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Insect general odorant-binding proteins (GOBPs) play irreplaceable roles in filtering, binding, and transporting host odorants to olfactory receptors. Grapholita funebrana(Treitscheke) (Lepidoptera: Tortricidae), an economically important pest of fruit crops, uses fruit volatiles as cues to locate host plants. However, the functions of GOBPs in G. funebranaare still unknown. Three GOBP genes, namely, GfunGOBP1, GfunGOBP2, and GfunGOBP3, were cloned, and their expression profiles in different tissues were detected by the method of real-time quantitative PCR (RT-qPCR). The binding properties of recombinant GfunGOBPs (rGfunGOBPs) to various ligands were investigated via fluorescence binding assays. The three GfunGOBPswere mainly expressed in the antennae of both male and female moths. All these three rGfunGOBPs could bind to sex pheromones, while having varying affinities toward these pheromones. The three rGfunGOBPs also displayed a wide range of ligand-binding spectrums with tested host odorants. The rGfunGOBP1, rGfunGOBP2, and rGfunGOBP3 bound to 34, 33, and 30 out of the 41 tested odorants, respectively. Three rGfunGOBPs had overlapping binding activities to β-myrcene, (-)-α-phellandrene, and ethyl isovalerate with the Kiless than 3.0 μM. The rGfunGOBP1 and rGfunGOBP3 could selectively bind to several insecticides, whereas rGfunGOBP2 could not. Three rGfunGOBPs had the dual functions of selectively binding to sex pheromones and host odorants. Moreover, the rGfunGOBP1 and rGfunGOBP3 can also serve as ‘signal proteins’ and bind to different insecticides. This study contributed to elucidating the potential molecular mechanism of the olfaction for G. funebrana, and thereby promotes the development of effective botanical attractants or pheromone synergists to control G. funebrana.

Migratory insects make diverse adaptive strategies in response to changes in external environment. Temperature has an impact on the survival, development, reproduction, and migration initiation of insects. Previous research has primarily been focused on the effects of constant temperature on populations, but changing temperature has received less attention. Three constant temperature treatments (20, 25 and 30°C) and three pupal-alternating temperature treatments (20–25, 25–20 and 25–30°C) were set up to study the relationship between temperature and population development by age-stage, two-sex life table analysis in the oriental armyworm, Mythimna separataWalker, a notorious migratory pest in grain crops. The 25°C treatment was considered optimal with 20 and 30°C as low suitable temperature and high temperatures, respectively. The survival rate was relatively low before third instar larvae at 20°C (63.0%) and 20–25°C (70.1%), and extreme low after pupal stage at 30°C (20.6%). Developmental duration of each stage was negatively correlated with temperature. The adult pre-oviposition period, when most migratory insects initiate migration, was the shortest at 25°C (2.69 d) but was lengthened at both low suitable (7.48 d for 20°C, 6.91 d for 25–20°C and 4.57 d for 20–25°C) and high temperatures (3.74 d for 25–30°C and 5.00 d for 30°C). Both low suitable and high temperature decreased lifetime fecundity, net reproductive rate and the intrinsic rate of increase, with variability observed across developmental duration and stage during non-optimal temperature. The results expand knowledge of the relationship between changing temperature and armyworm population development, and adaptive strategies in complex ambient environment.

Large-scale systematic patterns of body size are a basic concern of evolutionary biology. Identifying body size variation along altitudinal gradients may help us to understand the evolution of life history of animals. In this study, we investigated altitudinal variation in body size, age and growth rate in Chinese endemic frog, Pelophylax pleuraden. Data sampled from five populations covering an altitudinal span of 1413 to 1935 m in Sichuan province revealed that body size from five populations did not co-vary with altitudes, not following Bergmann's rule. Average adult SVL differed significantly among populations in males, but not in females. For both se:es, average adult age differed significantly among populations. Post-metamorphic growth rate did not co-vary with altitude, and females grew faster than males in all populations. When contrc.lling the effect of age, body size did not differ among populations in both sexes, suggesting that age did not affect variation in body size among populations. For females, there may be other factors, such as the allocation of energy between growth and reproduction, that eliminated the effect of age on body size. To our minds, the major reason of body size variation among populations in male frogs may be related to individual longevity. Our findings also suggest that factors other than age and growth rate may contribute to size differences among populations. [ABSTRACT FROM AUTHOR]

Theory predicts that the degree of testes asymmetry should be positively correlated with male body condition in species with directional testis asymmetry. We tested this prediction in Rhacophorus omeimontis, a species in which females mate with more than one male. Our results showed that the treefrogs did not exhibit the absence of directional asymmetry in testis size, but rather the occurrence of fluctuating asymmetry. Moreover, we also tested differences in body size, body mass, testis mass, testis asymmetry, and sperm size among initially paired, jointly paired, and unpaired males. We found that body size and mass, testis mass, testis asymmetry and sperm length did not differ among the three male types. Testis mass showed a positive relationship with soma mass, but the correlations between the extent of fluctuating testis asymmetry and sperm length, and between testis mass and sperm length were not significant. Our data suggest that testes size and sperm length do not play an important role in determining male mating success in the presence of sperm competition. [ABSTRACT FROM AUTHOR]

The objective of this research work is to provide a systematic method to perform molecular dynamics simulation or evaluation for adhesion of micro/nano gear train during sliding friction in MEMS. In this paper, molecular dynamics simulations of adhesion problems in micro gear train are proposed. The perfect MEMS gear train model is very complicated by considering the computing time. A simplified model to simulate surface sliding between metals by molecular dynamics (MD) is proposed because the surface property is a dominant factor for the performance of gear systems. Based on analysis of sliding friction and the transmitting characteristics of micro gear train, a model is established by utilizing the Morse potential function. The Verlet algorithm is employed to solve atom trajectories. The simulation results show that adhesion tends to occur between two micro gears after certain cycles and such adhesion accounts for the friction force and the temperature increase. The simulation results are in consistence with the experimental results in the literature. The model is meaningful to prolong the lifetime of micro gear train by selecting proper parameters.The objective of this research work is to provide a systematic method to perform molecular dynamics simulation or evaluation for adhesion of micro/nano gear train during sliding friction in MEMS. In this paper, molecular dynamics simulations of adhesion problems in micro gear train are proposed. The perfect MEMS gear train model is very complicated by considering the computing time. A simplified model to simulate surface sliding between metals by molecular dynamics (MD) is proposed because the surface property is a dominant factor for the performance of gear systems. Based on analysis of sliding friction and the transmitting characteristics of micro gear train, a model is established by utilizing the Morse potential function. The Verlet algorithm is employed to solve atom trajectories. The simulation results show that adhesion tends to occur between two micro gears after certain cycles and such adhesion accounts for the friction force and the temperature increase. The simulation results are in consistence with the experimental results in the literature. The model is meaningful to prolong the lifetime of micro gear train by selecting proper parameters.