Effect of Host Size on Adult Size and Sex Ratio of Bracon mellitor (Hymenoptera: Braconidae)

1993 ◽  
Vol 22 (5) ◽  
pp. 1161-1165 ◽  
Author(s):  
P. Glynn Tillman ◽  
James R. Cate
Keyword(s):  
Sex Ratio ◽  
Host Size ◽  
Adult Size ◽  
Bracon Mellitor

Demography and Group Structure in Wedgecapped Capuchin Monkeys, Cebus Olivaceus

Behaviour ◽  
1988 ◽  
Vol 104 (3-4) ◽  
pp. 202-232 ◽  
Author(s):  
John G. Robinson
Keyword(s):  
Sex Ratio ◽  
Life Table ◽  
Group Structure ◽  
Age Distribution ◽  
Capuchin Monkeys ◽  
Demographic Parameters ◽  
Adult Size ◽  
Sex Composition ◽  
Cebus Olivaceus ◽  
Age And Sex

AbstractThe extent to which population demography determines the age and sex composition of primate groups was examined using data from a population of wedge-capped capuchin monkeys Cebus olivaceus in central Venezuela. Demographic parameters were derived from censuses of individually recognized, aged, and sexed individuals living in nine groups over a ten year period. Animals were aged by extrapolation from census data. Animals of both sexes were classed as infants during their first year, and juveniles until they reached six years of age. Females reach sexual maturity at this time, while males were classed as subadults until they reached full adult size at age 12. Adulthood lasts at least 30 years in females, at least 24 years in males. Age-sex class specific mortality and fecundity rates generated a life table which indicated that the population was increasing (r = 0.087) between 1977 and 1986. The age and sex composition of the nine groups was described annually. On average, non-adults made up 60% of a group, with this percentage increasing with group size. There were more females than males in all groups in all years. The strong female-biased adult sex ratio (1:4.4) was a consequence of a biased birth sex ratio (1:1.9), higher female than male survivorship especially between the ages of 3 and 7 when males were dispersing, and a pronounced sexual bimaturism. The stable age distribution derived from the life table successfully predicted the observed average distribution of age-sex categories in groups. This suggests that the group structure of Cebus olivaceus groups is not a consequence of intragroup social interactions, but results from demographic parameters.

scholarly journals SEX-RATIO MANIPULATION BY THE PARASITOID WASPMUSCIDIFURAX RAPTORIN RESPONSE TO HOST SIZE

Evolution ◽  
1993 ◽  
Vol 47 (6) ◽  
pp. 1876-1882 ◽  
Author(s):  
Sandra E. Seidl ◽  
Bethia King
Keyword(s):  
Sex Ratio ◽  
Host Size

scholarly journals Sex allocation in haplodiploids is mediated by egg size: evidence in the spider mite Tetranychus urticae Koch

2010 ◽  
Vol 278 (1708) ◽  
pp. 1054-1063 ◽  
Author(s):  
Emilie Macke ◽  
Sara Magalhães ◽  
Hong Do-Thi Khan ◽  
Anthony Luciano ◽  
Adrien Frantz ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Tetranychus Urticae ◽  
Egg Size ◽  
Spider Mite ◽  
Sex Ratios ◽  
Size Difference ◽  
Adult Size ◽  
External Fertilization ◽  
Offspring Sex Ratio ◽  
Egg Provisioning

Haplodiploid species display extraordinary sex ratios. However, a differential investment in male and female offspring might also be achieved by a differential provisioning of eggs, as observed in birds and lizards. We investigated this hypothesis in the haplodiploid spider mite Tetranychus urticae , which displays highly female-biased sex ratios. We show that egg size significantly determines not only larval size, juvenile survival and adult size, but also fertilization probability, as in marine invertebrates with external fertilization, so that female (fertilized) eggs are significantly larger than male (unfertilized) eggs. Moreover, females with on average larger eggs before fertilization produce a more female-biased sex ratio afterwards. Egg size thus mediates sex-specific egg provisioning, sex and offspring sex ratio. Finally, sex-specific egg provisioning has another major consequence: male eggs produced by mated mothers are smaller than male eggs produced by virgins, and this size difference persists in adults. Virgin females might thus have a (male) fitness advantage over mated females.

The effect of host size on the sex ratio of Syngaster lepidus, a parasitoid of Eucalyptus longhorned borers (Phoracantha spp.)

2002 ◽  
Vol 24 (3) ◽  
pp. 207-213 ◽  
Author(s):  
Andrea L Joyce ◽  
Jocelyn G Millar ◽  
Timothy D Paine ◽  
Lawrence M Hanks
Keyword(s):  
Sex Ratio ◽  
Host Size

Host size, superparasitism and sex ratio in mass-reared Diachasmimorpha longicaudata, a fruit fly parasitoid

BioControl ◽  
2010 ◽  
Vol 56 (1) ◽  
pp. 11-17 ◽  
Author(s):  
Pablo Montoya ◽  
Jorge Cancino ◽  
Gabriela Pérez-Lachaud ◽  
Pablo Liedo
Keyword(s):  
Sex Ratio ◽  
Fruit Fly ◽  
Host Size ◽  
Diachasmimorpha Longicaudata
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