Differences in age structure among field cricket populations (Orthoptera; Gryllidae): possible influence of a sex-biased parasitoid

1995 ◽  
Vol 73 (7) ◽  
pp. 1207-1213 ◽  
Author(s):  
Anne-Marie Murray ◽  
William H. Cade
Keyword(s):  
Cross Sections ◽  
Age Structure ◽  
Life History Traits ◽  
Mating Behaviour ◽  
Field Cricket ◽  
Male Mating ◽  
Ormia Ochracea ◽  
Age Patterns ◽  
Gryllus Integer ◽  
Study Species

This study examined age structure in adult populations of three species of field cricket, Gryllus veletis, G. pennsylvanicus, and G. integer. Adults were aged by counting growth layers in cross sections of tibiae. The study species differ in several life-history traits including the likelihood of parasitism by Ormia ochracea, a tachinid that orients to calling males. Gryllus integer is parasitized whereas G. veletis and G. pennsylvanicus are not. Such differences between the species should result in different age patterns. Data from field collections demonstrated that adult G. veletis and G. pennsylvanicus had similar maximum life-spans of about 4 weeks, and males were similar in age or slightly older than females. The maximum age for female G. integer was also about 4 weeks, but few males > 20 days old were encountered. Moreover, male G. integer were significantly younger than females in five out of six samples. This pattern in G. integer, evident in 2 successive years, could be consistent with sex-biased mortality by Ormia ochracea. The results are discussed in relation to differential longevities and the intensity of sexual selection on male mating behaviour.

Temporal patterns of parasitoid fly (Ormia ochracea) attraction to field cricket song (Gryllus integer)

1996 ◽  
Vol 74 (2) ◽  
pp. 393-395 ◽  
Author(s):  
William H. Cade ◽  
Mark Ciceran ◽  
Anne-Marie Murray
Keyword(s):  
Mating Behaviour ◽  
Calling Song ◽  
Field Cricket ◽  
Lower Probability ◽  
Ormia Ochracea ◽  
The Hours ◽  
Cricket Song ◽  
Temporal Rate ◽  
Gryllus Integer ◽  
Male Cricket

Female flies, Ormia ochracea (Diptera, Tachinidae), orient to the calling song of the field cricket Gryllus integer (Orthoptera, Gryllidae) and deposit larvae that burrow into and consume the cricket host. Selection pressure from O. ochracea has probably been important in the evolution of male cricket songs and mating behaviour in G. integer and other cricket species. Tape-recorded G. integer calling song was broadcast to study the temporal rate of attraction of O. ochracea. Flies became phonotactic to cricket song approximately at sunset, and the highest level of attraction was observed in the following hours of the evening. Fly phonotaxis decreased in the hours immediately preceding sunrise and no flies were attracted during daylight hours. More male G. integer call at sunrise and in the preceding hours than earlier in the evening, perhaps in response to the lower probability of attracting O. ochracea.

Comparison of the Age Structure, Body Size, and Some Growth Parameters of Two Insular Populations of Lyciasalamandra fazilae from Southwestern Turkey

2020 ◽  
Vol 27 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Nazan Üzüm ◽  
Aziz Avcı ◽  
Çiçek Gümüş Özcan ◽  
Kurtuluş Olgun
Keyword(s):  
Body Size ◽  
Cross Sections ◽  
Age Structure ◽  
Life History Traits ◽  
Growth Parameters ◽  
Mediterranean Environment ◽  
Growth Coefficient ◽  
Significant Difference ◽  
Males And Females ◽  
Insular Populations

Some life-history traits (body size, age at maturity, longevity, and growth) of Lyciasalamandra fazilae from two insular populations (Tersane Island and Domuz Island) living in the Mediterranean environment of southwestern Turkey were investigated. We applied phalangeal skeletochronology to obtain the ages of juveniles and adults. Age was determined by counting the lines of arrested growth (LAGs) in cross-sections. No significant differences were found between the age distributions of the two sexes in the Tersane population but there was a significant difference in the Domuz population. The age structure of males and females varied significantly between populations, with highest mean ages observed in the Tersane Island. Males were on average larger than females in both populations. Both males and females from Tersane Island were found to be significantly larger than those of Domuz Island. The growth coefficient K and SVLmax were significantly different between the sexes in Tersane, but not in Domuz population. These parameters also showed significant interpopulational difference only for females indicating Domuz females grew faster than those of Tersane.

Life History Traits in a Population of Pelobates syriacus (Boettger, 1889) from Turkey

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  
Keyword(s):  
Life History ◽  
Age Structure ◽  
Life History Traits ◽  
Spadefoot Toad ◽  
Males And Females

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.

scholarly journals Male competition and the evolution of mating and life-history traits in experimental populations of Aedes aegypti

2019 ◽  
Vol 286 (1904) ◽  
pp. 20190591 ◽  
Author(s):  
Alima Qureshi ◽  
Andrew Aldersley ◽  
Brian Hollis ◽  
Alongkot Ponlawat ◽  
Lauren J. Cator
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Mating Success ◽  
Life History Traits ◽  
Male Competition ◽  
Male Mating ◽  
Male Mating Success ◽  
Reproductive Control ◽  
Evolutionary Response ◽  
Mating Conditions

Aedes aegypti is an important disease vector and a major target of reproductive control efforts. We manipulated the opportunity for sexual selection in populations of Ae . aegypti by controlling the number of males competing for a single female. Populations exposed to higher levels of male competition rapidly evolved higher male competitive mating success relative to populations evolved in the absence of competition, with an evolutionary response visible after only five generations. We also detected correlated evolution in other important mating and life-history traits, such as acoustic signalling, fecundity and body size. Our results indicate that there is ample segregating variation for determinants of male mating competitiveness in wild populations and that increased male mating success trades-off with other important life-history traits. The mating conditions imposed on laboratory-reared mosquitoes are likely a significant determinant of male mating success in populations destined for release.

scholarly journals Alternative phenotypes of male mating behaviour in the two-spotted spider mite

2013 ◽  
Vol 61 (1) ◽  
pp. 31-41 ◽  
Author(s):  
Yukie Sato ◽  
Maurice W. Sabelis ◽  
Martijn Egas ◽  
Farid Faraji
Keyword(s):  
Spider Mite ◽  
Mating Behaviour ◽  
Male Mating ◽  
Alternative Phenotypes ◽  
Two Spotted Spider Mite

scholarly journals Fertility decline and social change: new trends and challenges

2003 ◽  
Vol 30 (2) ◽  
pp. 297
Author(s):  
Bali Ram
Keyword(s):  
Social Change ◽  
Population Growth ◽  
Family Structure ◽  
Age Structure ◽  
Fertility Decline ◽  
Intergenerational Support ◽  
Population Stability ◽  
Future Prospects ◽  
Age Patterns

This article presents an overview of recent fertility declines and their effects on social change in both industrialized and industrializing countries. The focus is primarily on the levels and age patterns of fertility, which influence social change through three major mechanisms, reductions in population growth, modifications in age structure, and changes in family structure. Some future prospects are also discussed, especially in the view of the viability of immigration as a solution to population stability, graying of the industrialized world, intergenerational support, and loneliness.

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