Sequential Sampling Plan for Rice Planthoppers with Incorporation of Predator Effect (original) (raw)
Related papers
Journal of Applied and Natural Science, 2014
The present study on the effect of variety and planting date of rice on population of natural enemies of brown planthopper, Nilaparvata lugens (Stal) showed that during August, the mean population of spiders was statistically on par on CSR 30 and PR 114. The population differed with dates and was significantly (p=0.05) higher (9.0/10 hills) in D2 during 2011 only. There was no significant difference in the population of spiders on two varieties and dates of transplanting during September 2011 only. However, significantly higher population of spiders was recorded in variety PR 114 (21.65/10 hills) and D2 (20.52/10 hills) than on CSR 30 (13.67/10 hills) and D1 (14.80/10 hills) during September, 2012. The mean population of spiders did not differ significantly with the dates during October, 2011 and 2012. However, it was significantly higher on variety PR 114 (27.65/10 hills) than on CSR 30 during both the crop seasons. Mirid bugs did not appear in the month of August, 2011 and 2012 wh...
Journal of Scientific & Industrial Research, 2010
Multiple linear regression models (pest-weather models) were developed between monthly mean brown planthopper (BPH), Nilaparvata lugens light trap catches and monthly mean values of minimum temperature (Tmin), maximum temperature (Tmax), morning relative humidity (RH 1 ) and evening relative humidity (RH 2 ) observed at Maruteru, Andhra Pradesh during 2000-2007 kharif seasons. Comparison between predicted and observed BPH light trap catches at Nellore (kharif 2004 and 2005), Ragolu (kharif 2003-2007) and Rajendranagar (kharif 2005 and 2007) evinced very high level of congruence between them, thereby validating agro-ecological zoning of BPH incidence in Andhra Pradesh. Knowledge of BPH incidence levels in different zones would facilitate strategic decisions with regard to selection of crop cultivars and management practices, and prediction of probable life of resistant cultivars.
2018
Relationships among the population abundance of four predator groups for rice insect pests, namely: carabid beetles, staphylinid beetles, green mirid bugs, and spiders in three landscape categories were evaluated. Both rice plots and the associated bund margins of these rice plots found among three Bangladesh landscape categories were sampled by sweep net. The results revealed that the abundance significantly varied across landscapes. The rice landscape of one location harbored higher numbers of a specific predator than other location in other regions of Bangladesh. The results also showed a dependency on the width of the rice bund margins of the rice plots, where spiders populations increased with increased bund widths, but the population abundance of these predators did not depend on the diversity of the number of weed species found on the rice bund margins. The relative abundance of predator populations also significantly differed among the three landscapes, with the green mirid ...
Surrounding landscape influences the abundance of insect predators in rice field
BMC Zoology
Background Natural enemy abundance in a crop plot depends on its prey presence and also influenced by habitats close to field. Landscape changes are also important factors driving pest and natural enemy population abundance in a specific crop field. Examining these kinds of effects on insect pests or biocontrol agents, as well as analysis of their functional food webs, would be asset to make a fruitful pest management programme at local scales. Therefore, this study was undertaken to evaluate the impact of surrounding landscape on the abundance insect predators in rice field. Results This study revealed a dependency on rice bund margin width, with spider populations increasing with increased bund widths. Conversely, population abundance did not rely on the number of weed species observed on earthen ridge around the rice field. In general, relative abundances of predator populations differed significantly across the three landscapes tested. Among the four predators of rice insect pes...
2007
understand the population dynamics of whitebacked planthopper (WBPH) Sogatella furcifera and natural enemies of plant hoppers in Krishna-Godavari zone of Andhra Pradesh, India revealed that WBPH was present only during Kharif season. WBPH nymphal population was significantly correlated with spider and mirid bug population (r = 0.572 to 0.841). WBPH nymphal population and brown planthopper (BPH) nymphal population were significantly correlated (r= 0.615 to 0.995) indicating their coexistence. Mirid bugs (Cyrtorhinus lividipennis) and spiders as a group were present both during Kharif and Rabi seasons. Mirid bugs appeared in considerable numbers only 8-9 weeks after substantial WBPH and BPH nymphal population existed in the field. Spider populations were high from the beginning of the season but could not cope up with the dramatic rise in the WBPH and BPH populations. The LT catches of WBPH showed positive correlation with WBPH nymphal population present in the field. Among the weather parameters, minimum temperature showed consistent and significant negative correlation (-0.473 to-0.877) with mirid bugs indicating that increase in minimum temperature may adversely affect mirid bug population during Kharif. During Rabi minimum temperature and sunshine hours were positively correlated with BPH field population and spider population.
Ecological engineering in low land rice for brown plant hopper, Nilaparvata lugens (Stål) management
PeerJ
Rice field bunds and edges can act as near crop habitats, available for planting flowering plants to attract and conserve the natural enemies. We evaluated the effect of ecological engineering on the incidence of Brown Planthopper (BPH), Nilaparvata lugens (Stål) (Hemiptera; Delphacidae) and the abundance of its predators in the rice variety Pusa Basmati-1121. Plots included the oilseed crops viz. sesamum, sunflower and soybean, with plantings of flowering crops marigold, balsam and gaillardia as bund flora around the edges of rice plots. Ecologically engineered plots contained both crops+flowers and resulted in a significantly reduced BPH population per hill in rice plots for 2019 (6.3) and 2020 (9.4) compared to the control plots (9.8 and 14.4). Ecologically engineered plots also witnessed the delayed appearance of BPH during each growing season. Peak BPH populations are lower in the ecologically engineered plots than in the control grounds. Furthermore, the activity of natural en...
Effects of a Bank Plant on the Control of Rice Planthoppers: A Field Study
Annals of Agricultural & Crop Sciences, 2024
Utilizing ecological engineering to manage pests by enhancing the biological control function of natural predators through the selection of high-efficiency bank plants and the establishment of bank plant systems within agricultural ecosystems is an optimal strategy. While bank plant systems have found widespread use in greenhouse crop cultivation, their application in rice fields remains limited. This study aimed to assess the efficacy of Leersia sayanuka as a bank plant for controlling planthoppers and to explore the potential of sesame as a complementary plant to enhance the effectiveness of the bank plant system through field trials. The findings revealed that planting a strip of L. sayanuka, at least 50 cm wide and extending over 1 m in length, had a notable impact on planthopper control in paddy fields. Moreover, the incorporation of Sesamum indicum, a nectar plant, into the bank plant system consisting of L. sayanuka, Nilaparvata muiri, and Anagrus nilaparvatae, led to a significant increase in the population of Anagrus spp. in rice fields. This increase was accompanied by a rise in the egg parasitism rate targeting rice planthoppers, resulting in a marked improvement in overall rice planthopper control in paddy fields. Thus, the combined system demonstrated efficiency as an effective bank plant system for managing rice planthoppers.
Population dynamics of insect pests in rice ecosystem
Indian Journal Of Entomology, 2021
Investigations on major insect pests in rice was carried out at the Agricultural Research Farm, Banaras Hindu University, Varanasi during kharif 2017-18 and 2018-19. Observations on Scirpophaga incertulas incidence revealed that deadhearts and white ears were observed to be maximum during 1 st week of October (40 th SMW) and 3 rd week of November (47 th SMW), respectively. Likewise, Cnaphalocrocis medinalis was observed during 1 st week of August (31 st SMW) with maximum incidence being in the 1 st week of October (40 th SMW) with 11.39% damaged leaves/ 10 hills. Nilapravata lugens appeared from 2 nd week of August (33 rd SMW) and attained its peak in 1 st week of October (40 th SMW) as 17.33/ 10 hills. The maximum incidence of Nephotettix virescens was observed in the 4 th week of October (43 rd SMW)-15.67 insects/ 10 hills. The activity of Leptocorisa acuta commenced from 3 rd week of October (42 nd SMW) and reached its peak during 3 rd week of November (47 th SMW-14.67/ 10 sweeps in nets). Correlation analysis revealed that the rainfall and evening RH exhibited a negative impact on S. incertulas, C. medinalis, N. lugens, N. virescens and L. acuta; minimum and maximum temperature, and morning RH, showed both positive and a negative impact on these insect pests of rice.
tropentag.de
The cultivation of tropical Asian rice, which may have originated 9,000 years ago, represents an agricultural ecosystem of unrivalled ecological complexity. However, this crop is heavily infested with various pests. These pests have been reported to cause > 80 % damage to rice crop. The control strategies of these pests mainly rely on the application of chemical insecticides. However, indiscriminate use of chemical pesticides has led to health as well as environmental hazards and increasing the cost of cultivation. These studies were conducted in the major irrigated tropical rice fields of Leyte, Philippines. We have observed that abundance of various species of arthropod pests including leaf hoppers (Cicadellidae; Nephotettix species and others), plant hoppers (Delphacidae), bugs (Pentatomidae, Scotinophara coarctata and Coreidae), Coleoptera (mainly Chrysomelidae) and grasshoppers (Acrididae and Tettigoniidae), their natural enemies includes dragonflies (Anisoptera), damselflies (Zygoptera), ladybird beetles (Coccinellidae) and spiders (Araneae) were highly associated with various stages of the crop growth. In chemical treated site, maximum number of pest population was observed during the early tillering stage and remain present during the whole duration of the crop. Coreidae and Alydidae infested rice simultaneously, and remained abundant together, while Delphacids pests were noticed fare abundance in early stage of the crop. However in untreated site Cicadellidae pest was found more abundant during the tillering stage, high number of Alydidae, Coreidae were recorded during the milking and maturity stage of the crop. Spiders and Coccinellidae found more during tillering stage to milking stage. These results also give correlation as when the pest population developed; the predator population soon became abundant. On average pests found with more abundance than the predators.