02105nas a2200157 4500008004100000022001300041245008000054210006900134260001600203300001200219490000700231520159800238100002401836700002101860856006601881 1999 eng d a0003347200aNutritional effects on male calling behaviour in the variable field cricket0 aNutritional effects on male calling behaviour in the variable fi cJan-01-1999 a89 - 950 v573 a

In the variable field cricket,Gryllus lineaticeps, females prefer higher chirp rates and longer chirp durations in male calling song. Higher chirp rates are energetically more expensive to produce, but the energetic cost of calling does not vary with chirp duration. We tested the hypothesis that nutrition affects male chirp rate and chirp duration. Full-sibling brothers of similar age were placed on high- and low-nutrition feeding regimes. There was no effect of feeding regime on male weight; neither group showed a significant change in weight, and the two groups did not differ from each other in weight change. However, males on the high-nutrition feeding regime both called more frequently and called at higher chirp rates when they did call. The two groups did not differ in chirp duration, the duration of pulses within chirps or chirp dominant frequency. These results suggest that females select mates based on one nutrition-dependent call character (chirp rate) and one nutrition-independent call character (chirp duration). In addition, because males in the two groups did not show significant differences in weight change, and because males on the high-nutrition feeding regime engaged in energetically more expensive calling, these results suggest that males invest any excess energy above their basic maintenance requirements in the production of call types that increase their attractiveness to females. The absence of a relationship between body condition and calling song structure for males in the field may be a consequence of this pattern of energy allocation.

1 aWagner, William, E.1 aHoback, W. Wyatt uhttp://linkinghub.elsevier.com/retrieve/pii/S000334729890964201729nas a2200145 4500008004100000022001300041245015800054210006900212260001600281300001400297490000700311520118100318100001801499856006601517 1988 eng d a0003347200aThe calling song of the field cricket, Gryllus bimaculatus (de geer): constraints on transmission and its role in intermale competition and female choice0 acalling song of the field cricket Gryllus bimaculatus de geer co cJan-04-1988 a380 - 3940 v363 a

Field studies of calling male field crickets, Gryllus bimaculatus, showed that males formed calling aggregations. Within aggregations males appeared to maintain an exclusive female-attraction zone about their burrows; calling song may thus serve as an aggressive signal to neighbouring males to maintain spacing. Calling song attenuates with distance. Furthermore, calls became degraded with distance by the loss of low frequency components and a reduction in the interval between chirps and pulses due to reverberation. Playback experiments suggested that the predictable degrading properties of the call may serve as a distance-finding mechanism maintaining observed male spacing. The intensity of calls and the repetition rate of chirps and pulses was positively correlated with male size. While information contained within the intensity parameter of calls may prove unreliable due to unpredictable attenuation and irregular amplitude fluctuations, the repetition rate of chirps and pulses was not affected by distance degradation. Playback experiments in which intensity was controlled suggested that females orientate preferentially to the calls of large males.

1 aSimmons, L.W. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334728880009502192nas a2200217 4500008004100000022001300041245012200054210006900176260001600245300001400261490000700275520150200282653001201784653001901796653001501815653001901830653001401849100002501863700002001888856006601908 2011 eng d a0003347200aHost song selection by an acoustically orienting parasitoid fly exploiting a multispecies assemblage of cricket hosts0 aHost song selection by an acoustically orienting parasitoid fly  cJan-04-2011 a851 - 8580 v813 a

Specialization by predators, parasites and parasitoids is often viewed as adaptive because specialization will usually increase search efficiency for suitable hosts (prey). Although many studies have documented interspecific variation in the degree of host specialization, few studies have examined intraspecific variation in specialization among different populations exploiting different numbers of hosts, and even fewer have specifically examined variation in behavioural specialization. Here we examine the acoustic preferences of a parasitoid fly, Ormia ochracea, which attacks several Gryllus species of field crickets by using the male cricket song to locate hosts. All previous studies with this system have examined fly song preferences in populations of flies that primarily exploit a single host species of cricket. Here we tested a population of flies that naturally parasitizes multiple cricket species. We found significant interspecific host song preferences; however, as predicted, the strength of preference was reduced compared to single-host populations of flies. We also examined fly song selection for intraspecific variants of two of the cricket host species; flies showed significant preference for intraspecific song variants of one of the two cricket species. Our results demonstrate that the degree of behavioural specialization, in a very highly specialized fly, nevertheless shows interpopulation variation consistent with the numbers of host species utilized.

10aGryllus10aOrmia ochracea10aparasitoid10aspecialization10avariation1 aSakaguchi, Kelly, M.1 aGray, David, A. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721100027302583nas a2200277 4500008004100000022001300041245012600054210006900180260001600249300001400265490000700279520171500286653002002001653001902021653002502040653001202065653001302077653001802090653002202108653002102130653002102151653002102172100002302193700002302216856006602239 2011 eng d a0003347200aEffects of juvenile and adult condition on long-distance call components in the Jamaican field cricket, Gryllus assimilis0 aEffects of juvenile and adult condition on longdistance call com cJan-01-2011 a135 - 1440 v813 a

Complex signals may arise through either content- or efficacy-based selection. Content-based signals are thought to evolve because of the information content they provide to the receiver. Such signals may function as multiple messages, each relaying different information or types of information. For example, some signals or signal components may indicate different aspects of condition, or condition at different life stages (quality signals), while others relay information on signaller location, or function in species recognition. Or they may act as redundant signals of overall condition, or as backup signals of the same aspect of condition. Efficacy-based signals are proposed to evolve because of the way in which they influence the production, transmission, reception or processing of the signal. We manipulated juvenile and adult condition in male Jamaican field crickets, Gryllus assimilis, to test whether changes in components of the male’s long-distance acoustic mate attraction signal were consistent with content- or efficacy-based selection. Several call components exhibited condition-dependence, and may be under content-based selection. Interpulse duration, pulse rate and chirp duration appeared to honestly signal juvenile condition, while dominant frequency appeared to signal adult condition. Thus, these signal components appeared to be acting as multiple messages of quality. Pulse number, interchirp duration and chirp rate were highly stereotyped and probably function in species recognition. Call number increased with decreasing condition and was likely under efficacy-based selection. No call components appeared to have the potential to act as redundant signals.

10aacoustic signal10acomplex signal10acondition-dependence10acontent10aefficacy10aField cricket10amultiple messages10amultiple signals10aredundant signal10asexual selection1 aWhattam, Emily, M.1 aBertram, Susan, M. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334721000393301261nas a2200157 4500008004100000022001300041245006800054210006400122260001600186300001400202490000700216520077200223100002200995700002001017856006601037 1992 eng d a0003347200aThe quantitative genetics of sound production in Gryllus firmus0 aquantitative genetics of sound production in Gryllus firmus cJan-11-1992 a823 - 8320 v443 a

The species-specific calling songs of male cricket are used by females for species recognition and mate choice. Heritability of variation of morphological structures involved in song production, components of the calling song, and body size were estimated for the cricket Gryllus firmus. The heritabilities of morphological structures range from 0·42 to 0·73, while those of the song components range from 0·10 to 0·35. Comparison between sire and dam components suggests that there may be non-additive and/or maternal effects. As a result of the low correlation between body size and song components, it is unlikely that female G. firmus use the calling song to assess male body size or wing morph (micropterous or macropterous).

1 aWebb, Karen, Lynn1 aRoff, Derek, A. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334720580578001289nas a2200157 4500008004100000022001300041245014200054210006900196260001600265300001600281490000700297520072100304100002301025700001701048856006601065 1992 eng d a0003347200aVariability in call structure and pairing success of male field crickets, Gryllus bimaculatus: the effects of age, size and parasite load0 aVariability in call structure and pairing success of male field  cJan-12-1992 a1145 - 11520 v443 a

The effects of male body size, age and gregarine parasite load on the structure of calls and success at attracting mates were investigated in a natural population of the field cricket, Gryllus bimaculatus. The syllable rate within chirps was negatively related to male size, and the duration of syllables was positively related to size. Older males had more variable syllable rates within their chirps. Size did not influence pairing success. However, paired males were significantly older than solitary calling males. Parasitic infection influenced the pairing success of young males but not old males. These data are discussed in the context of direct and indirect selection for female mating preferences.

1 aSimmons, Leigh, W.1 aZuk, Marlene uhttp://linkinghub.elsevier.com/retrieve/pii/S000334720580326401774nas a2200157 4500008004100000022001300041245005100054210004700105260001600152300001400168490000700182520131900189100002001508700002201528856006601550 2001 eng d a0003347200aIs cricket courtship song condition dependent?0 acricket courtship song condition dependent cJan-11-2001 a871 - 8770 v623 a

Females of the Texas trilling field cricket, Gryllus texensis, show mating preferences based on male courtship song. To test experimentally the condition dependence of courtship song, we attempted to manipulate male condition via the diet. When the diet was manipulated at the adult moult, there was no effect on subsequent male courtship song or male condition measured as residual mass. When the diet was manipulated three moults prior to the adult moult, there was a significant effect on male residual mass, but no differences in courtship song were observed. To gain a second measure of condition in the diet-manipulated-as-nymphs group, we extracted their fat using petroleum ether in a refluxing Soxhlet apparatus. Crickets reared on the poor diet showed a clear relationship between the residual mass measure of condition and condition measured as energetic fat reserve, whereas the two measures of condition were unrelated in crickets reared on the good diet. Courtship song was unrelated to diet, fat reserve or residual mass. We conclude that courtship song does not reflect male condition in the laboratory despite its energetic cost. When given a mating opportunity it is probably in the evolutionary interest of males in poor condition to signal at as high a rate as males in good condition.

1 aGray, David, A.1 aEckhardt, Gillian uhttp://linkinghub.elsevier.com/retrieve/pii/S000334720191825101872nas a2200157 4500008004100000022001300041245011900054210006900173260001600242300001600258490000700274520132800281100002001609700002001629856006501649 1995 eng d a0003347200aFitness differences associated with calling behaviour in the two wing morphs of male sand crickets, Gryllus firmus0 aFitness differences associated with calling behaviour in the two cJan-01-1995 a1475 - 14810 v503 a

Alternate morphologies exist in a wide range of species. A commonly encountered dimorphism in insects is wing dimorphism, in which one morph is winged (macropterous=LW) and flight-capable while the other has reduced wings (micropterous=SW) and cannot fly. Gryllus firmus is a wing-dimorphic cricket found in the southeastern U.S.A. Although trade-offs associated with wing dimorphism are well established in female crickets, no such trade-offs have been demonstrated in male crickets. Differences between morphs in male G. firmus in the likelihood of attracting a female were tested in the laboratory using a simple T-maze where females chose between an LW male and an SW male. Time spent caling for each male was recorded on the sixth day of adult life. SW males were more likely to attract a female and spent more time calling than LW males. A logistic regression of female choice against the absolute proportional difference in calling time between males revealed that, as the difference in calling time between males increased, the likelihood of a female choosing the longer-calling male also increased. Therefore it is concluded that there is a trade-off between macroptery and the likelihood of attracting a female, and that it may be a primary factor in the maintenance of wing dimorphism in male G. firmus.

1 aCrnokrak, Peter1 aRoff, Derek, A. uhttp://linkinghub.elsevier.com/retrieve/pii/000334729580004201422nas a2200145 4500008004100000022001300041245010000054210006900154260001600223300001400239490000700253520092700260100002301187856006601210 1972 eng d a0003347200aGenetic control of the neuronal network generating cricket (Teleogryllus gryllus) song patterns0 aGenetic control of the neuronal network generating cricket Teleo cJan-08-1972 a478 - 4920 v203 a

Hybrid field crickets between Teleogryllus species and Gryllus species were produced to examine: (a) the genetic system controlling the neuronal network underlying song production: and (b) the neuronal mechanism responsible for the superimposed rhythms of chirping songs. Pulse numbers, intervals, and progressions were subjected to statistical and graphic analyses. Teleogryllus songs are controlled by a complex, polygenic, multichromosomal system, even at the level of ‘unitary’, acoustical parameters. Genes regulating certain pattern characteristics are on the X-chromosome’. The superficially similar chirping songs of two Gryllus species appear due to different neuronal mechanisms. One song appears to reflect a single rhythm generator with some relaxation oscillator properties, while the rhythms of the other song seem to be caused by the mixed effect of two resonant type oscillators.

1 aBentley, David, R. uhttp://linkinghub.elsevier.com/retrieve/pii/S0003347272800125