scholarly journals Seasonal variation in population and biochemical contents of brown planthopper, Nilaparvata lugens (Stål)

2022 ◽  
Vol 43 (1) ◽  
pp. 52-58
Author(s):  
S. Narayana ◽  
◽  
S. Chander ◽  
S. Doddachowdappa ◽  
S. Sabtharishi ◽  
...  

Aim: The present study was undertaken on population dynamics and estimation of protein, water-soluble carbohydrates and glycogen contents in the brown planthopper, Nilaparvata lugens to explore their migratory behaviour. Methodology: Brown planthopper populations were monitored and collected using sweep nets from 23rd standard meteorological week (SMW) to 47th SMW during 2017 and 2018 rainy seasons to understand population dynamics of the pest. The protein, water-soluble carbohydrates and glycogen contents were estimated from the pest samples collected during 36th to 44th SMW in 2017 and 2018 rainy seasons. Results: Brown planthopper population were not observed in rice farm during 23rd SMW to 28th SMW during two years of study. However, macropterous form of the pest first appeared in the farm during 29th SMW and peaked during 43rd SMW. Thereafter, population declined and disappeared after 47th SMW during both the years. Water-soluble carbohydrates and glycogen contents varied significantly different weeks which remained low during 36th-39th SMW, however, increased gradually towards the end of the rainy season 2017 and 2018. On the other hand, protein content significantly varied among different weeks unlike the trend of water-soluble carbohydrates and glycogen. Interpretation: The study revealed the absence of brown plant hopper during summer season preceding rainy season, and the accumulation of bio-chemical compounds towards the end of rainy season under Delhi environment is perhaps suggestive of migration of the pest from unknown areas during rainy season to Delhi and likely preparedness of the pest for emigration to safer areas from Delhi, respectively.

Author(s):  
B. Nagendra Reddy ◽  
V. Jhansi Lakshmi ◽  
T. Uma Maheswari ◽  
G.S. Laha

Background: Rice is the staple food of Indians and it is attacked by more than 100 species of insects. Among all, brown planthopper (BPH), Nilaparvata lugens (Stal) (Hemiptera: Delphacidae) is one of the major sucking insects, which can cause appreciable damage by sucking sap on other hand transmitting viral diseases. Farming community using several insecticides for managing the BPH. However, continuous use of these insecticides causes health hazards and environmental pollution and also leads to development of insecticide resistance. Keeping this view in mind, the present investigation has been planned with combined use of fungal formulations and commonly used neonicotinoid insecticides in rice eco system for managing BPH. Methods: This experiment was carried out in two parts, one is studied the compatibility between neonicotinoids (Thiamethoxam 25 SG and Dinotefuran 20 SG) and entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae and Lecanicillium lecanii =Verticillium lecanii) by following the standard poison food technique. Second one is after studied the compatibility between neonicotinoids and entomopathogenic fungal agents, inhibitory studies were conducted under glasshouse conditions.Result: The study revealed that two tested insecticides affected the radial growth of fungi partially at all the three concentrations (0.5RC, RC and 1.5RC). At recommended concentration (RC), dinotefuran 20 SG @0.4 g/l was found to be slightly harmful to all three fungi (20% - 35% reduction of the growth of the fungus) and thiamethoxam 25 SG @ 0.25g/l appeared to be slightly harmful to B. bassiana and M. anisopliae and moderately harmful to L. lecanii (35-50% reduction of the growth of the fungus). Thiamethoxam 25SG alone recorded 65.0% mortality of BPH and when mixed with B. bassiana and M. anisopliae gave 86.25% and 81.25% mortality of BPH respectively under glass house conditions. Similarly, Dinotefuron 20 SG alone could gave 98.75% mortality of BPH. 


2016 ◽  
Vol 14 (2) ◽  
pp. 261-269
Author(s):  
Nguyễn Thị Kim Liên ◽  
Nguyễn Huy Hoàng ◽  
Lê Bắc Việt ◽  
Phan Thị Bích Thu ◽  
Nguyễn Huy Chung

Brown plant hopper (Nilaparvata lugens Stal.) is the one of dangerous pests for rice that were reported in most of rice growing countries. Twenty seven BPH resistance genes have been detected in cultivated and wild rice. However, each resistance gene is able to resist with only strain or certain biotype. Besides, many studies indicated that the toxicity of BPH strains tend to change and loss the resistance of rice lines. The breeding of rice varieties that resist to many BPH biotypes is being the breeders towards. With helping of the development of molecular markers and genetic engineering, the breeders are hopping to identify the molecular markers that linked tightly with BPH resistance genes and develop the rice varieties can gather many resistance genes in a well genomic platform. In this study, we assessed the resistance of rice lines of Vietnam and imported rice lines. The resistance was ditermined by using assessement method in the galvanized box and molecular markers linkage with resistance genes (Bph1, bph2, Bph3, Bph9 and Bph17). The results showed that there was a high affinity between the two methods with 70.59% and 86.27% of lines that have the resistance (respectively). Among of 51 surveyed rice lines, 44 lines (86.27%) were determined to have at least one marker linkage with resistance genes. 19 lines (37.25%) harbored two or three markers linkage with resistance genes. These lines will be a good genetic resource for screening and breeding the resistant rice varieties.


2021 ◽  
Vol 9 (1) ◽  
pp. 5-11
Author(s):  
Srinivasa N ◽  
◽  
Subhash Chander ◽  
Padala Vinod Kumar ◽  
◽  
...  

The effect of elevated CO2 (570±25ppm) on the brown plant hopper (BPH) population, rice yield parameters, and efficacy of buprofezin (0.05%) in terms of spray volume was studied in an open top chamber (OTCs) during rainy season 2017 and 2018. The pest population was observed to be higher during 2017 compared to the rainy season of 2018. Under elevated CO2, rice plants had more vegetative tillers (18%) and reproductive tillers (22.1%), but there was a decrease in 1000-seed weight (11.2%), seed number per panicle (3.91%), and grain yield (18.8%) in comparison to ambient CO2 grown rice plants. The spray volumes of 700, 600, 500, and 400 l/ha each caused higher BPH mortality under ambient CO2 compared to elevated CO2. A spray volume of 500 l/ha did not prove as effective under elevated CO2 as under ambient CO2. Lower efficacy of spray volume of 500 l/ha under elevated CO2 could be ascribed to higher canopy size under elevated CO2 due to higher tillering. Increased crop canopy size under elevated CO2 may thus require higher spray volume to ensure proper coverage. Results of the study suggested a need to revise spray volume recommendations to facilitate effective management of BPH under climate change.


PLoS ONE ◽  
2012 ◽  
Vol 7 (10) ◽  
pp. e47413 ◽  
Author(s):  
Jiranan Piyaphongkul ◽  
Jeremy Pritchard ◽  
Jeff Bale

2015 ◽  
Vol 105 (4) ◽  
pp. 390-398 ◽  
Author(s):  
P.-J. Wan ◽  
L. Yang ◽  
S.-Y. Yuan ◽  
Y.-H. Tang ◽  
Q. Fu ◽  
...  

AbstractThe brown planthopper Nilaparvata lugens is a serious phloem-feeding pest of rice in China. The current study focuses on a saccharopine dehydrogenase (SDH) that catalyzes the penultimate reaction in biosynthesis of the amino acid lysine (Lys), which plays a role in insect growth and carnitine production (as a substrate). The protein, provisionally designated as NlylsSDH [a SDH derived from yeast-like symbiont (YLS) in N. lugens], had a higher transcript level in abdomens, compared with heads, wings, legs and thoraces, which agrees with YLS distribution in N. lugens. Ingestion of Nlylssdh targeted double-stranded RNA (dsNlylssdh) for 5, 10 and 15 days decreased the mRNA abundance in the hoppers by 47, 70 and 31%, respectively, comparing with those ingesting normal or dsegfp diets. Nlylssdh knockdown slightly decreased the body weights, significantly delayed the development of females, and killed approximately 30% of the nymphs. Moreover, some surviving adults showed two apparent phenotypic defects: wing deformation and nymphal cuticles remained on tips of the legs and abdomens. The brachypterours/macropterours and sex ratios (female/male) of the adults on the dsRNA diet were lowered compared with the adults on diets without dsRNA. These results suggest that Nlylssdh encodes a functional SDH protein. The adverse effect of Nlylssdh knockdown on N. lugens implies the importance of Lys in hopper development. This study provides a proof of concept example that Nlylssdh could serve as a possible dsRNA-based pesticide for planthopper control.


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