Trapping Effects of Different Treatments on Bactrocera dorsalis and Bactrocera cucurbitae

Five different trapping treatments, spraying attractant on bottle surface and spraying attractant inside the bottles with 0, 50,100 and 200 mL water, were set to trap Bactrocera dorsalis and B. cucurbitae in guava （Psidium guajava） park. The results showed that when the usage of attractant was 1 g, both Haonian and Wende had trapping effect on B. dorsalis and B. cucurbitae. The trapping effect of Haonian on B. dorsalis was better than that of Wende, while their trapping effects on B. cucurbitae was just the opposite. The trapping effects of different treatments had great difference. The trapping effect of Haonian on two species of fruit flies enhanced with the increasing volume of water, and reached the ma^mum value as the water volume was 200 mL. With the increasing volume of water, the trap- ping effect of Wende on two species of fruit flies first increased, and then decreased, which reached the maximum value as the water volume was 50 mL. Different treatments with attractants spraying inside bottles had better trapping effects on two species of fruit flies than that spraying on bottle surface.

Evaluation of trap effi ciency for the Asian longhorned beetle,Anoplophora glabripennis

The Asian longhorned beetle(ALB),Anoplophora glabripennis,is a well-known stem borer with high polyphagous properties causing frequent outbreaks in northeast China.An attractant-based trap is needed to improve the sensitivity,reliability,and effi ciency for detection of the beetle.In this study,the eff ects of attractants,trap types and color synergy of a trapping system were evaluated.Attractant blends comprised of the male-produced,two-component pheromone plus plant volatiles were used in the fi eld in Hengshui city.Plant volatiles(e.g.,1-pentanol,and 2-pentanol)in combination with male pheromones increased the mean number of trapped ALB compared to the pheromone alone.Males responded better than females to traps baited with plant volatiles alone,whereas traps emitting plant volatiles plus pheromone,regardless of trap type,captured more females than males.The ALB-trapping effi ciency of a modifi ed fl ight intercept panel trap was more than ten times as high as a woodborer panel trap and 1.2 times a fl ight intercept panel trap.The 1-pentanol and 2-pentanol attractants alone or in combination with male-produced pheromone were more eff ective for monitoring ALB than common lures.In laboratory Y-tube olfactometer experiments,the color brown was better at increasing attraction of both males and females to 1-pentanol,2-pentanol,1-pentanol+pheromone,and 2-pentanol+pheromone compared to the clear-glass control arm.The fi ndings provide a reliable and eff ective trap system to monitor ALB infestations.

Design and Performance of an Improved Trapped Vortex Combustor

A trapped vortex combustor （TVC） has been a very promising novel concept for it offers improvements in lean blow out, altitude relight, operating range, as well as a potential to decrease NOx emissions compared to conventional combustors. The present paper discusses the improved designs of the new combustor over the prior ones of our research group, including that：a） the over-all dimensions, both axial and radial, are reduced to those of an actual aero-engine combustor; b） the air flow distribution is optimized, and especially 15% of the air is fed into the liner as cooling air; c） a straight-wall diffuser with divergence angle 9°is added. A series of experiments （cavity-fueled only, under atmospheric pressure） has been conducted to investigate the performance of the improved TVC. Experimental results show that at the inlet temperature of 523 K, the inlet pressure of 0.1 MPa, stable operation of the TVC test rig is observed for the Mach number 0.15-0.34, indicating good flame stability; the combustion efficiency obtained in this paper falls into the range of 60%-96%; as the total excess air ratio increases, the combustion efficiency decreases, while the increase of the inlet temperature is beneficial to high combustion efficiency; besides, the optimal Mach numbers for high combustion efficiency under different inlet conditions are confirmed. The outlet temperature profiles feature a bottom in the midheight of the exit. This paper demonstrates the feasibility for the TVC to be applied to a realistic aero-engine preliminarily and provides reference for TVC design.