White-backed Planthopper Sogatella Furcifera Research Articles

Crucial role of a takeout protein in white-backed planthopper Sogatella furcifera (Horváth) orientation towards its host rice plants.

The takeout (TO) gene family impacts diverse physiological and behavioral functions in insects, yet specific olfactory-associated roles for the family have yet to be fully elucidated. To provide insights into TO function in rice planthoppers, the genomes of three rice planthoppers (white-backed planthopper, brown planthopper and small brown planthopper) were searched for TO homologs and their degree of conservation assessed via chromosomal localization, exon-intron boundaries, phylogenetic relationships and protein domains/motifs. We performed a tissue-specific expression analysis of the 20 TO genes in the white-backed planthopper (WBPH, Sogatella furcifera) and found that SfTO17 is enriched in adult antennae. RNAi-mediated knockdown of SfTO17 impaired WBPH olfaction and reduced host-seeking responses following exposure to rice plants. The binding profile of β-ionone, hexyl benzoate and benzyl benzoate with recombinant SfTO17 was evaluated via competitive fluorescence binding assays. Conformational prediction of SfTO17 coupled with molecular docking analyses revealed several amino acid residues potentially critical for odorant binding. This study demonstrates the olfactory function of SfTO17 in WBPH and highlights its potential as a target for controlling this rice pest. © 2024 Society of Chemical Industry.

Insecticidal activity against rice pest of oxazosulfyl, a novel sulfyl insecticide.

The development and commercialization of new chemical classes of insecticides are important for efficient crop protection, particularly for combatting insecticide resistance and providing sustainable agricultural production. This study reports on oxazosulfyl, a novel "sulfyl" class of insecticide, against a wide range of insect pests of rice. In the laboratory assay, oxazosulfyl showed insecticidal activity against all developmental stages of the brown planthopper Nilaparvata lugens (Stål). Phosphor imaging assays and soil drench bioassays demonstrated good systemic distribution in rice plants. Oxazosulfyl showed insecticidal activity against imidacloprid- and fipronil-resistant field populations of N. lugens, the white-backed planthopper Sogatella furcifera (Horváth), and the small brown planthopper Laodelphax striatellus (Fallén), as well as the respective susceptible strains. No cross-resistance was observed among oxazosulfyl, imidacloprid, and fipronil. Oxazosulfyl with a wide insecticidal spectrum is a potentially useful pest management tool for sustainable rice production.

Efficacy of Some Insecticides in Combination with Neem on Rice Planthoppers

A field experiment was carried out during kharif 2020, at the Agricultural College Farm, Bapatla to evaluate the efficacy of some insecticides in combination with neem against rice planthoppers in direct seeded rice crop. The results showed that triflumezopyrim 10.6SC @ 25g a.i. ha-1 was the most effective treatment against both brown planthopper Nilaparvata lugens (Stål) and white backed planthopper Sogatella furcifera (Horváth) with 73.61 and 77.69% reductions over untreated control, respectively at 5 DAT. The other effective treatments were dinotefuran 20SG @ 40 g a.i. ha-1 and pymetrozine 50WG @ 150 g a.i. ha-1 with 70.14 and 66.44% reduction of N. lugens and 71.89 and 69.66% reduction of S. furcifera, respectively over untreated control at 5 DAT. Neem formulation 1500 ppm revealed the lowest efficacy with 34.95 and 36.19% reduction of N. lugens and S. furcifera over the untreated control at 5 DAT.

RNA Interference-Screening of Potentially Lethal Gene Targets in the White-Backed Planthopper Sogatella furcifera via a Spray-Induced and Nanocarrier-Delivered Gene Silencing System.

RNA interference (RNAi) is a widespread post-transcriptional silencing mechanism that targets homologous mRNA sequences for specific degradation. An RNAi-based pest management strategy is target-specific and considered a sustainable biopesticide. However, the specific genes targeted and the efficiency of the delivery methods can vary widely across species. In this study, a spray-induced and nanocarrier-delivered gene silencing (SI-NDGS) system that incorporated gene-specific dsRNAs targeting conserved genes was used to evaluate phenotypic effects in white-backed planthopper (WBPH). At 2 days postspraying, transcript levels for all target genes were significantly reduced and knockdown of two gene orthologs, hsc70-3 and PP-α, resulted in an elevated mortality (>60%) and impaired ecdysis. These results highlight the utility of the SI-NDGS system for identifying genes involved in WBPH growth and development that could be potentially exploitable as high mortality target genes to develop an alternative method for WBPH control.

Expression of three neuropeptide genes (SfEH, SfETH, and SfCCAP) in response to insecticide stress on the white-backed planthopper Sogatella furcifera (Hemiptera: Delphacidae)

Expression of three neuropeptide genes (SfEH, SfETH, and SfCCAP) in response to insecticide stress on the white-backed planthopper Sogatella furcifera (Hemiptera: Delphacidae)

Macro-scale perspectives in conservation biological control: latitudinal differences in the effects of organic farming on insect pests and natural enemies in rice paddy ecosystems

The pest control services provided by natural enemies are important for maintaining crop productivity in environmentally friendly agriculture with reduced use of pesticides. Organic farming is generally considered to increase the abundance of natural enemies and to enhance ecosystem services, but species and guild compositions vary from region to region, and so the population levels of pests and their natural enemies can be expected to vary geographically. Here, we surveyed the abundance of rice insect pests and spiders as their natural enemies in 51 organic and 45 conventional paddy fields at 22 locations in Japan and examined latitudinal differences in the effects of farming practices on their abundance. Independently of latitudinal differences, organic farming had positive effects on the abundance and species diversity of spiders caught in nets and on Tetragnatha and lycosid spiders. It increased the abundances of the leafhopper Nephotettix cincticeps and the white-backed planthopper Sogatella furcifera, and decreased that of the small brown planthopper Laodelphax striatellus. Both spiders and insect pests showed diverse responses to the interaction between farming practice and latitude. In particular, insect pests distributed in warmer regions, such as So. furcifera and Ne. cincticeps, tended to be more abundant in the south. The ratios of spider to pest abundance, as indicators of pest suppression, were lowest in organic paddies at lower latitudes for So. furcifera and Ne. cincticeps; at higher latitudes they were higher in organic paddies than in conventional paddies for La. striatellus. These results suggest that the effectiveness of pest suppression by natural predators in organic paddy fields varies by region depending on the ecological characteristics of each organism. As such, it is necessary to devise field management strategies appropriate to each region to balance crop production and biodiversity.

The evolution of insecticide resistance in the white backed planthopper Sogatella furcifera (Horvath) of China in the period 2014–2022

The white-backed planthopper, Sogatella furcifera (Horváth), is a kind of important rice pest in China. Chemical control is the most effective method in the field control of S. furcifera. However, due to the intensive use of chemicals, it has developed resistance to multiple insecticides. Here, we conducted insecticide resistance monitoring of 55 field populations of S. furcifera over the period 2014–2022. Monitoring data demonstrated that most of the field populations showed increased resistance to neonicotinoids such as imidacloprid, dinotefuran and thiamethoxam, which had developed moderate resistance levels. All field populations were still susceptible to triflumezopyrim (RR = 0.1–4.1-fold). Nearly all populations developed a low to moderate level of resistance to pymetrozine (RR = 1.0–46.1). About half of the field populations kept high levels of resistance to buprofezin (RR = 18.4–351.6-fold), and nearly all populations kept moderate levels of resistance to chlorpyrifos (RR = 0.1–88.2-fold). Synergism assay was conducted on a field buprofezin-resistant population and no significant synergistic effect was observed for three inhibitors, which implies that other mechanisms may be involved in resistance evolution in white-backed planthopper.

Functional characterization of tyrosine melanin genes in the white-backed planthopper and utilization of a spray-based nanoparticle-wrapped dsRNA technique for pest control

As a significant pest of rice the white-backed planthopper (WBPH) Sogatella furcifera is a focus of pest management. However, traditional chemical-based control methods risk the development of pesticide resistance as well as severe ecological repercussions. Although nanoparticle-encapsulated dsRNAs provide a promising alternative method for sustainable pest management, gene targets specific to WBPH have yet to be optimized. Genes in the tyrosine-melanin pathway impact epidermal melanization and sclerotization, two processes essential for insect development and metabolism, have been proposed as good candidate targets for pest management. Seven genes (aaNAT, black, DDC, ebony, tan, TH, and yellow-y) in this group were identified from WBPH genome and functionally characterized by using RNAi for their impact on WBPH body color, development, and mortality. Knockdown of SfDDC, Sfblack, SfaaNAT, and Sftan caused cuticles to turn black, whereas Sfyellow-y and Sfebony knockdown resulted in yellow coloration. SfTH knockdown resulted in pale-colored bodies and high mortality. Additionally, an Escherichia coli expression system for large-scale dsRNA production was coupled with star polycation nanoparticles to develop a sprayable RNAi method targeting SfTH that induced high WBPH mortality rates on rice seedlings. These findings lay the groundwork for the development of large-scale dsRNA nanoparticle sprays as a WBPH control method.

Analysis of the Feeding Behavior and Life Table of Nilaparvata lugens and Sogatella furcifera (Hemiptera: Delphacidae) under Sublethal Concentrations of Imidacloprid and Sulfoxaflor

The brown planthopper (BPH) Nilaparvata lugens and white-backed planthopper (WBPH) Sogatella furcifera are serious rice insect pests that cannot overwinter in Korea and migrate from southeast Asian countries and China. In this study, we investigated the sublethal effects of imidacloprid and sulfoxaflor on the biological parameters and feeding behavior of planthoppers. These sublethal concentrations significantly decreased the net reproduction rate (R0), the intrinsic rate of increase (rm), and the mean generation time (T). For BPHs, the total durations of nonpenetration (NP) waveform by imidacloprid (LC10 = 164.74 and LC30 = 176.48 min) and sulfoxaflor (LC10 = 235.57 and LC30 = 226.93 min) were significantly different from those in the control group (52.73 min). In addition, on WBPHs, the total durations of NP waveform by imidacloprid (LC10 = 203.69 and LC30 = 169.9 min) and sulfoxaflor (LC10 = 134.02 and LC30 = 252.14 min) were significantly different from those in the control group (45.18 min). Moreover, the LC10 and LC30 of these insecticides significantly decreased the phloem feeding time. In conclusion, imidacloprid had a better effect on the inhibition of feeding of the WBPH, and sulfoxaflor showed a better effect on the inhibition of feeding of the BPH. Therefore, it is suggested that treatment with sublethal concentrations of the above insecticides will reduce the feeding of BPHs and WBPHs on rice phloem.

Pest Management Modules for Basmati Rice and Farmer’s Perception

The experimental trials were conducted to evaluate four IPM modules viz., M1-Integrated pest management, M2-Chemical module, M3-Farmer’s practice, and M4-untreated control against major insect pests viz., brown planthopper (BPH) Nilaparvata lugens (Stål), white backed planthopper (WBPH) Sogatella furcifera (Horvath), yellow stem borer (YSB) Scirpophaga incertulus (Walker), leaf folder (LF) Cnaphalocrocis medinalis L, in basmati rice in farmer fields at Hapur, Uttar Pradesh. These experiments were conducted in during kharif 2017 and 2018. The observations were made on the mean number of hoppers (plant and leafhoppers), % leaf damage, % dead heart and white earhead. Similarly, occurrence of spiders was also monitored. The results revealed that the M1- IPM module was observed as the best with minimum pest damage, and higher yield. This study concludes that integration of ecofriendly sustainable IPM practices not only minimize insecticide use and other input costs, but also increases the crop yield by safeguarding the natural enemy (spiders). Pre-season skill-oriented extension training programs, field demonstration-based farmer-first participatory approach, as well as regular communication through social media, would enhance their adoption in basmati rice production.

Field Evolution of Insecticide Resistance against Sogatella furcifera (Horváth) in Central China, 2011–2021

The white-backed planthopper Sogatella furcifera (Horváth) is an important pest on rice plants throughout Asia. The application of chemical insecticides is still the main approach to suppressing the field population of S. furcifera. However, misuse of chemical insecticides has promoted the development of insecticide resistance in this insect pest. Thus, in the present study, dose responses of 58 field populations of S. furcifera to 7 insecticides were analyzed by rice-stem dipping from 2011 to 2021 in Central China. The results indicated that field populations of S. furcifera showed moderate levels of resistance to nitenpyram (RR = 1.7–17.8-fold), thiamethoxam (RR = 1.4–25.8-fold), dinotefuran (RR = 1.5–25.3-fold), clothianidin (RR = 2.1–12.5-fold), chlorpyrifos (RR = 1.1–56.6-fold), etofenprox (RR = 1.1–14.8-fold) and isoprocarb (RR = 1.4–11.5-fold). The results presented here will be beneficial to improve our ability to identify and predict insecticide resistance, make better control recommendations and prevent further insecticide resistance development.

Effect of Crop Growth Stages on the Field Population of Rice Hoppers

The rice hoppers viz., brown plant hopper (BPH) Nilaparvata lugens (Stal), white-backed planthopper (WBPH) Sogatella furcifera (Horvath) and green leafhopper (GLH) Nephotettix virescens Distant cause loss in rice and the damage is influenced by plant growth stages. Field experiment has been conducted in this study to evaluate the effect of the growing stages on the incidence of these hoppers at the Agricultural Research Farm, Banaras Hindu University, Varanasi, Uttar Pradesh, India during kharif 2018 and 2019. The results revealed that the incidence is significantly varying among the growth stages, and positively correlated (p < 0.05). Nilaparvata lugens and S. furcifera are the most abundant during the maximum tillering to booting stage. In contrast that of N. virescens peaked during the booting to flowering stage.

Biology and lifetable of whitebacked planthopper Sogatella furcifera (Horvath) on rice

Whitebacked planthopper Sogatella furcifera (Horvath) is an important insect pest causing economic damage to rice. Studies on its biology in West Bengal revealed that the fecundity was 197± 13.37 eggs/ female. The incubation period was 7.6± 0.69 days in October, with nymphal duration being 16.2± 0.85 days; and longevity of male macropterous ones was 9.5± 2.06, while for brachypterous it was 7.3± 1.33 days; and female brachypterous lived for 13.50± 1.08 days. The net fecundity rate, intrinsic rate of increase, gross reproductive rate, generation time, doubling time, finite rate of increase and net reproductive rate were 31.30, 0.122, 108.60, 29.29, 5.68 days, 1.129 and 64.91, respectively. The seasonal abundance when studied on rice in rainy season revealed that slight incidence occurred at 60 days, and its peak was at 32.00 and 34.20/ hill at 120 DAT during second week of November. Then it disappeared from the third week of November with the onset of winter during 2019 and 2020.

Molecular Characterization of UDP-N-Acetylglucosamine Pyrophosphorylase and Its Role in the Growth and Development of the White-Backed Planthopper Sogatella furcifera (Hemiptera: Delphacidae).

UDP-N-acetylglucosamine pyrophosphorylase (UAP) is a key enzyme in the chitin biosynthesis pathway of insects. Here, we described the gene SfUAP in the white-backed planthopper Sogatella furcifera (Horváth) with an open reading frame of 1470 bp. Quantitative real-time polymerase chain reaction (qPCR) suggested that SfUAP exhibits a different developmental expression pattern and a higher expression after molting. The highest expression of SfUAP was observed in the integument tissues of adults, whereas head tissues showed negligible expression. RNAi-based gene silencing decreased the mRNA transcript levels in S. furcifera nymphs injected with double-stranded RNA of SfUAP. Finally, SfUAP silencing led to 84% mortality and malformed phenotypes in nymphs. Thus, our results can help better understand the role of SfUAP in S. furcifera.

Non-Preference Mechanism of Resistance in Rice Germplasm Accessions to Whitebacked Planthopper Sogatella furcifera (Horvath)

Non-Preference Mechanism of Resistance in Rice Germplasm Accessions to Whitebacked Planthopper Sogatella furcifera (Horvath)

Bioefficacy of ethiprole + pymetrozine against the white-backed planthopper Sogatella furcifera (Howard), in rice (ADT – 46)

The nymphs and adults of white-backed planthoppers (Sogatella furcifera, Howard) remove plant sap resulting in yield loss. Indiscriminate use of insecticides, results in the development of resistance by insects and ill effects on the environment opening the new era of chemicals with novel modes of action with good bioefficacy, higher selectivity, low mammalian toxicity and safety to the environment. Therefore, the introduction of newer insecticide molecules with alternate modes of action will play a serious role in pest management programs. Hence, an experiment was conducted to evaluate the bioefficacy of ethiprole + pymetrozine against white-backed planthopper of rice (ADT – 46) under laboratory and field conditions at Annamalai University, Chidambaram during 2018-20. Ethiprole + pymetrozine @ (T1 - 36.91 + 138), (T2 - 40.13 + 150) and (T3 - 45.47 + 170) g a.i ha-1 with standard checks T4 - pymetrozine @ (150) g a.i ha-1, T5 - buprofezin @ (200) g a.i ha-1 and T6 - ethiprole + imidacloprid @ (50 + 50) g a.i ha-1 were evaluated against white-backed planthopper. The standard checks were of positive control i.e., reference insecticides which is in common use The results revealed that T3 recorded the lowest population of white-backed planthopper/hill at 15 day after spraying (1.13 hoppers/hill in August – December 2018 and 1.79 hoppers/hill in August – December 2019 respectively) giving better yield. The population of natural enemies was comparatively lower in all insecticidal treatments than in the control.

Toxicity of Thiamethoxam 25WG and Sulfoxaflor 21.8SC tTo Rice White Backed Planthopper sogatella furcifera (Horvath)

Baseline toxicity of neonicotinoid insecticides viz., thiamethoxam 25WG and sulfoxaflor 21.8SC was assessed in the field collected populations of the rice white backed planthopper Sogatella furcifera (Horvath). The major rice growing regions of Tamil Nadu when studied revealed that the field populations vary in their susceptibility. Coimbatore and Bhavani populations were more susceptible compared to the Nagapattinam one. Baseline toxicity of thiamethoxam 25WG was relatively high with narrow variation (LC50 - 0.3130 to 1.7882 ppm; LC95 - 1.0993 to 6.3840 ppm); LC50 of sulfoxaflor 21.8SC ranged from 1.3121 to 3.8392 ppm, while the LC95 values were 3.1507 to 5.2754 ppm. The resistance ratios varied among the populations viz., thiamethoxam 25WG (2.5 to 5.6 folds) and sulfoxaflor 21.8SC (1.8 to 2.9 folds). Thus, the population from Nagapattinam exhibited maximum resistance.

Efficacy of Benzpyrimoxan 10SC Against Rice Planthoppers

The efficacy of foliar application of benzpyrimoxan 10SC @ 50, 75, 100, 125 and 150 g a.i./ ha besides the insecticidal checks imidacloprid 17.8SL @ 25 g a.i./ha and buprofezin 25SC @ 187.5 g a.i./ha was evaluated against the brown planthopper (BPH) Nilaparvata lugens (Stal.) and the white backed planthopper (WBPH) Sogatella furcifera (Horvath) on rice during kharif 2017 and 2018 at the Punjab Agricultural University, Ludhiana. Experimental design consisted of random blocks in three replications. Two years data revealed that benzpyrimoxan 10SC @ 100 g a.i./ha is significantly superior against the N. lugens and S. furcifera complex. Benzpyrimoxan 10SC @ 100 g a.i./ha gave significantly higher yield (34.17 q/ ha) than its lower doses but was statistically at par with its higher doses. Non-significant differences in number of spiders/hill among treated plots and untreated check at 10- and 15-DAS indicated the safety of benzpyrimoxan.

Effect of Ecological Engineering on Incidence of Key Rice Pests

Incidence of rice pests like white backed planthopper (WBPH) Sogatella furcifera, leaf folder Cnaphalocrocis medinalis, whorl maggot Hydrellia sasakii and stem borers - yellow stem borer Scirpophaga incertulas and the pink stem borer Sesamia inferens were studied in ecologically engineered rice fields during kharif 2019 and 2020. The WBPH population significantly reduced in fields planted with mixture of crop and flowering plants (0.66 ± 0.25 and 0.83 ± 0.44 WBPH/hill) during kharif 2019 and 2020, respectively. Rice plots planted with crops and flowering plants had lowest leaf folder damage in both the seasons (0.64 ± 0.11% and 0.54 ± 0.35%). Similarly, whorl maggot damage in mixture of crop and flowering plants found significantly reduced than control plots in both the seasons. Reduced pest activity in ecologically engineered fields significantly increased rice yield, particularly in rice plots planted with crops and flowering plants (5.60 ± 0.24 and 5.27 ± 0.06 mt/ ha). Study revealed that planting of crop and flowering plants around the rice field increased the natural enemy activity and reduced incidence of rice pests which eventually reduced the yield losses caused by insect pests and increased the rice grain yield.

Insecticide Resistance Monitoring in Field Populations of the Whitebacked Planthopper Sogatella furcifera (Horvath) in China, 2019-2020.

Simple SummaryThe whitebacked planthopper (WBPH), Sogatella furcifera (Horváth), is one of the most destructive pests that seriously threatens the high-quality and safe production of rice. Overuse of chemical insecticides has led to varying levels of resistance to insecticides in the field population of S. furcifera. In this study, we measured the susceptibility of 18 populations to 10 insecticides by the rice-seedling dip method. Enzyme assays were performed to measure the levels of esterase (EST), glutathione S- transferase (GST) and cytochrome P450 monooxygenase (P450). A risk of cross-resistance between some insecticides were found by pairwise correlation, and EST may be contributed to the resistance to nitenpyram, thiamethoxam and clothianidin in S. furcifera. Overall, our findings will help inform the effective insecticide resistance management strategies to delay the development of insecticide resistance in S. furcifera.Monitoring is an important component of insecticide resistance management. In this study, resistance monitoring was conducted on 18 field populations in China. The results showed that S. furcifera developed high levels of resistance to chlorpyrifos and buprofezin, and S. furcifera showed low to moderate levels of resistance to imidacloprid, thiamethoxam, dinotefuran, clothianidin, sulfoxaflor, isoprocarb and ethofenprox. Sogatella furcifera remained susceptible or low levels of resistance to nitenpyram. LC50 values of nitenpyram and dinotefuran, imidacloprid, thiamethoxam, clothianidin and chlorpyrifos exhibited significant correlations, as did those between dinotefuran and thiamethoxam, clothianidin, sulfoxaflor, imidacloprid, isoprocarb and buprofezin. Similarly, significant correlations were observed between thiamethoxam and clothianidin, sulfoxaflor and imidacloprid. In addition, the activity of EST in field populations of S. furcifera were significantly correlated with the LC50 values of nitenpyram, thiamethoxam and clothianidin. These results will help inform effective insecticide resistance management strategies to delay the development of insecticide resistance in S. furcifera.