RESUMEN
In the wild, larvae of several species of Drosophila develop in heterogeneous and rapidly changing environments sharing resources as food and space. In this scenario, sensory systems contribute to detect, localize and recognize congeners and heterospecifics, and provide information about the availability of food and chemical features of environments where animals live. We investigated the behavior of D. simulans and D. buzzatii larvae to chemicals emitted by conspecific and heterospecific larvae. Our goal was to understand the role of these substances in the selection of pupation sites in the two species that cohabit within decaying prickly pear fruits (Opuntia ficus-indica). In these breeding sites, larvae of D. simulans and D. buzzatii detect larvae of the other species changing their pupation site preferences. Larvae of the two species pupated in the part of the fruit containing no or few heterospecifics, and spent a longer time in/on spots marked by conspecifics rather than heterospecifics. In contrast, larvae of the two species reared in isolation from conspecifics pupated randomly over the substrate and spent a similar amount of time on spots marked by conspecifics and by heterospecifics. Our results indicate that early chemically-based experience with conspecific larvae is critical for the selection of the pupation sites in D. simulans and D. buzzatii, and that pupation site preferences of Drosophila larvae depend on species-specific chemical cues. These preferences can be modulate by the presence of larvae of the same or another species.
Asunto(s)
Drosophila/embriología , Drosophila/fisiología , Larva/fisiología , Pupa/fisiología , Animales , Conducta Animal , Drosophila/efectos de los fármacos , Ambiente , Frutas , Larva/efectos de los fármacos , Modelos Biológicos , Odorantes , Percepción , Pupa/efectos de los fármacos , Especificidad de la EspecieRESUMEN
Durante los últimos años en Chile se ha detectado una masificación en el uso de anticonceptivos orales. Sin embargo, en Chile y al igual que en casi todos los países latinoamericanos prácticamente no se han investigado sus implicancias sobre la conducta humana. Específicamente, este estudio evaluó el impacto del uso de estos anticonceptivos sobre la conducta de emparejamiento en un grupo de 164 mujeres jóvenes universitarias, con una media de edad igual a 19 años y provenientes de cuatro universidades chilenas. Para ello se utilizó la adaptación chilena del Cuestionario de Componentes del Valor de Pareja que está compuesto por 22 ítems que se responden en una escala Likert de siete valores. Los resultados señalan diferencias entre las mujeres que consumen píldoras anticonceptivas (PA) y las que no lo hacen. Las consumidoras presentan los mayores valores del índice general del cuestionario sobre los componentes del valor de pareja y las subescalas de historia de relaciones de pareja, apreciación desde el sexo opuesto y apariencia. Estos resultados indican que las mujeres consumidoras de la PA se autoperciben y creen que el sexo contrario las evalúa como atractivas y muestran una vida sexual más diversificada, no mostrando diferencias en los otros aspectos relevantes para el valor de pareja no vinculados centralmente al atractivo físico. En definitiva, los resultados parecen indicar que el consumo de anticonceptivos hormonales no modifica la conducta social y parental de las mujeres, aunque su uso parece estar asociado con una mayor autopercepción de atractivo y mayor diversidad sexual.
Oral contraceptives, also known as birth control pills (PAs from now on), have been available on the world market for five decades. At present, the use of PA is massifier worldwide, being consumed by more than 100 million women on the planet. In recent years, in Latin America has been detected a dramatic increase in the use of oral contraceptives, and Chile is not the exception. In this sense, it is probable that the increase in the consumption of PAs in Chile is linked to the increase of women who decide to pursue higher studies and to develop professional careers. Concurrently, a wide field of research has been focused on the physiological and psychological effect of the consumption of oral contraceptives on human behavior, being mating behavior one of the main topics of research. However, in Chile as in most Latin American countries there is a lack of studies on the implications of the consumption of oral contraceptives on human behavior. In the present study, we investigated in a group of 164 university young women (Mean ± Standard Deviation: 19.27± 2.88 years) of Chile the impact of the use of oral contraceptives on mating behavior. Accordingly, we have applied a validated psychometric test to assessed mate value, one of the more relevant components of mating behavior i.e., the Mate Value Questionnaire. Mate value can be defined as a construct that incorporates a number of physical, psychological, and social dimensions that are related to an individual's ability to find, attract, and successfully retain a partner. This questionnaire is composed by 22 items and 7 subscales that are answered in a Likert Scale of 7 values. The Mate Value Questionnaire showed a high reliability (α = .85). According with previous studies that showed a decrease in sexual satisfaction and desire on women that consume oral contraceptives, we predicted a decrease of mating behavior and, then, a decrease on Mate Value for those women that use oral contraceptives. This effect was expected for all subscales of this questionnaire with the exception of relationship history subscale since women that consume oral contraceptives reported to have more diverse sexual partners on previous studies. The results show differences between women who use oral contraceptives (n = 87 women: 19.60 ± 2.89 years) in comparison to those who do not (n = women: 18.90 ± 2.84 years). However, the differences were, in general, opposed to our expectations being the consumers of oral contraceptives who presented the highest values of the general index of the Mate Value Questionnaire, and, concretely, for the subscales of relationship history, views of the opposite sex, and looks. In addition, we have failed into found any differences between groups in subscales that were not associated to physical appearance, such as wealth, sociality and fear of failure. The results suggest that the use of hormonal contraceptives does not modify the social and parental behavior of the women, although their use seems to be associated with a greater self-perception of attractiveness and greater diversity in sexual life. This study provides new information that will increase the understanding and discussion about the hypothetical effect that would or would not, the consumption of the PA on the pairing behavior. It is important to point out that the field of research on changes in the sexual preferences of women, derived from hormonal states, is in an important discussion process. Therefore, we believe that it is critical to carry out research in the future in order to elucidate the real robustness of this phenomenon, improving our understanding about the behavioral effects of consuming oral contraceptives.