Structure and evolution of stridulatory mechanisms in New Zealand wetas (Orthoptera : Stenopelmatidae)

Four types of stridulatory mechanisms were found in 35 species (7 genera) of New Zealand wetas (Orthoptera : Stenopelmatidae). These include: (1) tergo-femoral; (2) tergo-tergal; (3) mandbbuao-mandibular; and (4) pleuro-coxal. These fell into 12 groups, based upon shape, density and pattern of tergal and femoral pegs, number of terga bearing pegs and presence of mandibular tusks bearing stridulatory tubercles. The plesiomorphic condition, consisting of spinose peg patches on 3 or more abdominal tergites rubbed by bands of pegs on the femur, is found in Hemiandrus spp. Apomorphically-derived tergal files have arisen separately in 3 other genera. In Hemideina, (2 species groups) well-formed files are very similar among species. In Deinacrida, (4 species groups), the trend is toward file reduction into one or 2 massive tergal ridges, and embellished femoral pegs. In the tusked wetas (2 gen., 2 spp.), one species has a crude file of many broken ridges. Stridulatory structures on mandibular tusks of both New Zealand species are unique, although the tusks appear to have their origin in African stenopelmatids. The plesiomorphic condition appears to have been deployed originally for defense stridulation (inter-specific communication). Additional intea-specific stridulatory communication developed in Hemideina and Deinacrida, using the apomorphic file and peg mechanisms. Here, the stridulation is associated with defense, calling, mating and disturbance behaviors.     

亚洲飞蝗发声器结构与鸣声时域特征研究

本文对亚洲飞蝗Locusta migratoria migratoria(L.)发声器的结构及鸣声的时域特征进行了研究.亚洲飞蝗主要的发声方式为前翅中闰脉-后足股节型,即前翅中闰脉的发声齿与后足股节内侧隆线相互摩擦发出鸣声.应用扫描电子显微镜技术对发声器的结构进行观察,结果表明,亚洲飞蝗前翅中闰脉具有单排规则排列的发声...     

Stridulatory structures in three green lacewings (Neuroptera : Chrysopidae)

The stridulatory structures that occur in Meleoma Fitch, Brinckochrysa Tjeder and Chrysocerca Weele (Neuroptera : Chrysopidae) have been examined for the first time, using scanning electron microscopy. The structures are made up of rows of tubercles, formed by modified microtrichia and setae or sclerotized plates, situated laterally on the second abdominal segment and inner surface of the hind femora. Although superficially similar in the 3 genera, the stridulatory structures have different derivations, and have probably arisen in the Chrysopidae on separate occasions. The arrangement of tubercles within each genus varies among species, and is sexually dimorphic. Sound is thought to be produced by rubbing the abdomen against the hind femora and probably forms part of a courtship display.     

Stridulation variability and morphology: an examination in dung beetles of the genus<Emphasis Type="Italic"> Trypocopris</Emphasis> (Coleoptera,Geotrupidae)

Distress signals produced by dung beetles of the genus Trypocopris (Coleoptera, Geotrupidae) were analysed to test whether interspecific and intraspecific acoustic variability are species- and subspecies-specific and to ascertain to what extent bioacoustic parameters depend upon the morphology of the stridulatory organs (pars stridens). Bioacoustic analyses showed that the three species were clearly differentiated, despite the fact that disturbance stridulations presented the same stereotyped spectrographic pattern. Within each species, most of the subspecies and populations considered were also bioacoustically distinguishable. Subspecies and populations within each species were differentiated with regard to body size and stridulatory organ, and the length of the pars stridens was positively correlated with the width of the coxa, in turn positively correlated with body size. A few spectrographic measures were significantly constrained by the morphology of the stridulatory apparatus; in particular the duration of sound emission was positively correlated with the length of the apparatus and the sub-pulse rate was negatively related to the distance between two consecutive crests. For T. pyrenaeus, with the largest number of populations sampled, there was no significant correlation between morphological and spectrographic distances, but there were significant positive correlations between morphological and geographical distances and between morphological and genetic distances. It is hypothesized that genetic differentiation might directly affect variability of the stridulatory apparata which would also be indirectly influenced and constrained by external morphological traits (like the width of the coxa and body size). Stridulatory organs, in turn, would affect the ways a few stridulatory traits (especially the temporal ones) change in time and space.     

Transmission of stridulatory signals of the burrower bugs, Scaptocoris castanea and Scaptocoris carvalhoi (Heteroptera: Cydnidae) through the soil and soybean

Abstract.  Males and females of the burrower bug species Scaptocoris castanea Perty and Scaptocoris carvalhoi Becker emit stridulatory signals when on the roots of soybean. The substrate-borne components of the signal can be recorded on the plant but not on the surrounding soil surface. The stridulatory apparatus is composed of the tergal plectrum (lima) and the stridulitrum (stridulatory vein) on the underside of the hind wings. The male plectrum has one ridge and the female lima has 13 ridges. Stridulitra of different species differ in the length and in the number of teeth. Rubbing of plectrum (lima) ridges over the stridulitrum in one or both directions produces pulse trains. The velocity of signals that are recorded less than 0.5 cm from the bug is below 0.013 mm s⁻¹ on the soil and below 0.066 mm s⁻¹ on the leaf surface. Broadband spectra have a dominant frequency of less than 1 kHz and subdominant peaks extending up to 7 kHz. The dominant frequency of the stridulatory signal transmitted through a plant decreases together with the proportion of its higher frequency spectral components. Signals are attenuated for 3–9 dB cm⁻¹ when transmitted through the soil or soybean leaf and for approximately 1 dB cm⁻¹ when transmitted through soybean stem.     

三种片蟋雄性发声器的比较研究(直翅目,蛣蟋科)

应用扫描电子显微镜观察了片蟋属Truljalia Gorochov 3种雄性声锉和声齿的超微结构,即瘤突片蟋T.tylacantha Wang et Woo,1992,梨片蟋T.hibinonis (Matsumura,1919),霍氏片蟋T.hofmanni(Saussure,1878).结果显示,声锉和声齿超微结构在属、种间差异显著,在种内差异不显著,且特征稳定.     

Diagnosis, classification, and phylogenetic relationships of the orphnine scarab beetles (Coleoptera, Scarabaeidae: Orphninae)

Orphnine scarab beetles (Orphninae) are widely distributed in the tropical and subtropical regions of the southern continents except for Australia. The catalogue of nominal taxa of orphnines includes 2 tribes, 15 genera, and 195 species. Diagnosis of the group, based on adult morphological characters, is as follows: antennae 10-segmented with 3-segmented club; mandibles with 2?C4 scissorial teeth and well developed mola; labrum and mandibles protruding past clypeus and visible from above; scutellum well developed in winged species, reduced but distinct in wingless species; wings with distinct anal area; apices of anterior tibia in males without spur but normally with a few robust setae; anterior coxa with longitudinal hollow on anterior surface; tarsi with 2 similar claws; middle and hind tibiae with 2 apical spurs; abdominal sternite 2 with sub-triangular to rounded plectrum; dorsal surface of hind coxae with oval flat stridulatory file; pygidium partly hidden under elytra; parameres symmetrical; bursa copulatrix sacciform, membranous; spermatheca C-shaped, not sclerotized; accessory vaginal glands developed; abdomen with 2 sclerotized tergites (VII?CVIII) and 6 visible sternites (III?CVIII). Preliminary phylogenetic analysis based on 47 characters of adult morphology shows that the tribe Aegidiini Paulian is a natural, monophyletic group. The genus Stenosternus Karsch described from a single specimen from S?o Tomé Island (Gulf of Guinea), is morphologically more similar to the New World taxa than to the Old World ones and is provisionally placed in Aegidiini. The tribe Orphnini Erichson seems non-monophyletic and has no synapomorphies. The genus Orphnus is apparently a polyphyletic group and it needs taxonomic revision. The hypothesis on sister-group relationship of Orphninae and Allidiostomatinae, based on molecular data, is not supported by the morphological characters. The stridulatory organs (the putative synapomorphy of Orphninae + Allidiostomatinae) are not identical in these groups; the mouthparts and female genitalia are essentially different. Orphninae have chewing mouthparts with large scissorial teeth and well developed mola, which is characteristic of generalist saprophagous species. Allidiostomatinae have mandibles with scissorial teeth and mola reduced; they also have sclerotized bursa copulatrix and sclerotized mandibular duct which opens on the dorsal side near condyle. Considering the present day development of alpha-taxonomy of most orphnine taxa, especially the speciose genus Orphnus, it seems premature to propose changes in higher classification of the subfamily. To clarify the phylogenetic position of the Orphninae among scarab beetles it is essential to include representative members of all taxa of orphnine lineage (sensu Browne, Scholtz, 1998) into the analysis.     

Description of the stridulatory apparatus of the Far Eastern bark beetles <Emphasis Type="Italic">Polygraphus proximus</Emphasis> Blandford, 1894 and <Emphasis Type="Italic">P. jezoensis</Emphasis> Niisima, 1909 (Coleoptera,Curculionidae: Scolytinae)

The stridulatory organ structure in two Far Eastern bark beetles, Polygraphus proximus and P. jezoensis, is described. The elytro-tergal type of the stridulatory apparatus is found in P. jezoensis. The structure involved in acoustic communication of P. jezoensis is present only in males. The plectrum of P. proximus males is re-described. Similarly to that in P. jezoensis, it is formed by two tubercles at the distal margin of tergite VII. An additional type of stridulatory organ used for the producing of precopulatory courtship signals is described for males of P. proximus. In this type of stridulatory organ, transverse ridges on the costal margin of the elytron act as pars stridens, and the hind tibia, as the plectrum.     

Larva and pupa of Cyphopisthes descarpentriesi Paulian (Coleoptera: Scarabaeoidea: Ceratocanthidae) and their phylogenetic implications

Abstract Pupae and mature larvae of the Australian ceratocanthid beetle, Cyphopisthes descarpentriesi Paulian 1977, are described and extensively illustrated. This is the sixth species of the family for which immature stages are known and the first from the Australian region. Unlike other ceratocanthid larvae described before, those of Cyphopisthes Gestro lack stridulatory teeth on the middle and hind legs and any trace of a frontoclypeal suture on the cranium. Reduced one-segmented labial palpi in Cyphopisthes are unique in Scarabaeoidea. Monophyly of the family is not corroborated by larval characters. Absence of spiracular closing apparatus in larvae is reported in the family for the first time. Like pupae of Ceratocanthus White and Germarostes Paulian, those of Cyphopisthes have thoracic projections, but their shape and location are different. Spiracles are found on abdominal segments 2−4 of pupa; that on segment 2 differs in colour and location from the others.     

Behavioral strategy of a lycaenid (Lepidoptera) caterpillar against aggressive ants in a Brazilian savanna

Myrmecophily is widespread in lycaenid butterflies, in which ants receive food resources and, in turn, protect caterpillars against natural enemies. This interaction ranges from obligate myrmecophily, in which immatures are invariably associated with ants and are dependent on ants for survival, and facultative myrmecophily, in which larvae are not dependent on ants for survival, but the presence of the latter may increase larvae survival. Lycaenids also include non-myrmecophilous butterflies, which do not have positive associations with ants and have developed strategies to avoid being attacked or preyed upon by them. In this study, we examined the relationship between the lycaenid Michaelus ira and two ant species associated with Distictella elongata (Bignoniaceae). This plant has extrafloral nectaries and is patrolled by Camponotus crassus and Ectatomma tuberculatum. Morphological analyses revealed that M. ira larvae have ant organs, such as dorsal nectary organs and perforated cupolas, structures associated with myrmecophily. We performed larval exposure experiments in the field, predicting that, in the absence of myrmecophily, the butterfly larva would present strategies to avoid ant attack. Results showed that larvae were attacked by both ant species. To escape ant molestation, larvae lived and fed inside silk-sealed D. elongata flower buds. We concluded that the M. ira bud-sheltering behavior was a defensive strategy against these ant species, while the dorsal nectary organs were apparently nonfunctional. Nonetheless, myrmecophily, in general, cannot be excluded in M. ira since relationships with other ant species may exist.     

Unusual abdomino-alary,defensive stridulatory mechanism in the bushcricket Pantecphylus cerambycinus (Orthoptera,Tettigonioidea, Pseudophyllidae)

The bushcricket Pantecphylus cerambycinus has two types of stridulatory mechanisms and acoustical signals. The elytro-elytral mechanism typical for tettigonioid bushcrickets is used to produce a narrow-band calling song (peak frequency 15 kHz). An abdomino-alary mechanism is used for disturbance stridulation. Its stridulatory file is situated on the hind edge of the abdominal tergites and consists of 50-70 parallel ridges, covering the whole width of the tergite. The broad-band sound (peak frequency 10 kHz) is produced by the contact between the file and ribs situated on the upper side of the hindwings which are folded in such a way that their upper side is directed toward the tergites. Defensive stridulation in bushcrickets is reviewed here, and its function and evolution discussed in the context of predator avoidance strategies. © 1996 Wiley-Liss, Inc.     

Simulium (Psilopelmia) virescens, a new black-fly species (Diptera: Simuliidae) from the southwestern region of the state of Bahia, Brazil

The last-instar larva, pupa, male and female of Simulium virescens sp. nov. are described and illustrated. This species has a peculiar larva, which has an elongated head capsule and light-green colour. The first thoracic segment has tubercle on its dorsal region and the third thoracic segment has one pair of tubercles; the first to the fourth abdominal segments have one pair of tubercles on each segment. Until now this new species had only been collected at the type locality, which is on the middle stretch of the Correntina River in the southwestern portion of the state of Bahia, Brazil. Females were voraciously biting humans during the field work. This new species represents the second species of Simulium (Psilopelmia) in Brazil and the first registered outside of the Brazilian Amazon Region.     

SOUND PRODUCTION BY AQUATIC INSECTS

1. Sound production by aquatic insects is found in four orders — Trichoptera, Odonata, Heteroptera and Coleoptera. 2. Immature aquatic insects that produce sound are rare, stridulation being present in one family of Trichoptera (Hydropsychidae) and one genus and species in a relic suborder of Odonata (Anisozygoptera) - Epiophlebia superstes. Hydropsychid larvae produce sound with a head/fore femur mechanism and use sound as part of aggressive behaviour for defence of feeding nets. Larval E. superstes use a hind femur/abdominal mechanism to dissuade predators. 3. Sound production has been documented in adults of all families of aquatic Heteroptera except Helotrephidae. In corixids and notonectids, acoustic signals play a role in mating. Members of the genus Buenoa (Notonectidae) are unique in having two stridulatory mechanisms in the same individual. Sound production has been most intensively studied in the Corixidae. Although sounds are used in mating by all singing corixids, their use seems to be facultative in some species and obligatory in others. Recent experiments by Theiss (1982) have shown that the air stores carried by corixids are used for both sound radiation and reception. 4. The adephagan beetle families Hygrobiidae, Dytiscidae and Haliplidae have all been shown to produce sound. Mechanisms of sound production have been established for haliplids and hygrobiids but have yet to be for most dytiscids. Sound production is used by beetles as part of sequences of aggressive/defensive and reproductive behaviour. 5. Sound production is especially well documented in the Hydrophilidae (Polyphaga). Hydrophilids use an abdominal/elytral mechanism and sound appears to be used in the same contexts as in adephagans. 6. Insects that produce sound under water must contend with the physical problems of sound transmission in a relatively dense, viscous medium with sharp boundaries. Because of potential distortion of the frequency components in a signal by reflection from the air/water interface in very shallow water, frequency is unreliable for encoding information. Aquatic insects use instead amplitude modulation and temporal patterning of signals. 7. For aquatic invertebrates, sound fields are different than those in air because the extent of the near field is approximately four times greater in water. This near field, a region in which displacement waves are predominant over pressure waves, extends to a greater distance than most aquatic insects communicate over. Such displacement waves could have important but as yet unconsidered effects. 8. The mass and viscosity of the water dictates that sound producing structures of aquatic insects should be heavier and more massive than those of terrestrial insects. A survey of stridulatory organs of aquatic insects reveals this to be true and reveals that the relatively fragile, membranous stridulatory organs of some terrestrial insects (especially Orthoptera) are absent. 9. The elaboration of sound producing structures in aquatic insects probably occurred at the family or subfamily level and for Heteroptera, Trichoptera and Odonata evolved after the invasion of the water. Acoustic signals used reproductively would probably be more closely associated with the emergence of new taxa. 10. Stridulatory structures have been derived from either structures devoted to some other function or from structures involved in the behaviour currently enhanced by sound production.     

Abdominal ventilatory pattern in crickets depends on the stridulatory motor pattern

Abstract. Ventilatory motor patterns were recorded from abdominal muscles in crickets, Gryllus campestris L.and Teleogryllus commodus (Walker), at rest and during three types of stridulatory motor activity; calling, courtship and aggressive song.
Increases in ventilatory period were almost exclusively due to an increase of the pause between expiratory bursts, whereas abdominal ventilatory bursts remained constant at 200 ms.Ventilatory patterns depended on the stridulatory motor pattern and indicated that the same basic respiratory oscillator exists in both cricket species.
In G.campestris there was a strict 1:1 coupling between chirps and ventilatory bursts.In T.commodus such a relationship was also observed for the chirp part of the songs, but less strictly for the trill part of the calling song and not for the courtship song.In both species the onset of the ventilatory burst was within ± 100 ms of a stridulatory chirp.Ventilatory burst lasted longer the earlier they began before a stridulatory chirp.This suggests strongly that the stridulatory motor pattern terminates the expiratory burst, and thus influences the ventilatory motor pattern.     

Two ways to be a myrmecophilous butterfly: natural history and comparative immature‐stage morphology of two species of Theope (Lepidoptera: Riodinidae)

Symbiotic interactions between butterfly larvae and ants, termed myrmecophily, require a range of behavioural and morphological adaptations (ant‐organs). Here, using light and scanning electron microscopy, we describe the complete life cycle of two species of Theope (Lepidoptera: Riodinidae) that have contrasting ways of life. Theope thestias larvae are facultatively tended by several ant species, whereas Theope pieridoides have obligate symbiotic interactions with Azteca ants that inhabit a myrmecophytic tree. Morphological differences associated with their different degrees of intimacy with tending ants are visible from hatching. In T. thestias, the untended first‐instar larva has elongated bifurcated setae and a few tiny perforated cupola organs (PCOs), whereas in T. pieridoides, the ant‐tended first instar has short dendritic setae, larger and more numerous PCOs, and functional tentacle nectary organs (TNOs). Throughout ontogeny, T. pieridoides always shows more conspicuous ant‐organs than T. thestias, with the exception of balloon setae, which are larger and more numerous in T. thestias. In addition, mature T. pieridoides larvae have an anterior set of ant‐organs, including a new type, here described and termed anterior glandular openings (AGOs). Based on the behavioural responses of ants in contact with these structures, a new interpretation for the mechanism whereby Theope larvae can manipulate the behaviour of their tending ants is proposed. Until now, three ecological syndromes can be defined among Theope species: (1) oligophagous larvae with facultative myrmecophily; (2) monophagous larvae with obligate myrmecophily; and (3) polyphagous larvae with obligate myrmecophily. These results suggest that differences in the degree of specificity in the ant–plant interactions may have an important role in the evolution of host‐plant use in Theope. © 2013 The Linnean Society of London     

Chiropteran tendon locking mechanism

Rather than the usual mammalian scheme in which tendon and sheath surfaces provide as little friction as possible, the tendons and sheaths of many bats have a locking segment on the manual and pedal flexor tendon complex. This tendon locking mechanism (TLM) exists opposite the proximal phalanges of each toe and pollex of many bats. Its structure, similar to a ratchet mechanism, assists bats in hanging with little muscular effort. The third digit of the pelvic limb and the pollex of species representing 15 chiropteran families were studied to determine the presence or absence, morphology, and function of the TLM. Most of the species studied have a TLM consisting of a patch of tubercles on the ventral surface of the flexor tendon associated with the proximal phalanx of each pollex or toe. The sheath adjacent to this portion of the flexor tendon has a series of transverse folds or ridges, which, when engaged with the tubercles on the tendon, lock the tendon in place. The TLM is similar in megachiropterans and microchiropterans possessing it. The TLM is absent, however, in some of the microchiropterans studied, most notably in the phyllostomids. Since many birds have a TLM similar to that of bats, it is an excellent example of the convergent evolution of a feature brought about by similar functional pressures on birds and bats. © 1993 Wiley-Liss, Inc.     

Three new species of Tricorythopsis (Ephemeroptera: Leptohyphidae) from southeastern Brazil

Three new species of Tricorythopsis Traver (Ephemeroptera: Leptohyphidae) are described and illustrated based on nymphs from southeastern Brazil. These new species can be distinguished from other species of the genus by the following characters: Tricorythopsis araponga sp. n.: (1) femora with long setae; (2) abdominal segments 5–7 with dorsal tubercles; (3) tarsal claws with 4–6 marginal denticles and 7 + 4 submarginal denticles. Tricorythopsis baptistai sp. n.: (1) tarsal claws with 4–5 large marginal denticles and one submarginal denticle on each side; (2) abdominal colour pattern; (3) abdomen without tubercles; (4) coxae without projections. Tricorythopsis pseudogibbus sp. n.: (1) abdominal segments 6–8 with small dorsal tubercles; (2) tarsal claws with four large marginal denticles, and 3 + 1 or 2 submarginal denticles; (3) coxae dorsally projected; (4) femora broad and with short setae; (5) pronotum with anterolateral projection.     

The complex stridulatory behavior of the cricket Eneoptera guyanensis Chopard (Orthoptera: Grylloidea: Eneopterinae)

Crickets produce stridulated sounds by rubbing their forewings together. The calling song of the cricket species Eneoptera guyanensis Chopard, 1931 alternates two song sections, at low and high dominant frequencies, corresponding to two distinct sections of the stridulatory file. In the present study we address the complex acoustic behavior of E. guyanensis by integrating information on the peculiar morphology of the stridulatory file, the acoustic analysis of its calling song and the forewing movements during sound production. The results show that even if E. guyanensis matches the normal cricket functioning for syllable production, the stridulation involves two different closing movements, corresponding to two types of syllables, allowing the plectrum to hit alternately each differentiated section of the file. Transition syllables combine high and low frequencies and are emitted by a complete forewing closure over the whole file. The double-teeth section of the stridulatory file may be used as a multiplier for the song frequency because of the morphological multiplication due to the double teeth, but also because of an increase of wing velocity when this file section is used. According to available phylogenetic and acoustic data, this complex stridulation may have evolved in a two-step process.     

Stridulatory Sound-Production and Its Function in Females of the Cicada Subpsaltria yangi

Acoustic behavior plays a crucial role in many aspects of cicada biology, such as reproduction and intrasexual competition. Although female sound production has been reported in some cicada species, acoustic behavior of female cicadas has received little attention. In cicada Subpsaltria yangi, the females possess a pair of unusually well-developed stridulatory organs. Here, sound production and its function in females of this remarkable cicada species were investigated. We revealed that the females could produce sounds by stridulatory mechanism during pair formation, and the sounds were able to elicit both acoustic and phonotactic responses from males. In addition, the forewings would strike the body during performing stridulatory sound-producing movements, which generated impact sounds. Acoustic playback experiments indicated that the impact sounds played no role in the behavioral context of pair formation. This study provides the first experimental evidence that females of a cicada species can generate sounds by stridulatory mechanism. We anticipate that our results will promote acoustic studies on females of other cicada species which also possess stridulatory system.     

Multiple male morphs in the leaf‐footed bug Mictis longicornis (Hemiptera: Coreidae)

Species within the coreid clade (Hemiptera: Coreidae) can often be observed competing in intrasexual competitions over access to mates and territories. Coreids that partake in these competitions typically possess sexually dimorphic hind legs that are used to strike and squeeze their rivals. In addition to their weaponized legs, some coreid species also possess sexually dimorphic abdominal tubercles, which are assumed to be sexually selected weapons. Still, much remains unknown about the morphology of these structures. Here, using the species Mictis longicornis Westwood, we investigate the frequency distribution and static allometry of abdominal thickness, a measure that includes tubercle length. Furthermore, we also investigate the morphological relationship between abdominal tubercles and weaponized hind legs. We find that male abdominal thickness is best explained by a bimodal distribution, thereby describing the first observed male polymorphism in the coreid clade; a phenomenon typically associated with alternative reproductive tactics. Additionally, we find that major males are characterized primarily by having large weaponized legs and abdominal tubercles, which further suggests that abdominal tubercles are used in male–male competition.