薇甘菊（Mikania micrantha）是一种快速生长的全球性入侵杂草，广泛分布在热带和亚热带地区。薇甘菊的入侵会对当地自然生态系统造成严重破坏，并对森林和作物生产造成巨大的经济损失。它在光合作用方面具有优势，其净光合速率与C₄植物相近，固碳能力较高。研究表明薇甘菊的光合能力是其快速生长和快速殖民新栖息地的重要原因之一。然而，目前尚没有研究揭示薇甘菊光合作用的进化机制和昼夜规律。本研究采用基因组学和转录组学相结合的方法，揭示了薇甘菊光合作用的进化机制和昼夜表达模式。结果显示，在薇甘菊中有16个正选择基因，主要集中于光反应和光同化物的利用两个过程中，并且叶绿素a/b结合蛋白、苹果酸脱氢酶、丙酮酸正磷酸二激酶和苹果酸酶家族的基因数量与C₄植物(高粱或玉米)相似，显著高于其他植物。在不同组织中，98.1%与光反应相关的基因在茎中具有较高表达，C₄循环相关的基因中有一半以上在茎中高于叶中的表达。气孔开闭过程中，2个碳酸酐酶基因在18:00的表达量高于8:00，SLAC1和HT1基因在18:00表达量最低。此外，与光合作用相关的基因在7:00和17:00表达量较高。因此我们推测，薇甘菊能够在茎和花器官中进行光合作用，并且叶片的一些气孔在夜间能够通过CO₂信号打开。此外，它的进化可能会减弱高光强时的光抑制，并在低光强时提高光合作用的效率。组织特异性光合类型和光合相关基因的不同昼夜模式可能有助于薇甘菊在新栖息地的快速定植。薇甘菊可能通过这些变化增加了它的种间优势和侵袭性。本文的研究结果为了解薇甘菊的光合作用机制及其控制和生物利用度提供了有价值的信息。

农作物害虫的传播扩散和气候变化下农作物和害虫之间复杂的相互作用威胁着全球粮食安全。窄缘施夜蛾是中国南方新发的马铃薯害虫，在中国马铃薯产区造成马铃薯减产和质量下降，对窄缘施夜蛾的早期预警监测可以对中国的农业生产起到保护作用。本研究利用最优的MaxEnt模型识别气候变化情景下窄缘施夜蛾在中国的潜在地理分布区，为预防窄缘施夜蛾造成进一步危害提供基础。研究结果表明，最优的MaxEnt模型准确性高于默认设置的MaxEnt模型。最冷月最低温度，最干月降水量，最冷季度降水量和人类影响指数对窄缘施夜蛾的潜在地理分布有着显著的影响。窄缘施夜蛾的高度和中度适宜生境主要位于中国东部和南部地区。气候变化情景下，窄缘施夜蛾在中国的潜在地理分布区将会缩小，主要表现为高度适宜生境转化为中度适宜生境。从现代气候条件下到2030年，窄缘施夜蛾的潜在地理分布中心呈向东北方向和高纬度地区迁移的趋势。马铃薯种植区的田间覆膜为窄缘施夜蛾的生存提供了有利的微气候，我们应更加重视窄缘施夜蛾的早期预警工作，防止其在中国冬种马铃薯区域进一步扩散。

昆虫蜕皮激素由Halloween家族基因合成，在几个关键的发育事件中发挥重要作用，包括蜕皮和变态。然而，这些Halloween基因在莲草直胸跳甲中的功能作用仍不清楚。在本研究中，通过RT-qPCR技术检测了两个Halloween基因AhCYP307A2和AhCYP314A1在不同发育阶段的表达模式。此外，利用RNA干扰（RNAi）技术探究了这两个基因的功能，并通过对莲草直胸跳甲雌性卵巢进行解剖观察其卵巢发育情况。qPCR结果显示，AhCYP307A2和AhCYP314A1在末龄幼虫和雌虫中均显著高表达。此外，AhCYP307A2在卵期和蛹中也有高表达，但显著低于在末龄幼虫和雌虫中的表达水平。RNAi结果显示，注射dsAhCYP307A2和dsAhCYP314A1显著抑制了它们的表达以及三个相关的卵黄原蛋白基因AhVgs的转录水平。敲除AhCYP307A2和AhCYP314A1可显著抑制幼虫蜕皮，破坏末龄幼虫-蛹-成虫的转变，延迟卵巢发育，停止产卵。以上研究结果表明，AhCYP307A2和AhCYP314A1在莲草直胸跳甲末龄幼虫-蛹-成虫转换期的蜕皮发育和繁殖过程中发挥重要的调控作用。

潜叶蝇（双翅目：潜蝇科）是一类体型小、物种多样的昆虫，主要以幼虫潜食寄主植物组织形成危害。该科的多个物种被认为是全球范围的入侵害虫，造成严重的农业经济损失。在中国，蔬菜和花卉等重要经济作物已受到这类害虫的严重危害，尤其是斑潜蝇。潜叶蝇种间形态相似而难以区分。在中国，潜叶蝇类农业害虫的种类和发生与分布仍不明晰。为探明中国潜叶蝇类害虫的种类及其系统发育关系，本研究基于2016年到2019年间在全国开展的潜叶蝇系统调查和采样，利用形态学特征和DNA条形码技术对它们进行了识别和鉴定。共采集与鉴定有分别属于5个属的27种潜叶蝇，包括16种斑潜蝇。随后基于线粒体基因与核基因分子标记重建了它们的系统发育关系并估计分化时间，获得了高度一致且支持度较高的贝叶斯与最大似然系统发育树。发育树中斑潜蝇属分为了两个主要支系，推断它们在大约2740万年前（95%最大后验密度：2300-3152万年前）的渐新世发生分化。这两个支系之间的分布格局和寄主植物关联存在差异，其中，支系2中的物种分布于凉爽气候的高纬度地区，表明斑潜蝇属可能已经分化出一个适应凉爽气候环境的谱系。

重大农业入侵害虫草地贪夜蛾原产于美洲，自2016年首次被发现入侵尼日利亚和加纳以来，短短3年时间内迅速入侵至47个非洲国家和18个亚洲国家。由于该虫寄主范围广（至少包含353种寄主植物）、能够适应多种生境、超强的迁飞能力、高繁殖力、暴食性，以及快速发展的农药抗性和病毒抗性等内在优势，是导致其具有入侵性的重要原因，目前已被公认为全球范围内的超级害虫。该害虫的综合治理策略主要依靠监测调查、农业防治、化学防治、病毒制剂、性诱剂、生物防治（寄生性天敌、捕食性天敌和昆虫病原体），以及植物源农药等多种防治策略的综合应用。目前尚需要进一步研究的主要内容包括：（1）明确草地贪夜蛾的入侵机制，（2）如何阻止其进一步扩散，（3）提供更有效的防治策略。本文总结了草地贪夜蛾的生物学特性，潜在的入侵性机制，以及综合治理策略，以期为今后的治理提供参考。

China is one of the countries in the world that is severely damaged by crop diseases, pests, and weeds.  There are more than 1 700 species of agricultural pests occurring annually, 53 of which are on the list of the 100 worst pests in the world (Chen and Wang 2014; Wu 2018).  Currently, China is still greatly challenged by a growing problem of agricultural pests that threaten the economy and health and pose ecological risks under the conditions of global climate change, economic integration, crop structure adjustment and so on.  Plant protection against crop diseases, insect pests and noxious weeds is necessary to ensure high-quality crop production and food safety.  However, traditional strategies of plant protection have mainly involved chemical pesticides, which bring a series of other problems, such as pesticide residues, pest resistance and resurgence.  During the past decades, Chinese scientists have been committed to
research on developing new plant protection methods through integrated pest management (IPM) in a safe, cost-effective and sustainable manner.  In this field, we organized this special issue to provide the most updated theories and technologies of plant protection.

There are 21 manuscripts accepted for publication in this special issue, including 13 reviews and eight research articles.  The 13 reviews involved a variety of relevant disciplines, such as insect ecology and molecular biology, phytopathology, biological invasions and pest management science.  Three papers documented the progress in insect ecology and molecular biology.  Bao and Zhang (2019) reported the recent molecular research in Nilaparvata
lugens on its endosymbionts, virus transmission, insecticide resistance, and host interaction.  Li et al. (2019) gave an overview of the discovery, biogenesis and functions of four kinds of ncRNAs, including miRNA, piRNA, circRNA and lncRNA in insects, and Xue et al. (2019) investigated thermal adaptation of Drosophila from three aspects of behavior, plastic responses and micro-evolution under global climate change.  Two papers investigated the threats from pathogenic microbes, Chinese wheat mosaic virus and fire blight disease, to wheat and pear production, respectively, in China, and provided cost-effective countermeasures to control these diseases in the future (Guo et al. 2019; Zhao Y Q et al. 2019).  Four other papers mainly focused on the introduction routes, expansion process (adaptation and interactions), ecological effects and control of invasive insects, including Bemisia tabaci, Phenacoccus solenopsis, Bactrocera dorsalis and Solenopsis invicta (Chu et al. 2019; Liu H et al. 2019; Tong et al. 2019; Wang et al. 2019a).  Additionally, there were three papers that provided sound prospects for improving the strategies currently employed in agricultural control, biological control and chemical control (Lu et al. 2019; Pan et al. 2019; Wang et al. 2019b).  Finally, Liu (2019) evaluated the current status and challenges of rodent biology and management in China.  

The eight research articles mainly involved the three aspects of reproductive biology and chemical ecology of pests, safety assessments of genetically modifed crop and weed control (He et al. 2019; Huang et al. 2019; Liu  Y M et al. 2019; Lü et al. 2019; Muhammad et al. 2019; Xiu et al. 2019; Zhao C C et al. 2019; Zheng et al. 2019).  Among those, there were two papers that explored the tradeoffs between reproduction and energy reserves (Huang et al. 2019; Zhao C C et al. 2019).  Liu Y M et al. (2019) proved that Bt maize expressing cry1Ab/2Aj or cry1Ac genes posed a negligible risk to adult Chrysoperla sinica.  In addition, Muhammad et al. (2019) and He et al. (2019) evaluated the effects of weed control under wheat stubble management and different culture patterns, respectively.

I believe these articles in this special issue should be of broad interest to a diverse audience at multiple levels in the areas of plant protection, and they are well-suited for the readers of Journal of Integrative Agriculture.  I sincerely appreciate all the authors who gave their high-quality contributions and efforts to this special issue.

The rapid development of omics provides new technologies and methodologies for the study of invasion biology. Agricultural Genomics Institute at Shenzhen (CAAS-AGIS) and Institute of Plant Protection, Chinese Academy of Agricultural Sciences (CAAS-IPP) initiated the “IAS1000 project” (A genome project of 1000 invasive alien species) and established the “IAS1000 alliance” in Shenzhen on November 14, 2018. Via deep-mining of omics data, the project aims for better understanding the ecological processes and molecular mechanisms of biological invasion, and developing new technologies and products for prevention and management of invasive alien species. Up to now, there have been more than 40 research institutes, universities and enterprises participating in this project, forming an omics team with multi-disciplinary members.

The main tasks of “IAS1000 project” include: (i) building a global collaboration platform for an in-depth research on molecular mechanisms of invasiveness; (ii) developing new technologies and products for prevention and control of invasive alien species, including RNA interference, gene editing, molecular pesticides with specific target carried by new physical/chemical materials, intelligent recognition of molecular odor, utilization of molecule-induced immunity, creation of new vaccines, and the restorer of soil ecological network; (iii) cultivating new elite talents in the integrated subjects encompassing omics, invasion biology, entomology and botany, etc.

   The whitefly Bemisia tabaci is a species complex, of which two invasive species, called MEAM1 and MED whiteflies, have invaded many parts of the world in the past 30 years and replaced native whitefly populations in many regions of invasions including many areas in China. One of the possible reasons for the invasion is that MEAM1 and MED whiteflies are more fecund than the native species. However, factors that affect reproduction and the molecular mechanism of vitellogenesis among various B. tabaci cryptic species are not clearly known. In this study, cDNAs of vitellogenin (Vg) genes were sequenced from native B. tabaci Asia II 1 and invasive B. tabaci MED in China. The deduced amino acid sequences were 2 182 residues in Asia II 1 and 2 217 residues in MED. Compared to the Vg gene cDNA sequence of Asia II 1 species, the Vg gene in MED could be cleaved at least into four subunits, with deduced molecular weight of 50, 90, 150 and 190 kDa, respectively. However, only two different subunits were cleaved between residues 459 and 460 in the Asia II 1. In addition, more than two serine-rich stretches located in both the N-terminal and the C-terminal region in invasive species. More GHN domains were revealed only in the N-terminal region of B. tabaci MED. Vg gene expression pattern was characterized using quantitative real-time (qRT)-PCR to compare the dynamic of vitellogenin gene mRNA level. Vg gene transcription reached the peak level at 13 d after eclosion in B. tabaci Asia II 1, 3 d later than that in MED and another invasive species of the B. tabaci complex MEAM1. We assumed that the present difference of Vg gene expression pattern is due to the different regulation pattern of vitellogenesis among species of the B. tabaci complex. These results provide useful information to reveal the mechanisms of reproduction in whitefly species complex.

    Currently, insecticides are considered as the primary approach for controlling western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). However, the heavy use of insecticides resulted in high insect resistance and serious environmental pollution. Given its characteristics of ease of operation and environmental friendliness, insect control using high temperature is receiving considerable renewed research interest. However, although the combination of insecticides and high temperature to control F. occidentalis has been studied before, few studies have focused on the short-term effect of such treatment. In a laboratory study, F. occidentalis adults and second-instar nymphs were exposed to 45°C for 2 h. Then, their susceptibility to acetamiprid, spinosad, methomyl, and beta-cypermethrin was tested after different periods of recovery time (2–36 h). Additionally, the specific activity of three detoxification enzymes (esterase, glutathione S-transferase, and cytochrome p450 (CYP) monooxygenase) of the treated insects was determined. The results indicated that the fluctuation of susceptibility to insecticides and detoxification enzyme activity during F. occidentalis recovery from heat shock are related. Furthermore, several recovery time points (2, 30, and 36 h) of significant susceptibility to four tested insecticides compared with the control were found during the treatment of adults that were heat-shocked. Recovery time points of higher susceptibility compared with the control depended on different insecticides during the second-instar nymph recovery from heat shock. Interestingly, the fluctuation of CYP monooxygenase activity exhibited a trend that was similar to the fluctuation of susceptibility to insecticides (especially spinosad) during the recovery from heat shock of adults. In addition, the glutathione S-transferase and CYP monooxygenase activity trend was similar to the trend of susceptibility to spinosad during the recovery from heat shock of second-instar nymphs. Our results provide a new approach for controlling F. occidentalis using the combined heat shock and insecticide. This effectively enhances the control efficiency of heat shock and significantly reduces the application of insecticides

Exotic plant invasion presents a serious threat to native ecosystem structure and function. Little is known about the role of soil microbial communities in facilitating or resisting the spread of invasive plants into native communities. The purpose of this research is to understand how the invasive annual plant Ambrosia artemisiifolia L. facilitates its competition capacity through changing the structure and function of soil microbial communities. The soil characteristics of different areas invaded by A. artemisiifolia were examined. Greenhouse experiments were designed to assess the effect of A. artemisiifolia invasion-induced changes of soil biota on co-occurring plant growth, and on the interactions between A. artemisiifolia and three co-occurring plant species. The results showed that the soil organic C content was the highest in heavily invaded sites, the lowest in native plant sites, and intermediate in newly invaded sites. Soil available N, P and K concentrations in heavily invaded site were 2.4, 1.9 and 1.7 times higher than those in native plant soil, respectively. Soil pH decreased as A. artemisiifolia invasion intensity increased, and was lower in invaded sites (heavily invaded and newly invaded) than in native plant sites. The soil microbial community structure was clearly separated in the three types of sites, and A. artemisiifolia invasion increased anaerobe, sulfate-reducing bacteria and actinomycete abundance. Soil biota of invaded sites inhibits growth of co-occurring plants (Galinsoga parviflora Cav., Medicago sativa L. and Setaria plicata (Lam.) T. Cooke.) compared to soil biota from un-invaded sites, but facilitates A. artemisiifolia growth and competition with co-occurring plants. A. artemisiifolia biomass was 50-130% greater when competing with three co-occurring plants, compared to single-species competition only (invasion by A. artemisiifolia alone), in heavily invaded soil. Results of the present study indicated that A. artemisiifolia invasion alters the soil microbial community in a way that favors itself while inhibiting native plant species, with measurable effects on performance of co-occurring plants.

Coexisting natural enemies that share a common host resource in the same guild usually exhibit variation in their life history traits, due to their need to share a similar ecological niche. In this study, we compared the immature development times and adult life history traits of two coexisting, host-feeding parasitoids, Diglyphus isaea Walker and Neochrysocharis formosa Westwood (Hymenoptera: Eulophidae), of which both attack larvae of the same agromyzid leafminers. These two species are both synovigenic, idiobiont parasitoids, whose adults consume host fluids (“host feeding”) and lay anhydropic eggs. Of the two, D. isaea has a larger body but little or no initial egg load, and engages in similar lifetime host-feeding events. However, it achieves higher fecundity, longer adult longevity, and higher host suppression ability than N. formosa, which has a smaller body and higher initial egg load. Although D. isaea engages in similar lifetime host-feeding events with N. formosa, all of its gains in life history traits per host-feeding event of D. isaea were larger than those of N. formosa. The age-specific fecundity and host mortality curves of N. formosa were more skewed in early life than those of D. isaea. In addition, the ovigeny index of N. formosa was negatively correlated to body size. Our results confirmed that two coexisting parasitoids, which share the same host resource, show different immature development patterns and life history traits, suggesting that different resource allocation mode could be a general rule of coexisting species sharing the same habitat or host.

The density seasonal dynamics of Bemisia tabaci MED were evaluated over two years in a cotton-growing area in Langfang, Hebei Province, northern China on cotton (Gossypium hirsutum L.) and six other co-occurring common plants, common ragweed (Ambrosia artemisiifolia L.), piemarker (Abutilon theophrasti Medicus), sunflower (Helianthus annuus L.), sweet potato (Ipomoea batatas L.), soybean (Glycine max L.), and maize (Zea mays L.). The whitefly species identity was repeatedly tested and confirmed; seasonal dynamics on the various host plants were standardized by the quartile method. B. tabaci MED appeared on weeds (the common ragweed and piemarker) about 10 days earlier than on cotton, or the other cultivated plants. The peak population densities were observed over a span of 2 to 3 weeks on cotton, starting in early (2010) or mid-August (2011). The common ragweed growing adjacent to cotton supported the highest B. tabaci densities (no. on 100 cm2 leaf surface), 12-22 fold higher than on cotton itself. Sunflower supported more B. tabaci than the other plants, and about 1.5-2 fold higher than cotton did. Our results indicate that weeds (esp. the common ragweed) around cotton fields could increase the population density of B. tabaci MED on cotton, while sunflower could act as a trap crop for decreasing pest pressure on cotton.

Thermal adaptation plays a fundamental role in shaping the distribution and abundance of insects, and heat shock proteins (Hsps) play important roles in the temperature adaptation of various organisms. To better understand the temperature tolerance of the indigenous ZHJ2-biotype of whitefly Bemisia tabaci species complex, we obtained complete cDNA sequences for hsp90, hsp70, and hsp20 and analyzed their expression profiles under different high temperature treatments by real-time quantitative polymerase chain reaction. The high temperature tolerance of B. tabaci ZHJ2-biotype was determined by survival rate after exposure to different high temperatures for 1 h. The results showed that after 41°C heat-shock treatment for 1 h, the survival rates of ZHJ2 adults declined significantly and the estimated temperature required to cause 50% mortality (LT50) is 42.85°C for 1 h. Temperatures for onset (Ton) or maximal (Tmax) induction of hsps expression in B. tabaci ZHJ2-biotype were 35 and 39°C (or 41°C). Compared with previous studies, indigenous ZHJ2- biotype exhibits lower heat temperature stress tolerance and Ton (or Tmax) than the invasive B-biotype.