[Cross-resistance and the underlying mechanisms of clothianidin resistant population of Frankliniella occidentalis to insecticides]. / 西花蓟马抗噻虫胺种群对杀虫剂的交互抗性及机制.

Clothianidin, belonging to neonicotinoid insecticide with systemic and contact mechanisms, is used to control the invasive pest Frankliniella occidentalis. To identify the resistance risk, we examined the cross-resistance to multiple insecticides and mechanisms of clothianidin resistant population of F. occidentalis. The results showed that F. occidentalis developed a high level of resis-tance to clothianidin (56.8-fold) after selecting for 45 generations. The resistant population of F. occidentalis had medium level of cross-resistance to thiamethoxam, imidacloprid, chlorpyrifos, cyhalothrin and emamectin benzoate (18.6>RR50>11.3), and the low level of cross-resistance to phoxim and methomyl, but no cross-resistance to chlorfenapyr and spinosad. The synergists piperonyl butoxide (PBO) and triphenyl phosphate (TPP) had significant synergistic effects on clothianidin in killing the resistant population (CL), Yunnan wild population (YN) and susceptible population (S). Compared with the sensitive population, the CL populations had significantly increased activities of mixed-functional oxidases P450(3.6-fold), b5(2.9-fold) and O-demethylase (4.9-fold), and carboxylesterase (2.5-fold), with no significant difference in the activities of glutathione S-transferases among CL and S populations. The results highlight the role of increasing mixed-functional oxidases and carboxylesterase in the resistance of F. occidentalis to clothianidin.

[Resistance risk and resistance stability of Frankliniella occidentalis to nitenpyram, clothianidin and thiamethoxam]. / 西花蓟马对烯啶虫胺、噻虫胺和噻虫嗪的抗性风险和抗性稳定性.

To effectively control the damage of Frankliniella occidentalis (Pergande), we evalutated the resistance risk and resistance stability of F. occidentalis to nitenpyram, clothianidin and thiamethoxam. With the method of dipping Phaseolus vuglaris, we selected the resistance populations from the susceptible population with nitenpyram, clothianidin and thiamethoxam, respectively. Both the resistance inheritance and resistance risk were analyzed with the resistance reality hereditary. After 30 generations' selections, the selected-populations showed high level of insecticide resistance to nitenpyram, clothianidin and thiamethoxam, with a resistance ratio of 44.7-fold, 45.5-fold, and 32.7-fold, respectively. The development rate of resistance to clothianidin, nitenpyram, and thiamethoxam reduced in turn, with a resistance reality heritability of 0.1503, 0.1336 and 0.1258, respectively. Stopping selection for 10 continuously generations, the resistance levels of selection resis-tance populations declined slowly, but could not regain the original susceptibility to nitenpyram, clothianidin and thiamethoxam. After resistance selection, the sensitivity of F. occidentalis nymphs to clothianidin, nitenpyram, and thiamethoxam was significantly higher than that of adults. F. occidentalis had the great potential to gain high level resistance to nitenpyram, clothianidin and thiamethoxam. Compared with other two insecticides, the resistance of F. occidentalis to thiamethoxam increased slower and decreased faster. Therefore, using thiamethoxam in nymph stage might be beneficial to effectively control F. occidentalis.

Temperature-Dependent Demographic Characteristics and Control Potential of Aphelinus asychis Reared from Sitobion avenae as a Biological Control Agent for Myzus persicae on Chili Peppers.

Aphelinus asychis, a polyphagous parasitoid, has been widely used as an efficient biological control agent against the aphid Myzus persicae. Aiming to evaluate the influence of temperature on the biological characteristics and control potential of A. asychis for M. persicae, we compared the life table parameters and control potential of A. asychis, which included the developmental time, longevity, fecundity, intrinsic rate of increase (r), and finite killing rate (θ). The results showed that increasing the temperature significantly decreased the developmental time and longevity of A. asychis. The r at 24 (0.2360 d-1) and 28 °C (0.2441 d-1) were significantly greater than those at 20 (0.1848 d-1) and 32 °C (0.1676 d-1). The θ at 24 (0.4495), 28 (0.5414), and 32 °C (0.4312) were also significantly greater than that at 20 °C (0.3140). The relationship between population fitness (r and θ) and temperature followed a unary quadratic function (R2 > 0.95). The temperatures for the expected maximum intrinsic rate of increase (rmax) and the maximum finite killing rate (θmax) were 25.7 and 27.4 °C, respectively. In conclusion, A. asychis could develop and produce progenies within the temperature range of 20-32 °C, and its control efficiency for M. persicae at 24, 28, and 32 °C was greater than that at 20 °C. The most suitable temperature range for controlling M. persicae with A. asychis in the field might be between 25.7 and 27.4 °C.

Effect of different irradiation dose treatment on the lipid oxidation, instrumental color and volatiles of fresh pork and their changes during storage.

This study mainly investigated the effect of different doses irradiation (0, 3, 5 or 7kGy) on the quality changes of pork during 4°C storage by determining the irradiation off-odor intensity, thiobarbituric acid reactive substances (TBARs), fatty acid composition, volatiles and color of the samples during whole storage. The results showed that ≥7kGy irradiation could make the samples produce obvious irradiation off-odor. However, after 7days storage irradiation off-odor was reduced. Lipid oxidation was also promoted by irradiation. Benzyl methyl sulfide was produced newly and significantly increased (P<0.05) by irradiation. Fatty acids in pork samples decreased significantly with irradiation dose increase within the range of <7kGy, but significantly increased (P<0.05) in samples of 7kGy. Irradiation significantly increased the a* values regardless of storage time but had little effects on b* and L* values, and the increase of a* values was dose-dependent.

[Temporal and spatial variations of soil NO(3-)-N in Orychophragmus violaceus/spring maize rotation system in North China].

The February orchid (Orychophragmus violaceus)-spring maize rotation system is established to resolve the problems caused by the expansion of fallow fields in North China. Based on a site-specific experiment, temporal and spatial variations of soil NO(3-)-N were investigated during the period from February orchid incorporation to maize harvest. The results showed that the nitrate content in soil profiles not only showed a temporal characteristic, i. e., increasing at the beginning of the maize season and decreasing then after, but also showed a spatial characteristic, i. e., the gradual occurrence of the peak of nitrate content from shallower to deeper layer with the growth season of maize. Meanwhile, incorporation of February orchid could affect temporal and spatial variations of soil NO(3-)-N. February orchid planting reduced the soil NO(3-)-N accumulation in the profile of 0180 cm. After incorporation of February orchid, similar characteristics were observed at the seedling and bell stages of maize, i. e., the soil NO(3-)-N mainly stayed in the profile of 0-20 cm, and NO(3-)-N concentrations in the treatments with February orchid were higher in 0-100 cm layer and lower in 100-180 cm layer than those of the treatments without February orchid. After tasseling stage, opposite phenomena were found, and the soil NO(3-)-N content was all relative low. Overall, incorporation of February orchid could increase the storage capacity of soil NO(3-)-N in the profile of 0-180 cm.

Specific leaf area relates to the differences in leaf construction cost, photosynthesis, nitrogen allocation, and use efficiencies between invasive and noninvasive alien congeners.

Comparisons between invasive and native species may not characterize the traits of invasive species, as native species might be invasive elsewhere if they were introduced. In this study, invasive Oxalis corymbosa and Peperomia pellucida were compared with their respective noninvasive alien congeners. We hypothesized that the invasive species have higher specific leaf (SLA) than their respective noninvasive alien congeners, and analyzed the physiological and ecological consequences of the higher SLA. Higher SLA was indeed the most important trait for the two invaders, which was associated with their lower leaf construction cost, higher nitrogen (N) allocation to photosynthesis and photosynthetic N use efficiency (PNUE). The higher N allocation to photosynthesis of the invaders in turn increased their PNUE, N content in photosynthesis, biochemical capacity for photosynthesis, and therefore light-saturated photosynthetic rate. The above resource capture-, use- and growth-related traits may facilitate the two invaders' invasion, while further comparative studies on a wider range of invasive and noninvasive congeners are needed to understand the generality of this pattern and to fully assess the competitive advantages afforded by these traits.

5,5'-Bis(diethyl-amino)-2,2'-[butane-1,4-diyldioxy-bis(nitrilo-methyl-idyne)]-diphenol.

The title complex, C(26)H(38)N(4)O(4), was synthesized by the reaction of 4-diethyl-amino-2-hydroxy-benzaldehyde with 1,4-bis-(amino-oxy)butane in ethanol. It crystallizes as discrete centrosymmetric molecules adopting an extended conformation where the two salicylaldoxime groups are separated from each other. Intra-molecular O-H⋯N hydrogen bonding is observed between the hydr-oxy groups and oxime N atoms. Inter-molecular π-π stacking inter-actions [3.979 (2) Å] between aromatic rings are apparent in the crystal structure. Each ethyl group is disordered over two positions; in one the site occupancy factors are 0.55 and 0.45, in the other 0.53 and 0.47.