Leonor Rodrigues

Incomplete species recognition entails few costs in spider mites, despite first-male precedence

The consequences of heterospecific matings may hinge on interspecies interactions, but also on characteristics of the intraspecies mating system, namely sperm precedence. Indeed, first-male precedence may entail costs of heterospecific matings that are usually overlooked in other systems, such as fertilization of oocytes that become unavailable to subsequent conspecific males or a decrease in female receptivity. Here, we used a system composed of two co-occurring haplodiploid spider-mite species with first-male precedence, Tetranychus urticae and Tetranychus evansi, to investigate (a) the potential costs of heterospecific matings and (b) whether mites avoid heterospecific mates. We found that heterospecific matings did not result in fertilized offspring (i.e. females). Moreover, fecundity (i.e. male offspring) of heterospecifically mated females did not differ from that of virgins, indicating that oocyte viability was not affected by heterospecific males. Furthermore, heterospecific matings did not trigger behavioural changes that typically derive from conspecific matings, namely reduced female receptivity for subsequent matings. In avoidance tests, we found that T. evansi females and T. urticae males mated as often with conspecifics as with heterospecifics, whereas T. evansi males and T. urticae females mated assortatively more often. Also, latency to copulation in virgin and mated females did not differ between conspecific and heterospecific matings, but matings between T. urticae individuals lasted longer than heterospecific matings. Therefore, heterospecific matings result in few costs despite first-male precedence and, concomitantly, species discrimination is low. Still, this study highlights the need to account for intraspecific mating systems in tests of the reproductive consequences of mating with heterospecifics.Significance statementIn species where the first male fertilizes all the offspring (first-male precedence), mating with individuals from other species often yields few benefits and entails potential costs in terms of future mating events. Yet, several species exhibit incomplete recognition of conspecifics. We here show that this is the case among two spider-mite species that co-occur under natural conditions. However, we also demonstrate that the cost of mating with the ‘wrong’ species is low, even though they exhibit first-male precedence.

Integrating Competition for Food, Hosts, or Mates via Experimental Evolution

Competitive interactions shape the evolution of organisms. However, often it is not clear whether competition is the driving force behind the patterns observed. The recent use of experimental evolution in competitive environments can help establish such causality. Unfortunately, this literature is scattered, as competition for food, mates, and hosts are subject areas that belong to different research fields. Here, we group these bodies of literature, extract common processes and patterns concerning the role of competition in shaping evolutionary trajectories, and suggest perspectives stemming from an integrative view of competition across these research fields. This review reinstates the power of experimental evolution in addressing the evolutionary consequences of competition, but highlights potential pitfalls in the design of such experiments.

The decision of out-of-home placement in residential care after parental neglect: empirically testing a psychosocial model

Out-of-home placement decisions in residential care are complex, ambiguous and full of uncertainty, especially in cases of parental neglect. Literature on this topic is so far unable to understand and demonstrate the source of errors involved in those decisions and still fails to focus on professionals decision making process. Therefore, this work intends to test a socio-psychological model of decision-making that is a more integrated, dualistic and ecological version of the Theory of Planned Behaviors model. It describes the process through which the decision maker takes into account personal, contextual and social factors of the Decision-Making Ecology in the definition of his/her decision threshold. One hundred and ninety-five professionals from different Children and Youth Protection Units, throughout the Portuguese territory, participated in this online study. After reading a vignette of a (psychological and physical) neglect case toward a one-year-old child, participants were presented with a group of questions that measured workers assessment of risk, intention, attitude, subjective norm, behavior control and beliefs toward residential care placement decision, as well as workers behavior experience, emotions and family/child-related-values involved in that decision. A set of structural equation modeling analyses have proven the good fit of the proposed model. The intention to propose a residential care placement decision was determined by cognitive, social, affective, value-laden and experience variables and the perceived risk. Altogether our model explained 61% of professionals decision toward a parental neglect case. The theoretical and practical implications of these results are discussed, namely the importance of raising awareness about the existence of these biased psychosocial determinants.

Despite reproductive interference, the net outcome of reproductive interactions among spider mite species is not necessarily costly

Some closely-related species have reproductive interactions between them. Here, we show that the outcome of such interactions is highly variable. We did crosses among 3 species of herbivorous spider mites that co-occur in the Mediterranean and found that, depending on the order and timings of matings, they could be negative, neutral or positive. Therefore, the study of such interactions needs to account for the details of mating events, as the devil may be in them!

Costs and benefits of mating with fertilized females in a species with first male sperm precedence

Different patterns of sperm precedence are expected to result in specific mating costs and benefits for each sex, generating different selection pressures on males and females. However, most studies concern species with mixed paternity or last male sperm precedence, neglecting species with first male sperm precedence, in which only the first mating is effective. Here, we measured costs and benefits of multiple mating for both sexes of the spider mite Tetranychus urticae. First, we assessed the stability of the sperm precedence pattern, by mating females to one, two or several males, immediately after the first mating or 24 hours later. We found complete first male precedence, independently of the mating interval and the number of matings. Females paid a cost of polyandry, as multiply-mated females laid fewer eggs than once-mated females. However, while first males had reduced survival when exposed to an intermediate number of virgin females, second males paid no additional costs by matings with several mated females. Moreover, by mating multiply with mated females, males decreased the total number of offspring sired by first males, which suggests that these matings may entail a relative benefit for second males, despite being ineffective. Our results show that complex costs and benefits may arise in males in species with first male precedence. How these costs and benefits affect the maintenance of selection for polyandry remains an open question.

Environments with a high probability of incompatible crosses do not select for mate avoidance in spider mites

Arthropods are often infected with Wolbachia inducing cytoplasmic incompatibility (CI), whereby crosses between uninfected females and infected males yield unviable fertilized offspring. Although uninfected females benefit from avoiding mating with Wolbachia-infected males, this behaviour is not present in all host species. Here we measured the prevalence of this behaviour across populations of the spider mite Tetranychus urticae. Females from five populations originally fully infected with Wolbachia showed no preference, possibly because they did not face the choice between compatible and incompatible mates in their environment. Hence, to determine whether this behaviour could be selected in populations with intermediate Wolbachia infection frequency, we performed 15 generations of experimental evolution of spider-mite populations under i) full Wolbachia infection, ii) no infection, or iii) mixed infection. In the latter selection regime, where uninfected females were exposed to infected and uninfected males at every generation, mating duration increased relative to the uninfected regime, suggesting the presence of genetic variation for mating traits. However, mate choice did not evolve. Together, these results show that CI-inducing Wolbachia alone does not necessarily lead to the evolution of pre-copulatory strategies in uninfected hosts, even at intermediate infection frequency.

Parent–Child Interactions as a Source of Parent Cognition in the Context of Child Maltreatment

This chapter describes how violence lies in the maltreatment of children, focusing on one key factor of this phenomenon: Caregivers’ cognition in parent–child interactions. After reviewing literature on different sources of variability in these cognitions as well as on the importance of caregiver cognition for the explanation of maltreatment, the chapter presents original research with a sample of abusive mothers. This study tests how much previous experiences with the child in focus and other children, as well as current perceptions of the child may influence abusive mothers’ values, beliefs, and situational attributions. With some exceptions results seem to indicate that previous experience is much less important than current perceptions of the child, and if there is any impact of previous experience it is there rather because it shapes current perception as well. In their own way, these results underline the value that a social-psychological approach has for the understanding of child maltreatment.