Effect of Diet,Photoperiod and Host Density on Parasitism of Anisopteromalus calandrae on the Tobacco Beetle and Biological Parameters of the Parasitoid

Lasioderma serricorne is known to be pest of tobacco, besides of attacking other products in storage. Anisopteromalus calandrae is an ectoparasitoid of coleopteran larvae also parasitizing the tobacco beetle. This study was aimed to evaluate the parasitism of A. calandrae on different densities of L. serricorne larvae grown in different diets and photoperiods, and to record the longevity and reproductive potential of A. calandrae. Individuals of L. serricorne were raised in three diets: wheat flour (F);wheat flour and brewer’s yeast (FY) and wheat flour and dried tobacco (FT). Different amounts of host larvae (10, 20, 50 and 100) for each diet were exposed to a couple of parasitoids. The same larval densities from diet F were exposed for 24 h to a couple of adult parasitoids maintained in three photoperiods (0:24, 12:12 and 24:0 - scotophase: photophase). The highest values of apparent parasitism were in the density of 50 larvae in the FY diet (96.34%) and 100 F (92.91%). There was no significant difference in the parameters in each photoperiod in all larval densities. However, the treatment in which hosts and parasitoids always remained in scotophase, was the one that had a significantly higher sex ratio. Females had longer longevity than males surviving for up to 25 days. On the fourth day of larvae exposure occurred, the maximum number of offspring generated. It is inferred that A. calandrae has potential to be used as a control agent for coleopterans that attack stored products.

Male reproductive system and simulated high-altitude environment:preliminary results in rats

This study assessed the effects of a simulated high-altitude environment on the reproductive system of prepubertal male rats and the reversibility of these effects upon return to a normal environment.Three-week-old male Wistar rats were randomly allocated to 4 groups that were exposed to different conditions:a normal environment for 6 weeks and 12 weeks,respectively,hypobaric hypoxia for 6 weeks,and hypobaric hypoxia for 6 weeks followed by a normal environment for 6 weeks.Multiple pathophysiological parameters were evaluated at the histological,endocrine,and molecular levels.Hypobaric hypoxia exposure for 6 weeks during the prepubertal phase significantly altered physiological parameters,body functions,blood indices,and reproductive potential.Six weeks after returning to a normal environment,the damaged reproductive functions partially recovered due to compensatory mechanisms.However,several changes were not reversed after returning to a normal environment for 6 weeks,including disorders of body development and metabolism,increased red blood cells,increased fasting blood glucose,abnormal blood lipid metabolism,decreased testicular and epididymis weights,abnormal reproductive hormone levels,excessive apoptosis of reproductive cells,and decreased sperm concentration.In summary,a hypobaric hypoxic environment significantly impaired the reproductive function of prepubertal male rats,and a return to normal conditions during the postpubertal phase did not fully recover these impairments.