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Continuous rearing of the brown planthopper, Nilaparvata lugens (Stål), was achieved on a chemically defined diet D-97 developed in this laboratory. The performance of N. lugens reared on D-97 was much better than that on a previously reported artificial diet MMD-1, although it was inferior to the susceptible rice variety TN1. N. lugens can not finish a complete generation on MMD-1 due to poor fecundity and unhatchability of eggs, but it has been successfully reared for more than 6 generations on D-97. In comparison with TN1-reared N. lugens, D-97-reared insects had a longer nymphal period (more than 3 days longer for males and 5 days longer for females), lighter weight (over 25% lighter for males and 35% lighter for females) and lower fecundity (over 50% less). Of the six generations on D-97, the first two generations had a significantly higher rate of emergence and hatchability. The possible factors influencing rearing efficiency and the potential applications of this diet are also discussed.

BackgroundSurgical masks (SMs) are used to reduce bacterial shedding from the mouth, nose and face. This study aimed to investigate whether SMs may be a potential source of bacterial shedding leading to an increased risk of surgical site infection.MethodsBacterial contamination of the SMs was tested by making an impression of the external surface of the mask on sterile culture media immediately. We investigated the difference in bacterial counts between the SMs worn by surgeons and those placed unused in the operating room (OR), and the bacterial count variation with indicated wearing time. Moreover, the difference in bacterial counts on the external surface between the first and second layers of double-layered SMs was also assessed.ResultsThe bacterial count on the surface of SMs increased with extended operating times; significant difference was found between the 4- to 6-hour and 0-hour groups (p < 0.05). When we analysed the bacterial counts from the same surgeon, a significant increase was noted in the 2-hours group. Moreover, the bacterial counts were significantly higher among the surgeons than the OR. Additionally, the bacterial count of the external surface of the second mask was significantly higher than that of the first one.ConclusionsThe source of bacterial contamination in SMs was the body surface of the surgeons rather than the OR environment. Moreover, we recommend that surgeons should change the mask after each operation, especially those beyond 2 hours. Double-layered SMs or those with excellent filtration function may also be a better alternative.The translational potential of this articleThis study provides strong evidence for the identification that SMs as source of bacterial contamination during operative procedures, which should be a cause for alarm and attention in the prevention of surgical site infection in clinical practice.