[Regulating effect of agricultural landscape pattern on ecological pest control by natural enemies.] / å†œç”°æ™¯è§‚æ ¼å±€å¯¹å®³è™«å¤©æ•Œç”Ÿæ€æŽ§å®³åŠŸèƒ½çš„è°ƒæŽ§ä½œç”¨.

It's well known that regional agricultural landscape pattern can significantly regulate the relationship between plants, herbivorous insects and natural enemies. The improvement of the ecosystem services of regional agricultural landscape pattern has profound impacts on pest control, which has received much interests in current landscape ecology and pest control studies. This review systematically summarized the impacts of agricultural landscape pattern, as well as its succession on the diversity and ecological pests control of important natural enemies. From the perspective of different natural enemies, the impacts of agricultural landscape pattern on natural predators, parasi-toids, beneficial microorganisms and its ecological pests control functions were all recapped. We outlined crop spatial distribution and vegetation habitat management strategies. This review could provide useful insights in improving the ecosystem services of natural enemies in agricultural landscape based on the vegetation habitat management, and offer theoretical support for regional ecological agriculture in response to the strategy of 'chemical pesticide reduction application'.

Molecular characterization of three Hsp90 from Pieris and expression patterns in response to cold and thermal stress in summer and winter diapause of Pieris melete.

Heat shock proteins (Hsps) have been linked to stresses and winter diapause in insects, but whether they are components of summer diapause is still unknown. In this study, complementary DNAs of Hsp90 from Pieris melete, Pieris rapae and Pieris canidia named PmHsp90, PrHsp90 and PcHsp90, respectively, were cloned and sequenced. The deduced amino acid sequence consisted of 718 amino acid residues with a putative molecular mass of 82.6, 82.6 and 82.7 kDa, respectively. The amino acid sequences contained all of the five conserved signature motifs in the Hsp90 family and a bHLH protein folding activity region. The differential expression pattern of PmHsp90 in response to summer diapause and winter diapause, which are related to heat/cold stress, was investigated. Cold stress induced Hsp90 up-regulation in summer and winter diapause pupae, but not in non-diapause individuals. Heat shock up-regulated PmHsp90 gradually with an increase in temperature in summer diapause, and PmHsp90 was rapidly up-regulated in winter diapause. After 30 min heat shock at 39°C, substantial up-regulation of PmHsp90 transcript levels were observed both in summer and winter diapause. However, in non-diapause a relatively stable expression was found under different durations of 39°C heat shock. Compared to the optimal treatment of 18°C for diapause development, a high temperature acclimation of 31°C induced PmHsp90 up-regulation in summer diapause, whereas a low temperature acclimation of 4°C induced up-regulation in winter diapause. The current results indicate that Hsp90 may play an important role in response to heat/cold stress both in summer and winter diapause.

Life-history responses of the rice stem borer Chilo suppressalis to temperature change: Breaking the temperature-size rule.

Temperature is a key environmental factor for ectotherms and affects a large number of life history traits. In the present study, development time from hatching to pupation and adult eclosion, pupal and adult weights of the rice stem borer, Chilo suppressalis were examined at 22, 25, 28 and 31°C under L18:D 6. Larval and pupal times were significantly decreased with increasing rearing temperature and growth rate was positively correlated with temperature. Larval and pupal developmental times were not significantly different between females and males. The relationship between body weight and rearing temperature in C. suppressalis did not follow the temperature-size rule (TSR), both males and females gained the highest body weight at 31°C. Females were significantly larger than males at all temperatures, showing a female biased sex size dimorphism (SSD). Contrary to Rensch's rule, SSD and body weight in C. suppressalis tended to increase with rising temperature. Male pupae lost significantly more weight at metamorphosis compared to females. We discuss the adaptive significance of the reverse-TSR in the moth's life history.