Pymetrozine,a Fast-Acting and Selective Inhibitor of Aphid Feeding. In-situ Studies with Electronic Monitoring of Feeding Behaviour

Pymetrozine, a pyridine azomethine compound, represents a novel insecticide with a selective activity against homopteran insects. It acts in a unique way: aphids are not knocked down on contact but seem to die of starvation. This implies an effect of pymetrozine on feeding behaviour. The aim of the present work was to elucidate how and at which step pymetrozine interferes with the complex mechanisms underlying phloem feeding. The effect of pymetrozine, applied in various ways, on different phases of stylet penetration and feeding activity of individual aphids was studied using the Electrical Penetration Graph technique (EPG). Initial choice experiments indicated that pymetrozine does not have a deterrent or antifeedant action. Topical application (150 ng pymetrozine mg^-1 fresh weight) inhibited stylet insertion into the plant. When injected, less than 30 ng mg^-1 was sufficient to produce the same effect. When pymetrozine was systemically applied via plant spraying or root uptake, aphids started feeding normally. After some time, however, they withdrew their stylets from the phloem and walked around with unaffected locomotion. At low doses aphids eventually recovered and resumed feeding. High doses, however, irreversibly disrupted feeding and prevented stylet reinsertion. Aphid motility was not affected up to an estimated haemolymph concentration of 1 mM pymetrozine. Aphids which eventually stopped feeding on pymetrozine-treated plants showed EPGs with distorted salivation/ingestion patterns. It is concluded that pymetrozine does not have a general toxic effect on aphids but selectively interferes with the nervous regulation of feeding behaviour which consequently results in death due to starvation after a few days. © 1997 SCI.     

Effects of pymetrozine, an antifeedant of Hemiptera, on Asian citrus psyllid, Diaphorina citri, feeding behavior, survival and transmission of Candidatus Liberibacter asiaticus

BACKGROUND: Vector‐borne plant disease management can be enhanced by deployment of antifeedants in addition to the use of broad‐spectrum neurotoxic insecticides. The effects of pymetrozine on Asian citrus psyllid (ACP), Diaphorina citri Kuwayama, feeding behaviour, survival and transmission of Candidatus Liberibacter asiaticus (Las), the presumed causal pathogen of huanglongbing, were investigated. RESULTS: Pymetrozine applied at 52 and 104 µg mL^?1 to citrus plants [Swingle citrumelo (X Citroncirus webberi Ingram and Moore)] modified the feeding behavior of ACP and increased the amount of time spent performing non‐penetration behaviors while decreasing the time spent performing ingestion behaviors compared with the controls 1 day after treatment. However, the antifeedant effect of pymetrozine subsided 5 days after application. Pymetrozine reduced the survival of both adults and nymphs on treated plants compared with the control. However, it had a greater impact on survival of nymphs than on survival of adults. Pymetrozine applied at 52 and 104 µg mL^?1 on Las‐infected ‘Valencia’ sweet orange plants [Citrus sinensis L. (Osbeck)] reduced acquisition (12 and 21% respectively) and transmission (11 and 18% respectively) of Las by feeding ACP adults compared with the controls; however, these reductions were not statistically significant. CONCLUSIONS: Pymetrozine exhibited moderate antifeedant effects by modifying the feeding behavior of ACP adults with short residual activity. The impact of pymetrozine on survival of nymphs was greater than on adults at the higher concentrations tested. Pymetrozine also reduced the acquisition and transmission of Las by feeding ACP adults up to 21 and 18%, respectively, compared with untreated controls. Copyright © 2010 Society of Chemical Industry     

Effects of cycloxaprid,a novel cis‐nitromethylene neonicotinoid insecticide,on the feeding behaviour of Sitobion avenae

BACKGROUND: Cycloxaprid with cis‐configuration is a novel neonicotinoid insecticide, developed in China, that has good industrialisation prospects for its high activity against imidacloprid‐resistant pests. Studies were carried out to investigate the biological activity of cycloxaprid and its effect on the feeding behaviour of Sitobion avenae. RESULTS: The results demonstrated that cycloxaprid had good contact and root‐systemic activity. The electrical penetration graph (EPG) revealed that cycloxaprid significantly increased the total time of non‐probing periods and greatly inhibited phloem ingestion of treated aphids because it significantly reduced the total time and the frequency of phloem ingestion. Furthermore, cycloxaprid can increase the phloem salivation of treated aphids by comparison with aphids treated with imdacloprid and distilled water. Consequently, a sublethal dose of cycloxaprid impaired aphid ingestion of phloem sap and thereby reduced the weight of aphids. On the other hand, EPG data showed that a sublethal dose of cycloxaprid had no significant effect on xylem sap ingestion, in contrast to imidacloprid. CONCLUSION: All these tests indicated that cycloxaprid had both contact and root‐systemic activity, with sublethal effects resulting in reduction in Sitobion avenae phloem‐feeding behaviour and growth rate. Copyright © 2012 Society of Chemical Industry     

Systemic action of novel neonicotinoid insecticide IPP‐10 and its effect on the feeding behaviour of Rhopalosiphum padi on wheat

BACKGROUND: IPP‐10 is a novel neonicotinoid insecticide recently developed in China and has good activity against sucking insects. Studies were carried out to investigate the activity of IPP‐10 against Rhopalosiphum padi L. RESULTS: The results demonstrated that IPP‐10 had both contact and systemic activity, including acropetal and basipetal translocation in wheat vascular bundles. Starved R. padi were allowed to stay on wheat treated with a sublethal dose of IPP‐10. The results of studying their feeding behaviour from an electrical penetration graph (EPG) revealed a decrease in total time and bout duration of xylem and phloem ingestion, but the total time and bout duration of phloem salivation were significantly prolonged. The frequency (7.03 ± 0.49 Hz) of the xylem ingestion waveform produced by aphids on wheat treated with IPP‐10 was significantly lower than that of blank control aphids (8.20 ± 0.30 Hz). Consequently, aphids born on wheat treated with IPP‐10 were obviously lighter and less fecund than the control aphids. CONCLUSION: These tests indicated that IPP‐10 had both contact and systemic activity, with sublethal effects resulting in reduction in R. padi feeding behaviour, growth rate and fecundity. Copyright © 2010 Society of Chemical Industry     

Translocation of Pymetrozine in Plants

Pymetrozine, a pyridine-azomethine, is a selective biocide against aphids, whiteflies and plant hoppers with a high plant systemic activity. By means of bioassays and autoradiographic techniques it has been shown that this systemic behaviour originates not only from xylem but also from phloem mobility. After foliar application the growing points of plants are protected by pymetrozine imports mainly from leaves. This indicates a high importance of phloem mobility for the systemic activity of pymetrozine against plant-sucking insects. © 1997 SCI.     

Divergent effects of PVY-infected potato plant on aphids

Host plant selection by aphids can be positively or negatively affected when plants are infected by phytoviruses. Potato plants infected by Potato virus Y (PVY), a non-persistent virus, are reported to affect settling behaviour and growth parameters of Myzus persicae Sulzer and Macrosiphum euphorbiae Thomas. Using the Electrical penetration graph system (EPG), we demonstrated that PVY-infection of potato plants influences the feeding behaviour of these two aphid species. Myzus persicae exhibited increased phloem sap ingestion and reduced non-probing duration. Macrosiphum euphorbiae showed delayed stylet insertion, reduced activity in the phloem vessels and an enhanced non-probing duration. In addition, we showed that these two species exhibited different transmission rates. The opposite effects of PVY-infected potato plant on these two aphids are discussed in terms of PVY spreading in the field.     

Effects of jasmonic acid-induced resistance in rice on the plant brownhopper, Nilaparvata lugens Stål (Homoptera: Delphacidae)

It has been established that jasmonate and its pure derivative, Jasmonic Acid can induce the emission of volatiles similar to those induced by herbivory which fed on the plant. Although the effects of induced resistance on chewing insects have been extensively studied, relatively little is known about their potential effects on phloem-feeding insects such as brown planthoppers. We studied the pattern of within-plant preference in the brown planthopper, Nilaparvata lugens (Stål) (BPH) (Homoptera: Delphacidae) and its consequences for offspring performance on the host-plant Oryza sativa L. (Taebaegbyeo variety) regarding the role of induced resistance of rice plants to hopper feeding. The present study examined the effects of induced resistance on the feeding (food assimilation and digestion), development, egg hatchability and survival. In this study, induced resistance was activated in rice using a foliar application of synthetic jasmonic acid (JA) (low 2.5 mM and high 5 mM). Induced resistance significantly reduced the longevity and egg hatchability of the adult N. lugens, as well as the percentage of nymphs surviving to maturity (only at high dose). This study also observed N. lugens food utilization, in order to evaluate the potential influence of induced resistance on N. lugens feeding behavior. The quantity of food ingested and assimilated by N. lugens on JA treated rice plants was significantly affected at the high dose of JA. These results indicate that JA application induces systemic defenses in rice that have a direct negative impact on N. lugens survivorship. At high concentration (5 mM) several abnormalities possibly related to defective moulting, were observed along with malformed eggs. These findings expand our knowledge the effects of JA-dependent defenses on phloem-feeding insects.     

RNA interference in Nilaparvata lugens (Homoptera: Delphacidae) based on dsRNA ingestion

BACKGROUND: An efficient and convenient RNA interference (RNAi) technique involving double‐stranded RNA (dsRNA) ingestion is useful for gene function studies of non‐model insects. RESULTS: Three dsRNAs targeting different sites within a gene encoding vacuolar ATP synthase subunit E (V‐ATPase‐E, 21E01) were synthesised for RNAi in Nilaparvata lugens. dsRNA was found to be stable in 0.1 g mL^?1 sucrose solution, but unstable in artificial fodder. Therefore, dsRNAs were orally delivered into N. lugens in 0.1 g mL^?1 sucrose solution. RNAi was induced by all three of the dsRNAs at 0.05 µg µL^?1 in N. lugens. Time dynamics analysis of gene silencing indicated that significant suppression of the target gene began as early as 2 days after ingestion of ds2‐21E01 and ds3‐21E01. However, significant repressive effects were recorded up to 10 days after exposure to ds1‐21E01. The maximum reduction in target gene mRNA was observed after 10 days of treatment, with suppression ratios induced by ds1‐21E01, ds2‐21E01 and ds3‐21E01 of 41, 55 and 48% respectively. CONCLUSION: An efficient and convenient RNAi technique involving dsRNA ingestion has been successfully developed for N. lugens. This will be a useful tool for further functional genomic investigation in this organism. Copyright © 2011 Society of Chemical Industry     

Insecticidal spider venom toxin fused to snowdrop lectin is toxic to the peach-potato aphid, Myzus persicae (Hemiptera: Aphididae) and the rice brown planthopper, Nilaparvata lugens (Hemiptera: Delphacidae)

The SFI1/GNA fusion protein, comprising of snowdrop lectin (Galanthus nivalis agglutinin, GNA) fused to an insecticidal spider venom neurotoxin (Segestria florentina toxin 1, SFI1) was tested for toxicity against the rice brown planthopper Nilaparvata lugens (Stål) and the peach‐potato aphid Myzus persicae (Sulzer) by incorporation into artificial diets. Significant effects on the mortality of N. lugens were observed, with 100% of the insects fed on the SFI1/GNA fusion protein diet dead by day 7. The survival of the aphid M. persicae was also reduced when fed on the SFI1/GNA fusion protein. After 14 days, only 49% of the aphids that were fed on the fusion protein were still alive compared with approximately 90% of the aphids fed on the control diet or on diet containing GNA only. The SFI1/GNA fusion protein also slowed the development of M. persicae, and the reproductive capacity of the aphids fed on the SFI1/GNA fusion protein was severely reduced. The ability of GNA to act as a carrier protein, and deliver the SFI1 neurotoxin to the haemolymph of N. lugens, following oral ingestion, was investigated. The successful delivery of intact SFI1/GNA fusion protein to the haemolymph of these insects was shown by western blotting. Haemolymph taken from the insects that were fed on the fusion protein contained two GNA‐immunoreactive proteins of molecular weights corresponding to GNA and to the SFI1/GNA fusion protein. © 2005 British Crown Copyright. Published for SCI by John Wiley & Sons, Ltd.     

Pymetrozine interferes with transmission of<Emphasis Type="Italic">Tomato yellow leaf curl virus</Emphasis> by the whitefly<Emphasis Type="Italic">Bemisia tabaci</Emphasis>

Pymetrozine, a novel compound belonging to the class pyridine-azomethines, is a feeding inhibitor labeled for use against plant pests in the order Hemiptera. Pymetrozine was evaluated for its ability to interfere with whitefly transmission of the begomovirusTomato yellow leaf curl virus (TYLCV). Pymetrozine was applied as Fulfill ^TM 50 WG at two rates (0.291 and 0.582 g formulationl ⁻¹) to tomato seedlings with four to six true leaves. Viruliferous whiteflies (three to five per plant) were added 1, 4, 7 and 11 d after a single application of pymetrozine, and transmission rates were determined 4 wk after the addition of whiteflies. Pymetrozine provided protection against transmission of TYLCV by viruliferous whiteflies for up to 1 wk after a single apliation. No phytotoxicity was observed on tomato transplants. These results indicate that pymetrozine could be an effective tool for tomato transplant producers to protect susceptible transplants from infection by begomoviruses, such as TYLCV. Pymetrozine might also work well as part of an integrated approach to begomovirus management in greenhouse tomato fruit production. http://www.phytoparasitica.org positing Oct. 20, 2003.     

Effects of herbicides on rice resistance and on multiplication and feeding of brown planthopper (BPH), Nilaparvata lugens (StÅl) (Homoptera: Delphacidae)

Two-way effects of herbicide on rice resistance and multiplication and feeding of the rice brown planthopper (BPH), Nilaparvata lugens (Stål) were studied. Four of 11 herbicides tested, butachlor, metolachlor, oxadiazon and bentazone, had significantly stimulating effects on multiplication and feeding of BPH. Multiplication times (N ₁/N ₀) of BPH on the rice treated with the four herbicides were 674, 367, 322 and 311, respectively, while that of N. lugens on the untreated plants was 159. The results of measurements of honeydew production by BPH indicated that the feeding rates of the brown planthoppers increased when the insects fed on the plants treated with bentazone, quinclorac, oxadiazon and quinclorac. Survival rates of N. lugens first to third-instars rose on the rice plants treated with butachlor, bentazone, but that of the fourth and fifth instars were not affected. Furthermore, all of those herbicides tested led to a decline of rice resistance, i.e. the injury scales of the treated plants were larger than that of the control under the same pest stress. Based on their effects on rice resistance and on BPH, the herbicides tested can be divided into two categories, one affecting rice resistance and BPH multiplication, the other affecting rice resistance only.     

基于EPG分析无翅型和有翅型柑橘蚜虫的取食行为

为明确无翅型、有翅型柑橘蚜虫取食行为的差异,采用EPG技术对褐色橘蚜Toxoptera citricida(Kirkaldy)和棉蚜Aphis gossypii Glover的有翅型、无翅型成蚜在柑橘苗上的取食行为进行测定。结果表明,褐色橘蚜无翅型和有翅型的EPG均记录到7种取食波形,依次为非刺探波np、路径波A、B和C、电位下降波pd、韧皮部取食波E1和E2;棉蚜无翅型和有翅型的EPG记录到9种取食波形,除上述7种外,还包括木质部主动吸食波G和口针阻碍波F。褐色橘蚜有翅型和无翅型的np波持续时间为25.73 min和8.39 min,二者间差异显著;棉蚜有翅型的np波持续时间、刺探次数、C波次数分别为27.34 min、19.16次、20.21次,显著高于无翅型,而刺探总持续时间为332.66 min,显著低于无翅型。棉蚜的C波次数及总持续时间、刺探次数、pd波次数及总持续时间均显著高于褐色橘蚜,而E2波总持续时间及平均持续时间均显著小于褐色橘蚜。表明棉蚜无翅型比有翅型在柑橘上更容易取食,影响有翅型蚜虫取食的抗性因子可能位于柑橘表面;褐色橘蚜比棉蚜对柑橘的适应性更强。     

Imidacloprid‐susceptible Nilaparvata lugens individuals exceeded resistant individuals in a mixture population with density pressure

BACKGROUND

Fitness costs associated with insecticide resistance in pest insects have mainly been studied under optimal laboratory conditions. However, resistant insects face more stressors than just insecticides in the field, and how the resistant population reacts to these stressors is of practical importance for the control of pest insects such as the brown planthopper Nilaparvata lugens. The aim of the present study was to explore the impact of population density on the competitiveness of resistant and susceptible individuals.

RESULTS

Two isogenic N. lugens populations, a highly imidacloprid‐resistant population (HZ‐R) with a resistance ratio (RR) of 227.10 and a relatively susceptible population (HZ‐S) with an RR of 2.99, were created from a field‐resistant population (HZ; RR 62.51). The high resistance levels of HZ‐R and HZ were mainly attributable to the overexpression of multiple cytochrome P450 (CYP) genes such as CYP6ER1, CYP6AY1, CYP6CW1 and CYP4CE1 compared with HZ‐S, this being supported by piperonyl butoxide synergism. HZ‐R was observed to be more resistant to thiacloprid and etofenprox compared with HZ and HZ‐S. Most interestingly, in high population density treatments, HZ‐S individuals were much more competitive than HZ‐R individuals.

CONCLUSION

Imidacloprid‐resistant individuals of N. lugens are less competitive than their susceptible counterparts under density pressure. © 2017 Society of Chemical Industry     

吡蚜酮对禾谷缢管蚜的亚致死效应

本文研究了吡蚜酮对禾谷缢管蚜的亚致死效应。试验利用刺探电位图谱(EPG)技术测定了亚致死剂量的吡蚜酮对禾谷缢管蚜成虫取食行为的影响,结果表明:经吡蚜酮处理的蚜虫口针从开始刺探到持续吸食韧皮部和木质部汁液的时间明显延长,分别延长至(199.9±34.0)min和(236.4±29.5)min,对照分别为(155.5±18.1)min和(145.5±27.1)min。并且,经药剂处理的蚜虫口针在韧皮部和木质部中持续取食的时间明显缩短,分别为(44.7±9.4)min和(11.8±2.5)min,对照分别为(93.0±24.9)min和(19.0±3.6)min。通过生长和繁殖试验可知:亚致死剂量的吡蚜酮使禾谷缢管蚜的重量显著减轻,繁殖率明显降低。经药剂处理的蚜虫最大重量和最高繁殖率分别为(1.28±0.025)mg/10头和(2.9±0.2)头/成蚜,而对照分别为(1.56±0.099)mg/10头,(5.2±0.2)头/成蚜。     

长翅型与短翅型褐飞虱对杀虫剂的敏感性比较

采用稻苗浸渍法测定了长、短翅型褐飞虱对烯啶虫胺、环氧虫啶、呋虫胺、噻虫嗪、噻虫胺、吡虫啉、毒死蜱、敌敌畏、噻嗪酮、异丙威、吡蚜酮和醚菊酯的敏感性,并对其体内解毒酶活力进行了比较分析。结果表明:长翅型与短翅型褐飞虱若虫对新烟碱类杀虫剂呋虫胺、噻虫嗪、噻虫胺和吡虫啉的敏感性存在显著差异,长翅型比短翅型更敏感;相反,对于有机磷类杀虫剂毒死蜱,短翅型褐飞虱则更敏感;2种生物型对烯啶虫胺、环氧虫啶、敌敌畏、噻嗪酮、异丙威、吡蚜酮和醚菊酯的敏感性无显著差异。解毒酶相对比活力测定结果表明,长翅型褐飞虱若虫酯酶比活力显著高于短翅型,细胞色素P450单加氧酶比活力显著低于短翅型,而谷胱甘肽S-转移酶比活力无显著性差异。本研究结果可为褐飞虱的有效防控提供科学参考。     

水稻锯齿叶矮缩病毒对褐飞虱生长发育和生殖的影响

为明确水稻锯齿叶矮缩病毒（rice ragged stunt virus,RRSV）对褐飞虱Nilaparvata lugens生长发育和生殖的影响,分别比较带毒褐飞虱与未带毒褐飞虱的若虫发育历期、成虫寿命、性比、翅型及产卵量,并利用实时荧光定量PCR（real-time quantitative PCR,RT-qPCR）技术分析RRSV侵染后褐飞虱体内卵黄原蛋白（vitellogenin,Vg）与其受体（vitellogenin receptor,VgR）以及海藻糖代谢途径中相关基因表达量的情况。结果显示,带毒褐飞虱的若虫历期显著高于未带毒褐飞虱的若虫历期,分别为17.56 d和15.90 d;带毒褐飞虱的成虫寿命、雌虫比例和短翅比例均高于未带毒褐飞虱的,但两者间均无显著差异;带毒褐飞虱较未带毒褐飞虱单雌日产卵量显著提升,分别为11.26粒和6.45粒;带毒褐飞虱的Vg、VgR和海藻糖转运蛋白基因（trehalose transporter,TRET）表达量均显著高于未带毒褐飞虱的。表明RRSV侵染会显著延长褐飞虱若虫发育历期,同时可能通过上调Vg、VgR以及TRET的表达量以促进褐飞虱生殖。     

Susceptibility to neonicotinoids and risk of resistance development in the brown planthopper, Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

BACKGROUND: In recent years, outbreaks of the brown planthopper, Nilaparvata lugens (Stål), have occurred more frequently in China. The objective of this study was to determine the susceptibility of N. lugens to neonicotinoids and other insecticides in major rice production areas in China. RESULTS: Results indicated that substantial variations in the susceptibility to different insecticides existed in N. lugens. Field populations had developed variable resistance levels to neonicotinoids, with a high resistance level to imidacloprid (RR: 135.3–301.3‐fold), a medium resistance level to imidaclothiz (RR: 35–41.2‐fold), a low resistance level to thiamethoxam (up to 9.9‐fold) and no resistance to dinotefuran, nitenpyram and thiacloprid (RR < 3‐fold). Further examinations indicated that a field population had developed medium resistance level to fipronil (up to 10.5‐fold), and some field populations had evolved a low resistance level to buprofezin. In addition, N. lugens had been able to develop 1424‐fold resistance to imidacloprid in the laboratory after the insect was selected with imidacloprid for 26 generations. CONCLUSION: Long‐term use of imidacloprid in a wide range of rice‐growing areas might be associated with high levels of resistance in N. lugens. Therefore, insecticide resistance management strategies must be developed to prevent further increase in resistance. Copyright © 2008 Society of Chemical Industry     

六种植物精油对褐飞虱和稻虱缨小蜂行为的影响

为研发基于植物精油的褐飞虱Nilaparvata lugens驱避剂和稻虱缨小蜂Anagrus nilaparvatae引诱剂,利用嗅觉仪测试了6种植物精油在不同浓度下对褐飞虱和稻虱缨小蜂的行为反应。结果表明,6种植物精油对褐飞虱和稻虱缨小蜂行为的影响具有种类差异性,不同植物精油对昆虫的行为影响有较大差异。此外,褐飞虱和稻虱缨小蜂对植物精油的嗅觉反应还与精油浓度有关,精油浓度范围在100～5 000 mg/L时,山楂油、白木香油、金银花油、肉桂油和鱼腥草油对褐飞虱雌成虫表现出明显的趋避效果,其中山楂油和金银花油的驱避效果最好,二者在100、500、1 000和5 000 mg/L这4个浓度下均能显著驱避褐飞虱。0.1 mg/L和1 mg/L浓度的山楂油、0.1 mg/L浓度的白木香油和1 mg/L浓度的丁香花蕾油对稻虱缨小蜂雌成虫有较强的吸引力。较高浓度10 mg/L的鱼腥草油对稻虱缨小蜂有明显的驱避性。表明植物精油可以明显地影响褐飞虱和稻虱缨小蜂的行为,可作为行为调控物在"推-拉"策略中防控褐飞虱。     

Inheritance mode and realized heritability of resistance to imidacloprid in the brown planthopper,Nilaparvata lugens (Stål) (Homoptera: Delphacidae)

BACKGROUND: The brown planthopper, Nilaparvata lugens (Stål), is a serious pest that causes enormous losses to the rice crop in Asia. The genetic basis of imidacloprid resistance was investigated in N. lugens. RESULTS: The resistant strain, selected for imidacloprid resistance from a field population of N. lugens collected from Nanjing, Jiangsu Province, China, showed a 964‐fold resistance compared with the laboratory strain. Progenies of reciprocal crosses (F₁ and F₁′) showed similar dose–mortality responses (LC₅₀) to imidacloprid, and also exhibited a similar degree of dominance (D), 0.58 for F₁ and 0.63 for F₁′. Chi‐square analyses of self‐bred and backcross progenies (F₂, F₂′ and BC respectively) rejected the hypothesis for a single gene control of the resistance. The estimated realized heritability (h²) of imidacloprid resistance was 0.1141 in the resistant strain of N. lugens. CONCLUSION: The results showed that imidacloprid resistance in N. lugens was autosomal and was expressed as an incompletely dominant trait, probably controlled by multiple genes. Copyright © 2009 Society of Chemical Industry     

CTV强弱毒株促进褐色橘蚜的取食

正由柑橘衰退病病毒(Citrus tristeza virus,CTV)引起的柑橘衰退病,对全世界柑橘产业造成了严重威胁。褐色橘蚜Toxoptera citricida(Kirkaldy)属半翅目蚜科,以非循回型半持久方式传播CTV,是CTV的最有效传播媒介~([1])。我国广泛分布着CTV的各种株系和传媒褐色橘蚜,对我