Egypt. J. Plant Prot. Res. Inst. (2020), 3 (1): 316 - 325 Egyptian Journal of Plant Protection Research Institute www.ejppri.eg.net Effects of neonicotinoids and sulfoxaflor application against sucking pests infesting watermelon and their associated predators Ahmed, A. Barrania Plant Protection Research Institute, Etay El-Baroud, Agricultural Research Station, Agricultural Research Center, Egypt. ARTICLE INFO Abstract: Article History Field studies were carried out during 2018 and 2019 summer Received: 1 / 2/ 2020 seasons, at Nubarya district, El-Beheira Governorate to evaluate the Accepted: 19/ 3/2020 effects of some neonicotinoid insecticides (Imidacloprid, clothianidin, Keywords thiamethoxam and acetamiprid) compared with sulfoxaflor, at Efficiency, recommended rates against sucking pests infesting watermelon and neonicotinoids, their associated predators. Results showed that, all treatments exhibited sulfoxaflor, sucking excellent and fast action activity against Bemisia tabaci (Gennadius) insects, predators (‎Hemiptera: Aleyrodidae) and the least reduction percentages were and watermelon. recorded by acetamiprid at both seasons. Under the same conditions, neonicotinoid insecticides have toxic effect on predators; Chrysoperla carnea (Stephens) (Neuroptera:‎Chrysopidae), Paederus alfierii Koch. (Coleoptera: Staphylinidae) and Coccinella spp.) (‎Coleoptera‎: ‎Coccinellidae) while, sulfoxaflor has slightly toxic effect. The present study suggests neonicotinoid insecticides can be disruptive to natural and biological control by reducing insect predators populations, so the population of Tetranychus urticae Koch. (Acari: Tetranychidae) will be increased during both seasons. Yet, sulfoxaflor is also reported as being slightly harmful to biological control agents, it as a preferred insecticide, with less harmful effects on the fitness components of natural enemies, for integrated pest management of sucking insects (B. tabaci) on watermelon plantations. Introduction Watermelon, a popular summer Aleyrodidae) and Spodoptera sp. vegetable crop worldwide (Wu et al., (Lepidoptera: Noctuidae) larvae (Wu et 2014) is an important crop and provides al., 2012). The sweet potato whitefly, B. phytochemicals. However, watermelon is tabaci attacks watermelon and a wide susceptible to numerous diseases and range of other plant species and on a pests, such as Tetranychus urticae Koch. global scale. In addition to injuries from (Acari: Tetranychidae), Aphis direct feeding, problems from this pest gossypii Glover (Hemiptera: Aphididae), are intensified because its vectors Bemisia tabaci (Gennadius) (‎Hemiptera: 316 Barrania, 2020 over 100 plant viruses (Jones, 2003 and The sulfoximines are a new class of Simmons et al., 2010). As it is farmed insecticides targeting sap-feeding insects primarily by protected and successive including the aphids, whiteflies, hoppers, cultivation techniques, many pesticides and lygus (Nawaz et al., 2018; Babcock are required for the control of pests (Park et al., 2011 and Zhu et al., 2011), that are et al., 2010). resistant to other classes of insecticides, Neonicotinoid insecticides and that are resistant to the represent the fastest-growing class of neonicotinoids (Sparks et al., 2013). insecticides introduced to the market Sulfoxaflor is the initial compound in this since the launch of pyrethroids (Nauen class selected for commercial and Bretschneider, 2002) and are the development and is an agonist at insect most used class of insecticides for nicotinic acetylcholine receptors controlling sucking insects (Jiang et al., (nAChRs) (Liao et al.,2017; Watson et 2019). Neonicotinoids interfere with the al., 2017 and Sparks et al., 2013). Yet, nicotinic acetylcholine receptor and sulfoxaflor is also reported as being therefore have specific activity against slightly harmful to biological control the insect nervous system (Maienfisch et agents, including Nesidiocoris tenuis al., 2001). It is considered an important (Reuter) (Hemiptera: Miridae), group of insecticides being used against Chrysoperla carnea (Stephens) sucking insects for several years (Neuroptera: Chrysopidae), and Adalia (Muhammad et al., 2011), especially bipunctata (L.) (Coleoptera: active on hemipteran pest species such as Coccinellidae) (Sparks et al. ,2013; aphids, whiteflies, thrips, leaf miners and Wanumen et al., 2016 and Nawaz et al., plant hoppers, but also commercialized to 2018). control many coleopteran and some Therefore, two field experiments lepidopteran pest species (Elbert et al., were carried out during 2018 and 2019 1998 and Nauen et al., 2003). Due to the summer seasons, at Nubarya district, El- potent systemic characteristics, they can Beheira Governorate to evaluate the side be absorbed via the roots and transferred effect of sulfoxaflor and some to almost all parts of targeted crops neonicotinoids treatment against sucking (Jeschke and Nauen, 2008). But this pests infesting watermelon and their irreversible uniting effect may not vary associated predators at recommended much between target and non-target rates. species, inducing similar detrimental Materials and methods impacts on the biocontrol agents 1.Tested compounds: (predators) (Cloyd and Bethke, 2011). Sulfoxaflor (Closer 24% SC) was Currently, global concerns about the provided by Dow Agro Sciences Co., negative influence of neonicotinoids on Ltd. Imidacloprid (Gaucho® 70%WS) non-target organisms (particularly bees) was provided by Bayer Crop Science. and human have led to the regulation by Clothianidin (Supertox-1® 48%SC) was the European Union (EU) since 2013, to provided by Jiangs Jiag chemical industry date, the use of three typical Co. Ltd China. Thiamethoxam (Actara neonicotinoids i.e. imidacloprid, 25% WG) provided by Syngenta thiamethoxam and clothianidin has been Company. Acetamiprid (Mospilan 20% totally banned on field crops by EU SP) provided by Nippon Soda Chemical (Jiang et al., 2019). Industry Co. Ltd. 317 Egypt. J. Plant Prot. Res. Inst. (2020), 3 (1): 316 - 325 2. Field trials: aphid lion, C. carnea, the rove beetle, Field experiments were carried out Paederus alfierii and the lady birds, throughout two successive seasons (2018 Coccinella spp. were counted. Counts and 2019) during summer plantation in were done by the lenses in the early Nubarya district, El-Beheira Governorate. morning when flight activity is minimal These experiments were cultivated with according to Butler et al. (1988). watermelon. The experimental site was Percentage of pest reduction numbers divided into 24 plots, each plot 1/100 were calculated according to Henderson feddan (42m²). Randomized complete and Tilton equation (1955) and blocks design was used with four subjected to analysis of variance replicates for each treatment with the (ANOVA) (CoStat Statistical control plots. Field concentrations were software,1998). 40ml, 60gm, 1000ml, 60gm and Results and discussion 50gm/200 liter per feddan for sulfoxaflor, In this study, field evaluation of some imidacloprid, clothianidin, insecticides treatments against B. tabaci thiamethoxam, and acetamiprid, immature stages on watermelon respectively. The insecticides were plantation at 2018 and 2019 seasons was sprayed by Knapsack sprayer equipment carried out. The % reductions of B. (CP3). For counting the numbers of tabaci caused by sulfoxaflor, whiteflies, B. tabaci (immature stages), imidacloprid, clothianidin, and T. urticae, samples of 25 leaves thiamethoxam, and acetamiprid (from three different levels of the plants) formulation were summarized in Table were collected at random in the morning (1). Mean of % reduction was 95.47, for both diagonals of the inner square 95.35, 91.25, 92.87 and 85.25%, area of each experimental plot. Pre- respectively at 2018, while were 95.62, treatment counts were done in the early 91.17, 93.27, 92.97 and 79.72%, morning just before application while respectively at 2019 season. In both post-treatment counts were done on 1, 4, seasons, the highest reduction 7and 10 days after treatment. In the same percentages were achieved sulfoxaflor time, sample of 25 watermelon plants where the least reduction percentages were examined and the number of the were recorded by acetamiprid. Table (1): Efficacy of certain treatments against Bemisia tabaci immature stages on watermelon plantations. Season Tested Rate / %Reduction After compounds feddan 1-day 4-days 7-days 10-days Mean Sulfoxaflor 40ml 85.4 96.5 100.0 100.0 95.47a Imidacloprid 60g 88.5 94.5 98.4 100.0 95.35a Clothianidin 1000ml 82.2 92.3 96.5 94.0 91.25b Thiamethoxam 60g 81.5 94.2 97.4 98.4 92.87b 2018 Acetamiprid 50ml 77.4 85.1 88.7 89.8 85.25c Sulfoxaflor 40ml 88.1 94.4 100.0 100.0 95.62a Imidacloprid 60g 78.2 90.2 96.3 100.0 91.17a Clothianidin 1000ml 80.5 96.3 100.0 96.3 93.27a Thiamethoxam 60g 81.3 100.0 96.3 94.3 92.97a Acetamiprid 50ml 72.3 80.0 84.3 82.3 79.72b 2019 Means within the same column followed by the same letters are not significantly different according to the LSD0.05 for the same season. 318 Barrania, 2020 This result indicates that, C. carnea, P. alfierii and Coccinella spp. neonicotinoids provides excellent control caused by sulfoxaflor, imidacloprid, B. tabaci (Kuhar et al., 2002). clothianidin, thiamethoxam, and Muhammad et al. (2011 and 2013) acetamiprid. For C. carnea were 31.47, reported that, B. tabaci has developed 49.55, 47.67, 44.55 and 37.50%, resistance to some of neonicotinoids. respectively at 2018 and 30.15, 48.85, Sulfoxaflor is also effective against a 54.52, 43.10and 33.90%, respectively at wide range of sap-feeding