@article {50521, title = {Inheritance of song and stridulatory peg number divergence between Chorthippus brunneus and C. jacobsi, two naturally hybridizing grasshopper species (Orthoptera: Acrididae)}, journal = {Journal of Evolutionary Biology}, volume = {18}, year = {2005}, month = {Jan-05-2005}, pages = {703 - 712}, abstract = {

Knowledge of the genetic basis of divergence in mating signal characters that contribute to reproductive isolation is critical to understanding speciation. Here, we describe a semi-automated system for characterizing grasshopper acoustic signals. We used this system to study the genetic basis of divergence in three male calling song components [echeme (EL), syllable (SL) and phrase (PL) lengths] between Chorthippus brunneus and C. jacobsi , two species of grasshoppers that hybridize in northern Spain. We also studied the number of pegs in the stridulatory file. For all characters, additive effects accounted for most of the genetic differentiation between species. However, the three song components also showed small but significant epistatic effects. No sex linkage was detected. Wright\–Castle\–Lande estimates of the minimum numbers of genetic factors underlying song and peg number divergence were low: peg number ( n e \¼ 5.87 \± 5.84), SL ( n e \¼ 2.37 \± 4.79) and PL ( n e \¼ 0.87 \± 0.86). On the other hand, EL appeared to be controlled by many genes. These results suggest that divergence in SL and PL might be driven by sexual selection whereas EL might not be under selection. This is consistent with experimental results on female song preference in related species. However, the fact that few factors appear to underlie the differences in peg number is surprising. Peg number is not closely related to song characteristics. It often varies between closely related grasshopper species and it has been assumed to be a neutral character. The biometrical approaches used here tend to underestimate the number of factors influencing a trait but provide valuable background for subsequent quantitative trait loci analyses.

}, keywords = {additive effects, dominance effects, effective number of factors, epistasis, mosaic hybrid zones, quantitative trait loci, sexual selection, wavelet transformation}, doi = {10.1111/jeb.2005.18.issue-310.1111/j.1420-9101.2004.00838.x}, url = {http://blackwell-synergy.com/doi/abs/10.1111/jeb.2005.18.issue-3}, author = {C. I. Sadamando and S. Miyaguchi and H. Tatsuta and H. Kishino and J. R. Bridle and R. K. Butlin} } @article {47580, title = {Stridulation and associated behaviour in certain orthoptera. 2. Stridulation of females and their behaviour with males}, journal = {Animal Behaviour}, volume = {6}, year = {1958}, month = {Jan-01-1958}, pages = {27 - 42}, abstract = {

1. The stridulation of females and their behaviour in relation to males was studied comparatively in the following species of Truxalinae: Stenobothrus lineatus (Panzer); Omocestus viridulus (Linnaeus); Chorthippus parallelus (Zetterstedt); and Chorthippus brunneus (Thunberg) (= C. bicolor Charp.).

2. Descriptions of the \“typical behaviour\” of females in response to normal song are given. This behaviour is similar in all species and consists of three phases: response stridulation, orientation towards and locomotion to the male. Arrived near the male, the female stridulates in response to mate song; the male, on noticing the female, sings the courtship song, engages the genitalia and copulation ensues. Females showing such typical behaviour are said to be in the \“responsive state\”.

3. This responsive state in females of the four species appears at maturation, is inhibited for periods up to 24 hours prior to oviposition, is regained shortly afterwards and is lost some days prior to death. Complete copulation involving the transfer of a spermatophore also inhibits the responsive state in the females; if the latter are isolated after copulation, they regain their responsiveness in a period of from 6\–20 days dependent on the species. This recovery is delayed or prevented if the females are kept after copulation with males or within the sound of male normal song.

4. The responsive state is characterised in most females of all four species by the emission of stridulation in response to male normal song. In all cases, the movements of the hind femora of a female emitting this stridulation are very similar to those of a male of the same species singing the normal song. In the case of S. lineatus, O. viridulus and C. brunneus, audible sounds are emitted by the females, which in the case of the latter two species show marked affinity to male normal song. Physical analyses of these sounds are presented. Females of C. parallelus, being brachypterous, emit no sound while making stridulation movements of the hind femora.

5. It is postulated that the discrimination mechanism responsible for distinguishing between various specific songs is closely linked to the inherited motor mechanism which causes typical stridulation in both sexes. It is further suggested that the basic behaviour reactions of males and females to male normal song are the same, consisting of stridulation response movements, orientation and locomotion towards the male. Normally in the field, the last two phases are suppressed in males, the whole sequence in females. Isolation restores full typical behaviour in both males and females and, in the latter, stridulation is always an indicator of the return of the responsive state.

6. The observations are used to construct a possible picture of events in the field concerned with courtship and mating in the present species.

}, issn = {00033472}, doi = {10.1016/0003-3472(58)90005-8}, url = {http://linkinghub.elsevier.com/retrieve/pii/0003347258900058}, author = {Peter Thomas Haskell} } @article {11153, title = {A putative hybrid in nature between Chorthippus brunneus and C. biguttulus (Orthoptera : Acrididae)}, journal = {Systematic Entomology}, volume = {1}, year = {1976}, pages = {71-74}, chapter = {71}, abstract = {

The characteristics of the song and morphology of a probable natural hybrid between the two grass- hoppers Chorthippus brunneus (Thunberg) and C. bigurruius (L.) are described and compared with those of the parent species. The status of C. eisentrauti (Ramme) is briefly discussed.

}, doi = {10.1111/j.1365-3113.1976.tb00033.x}, author = {D. R. Ragge} } @article {11152, title = {The songs and taxonomy of the grasshoppers of the Chorthippus biguttulus group in the Iberian Peninsula (Orthoptera: Acrididae)}, journal = {Journal of Natural History}, volume = {22}, year = {1988}, pages = {897-929}, chapter = {897}, abstract = {

The Chorthippus biguttulus group includes a number of common European species that are difficult to distinguish morphologically but are easily recognized in the field by the distinctive calling songs of the males. These song-patterns have not previously been studied in Spain and as a result the Iberian members of the group have been misidentified in almost all the extensive Spanish literature on the ecology and cytogenetics of these insects. In this study the male calling songs of all six members of the group known from the Iberian Peninsula and North Africa are fully described and illustrated with oscillograms at several different speeds. The songs of the three species known only from Iberia or North Africa, jacobsi, yersini and marocanus, are fully described for the first time (marocanus is here raised in rank from subspecies). Notes on recognition, using both morphology and song, are given for each species, and two identification keys are provided, one based on morphology and the other on song. It is shown that the three species biguttulus, brunneus and mollis, previously believed to be widespread in Iberia, are absent from most of the peninsula.

}, keywords = {acoustics, Acrididae, Chorthippus, grasshoppers, Iberia, North Africa, Orthoptera, song, taxonomy}, doi = {10.1080/00222938800770611}, author = {D. R. Ragge and W. J. Reynolds} }