Anoplophora glabripennis (ALB) is one of the most devastating wood boring insects of poplars. Populus deltoides ‘Shalinyang’ (PdS), a new poplar variety, shows strong resistance to ALB infestation. However, the molecular mechanism of insect resistance in PdS is unclear. Here, we found that lignan content was much higher in PdS phloem after ALB infestation than in healthy trees, and that adding lignan to artificial diet significantly reduced: larval weight; digestive enzyme activity (cellulase [CL], polygalacturonase [PG]); detoxification enzyme activity (carboxylesterase [CarE], glutathione S-transferase [GSH-ST]); and defense enzyme activity (Catalase [CAT]). We further identified the lignan biosynthesis-related PdPLR1 gene (Pinoresinol-lariciresinol reductase, PLR) based on transcriptome analysis, and it was significantly up-regulated in the PdS phloem attacked by ALB. Overexpression of PdPLR1 in Arabidopsis increased th lignan content. In contrast, silencing PdPLR1 in PdS significantly decreased expression levels of PdPLR1 and lignan content by 82.45% and 56.85%. However, silencing PdPLR1 increased the number of adults ovipositions and eggs hatching. The activity of CL, PG, CarE, GSH-ST and CAT and the biomass of larvae fed on phloem of PdS with silenced PdPLR1 were significantly higher than in the control. Taken together, up regulation of PdPLR1 enhanced PdS resistance to ALB by regulating lignan synthesis. Our findings provide in-depth insights into the molecular mechanisms of PdS-ALB interactions, which lay the foundation for understanding of defense in poplars to pest infection.

Anoplophora glabripennis (Motschulsky), the Asian longhorned beetle, is a serious wood-boring pest of hardwood trees. There have been records that suggest Elaeagnus angustifolia L. (Elaeagnaceae) might be an "attract and kill" tree species for A. glabripennis, i.e., a tree that is attractive to A. glabripennis adults but kills their oviposited eggs. To evaluate the possibility of E. angustifolia as a control measure for A. glabripennis, we carried out a series of behavioral experiments in the laboratory and in the field. Results showed that: (i) A. glabripennis females preferred E. angustifolia branches and leaves over poplar tree species evaluated; the weight of feces from both female and male A. glabripennis feeding on E. angustifolia was significantly higher than from those feeding on Populus deltoides 'Shalinyang' or Populus alba. L. var. pyramidalis; (ii) the average lifespan of females and males feeding on E. angustifolia was significantly longer than those feeding on other host trees evaluated; (iii) in the laboratory oviposition choice experiment, there were significantly fewer egg notch grooves on E. angustifolia than on P. deltoides 'Shalinyang', and those made in E. angustifolia were without eggs; (iv) in the field, the number of egg notch grooves on E. angustifolia was 43.6 +/- 18.1 per stem, but the number of eggs laid was only 14.4 +/- 6.4 per stem; and (v) Field surveys of existing mixed forests showed that when E. angustifolia was planted with P. alba. var. pyramidalis or Populus simonii x (Populus pyramidalis + Salix matsudana) 'Poparis' in the mixed forest, both poplar varieties suffered greater infestation than E. angustifolia. Therefore, E. angustifolia is not a suitable attract and kill tree to be extensively planted in mixed forests for control of A. glabripennis.

Anoplophora glabripennis is one of the most devastating wood-boring beetles that attacks poplars. However, one poplar species, Populus deltoides, has strong resistance to Anoplophora glabripennis infestation, the underlying defense mechanisms against Anoplophora glabripennis are poorly understood. Secondary metabolites play a crucial role in plants to combat biological stress. Here, based on transcriptome and metabolome, we demonstrated that the mechanisms for responses to mechanical damage and insect infestation were different. The degree of reactions to adult groove production, larval incubation, and larval frass production was not identical. In addition, the potential genes with insect resistance activity were identified. Predominant differentially expressed genes (DEGs) found in the phloem of Populus deltoides include anthocyanidin 3-O-glucosyltransferase5 (PdUGT72E), peroxidase 73 (PdPod73), peroxidase A2 (PdPodA2) and macrophage migration inhibitory factor (PdMIF) responded to stress caused by Anoplophora glabripennis, which further resulted in activation of the plant defense system against insects via changes in regulation of metabolic pathways, such as tyrosine metabolism pathway, phenylpropanoid biosynthesis pathway and flavonoid biosynthesis pathway. Therefore, this work has laid a foundation for further unraveling the mechanisms involved in this interaction.

Parasitoids of wood borers and bark beetles rarely encounter different host species simultaneously in nature, so whether they exhibit any preferences for particular species, and the relative suitability of different host species is unclear. Sclerodermus guani (Hymenoptera: Bethylidae) is an ectoparasitoid of cerambycid larvae and has also been reported from multiple host species. In this study we used S. guani as a model parasitoid to evaluate preferences for different host species. Moreover, we determined how levels of intraspecific interaction amongst S. guani adults affect host species preference, and subsequent mortality of those different hosts. S. guani adults display high levels of preference for particular hosts and cause rates of non-reproductive mortality of Aromia bungii (Coleoptera: Cerambycidae) and Monochamus alternatus (Cerambycidae) larvae that are higher than the reproductivity mortality of both hosts. Under different parasitoid densities interaction, S. guani always preferred A. bungii and Monochamus saltuarius (Cerambycidae) and varied in its responses to Thyestilla gebleri (Cerambycidae) and M. alternatus. In addition, the mortalities of single T. gebleri, A. bungii or M. saltuarius larvae caused by the parasitoids (1–3 individuals) were all 100

桃红颈天牛是桃树的主要蛀干害虫,化学防治仍是控制桃红颈天牛危害的重要措施.为使防治达到减量增效的目的,首先测试了 3种增效剂对吡虫啉和杀虫双2种农药物理性能的影响,并将优选出的增效剂添加到稀释一定倍数的2种农药中开展药效试验和减量药效试验.结果显示:增效剂杰效利可以有效降低供试药剂的表面张力,提高其润湿性、铺展性和树干持药量;可提高2种药剂对桃红颈天牛初孵幼虫的防治效果;即使在药剂减量30％的情形下,也可使吡虫啉和杀虫双对天牛初孵幼虫达到较好的控制效果,施药24 h的较正死亡率分别达到62.89±3.46％和64.10±3.45％.

[目的]新疆杨是目前我国西北地区防护林建设的首选树种,长期单一化的种植模式使其受到了光肩星天牛的较大危害.沙枣对光肩星天牛有一定的诱杀效应,但是否可用于保护新疆杨尚不清楚.[方法]本研究通过测试光肩星天牛成虫对新疆杨和沙枣枝叶气味偏好性和树干产卵试验,以及树木挥发物的触角电位活性测定等,初步评估了沙枣作为保护树种的可行性.[结果]1)当新疆杨vs沙枣枝叶时,雌虫偏好沙枣枝叶气味,占作出选择成虫数的80.65％,雄虫对二者选择无显著差异;2)雌虫触角对新疆杨挥发物中的叶醇和乙酸叶醇酯以及沙枣挥发物中3-蒈烯、乙酸叶醇酯和叶醇表现出电生理活性,新疆杨和沙枣挥发物中叶醇含量之比为2.66∶1,乙酸叶醇酯之比为1.19∶1,因其含量不同所表现出来的电生理活性刺激强度也不同;3)室内试验新疆杨vs沙枣树干时,雌虫偏好在沙枣上产卵,每个供试树段上的刻槽数达18±1.73个,但单选试验中在新疆杨上的有效产卵率高于沙枣,分别为75.00％和58.33％;4)在林间寄主树干上的套笼试验表明,雌虫在无选择条件下在二者上的刻槽数无显著差异,但幼虫在沙枣上均未成活.[结论]上述结果证实了沙枣对光肩星天牛成虫有一定引诱性,但沙枣在一定区域内是否会有效控制光肩天牛种群的增长,还需进一步的研究.

Abstract Aromia bungii Faldermann is an important economic wood borer infested many fruits and ornamental tree in Rosacea family, and is listed as a world quarantine pest. Both chemical and biological control methods have been used to control its damage, but what is their interact effect is unknown. 【Objective】To figure out whether sublethal imidacloprid stimulate the physical and biochemical response of A. bungii larvae so to affect the parasitism rate and offspring development of its parasitoids Sclerodermus guani. 【Method】We detected the activity of detoxification and defense enzymes in the A. bungii larvae treated with sublethal dose of imidacloprid, and investigated its effects on the S. guani. Firstly, LC10, LC20, and LC30 of the imidacloprid were tested to determine the sublethal dose. Then the larvae were treated with the sublethal dose of imidacloprid with artificial diet. 【Result】The sublethal imidacloprid can induce the activity of GST enzyme and inhibition of the CarE activity in A. bungii larvae; the activity of CAT, SOD and POD enzymes was induced and there is a dose effect; the developmental duration of S. guani was not significantly affected, but the parasitism rate, fecundity, the emergence rate and the mortality rate were seriously affected compared with the control. 【Conclusion】The sublethal dose of imidacloprid can induce the strong physical and biochemical response of A. bungii larvae, and had a significant impact on the parasitism success rate and fecundity of S. guani. The results could help us to rational use of insecticides to collaborative with the biological control of the A. bungii with parasitoid.