The effect of male size and operational sex ratio on male mating success in the common spider mite, Tetranychus urticae Koch (Acari: Tetranychidae)

Foraging and agonistic activity co-occur in free-ranging blue crabs (Callinectes sapidus): observation of animals by ultrasonic telemetry

“…Blue crabs spent an overall mean of roughly 2% of their time in agonistic activity, in line with that reported for other arthropods contesting resources (e.g., fiddler crabs and spider mites competing for mates, and fiddler crabs competing for burrows) (Christy, 1988;Enders, 1993). That blue crabs spent up to nearly 40% of some hourly observation intervals in meral spread posturing, among the highest occurrence of threat display reported for arthropods, underlines the bellicose nature of the species.…”

Sex-ratio adjustment in response to local mate competition is achieved through an alteration of egg size in a haplodiploid spider mite

“…In spider mites, competition between males can be very intense, particularly when males are numerous, because females, for whom only the first mating is effective, are available for reproduction for a very short period [39,44]. To enhance their chance of being the first to mate, males guard quiescent females prior to their final moult, and have to resist attempted interference from other males [39,44]; larger males are more likely to win the competition than smaller ones [44,45]. Hence, a large egg size would be advantageous under both LMC and Panmixia conditions, in terms of overall fitness.…”

Do sexually dimorphic glands in the harvestman Gryne perlata (Arachnida: Opiliones) release contact pheromones during mating?

“…In pholcid spiders, females respond to male pressure on her genitalia by stridulating, after which the males relax the pressure . In those cases when female harvestmen resumed mating and the males responded, they increased the time spent mating, which may lead to more sperm being transferred to the females (Enders, 1993;Cuatianquiz & Cordero, 2006;Machado & Macías-Ordóñez, 2007;Pérez-Staples et al, 2010).…”