthoscirtes on Phlesirtes kevani Chopard from northern Kenya. The majority of Fulvoscirtes spp. are confined to open grasslands in the submontane zone of mountains. Fulvoscirtes contains eight species, seven of which are newly described in this paper. Three species and one subspecies occur on Mt Kilimanjaro. These are F. kilimandjaricum (Sjöstedt) constricted to the southern slopes, F. legumishera n.sp. confined to the northern side and F. sylvaticus n.sp. occurring on the western side of Kilimanjaro and on the eastern slopes of Mt Meru. Fulvoscirtes fulvus n.sp. is divided into two subspecies, F. fulvus fulvus n.ssp. found in the submontane zone of east Kilimanjaro and F. fulvus parensis n.ssp. in submontane to montane localities of the North and South Pare mountains. Fulvoscirtes fulvotaitensis n.sp. occurs in the Taita Hills of southern Kenya. Fulvoscirtes viridis n.sp. is described from savannah habitats between Mts Longido and Meru. Fulvoscirtes laticercus n.sp. is found in the Kenyan highlands, while the most southerly occurring species, Fulvoscirtes manyara n.sp. , is found on Mt Hanang and the Mbulu highlands of northwestern Tanzania. Acanthoscirtes contains three species, of which A. albostriatus n.sp. is described newly from savannah habitas of eastern Kilimanjaro. Information is given on the ecology and the acoustic behaviour of some of the species together with keys to the genera of the Karniellina and the species of Fulvoscirtes and Acanthoscirtes. The genera of Karniellina probably evolved at a time when grasslands spread in East Africa due to an increasing aridification of the climate. The earliest lineage, the genus Karniella, is adapted to more forested habitats while the majority of the genera of Karniellina prefer open grasslands. Major splits within Karniellina probably occurred with the emergence of savannah grasslands due to the ongoing fragmentation of forest habitats several millions years ago, but most species within the genera are geologically young, their radiation being boosted by climatic fluctuations of the past 1–2 Ma.     

Circadian Patterns of Migration of Strinatia brevipennis (Orthoptera: Phalangopsidae) inside a Cave

The distribution pattern of a population of the cricket Strinatia brevipennis was studied in a cave in Southeastern Brazil. The individuals do not move very often, but the population, as a whole, changes position along the day and night. Although the crickets never leave the cave, they approach the entrance during the night for fee ding. During the day, they return to the deep regions and remain almost motionless. The migration seems to be related to light intensity but not to temperature or relative humidity. A photophobic response is slightly evident but the possibility of the presence of an endogenous control of both, sensitivity to light and activity, must also be considered.     

Diet influences male-female interactions in the bushcricketRequena verticalis (Orthoptera: Tettigoniidae)

The influence of diet on the courtship roles of male and female Requena verticaliswas investigated in the laboratory. The protein content of available food was found to affect the frequency of mating attempts. Pairs which were fed on a low-protein diet were involved in fewer mating attempts than pairs which were fed on a high-protein diet. Diet also influenced the relative frequencies of male and female rejections. Males rejected their virgin female partners more often than females rejected their male partners when the pairs were kept on a low-protein diet. The opposite was found when the female had mated once before. No difference in the frequency of male and female rejections was found when the pair was kept on a high-protein diet irrespective of the mating status of the female.     

Circadian Patterns of Migration of Strinatia brevipennis (Orthoptera: Phalangopsidae) inside a Cave

The distribution pattern of a population of the cricket Strinatia brevipennis was studied in a cave in Southeastern Brazil. The individuals do not move very often, but the population, as a whole, changes position along the day and night. Although the crickets never leave the cave, they approach the entrance during the night for fee ding. During the day, they return to the deep regions and remain almost motionless. The migration seems to be related to light intensity but not to temperature or relative humidity. A photophobic response is slightly evident but the possibility of the presence of an endogenous control of both, sensitivity to light and activity, must also be considered.     

Systematics and phylogeny of Parapholidoptera (Orthoptera: Tettigoniidae: Tettigoniinae)

Genus Parapholidoptera is revised and three species, P. yoruka sp.n., P. bolkarensis sp.n. and P. salmani sp.n., are described. Parapholidoptera delineata Stolyarov is placed in synonymy with P. ziganensis Karaba?. Parapholidoptera bodenheimeri Karaba? and P. distincta bodenheimeri Karaba? are placed in synonymy with P. distincta (Uvarov). Parapholidoptera flexuosa Karaba?, previously a subspecies of P. castaneoviridis (Brunner von Wattenwyl), is recognized as a separate species. A key to world species is provided. Cladistic analysis revealed the monophyly of the genus with two major clades. A short account of distribution is presented.     

The plurennial life cycles of the European Tettigoniidae (Insecta: Orthoptera)

Summary The effect of drought on embryonic development and on hatching was studied in 13 European Tettigoniidae species. Drought can affect development in three different ways: (1) Embryonic development proceeds slower than if the eggs are in contact with water; (2) it stops (for final diapause) in an earlier embryonic stage; (3) it affects maintenance and termination of the initial embryonic diapause.In many Tettigoniidae species, the initial diapause is prolonged, and may last several years. Without draught stress, between 1 and 7 cold treatments in the laboratory, and with eggs of the Tettigonia-species between 1 and 6 winters in the field were necessary to enable all eggs to complete initial diapause. In Central European species, the number of eggs maintaining initial diapause significantly increased when the eggs had no contact with water at the time when they should recover from diapause. In contrast, termination of initial diapause in Tettigonia caudata from Greece, when the environment became favorable for growth again, was highest in that group of eggs that had lost most water in a preceding period of drought. The importance of the prolonged initial diapause for the survival of unpredictable adverse conditions is discussed.     

Determinants of Male Spacing Behaviour in Panacanthus pallicornis (Orthoptera: Tettigoniidae)

Panacanthus pallicornis is a neotropical species of katydid endemic to Colombia that inhabits premontane forests, and individuals are found in regenerating (RF) and dense forest (DF) habits. Members of this species are made conspicuous by their colouration, remarkable defensive body thorns and the loud mating calls of the males. Through capture, marking, and recapture, we determined singing‐site characteristics in two different natural habitats: an RF and a DF. Using nearest neighbour analysis, we found male distribution tends to uniformity in forest habitats, but in the RF, male distribution is more random. Males also showed preference for high singing sites and these were correlated with host plant height. Although host plants in DF were taller than those in the RF, male’s perch preference was independent from the habitat; and in RF, males select lower perches. To investigate if male spacing was a function of the calling song, we manipulated two groups of males from a different population, one group deafened (tympanic membranes torn), and another control group with tympanic membranes intact. Insects were released from a single location in the two different zones of similar area. After a number of days we measured male displacement, and found that the deafened group distribution tended to aggregation, while the control group spread throughout the experimental zone with a random distribution. These results suggest that male spacing behaviour is one of the functions of the calling song. Based on a pre‐established phylogenetic framework of the genus Panacanthus, we discuss some implications for the evolution of the calling song of P. pallicornis in both RF and DF.