Sensory Cues Involved in Social Facilitation of Reproduction in Blattella germanica Females
نویسندگان
چکیده
Cockroaches, like many other animal species, form aggregations in which social stimuli from conspecifics can alter the physiology, morphology, or behavior of individuals. In adult females of the German cockroach, Blattella germanica, social isolation slows oocyte development, sexual maturation, and sexual receptivity, whereas social interactions as minimal as between just two females accelerate reproduction; however, the sensory modalities and pathways that mediate these physiological and behavioral changes are poorly understood. We explored the roles of visual, olfactory, and tactile cues in the reproductive physiology of German cockroach females, and whether their effects are species-specific and related to circadian time. Our results show that tactile cues are the primary sensory input associated with social conditions--with no evidence for involvement of the visual and olfactory systems--and that the antennae play an important role in the reception of these tactile cues. This conclusion is supported by the observation that interactions with other insect species of similar or larger size and with similar antennal morphology also stimulate oocyte development in B. germanica. Social facilitation of reproduction is expected to be influenced by the circadian timing system, as females engage in more social contact during the day when they shelter in aggregations with conspecifics. Surprisingly, however, the female's reproductive rate was unresponsive to social interactions during the photophase, whereas social interactions as short as two hours during the scotophase were sufficient to induce faster reproduction.We discuss the adaptive significance of these sensory-neuroendocrine responses in the German cockroach.
منابع مشابه
Social facilitation of insect reproduction with motor-driven tactile stimuli.
Tactile stimuli provide animals with important information about the environment, including physical features such as obstacles, and biologically relevant cues related to food, mates, hosts and predators. The antennae, the principal sensory organs of insects, house an array of sensory receptors for olfaction, gustation, audition, nociception, balance, stability, graviception, static electric fi...
متن کاملDifferential physiological responses of the German cockroach to social interactions during the ovarian cycle.
In many animal species, social interactions can influence the morphology, physiology and behavior of individuals, including their rate of development and reproduction. Reproduction in cockroaches is regulated by juvenile hormone III (JH), and social interactions have been shown to accelerate female reproduction in the German cockroach, Blattella germanica (L.), by stimulating JH production. How...
متن کاملReproductive Biology of the German Cockroach, Blattella germanica: Juvenile Hormone as a Pleiotropic Master Regulator
Juvenile hormone (JH) exerts major pleiotropic effects on cockroach development and reproduction. The production of JH by the corpora allata (CA) in the adult female German cockroach, Blattella germanica, is dependent upon and modulated by both internal and environmental stimuli. Mating, intake of highquality food, social interactions, and the presence of vitellogenic ovaries facilitate JH synt...
متن کاملRole of feeding in the reproductive 'group effect' in females of the German cockroach Blattella germanica (L.).
We have found that whether a female German cockroach, Blattella germanica (L.), is kept alone or in the presence of another female has a major impact on how fast it reproduces and how much it eats. By the sixth day of adulthood, females paired since adult eclosion had substantially larger oöcytes than did females isolated during the same time, and females paired with intact females, or with one...
متن کاملEffects of protein type and concentration on development and reproduction of the German cockroach, <Emphasis Type="Italic">Blattella germanica</Emphasis>
Nymphal development and adult female reproduction were examined in the German cockroach, Blattella germanica, using a defined artificial diet in which the type of protein was varied. Milk proteins, including casein, supported development poorly compared to meat and plant proteins. Soybean protein supported development better than all other highly purified proteins including vitamin-free casein ...
متن کامل