RESUMO
BACKGROUND: Sex pheromones of the potato tuber moths Phthorimaea operculella (Zeller) and Symmetrischema tangolias (Gyen) are ideal tools to monitor pest flight activity but are not used as means of control. The aim of the present study was to test the suitability of an attract-and-kill strategy consisting of pure pheromones and the contact insecticide cyfluthrin as the active ingredient, formulated with plant oils and ultraviolet absorbers, and applied in droplet sizes of 100 microL. RESULTS: Cyfluthrin at a concentration of 5 g L(-1) resulted in the highest and fastest killing of males after 48 h, with a 100% mortality after 3-4 days. In contrast, control males survived for 13 days. In olfactometer experiments, the pheromone concentration of 0.5 g L(-1) was significantly most attractive against eight virgin females. At controlled conditions (20 degrees C), no reduction in efficacy of the attract-and-kill formulation was observed for a minimum period of 36 days, whereas under natural environmental conditions the efficacy reduced gradually after day 6 of exposure. The longer the droplet was exposed, the longer was the time to reach 100% mortality of males. CONCLUSIONS: Compared with attract-and-kill studies for other pest species, the results are promising as a means of achieving highly effective control of potato tuber moths under field conditions.
Assuntos
Controle de Insetos/métodos , Inseticidas , Mariposas/efeitos dos fármacos , Tubérculos , Atrativos Sexuais/farmacologia , Solanum tuberosum , Animais , Bioensaio , Química Farmacêutica , Estabilidade de Medicamentos , Feminino , Inseticidas/administração & dosagem , Inseticidas/química , Laboratórios , Masculino , Nitrilas/química , Piretrinas/química , Atrativos Sexuais/administração & dosagem , Atrativos Sexuais/químicaRESUMO
Leptin acts via its receptor (LepRb) on specific CNS neurons to signal the adequacy of long-term energy stores, thereby permitting the expenditure of resources on energy-intensive processes such as reproduction. The ventral premammillary nucleus of the hypothalamus (PMv), which has been implicated in the stimulation of gonadotropin release by olfactory cues, contains numerous LepRb neurons, suggesting a potential role for LepRb PMv neurons in transmitting both metabolic and odorant signals to the neuroendocrine reproductive system. Indeed, Fos immunoreactivity and electrophysiologic recordings revealed the direct activation of LepRb PMv neurons by leptin, and exposure to odors from mice of the opposite sex promoted Fos immunoreactivity (Fos-IR) in many LepRb PMv neurons. To determine the regions innervated by the LepRb PMv neurons, we used two novel cre-activated tract-tracing systems in Lepr(cre) animals; data from these systems and from standard tracing techniques revealed that LepRb PMv neurons project to a subset of the regions, including the preoptic area, that are innervated by the PMv as a whole. Furthermore, the retrograde accumulation in LepRb PMv neurons of a trans-synaptic tracer from GnRH neurons revealed the direct innervation of GnRH neurons by many LepRb PMv neurons. Thus, LepRb PMv neurons sense metabolic and sexual odorant cues and project to the rostral hypothalamus to directly innervate GnRH neurons. These results are consistent with a role for LepRb PMv neurons in regulating the reproductive axis in response to metabolic and odorant stimuli.
Assuntos
Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/química , Neurônios/metabolismo , Receptores para Leptina/fisiologia , Receptores Odorantes/análise , Atrativos Sexuais/administração & dosagem , Animais , Feminino , Técnicas de Introdução de Genes , Hormônio Liberador de Gonadotropina/análise , Hipotálamo/efeitos dos fármacos , Hipotálamo/fisiologia , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Rede Nervosa/química , Rede Nervosa/efeitos dos fármacos , Rede Nervosa/metabolismo , Neurônios/química , Neurônios/efeitos dos fármacos , Receptores para Leptina/genética , Receptores Odorantes/fisiologia , Atrativos Sexuais/fisiologiaRESUMO
This study reports the hormonal pattern of pheromonal restoration of cyclic activity (PRCA) in irregularly cycling (IC) and in anovulatory persistent-estrus (PE) aging female middle-aged Wistar rats. Hypothalamic content of LHRH and plasma levels of LH, FSH, estradiol (E2), and progesterone (P) were measured by RIA methods, and prolactin (PRL) was examined by ELISA in 1) normal four-day cycling rats, 2) saline-treated IC and PE rats, and 3) IC and PE rats treated with sprays of male urine (50 microliters every 10 min for 1 h on only one day, at a distance of 1 cm from the nostrils). Group 1 showed low levels of LHRH and high levels of LH, FSH, E2, P, and PRL in the afternoon of proestrus (PR). In group 2, the pattern was not cyclical and the levels of the hormones were higher than basal for the cyclic rats, except for P, which was lower. Group 3 showed a depletion of the hypothalamic LHRH and an increase in plasma LH, FSH, E2, Pm, and PRL. FSH, E2, and P showed the strongest rise, leading to an elevated ratio of FSH to LH. Four-day estrous cycles reappeared in urine-treated rats on the succeeding days. The cyclic behavior of the PRCA hormones was, qualitatively, the same as in the normally cycling rats. According to the results, the origin of the PRCA effect is an olfactory input to the hypophysiotropic area of the hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)