Journal of Pest Science https://doi.org/10.1007/s10340-020-01223-9

ORIGINAL PAPER

Efective control of Frankliniella occidentalis by Metarhizium anisopliae CQMa421 under feld conditions

Jun Li1,2,3 · Jiaqin Xie1,2,3 · Deyu Zeng1,2,3 · Yuxian Xia1,2,3 · Guoxiong Peng1,2,3

Received: 30 May 2019 / Revised: 22 February 2020 / Accepted: 6 April 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract Annual economic losses of eggplant due to western fower thrips (Frankliniella occidentalis) infestations are considerable. F. occidentalis is difcult to control due to rapid proliferation rates and resistance to chemical insecticides. A more efective biological control strategy is urgently required. To assess the potential efcacy of M. anisopliae CQMa421 in the biologi- cal control of F. occidentalis on eggplant, we evaluated its virulence and insecticidal activity in the laboratory and feld. 7 The laboratory results indicated that the ­LT50 of M. anisopliae CQMa421 against F. occidentalis at 2 × 10 conidia/ml was 5.5 days. The results from the experimental feld trial showed that a single spray of M. anisopliae CQMa421 reduced thrips by 50–70% compared to the control; this was signifcantly lower than for the chemical insecticide imidacloprid. However, the results from demonstration feld trials where consecutive sprays were made indicated that M. anisopliae CQMa421 controlled the pests at a level equivalent to that obtained with a chemical insecticide. The fndings clearly demonstrated the feasibility of using M. anisopliae CQMa421 as an alternative to chemical insecticides in the control of F. occidentalis under feld conditions.

Keywords Metarhizium anisopliae · Western fower thrips · Eggplant · Virulence · Field trials · Biological control

Key message • Application of Metarhizium anisopliae CQMa421 can control Frankliniella occidentalis under feld conditions. • The efcacy of M. anisopliae CQMa421, when applied • There is a lack of efective biocontrol tactics for western several times over a growing season, was as good as that fower thrips which are important pests of feld vegetable obtained from a spray program based on multiple chemi- crops in China. cal insecticides. • M. anisopliae CQMa421 could be a viable alternative to chemical insecticides. Communicated by S. Reitz.

Special issue on novel management tactics for the western fower thrips. Introduction

* Yuxian Xia Western fower thrips, Frankliniella occidentalis Pergande [email protected] (Thysanoptera: Thripidae), is a devastating pest of vegetable * Guoxiong Peng crops (Kirk and Terry 2003; Kutuk 2017; Zhang et al. 2019). [email protected] F. occidentalis feeds on the contents of plant cells, which 1 School of Life Sciences, Chongqing University, Huxi reduces photosynthetic capacity and can transmit several Campus, No. 55 Daxuecheng South Road, Shapingba important plant viruses. Economic losses result from direct District, Chongqing 401331, China feeding damage, reduced production and damaged fruits 2 Chongqing Engineering Research Center for Fungal (Wetering et al. 1999; Kutuk 2017). Insecticides, Chongqing 401331, China Currently, the main strategy used to control F. occiden- 3 Key Laboratory of Gene Function and Regulation talis is the large-scale application of chemical insecticides. Technologies under Chongqing Municipal Education In China, chemical insecticides make up 90% of all control Commission, Chongqing 401331, China

Vol.:(0123456789)1 3 Journal of Pest Science agents used. High dosages and mixtures of various chemical Materials and methods insecticides are applied frequently to vegetable crops. This heavy reliance on chemical insecticides caused the resistance Preparation of fungal cultures and conidial of F. occidentalis to chemical insecticides such as abamectin suspensions (resistance raised 45.5-fold), spinosad (resistance raised > 104- fold), acrinathrin (resistance raised 43-fold) and benzoylurea M. anisopliae var. anisopliae strain CQMa421 was obtained (resistance raised 3.2–220-fold) has rapidly evolved (Wan et al. from the Genetic Engineering Research Center, College of 2018; Meng et al. 2018; Suzuki et al. 2017; Bielza et al. 2008). Life Science, Chongqing University, China. Conidia of were Additionally, eggs and pupae are hidden in plant tissues and produced as previously reported (Peng et al. 2008). Briefy, soil, protecting them from direct exposure to the pesticides mycelia were cultured in 1/4 SDAY liquid medium at 28 °C (Jensen 2000). The heavy usage of chemical insecticides is for 3 days using fermentation reactor and inoculated 10% also a hazard to ecosystems and human health (Ventura et al. culture (v/w) to autoclaved rice with water content 40–50%. 2019; Yan et al. 2018). The conidia were harvested with griddle (100 orders) after Entomopathogenic fungi are important control factors for 15 days of growth and then allowed to air-dry at room tem- pests in the natural environment. They infect and kill pests by perature. A batch of conidia more than 80% germination on penetrating the integument through physical force and enzy- solid medium was used for following experiments. In fol- matic degradation of the insect cuticle, proliferation within the low-up trials, working suspensions were prepared in sterile host and secreting toxins (Ortiz-Urquiza et al. 2015). Owing 0.01% Tween-80 solution (Sigma Chemical Co. Ltd., UK). to these multiple modes of action, it is more challenging for insects to build resistance against these biocontrol agents. Bioassays Entomopathogenic fungi, including Metarhizium brunneum Petch and Beauveria bassiana (Balsamo) Vuillemin, have The suspension of M. anisopliae CQMa421 conidia in been developed as mycoinsecticides to control pests and mini- 0.1% Tween-80 solution (Sigma Chemical Co. Ltd., UK) mize the damage they cause (de Faria and Wraight 2007). A was adjusted to the following serial concentrations: 8 × 105, strain of Metarhizium brunneum Petch (formerly known as 4 × 106, 2 × 107, 1 × 108 and 5 × 108 conidia/ml. The 0.1% M. anisopliae), which was isolated from Cydia pomonella, is Tween-80 solution was as control. The suspensions were pathogenic to F. occidentalis, and its use to control thrips in sprayed onto leaves of eggplant seedlings with 2–3 leaves laboratories and greenhouses has been reported (Vestergaard (1 ml per leaf) using a Potter Precision Spray Tower (Burk- et al. 1995; Saito and Brownbridge 2018; Zhang et al. 2019). ard Manufacturing, UK). F. occidentalis adults were col- These results suggest that M. anisopliae has the potential to lected from eggplant fowers under feld condition, chilled control F. occidentalis on eggplant under feld conditions. M. and placed at 8–10 °C for 10 min and then 20 individuals anisopliae var. anisopliae CQMa421, isolated from muscar- placed onto 3 leaves of the eggplant seedlings. The seed- dine cadavers of rice leafroller (Cnaphalocrocis medinalis), lings were transferred into Petri dishes (15 cm diameter) has a wide range of hosts and has been successfully applied to and placed into illuminated incubators at 26 ± 1 °C with a control plant hopper, Nilaparvata lugens, Sogatella furcifera cycle of 16 h light/8 h dark in 60–80% relative humidity. and Laodelphax striatellus on rice in China (Hong et al. 2017). Four replicates of each treatment were conducted. F. occi- Eggplant, Solanum melongena L., one of the most eco- dentalis mortality was checked daily for 7 days. To verify nomically important vegetables in Asia (Van Eck and Snyder the carcasses killed by M. anisopliae, all of them were put 2006), and approximately one-third of the global acreage is in a Petri dish (diameter 3.5 cm) and cultured at 26 ± 1 °C grown in the region (from the Food and Agriculture Organi- for 3–4 days in an incubator. zation of the United Nations). Eggplant is susceptible to F. occidentalis. To determine whether M. anisopliae CQMa421 Field trials and data collection could be used to control F. occidentalis on eggplant, the fun- gus was frst evaluated in the laboratory and small-scale feld Experimental feld trials trials, followed by a large-scale trial in feld-grown eggplant. About 0.2-hectare (ha) area of S. melongena (var. Jing- qie No. 6) infested with F. occidentalis was selected for the experimental trial. The trial area was divided equally into 20 plots with 10 m × 10 m. Distance of 1 m was set up among the plots. Four plots were assigned at random to each treatment. M. anisopliae CQMa421 suspensions con- taining 4 × 106, 2 × 107 and 1 × 108 conidia/ml were sprayed

1 3 Journal of Pest Science at a rate equivalent to 45 l/h onto the eggplants using an thrips extracted from per fower. In the experimental trials, the electric sprayer (Lanou Ltd., Corp., China). Imidacloprid relative control efcacy (%) of each treatment was based on (working concentration 0.15 g/l, Admire­ ® 70% WG, Bayer, the population density of F. occidentalis on eggplants and was Germany) and water acted as positive and negative controls, calculated as follows (Tong and Feng 2016): respectively. F. occidentalis on fower samples were counted 1 − D D D D ×% before spraying with the insecticides and 7 and 14 days after tj c0 t0 cj spraying, using sampling and processing protocols described Here Dc and Dcj represent the numbers of F. occidentalis below. 0 observed in the control on the day before spraying and the j D D Demonstration feld trials th day after spraying, respectively. t0 and tj represent the numbers of F. occidentalis observed after treatment with M. anisopliae CQMa421 or imidacloprid on the corresponding A 3.0-ha planting area was chosen for the demonstration tri- days. als and divided equally into eight plots with 60 × 60 m. Four M. anisopliae replicate plots were assigned at random to the Statistical analysis CQMa421 treatment (containing 2 × 107 conidia/ml) and four to the treatment of chemical insecticides. A spray rota- All datasets were analyzed using SPSS 20 (IBM SPSS Sta- tion of three chemical insecticides was used, including cyan- tistical, Chicago, USA). The median lethal concentration traniliprole ­(Cyazypyr® 10% OFK, DuPont, USA), sulfoxafor ­(LC ) and median lethal time ­(LT ) for all efective con- ­(Isoclast® 20% WG, Dow AgroSciences, USA) and imida- 50 50 centrations were calculated by probit analysis. A one-way cloprid (Admire­ ® 70% WG, Bayer, Germany). Application analysis of variance (ANOVA) followed by Tukey’s test was rate was same as the above description. The spray interval used to analyze the data from the experimental feld trial. depended on the population density of F. occidentalis, but the The data collected from the demonstration feld trials were both treatments were applied on the same dates. The applica- analyzed using an independent sample t test. The signif- tion dates are available in Fig. 3. cance level of all analyses was set at 0.05. The confdence Data collection level was set at 95% for all the tests.

Plots were sampled weekly to assess the relative efcacy of Results each treatment. A fve-point sampling method was used in each plot in both feld trials (experimental and demonstration). In the laboratory assays, F. occidentalis mortality ranges The distance of 1.6 m to plot margin was not survey. Each data from 30.0% in the 8 × 105 conidia/ml treatment to 100.0% point was obtained by sampling fve fowers in the experi- in the 5 × 108 conidia/ml treatment after 7 days (Fig. 1). In mental trials and ten fowers in the demonstration trials; fow- addition, low mortality also was observed in control (Fig. 1 ers were selected at random within each point. Sampling was and Table 1). The calculated ­LT value for the highest performed between 2:00 and 3:00 p.m., when F. occidentalis 50 concentration tested, i.e., 5 × 108 conidia/ml, was 3.8 days, are typically hidden in the fowers due to the relatively high whereas 6.7 days were required to achieve 50% mortality ambient temperatures. Insects were extracted from the fowers at 4 × 106 conidia/ml (Table 1). The calculated ­LC values by fushing them with water using a wash bottle, collecting the 50 were 4.9 × 107, 9.8 × 106 and 2.9 × 106 conidia/ml for days liquid in a white porcelain bowl and recording the number of

Fig. 1 a Mortality (mean ± SE) of Frankliniella occidentalis after treatment with Metarhi- zium anisopliae CQMa421 conidia in the laboratory. F. occidentalis carcass in control b and in treatment showing symptoms of infection with M. anisopliae c cultured by incuba- tor at 26 °C for 2–3 days

1 3 Journal of Pest Science

Table 1 Mean percentage thrips mortality 7 days after treatment and median lethal time (LT50) for infection by Metarhizium anisopliae CQMa421 at diferent test concentrations

Concentration Mortality (%) at LT50 (days) 95% fducial (conidia/ml) 7 days (± SE) limits (spores)

8.0 × 105 30.00 ± 5.77a – – 4.0 × 106 52.50 ± 2.89b 6.7 6.49–6.91 2.0 × 107 77.50 ± 6.45c 5.6 5.43–5.70 1.0 × 108 100.00 ± 0.00c 4.6 4.39–4.80 5.0 × 108 100.00 ± 0.00c 3.8 3.65–3.99 Control 2.50 ± 2.89 – – Fig. 2 The relative control efcacy (mean ± SE) of Metarhizium anisopliae CQMa421 sprayed on to eggplant in experimental feld All lines are signifcantly a good ft (P < 0.05) trial, 7 and 14 days after spraying. n.s represents no signifcant dif- Within a column, means followed by same letter are not signifcantly ference. Asterisks indicate signifcance levels of *P < 0.05 and diferent and diferent lowercase letters are signifcantly diferent **P < 0.01 (Tukey test by one-way ANOVA) fve, six and seven, respectively (Table 2). To confrm that imidacloprid (94.0 and 89.9% on Days 7 and 14, respec- the dead F. occidentalis were infected with M. anisopliae tively) (Fig. 2). CQMa421, all carcasses were handled as described above F. occidentalis infest eggplant throughout 5 months of and examined for fungal outgrowth after 3–4 days. M. a production cycle. Typically, chemical insecticides are anisopliae hyphae and conidia were observed on the sur- applied 10–15 times over this cycle to control F. occidenta- faces of the F. occidentalis cadavers recovered from plants lis. Therefore, in the demonstration feld trial, M. anisopliae treated with the fungus (Fig. 1c), whereas no M. anisopliae CQMa421 was applied several times in each of the 2017 and outgrowth was detected on cadavers recovered from the con- 2018 growing seasons. The results from these experiments trols (Fig. 1b). are presented in Fig. 3a (2017) and 3b (2018). F. occiden- In the feld experimental trial, the results showed that F. talis populations were similar between the M. anisopliae occidentalis control with M. anisopliae CQMa421 was as CQMa421-treated and chemical insecticide-treated crops dosage dependent as that of the laboratory-based bioassay (Fig. 3). In the late phases of 2017 and 2018, the numbers (Fig. 2). A relative control efcacy of 54.2% was obtained of F. occidentalis on the M. anisopliae CQMa421-treated when 4 × 106 conidia/ml was applied, signifcantly lower eggplants were, signifcantly lower than on the chemical than that obtained from the 2 × 107 conidia/ml and 1 × 108 insecticide-treated plants (Fig. 3). Of note, the population conidia/ml treatments (66.3% and 70.2%, respectively) by density of F. occidentalis fuctuated more during the early Day 7 (Fig. 2). By Day 14, there was no signifcant difer- stages of the 2018 trial than in the other periods (Fig. 3b). ence in the relative control efcacy values among the three This may have been as a result of frequent rainfall events and treatments (51.1%, 61.0% and 59.2%, at 4 × 106 conidia/ variable temperatures that occurred during May and June. ml, 2 × 107 conidia/ml and 1 × 108 conidia/ml, respectively) (Fig. 2). These results indicate that a single spray of M. anisopliae CQMa421 could efectively suppress F. occi- dentalis on eggplant. However, the efcacy of the fungal treatment was signifcantly lower than that obtained with

Table 2 Calculated median lethal concentration (LC50) values for Metarhizium anisopliae CQMa421 (conidia/ml) against Frankliniella occi- dentalis on 5, 6 and 7 days after treatment

2 Time (days) LC50 df χ Regression equation 95% fducial limits (spores/ml)

5 4.9 × 107 3 1.491 p =−4.377 + 0.569 × lg X 3.1 × 107–8.6 × 107 6 9.8 × 106 3 16.036 p =−5.790 + 0.828 × lg X 1.4 × 106–1.3 × 107 7 2.9 × 106 3 8.776 p =−7.664 + 1.185 × lg X 9.4 × 105–6.5 × 106

Concentrations of ­LC50 are in number of conidia/ml to treat Frankliniella occidentalis p represents probit-transformed mortality (%); X represents concentration (conidia/ml)

1 3 Journal of Pest Science

Fig. 3 The numbers (mean ± SE) of Frankliniella occidentalis per fower in demonstration feld trials during a 2017 and b 2018. Hash tags indicate when insecticides were applied. The samples were collected before the insecticide applications. Asterisks indicate signifcant diferences *P < 0.05 and **P < 0.01 (independent sample t-test)

Discussion single fungal spray would control or successfully infect all stages present at the time of spraying. Furthermore, The bioassay results showed that M. anisopliae CQMa421 any foliar sprays would not contact non-motile stages, efectively controlled F. occidentalis in the laboratory. i.e., eggs and pupae. Thus, it is safe to assume that the This is consistent with previous reports (Vestergaard et al. relative efcacy of a single M. anisopliae spray would be 1995). A relative efcacy of 60–70% control was obtained lower than for a standard chemical insecticide. However, in experimental field trials using 2 × 107 and 1 × 108 when the population density of F. occidentalis on eggplant conidia/ml, 7 days after spraying. The fndings suggest that is relatively low, a control efcacy of 60–70%, as exhib- M. anisopliae CQMa421 is a candidate control agent for F. ited by M. anisopliae CQMa421, is sufcient to prevent occidentalis under feld conditions. However, the relative F. occidentalis populations from reaching damaging lev- control efcacy of M. anisopliae CQMa421 in the experi- els. However, a single spray is not sufcient to suppress mental feld trial was signifcantly lower than that obtained F. occidentalis population growth under feld conditions. using imidacloprid. Entomogenous fungi take longer to Like other biocontrols, M. anisopliae is best used in a pre- kill their hosts than chemical insecticides, and insect infec- ventative manner and these results suggest that the fungus tion is infuenced by prevailing environmental conditions. could provide the necessary level of control if applied sev- Additionally, the efect of the fungus varies depending eral times over a growing season within an IPM program. on the developmental stage of the pest. For example, M. At present, chemical insecticide mixtures composed of anisopliae strain 275 infected adult thrips more readily multiple products are often used to control thrips on com- than larvae or pupae (Vestergaard et al. 1995). All devel- mercial crops. Although these mixtures are transiently efec- opmental stages of F. occidentalis are present on plants tive, they inevitably promote insect resistance and pose a risk under feld conditions. As a result, it is unlikely that a to applicators and the environment. When applied several

1 3 Journal of Pest Science times over a growing season, M. anisopliae CQMa421 de Faria MR, Wraight SP (2007) Mycoinsecticides and Mycoacari- controlled F. occidentalis as well as a standard chemical cides: a comprehensive list with worldwide coverage and inter- national classifcation of formulation types. Biol Control 43:237– program. Consecutive applications of the fungus ensure 256. https​://doi.org/10.1016/j.bioco​ntrol​.2007.08.001 that high levels of infective inoculum are maintained in the González-Mas N, Ortega-García L, Garrido-Jurado I, Dembilio O, pest’s environment (Vänninen et al. 2000; González-Mas Jaques JA, Quesada-Moraga E (2019) Which came first: the F. occidentalis disease or the pest? Is there a host mediated spread of Beau- et al. 2019). Furthermore, predators of such veria bassiana Orius M. anisopliae (Ascomycota: Hypocreales) by invasive palm as mites and spp. are not afected by pests? J Invertebr Pathol 162:26–42. https​://doi.org/10.1016/j. (Pourian et al. 2010; Saito and Brownbridge 2018; Midthas- jip.2019.01.007 sel et al. 2016), which may indirectly enhance the efcacy Hong MS, Peng GX, Keyhani NO, Xia YX (2017) Application of the Metarhizium anisopliae of this mycoinsecticide. entomogenous fungus, , for leafroller (Cnaphalocrocis medinalis) control and its efect on rice phyllo- The evaluation of mycoinsecticides using methods sphere microbial diversity. Appl Microbiol Biotechnol 101:6793– devised for chemical insecticides can provide misleading 6807. https​://doi.org/10.1007/s0025​3-017-8390-6 results that do not demonstrate their full potential util- Jensen SE (2000) Insecticide resistance in the western fower thrips, Frankliniella occidentalis ity in IPM. This has undoubtedly impeded development . Integr Pest Manag Rev 5:131–146. https​://doi.org/10.1023/a:10096​00426​262 to facilitate large-scale applications. The results from the Kirk WDJ, Terry LI (2003) The spread of the western fower thrips demonstration feld trial have revealed that the evaluation of Frankliniella occidentalis (Pergande). Agr Forest Entomol 5:301– mycoinsecticides should take into account a range of factors 310. https​://doi.org/10.1046/j.14619​563.2003.00192​.x Amblyseius swirskii such as host susceptibility (life stage), use in a preventative Kutuk H (2017) Performance of the predator (Acari: Phytoseiidae) on greenhouse eggplants in the absence and manner and compatibility with other natural control agents. presence of pine Pinus brutia (Pinales: Pinaceae) pollen. Entomol The results of the current study, together with other demon- Res 47:263–269. https​://doi.org/10.1111/1748-5967.12222​ strated attributes of the fungus, suggest that M. anisopliae Meng XK, Xie ZJ, Zhang N, Ji CH, Dong F, Qian K, Wang JJ (2018) CQMa421 would be an excellent addition to a biological Molecular cloning and characterization of GABA receptor and GluCl subunits in the western fower thrips, Frankliniella occiden- control program for thrips on eggplant. talis. Pestic Biochem Phys 150:33–39. https​://doi.org/10.1016/j. pestb​p.2018.06.012 Midthassel A, Leather SR, Wright DJ, Baxter IH (2016) Compatibility of Amblyseius swirskii with Beauveria bassiana: two potentially Author contributions complimentary biocontrol agents. Biocontrol 61:437–447. https​ ://doi.org/10.1007/s1052​6-016-9718-3 Ortiz-Urquiza A, Luo ZB, Keyhani NO (2015) Improving mycoinsec- PG and XY conceived study. PG, XJ, ZD and LJ designed ticides for insect biological control. Appl Microbiol Biotechnol and conducted experiments and collected data. LJ and PG 99:1057–1068. https​://doi.org/10.1007/s0025​3-014-6270-x analyzed the data and wrote the manuscript. All authors read Peng GX, Wang ZK, Yin YP, Zeng DY, Xia YX (2008) Field trials of and approved the manuscript. Metarhizium anisopliae var. acridum (Ascomycota: Hypocreales) against oriental migratory locusts, Locusta migratoria manilensis (Meyen) in Northern China. Crop Prot 27:1244–1250. https://doi.​ Acknowledgements This work was supported by National Key org/10.1016/j.cropr​o.2008.03.007 R&D Program of China (No. 2017YFD0201200) and Techno- Pourian HR, Talaei-Hassanloui R, Kosari AA, Ashouri A (2010) logical Innovation and Application Demonstration Project of CQ Efects of Metarhizium anisopliae on searching, feeding and pre- (cstc2018jscx-msybX0222). dation by Orius albidipennis (Hem., Anthocoridae) on Thrips tabaci (Thy., Thripidae) larvae. Biocontrol Sci Technol 21:15–21. Compliance with ethical standards https​://doi.org/10.1080/09583​157.2010.51760​3 Saito T, Brownbridge M (2018) Compatibility of foliage-dwelling Conflict of interest The authors declare that they have no confict of predatory mites and mycoinsecticides, and their combined efcacy interest. against western fower thrips Frankliniella occidentalis. J Pest Sci 91:1291–1300. https​://doi.org/10.1007/s1034​0-018-0991-z Human and animal rights statement This article does not contain any Suzuki Y, Shiotsuki T, Jouraku A, Miura K, Minakuchi C (2017) studies with human participants or animals performed by any of the Benzoylurea resistance in western fower thrips Frankliniella authors. occidentalis (Thysanoptera: Thripidae): the presence of a point mutation in chitin synthase 1. J Pestic Sci 42:93–96. https​://doi. org/10.1584/jpest​ics.D17-023 Tong SM, Feng MG (2016) A mixture of putative sodium salts of camptothecin and bamboo tar is a novel botanical insecticide References against rice planthoppers and stem borers. J Pest Sci 89:1003– 1011. https​://doi.org/10.1007/s1034​0-015-0717-4 Solanum melongena Bielza P, Quinto V, Fernández E, Grávalos C, Abellán J, Cifuentes D Van Eck J, Snyder A (2006) Eggplant ( L.). Meth- (2008) Inheritance of resistance to acrinathrin in Frankliniella ods Mol Biol 343:439–447. https​://doi.org/10.1385/1-59745​ occidentalis (Thysanoptera: Thripidae). Pest Manag Sci 64:584– -130-4:439 588. https​://doi.org/10.1002/ps.1540 Vänninen I, Tyni-Juslin J, Hokkanen H (2000) Persistence of aug- mented Metarhizium anisopliae and Beauveria bassiana in

1 3 Journal of Pest Science

Finnish agricultural soils. Biocontrol 45:201–222. https​://doi. Frankliniella occidentalis (Thysanoptera: Thripidae). Bull Ento- org/10.1016/10.1023/A:10099​98919​531 mol Res 89:579–588. https://doi.org/10.1017/S0007​ 48539​ 90007​ 35​ Ventura C, Zappia CD, Lasagna M, Pavicic W, Richard S, Bolzan AD, Yan DD, Zhang YJ, Liu LG, Shi N, Yan H (2018) Pesticide exposure Monczor F, Núñez M, Cocca C (2019) Efects of the pesticide and risk of Parkinson’s disease: dose–response meta-analysis of chlorpyrifos on breast cancer disease. Implication of epigenetic observational studies. Regul Toxicol Pharm 96:57–63. https://doi.​ mechanisms. J Steroid Biochem Mol Biol 186:96–104. https://doi.​ org/10.1016/j.yrtph​.2018.05.005 org/10.1016/j.jsbmb​.2018.09.021 Zhang XR, Lei ZR, Reitz SR, Wu SY, Gao YL (2019) Laboratory Vestergaard S, Gillespie AT, Butt TM, Schreiter G, Eilenberg J (1995) and greenhouse evaluation of a granular formulation of Beauve- Pathogenicity of the Hyphomycete Fungi Verticillium lecanii and ria bassiana for control of western fower thrips, Frankliniella Metarhizium anisopliae to the Western Flower Thrips, Franklin- occidentalis. Insects 10:1–11. https​://doi.org/10.3390/insec​ts100​ iella occidentalis. Biocontrol Sci Technol 5:185–192. https://doi.​ 20058​ org/10.1080/09583​15955​00399​09 Wan RY, Yuan GD, He BQ, Xu BY, Xie W, Wang SL, Zhang YJ, Wu Publisher’s Note Springer Nature remains neutral with regard to QJ, Zhou XG (2018) Focc α6, a truncated nAChR subunit, posi- jurisdictional claims in published maps and institutional afliations. tively correlates with spinosad resistance in the western fower thrips, Frankliniella occidentalis (Pergande). Insect Biochem Mol 99:1–10. https​://doi.org/10.1016/j.ibmb.2018.05.002 Wetering FVD, Hoek MVD, Goldbach R, Mollema C, Peters D (1999) Variation in tospovirus transmission between populations of

1 3