Effects of photoperiod on egg production and hatching success, naupliar and copepodite development, adult sex ratio and life expectancy of the tropical calanoid copepod Acartia sinjiensis

Aquaculture ◽  
2008 ◽  
Vol 280 (1-4) ◽  
pp. 220-226 ◽  
Author(s):  
Thomas Camus ◽  
Chaoshu Zeng
Keyword(s):  
Life Expectancy ◽  
Sex Ratio ◽  
Egg Production ◽  
Calanoid Copepod ◽  
Hatching Success ◽  
Adult Sex Ratio

Effects of Adult Sex Ratio and Stocking Rate on Viable Egg Production of Anopheles Albimanus (Diptera: Culicidae)1

1980 ◽  
Vol 17 (6) ◽  
pp. 563-566 ◽  
Author(s):  
Donald L. Bailey ◽  
Ronald E. Lowe ◽  
Joyce E. F. Fowler ◽  
Dana A. Focks
Keyword(s):  
Sex Ratio ◽  
Egg Production ◽  
Stocking Rate ◽  
Anopheles Albimanus ◽  
Adult Sex Ratio

The Life-History of Badumna-Candida (Araneae, Amaurobioidea)

1993 ◽  
Vol 41 (5) ◽  
pp. 441 ◽  
Author(s):  
MF Downes
Keyword(s):  
Sex Ratio ◽  
Egg Production ◽  
Production Cycle ◽  
Social Spider ◽  
Social Spiders ◽  
Primary Sex Ratio ◽  
The Social ◽  
The Status ◽  
History Of ◽  
Changes Over Time

A two-year study of the social spider Badumna candida at Townsville, Queensland, provided information on colony size and changes over time, maturation synchrony, temperature effects on development, sex ratio, dispersal, colony foundation, fecundity and oviposition. Key findings were that B. candida outbred, had an iteroparous egg-production cycle between March and October, had an even primary sex ratio and achieved maturation synchrony by retarding the development of males, which matured faster than females at constant temperature. There was no overlap of generations, the cohort of young from a nest founded by a solitary female in summer dispersing the following summer as subadults (females) or subadults and adults (males). These findings confirm the status of B. candida as a periodic-social spider (an annual outbreeder), in contrast to the few known permanent-social spider species whose generations overlap. Cannibalism, normally rare in social spiders, rose to 48% when spiders were reared at a high temperature. This may be evidence that volatile recognition pheromones suppress predatory instincts in social spiders.

Effects of phytoseiid predators on the sex ratio of the spider mite Panonychus ulmi

1991 ◽  
Vol 69 (1) ◽  
pp. 208-212 ◽  
Author(s):  
Dan L. Johnson ◽  
Heather C. Proctor
Keyword(s):  
Population Density ◽  
Sex Ratio ◽  
Spider Mite ◽  
Total Population ◽  
Panonychus Ulmi ◽  
Encounter Rate ◽  
Male Mortality ◽  
Adult Sex Ratio ◽  
Biased Sex Ratio ◽  
Male Activity

The effect of predator presence on the adult sex ratio of a spider mite (Panonychus ulmi) was examined in a field experiment. Phytoseiid predators (chiefly Typhlodromus occidentalis) were removed from 32 trees harboring P. ulmi populations, and allowed to remain at natural levels on 32 other trees. Both total population density and proportion of males in the prey population were significantly higher in predator-free trees. Mechanisms that could explain the increase in the proportion of males are examined. The most probable is that greater male activity results in a higher encounter rate between predator and prey, and that subsequent higher male mortality when predators are present exaggerates the female-biased sex ratio. The theoretical effects of sex-biased predation on diplo-diploid and haplo-diploid organisms are discussed.

Effects of adult stocking density on egg production and viability in cultures of the calanoid copepod Acartia tonsa (Dana)

2007 ◽  
Vol 38 (7) ◽  
pp. 764-772 ◽  
Author(s):  
Per M Jepsen ◽  
Nikolaj Andersen ◽  
Thue Holm ◽  
Anders T Jørgensen ◽  
Jonas K Højgaard ◽  
...  
Keyword(s):  
Egg Production ◽  
Calanoid Copepod ◽  
Stocking Density ◽  
Acartia Tonsa
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