Waking beauties: mating quiescence in arachnids females

CARGNELUTTI, FRANCO; BOLLATTI, FEDRA; MATIAS IZQUIERDO; ABREGU, DEBORA; OVIEDO DIEGO, MARIELA; VRECH, DAVID E.; OLIVERO, PAOLA; CALBACHO-ROSA, LUCÍA; SIMIAN, CATALINA; PALEN-PIETRI, ROCÍO; MATTONI, CAMILO; PERETTI, ALFREDO V.

Montevideo

Congreso; XXII International Congress of Arachnology; 2023

Although strongly criticized since the 90s, there is still a heavy bias in the field of sexual selection towards studying males. Arachnids are no exception, with most researchers ignoring female behaviors. A stunning example is that of female quiescence during or after copulation, defined with different terms but in ways that seem to nullify female autonomy. Although female quiescence has been reported mainly for spiders, it also occurs in other arachnid orders. In this review, we first systematically compile information on the occurrence of female quiescence in arachnids, a major arthropod clade that includes 13 orders and more than 100,000 species. Then, we (i) propose terminology to describe quiescence in a way that best represents the available information in the literature, (ii) review evidence regarding whether female quiescence is triggered by male behaviors, (iii) evaluate the generality of hypotheses for quiescence formulated for some specific taxa, and (iv) suggest possible contexts that may favor, in arachnids, the evolution of female quiescence. In our literature search, we found reports of female quiescence mainly in three orders: Araneae, Scorpiones, and Solifugae. We propose ‘mate choice’ and ‘communication during copulation’ as two main hypotheses to explain female quiescence. In both hypotheses, females play a highly active role, contrasting with other hypotheses that interpret female quiescence as male-induced. Since reports of quiescence are usually vague, we encourage researchers to document and describe female mating quiescence behavior in more detail, including by carefully naming each behavioral unit, and to avoid promoting indirect hypotheses that remain untested.