scholarly journals Dinamika populasi wereng punggung putih, sogatella furcifera Stål (Hemiptera: Delphacidae) di jawa tengah

2017 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
I Nyoman Widiarta ◽  
E.S. Wijay ◽  
Hiroichi Sawada
Keyword(s):  
Population Density ◽  
Population Growth ◽  
Brown Planthopper ◽  
Rice Cultivar ◽  
Growth Patterns ◽  
Thermal Constant ◽  
Sogatella Furcifera ◽  
Wet Season ◽  
Crop Season ◽  
Whitebacked Planthopper

A field study was conducted at paddy fields in Petarukan and Pekalongan regencies of Central Java province during wet season crop 1989/90 and 1990/91 to elucidate population dynamic of whitebacked planthopper, Sogatella furcifera Stål. Seven and three observation fields were set up in 1989/90 and the 1990/91, respectively. Cisadane rice cultivar was transplanted following the usual farmer’s parctices except that no pesticide was applied. The population of the whitebacked planthopper and the brown planthopper, (Nilaparvata lugens Stål) were sampled by using an insect suction catcher, a farmcop. Identification of generation was based on thermal constant required by the whitebacked planthopper to complete one generation and mean population density was calculated by graphical method. Two distinct seasonal population growth patterns were identified. The population with short population growth pattern completed four generations in one crop season in which their population density increased consecutively in two generations since immigrant generation, and thereafter decreased. The population with long population growth completed five generations in one crop season in which their population density increased consecutively in three generations, and thereafter decreased. The density of brachiptera adults determined 90% of the total population density. The proportion of brachiptera adults were not correlated with large nymphal density in both vegetative and generative stages of rice. The proportion of brachiptera adults showed significant negative linear regression with population density of the brown planthopper. Therefore, interspesific competition determined the proportion of wingform and population dynamics of the whitebacked planthopper.

scholarly journals Rice Resistance Buffers against the Induced Enhancement of Brown Planthopper Fitness by Some Insecticides

Crops ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 166-184
Author(s):  
Finbarr G. Horgan ◽  
Ainara Peñalver-Cruz ◽  
Maria Liberty P. Almazan
Keyword(s):  
Host Resistance ◽  
Management Practices ◽  
Brown Planthopper ◽  
Nilaparvata Lugens ◽  
Susceptible Variety ◽  
Egg Laying ◽  
Varietal Resistance ◽  
Sogatella Furcifera ◽  
Nilaparvata Lugens Stål ◽  
Whitebacked Planthopper

The brown planthopper, Nilaparvata lugens (Stål)[BPH], is a damaging pest of rice in Asia. Insecticides and rice varietal resistance are widely implemented BPH management practices. However, outbreaks of BPH have been linked to excessive insecticide use—challenging the compatibility of these two management practices. IR62 is a variety with resistance against BPH, the whitebacked planthopper, Sogatella furcifera Horváth [WBPH], and the green leafhopper, Nephotettix virescens (Distant)[GLH]. We compared BPH responses to IR62 and to the susceptible variety IR64 treated with buprofezin, carbofuran, cartap hydrochloride, cypermethrin, deltamethrin, fipronil, or thiamethoxam + chlorantraniliprole. In greenhouse bioassays, cypermethrin, fipronil and thiamethoxam + chlorantraniliprole reduced egg laying on both varieties, and, together with buprofezin, reduced nymph survival to zero. Buprofezin, carbofuran, and cartap hydrochloride stimulated egg laying, and carbofuran increased nymph biomass, but these effects were reduced on IR62. Planthopper populations were ten times higher on deltamethrin-treated rice than untreated rice in a screenhouse experiment. Host resistance failed to buffer against this insecticide-induced resurgence in BPH and WBPH. However, IR62 reduced the effect in GLH. Rice treated with cypermethrin and fipronil had reduced yields compared to untreated controls, suggesting possible phytotoxic effects. We found little evidence of synergies between the two management practices; but host resistance did buffer against the undesirable effects of some insecticides.

scholarly journals Changing Land Use and Population Density Are Degrading Water Quality in the Lower Mekong Basin

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1948
Author(s):  
Flavia Tromboni ◽  
Thomas E. Dilts ◽  
Sarah E. Null ◽  
Sapana Lohani ◽  
Peng Bun Ngor ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Population Density ◽  
Local Population ◽  
Reference Conditions ◽  
Mekong River ◽  
Land Use Impacts ◽  
Wet Season ◽  
Mekong Basin ◽  
Lower Mekong Basin

Establishing reference conditions in rivers is important to understand environmental change and protect ecosystem integrity. Ranked third globally for fish biodiversity, the Mekong River has the world’s largest inland fishery providing livelihoods, food security, and protein to the local population. It is therefore of paramount importance to maintain the water quality and biotic integrity of this ecosystem. We analyzed land use impacts on water quality constituents (TSS, TN, TP, DO, NO3−, NH4+, PO43−) in the Lower Mekong Basin. We then used a best-model regression approach with anthropogenic land-use as independent variables and water quality parameters as the dependent variables, to define reference conditions in the absence of human activities (corresponding to the intercept value). From 2000–2017, the population and the percentage of crop, rice, and plantation land cover increased, while there was a decrease in upland forest and flooded forest. Agriculture, urbanization, and population density were associated with decreasing water quality health in the Lower Mekong Basin. In several sites, Thailand and Laos had higher TN, NO3−, and NH4+ concentrations compared to reference conditions, while Cambodia had higher TP values than reference conditions, showing water quality degradation. TSS was higher than reference conditions in the dry season in Cambodia, but was lower than reference values in the wet season in Thailand and Laos. This study shows how deforestation from agriculture conversion and increasing urbanization pressure causes water quality decline in the Lower Mekong Basin, and provides a first characterization of reference water quality conditions for the Lower Mekong River and its tributaries.

scholarly journals Isolation, characterization, and cross-transferability of microsatellite markers from the whitebacked planthopper (Sogatella furcifera)

2014 ◽  
Vol 13 (3) ◽  
pp. 6248-6252
Author(s):  
L. Zhang ◽  
G. Li ◽  
G.C. He ◽  
L.L. Zhu ◽  
R. Qin ◽  
...  
Keyword(s):  
Microsatellite Markers ◽  
Sogatella Furcifera ◽  
Whitebacked Planthopper

scholarly journals Mapping of a Major Resistance Gene to the Brown Planthopper in the Rice Cultivar Rathu Heenati

2005 ◽  
Vol 55 (4) ◽  
pp. 391-396 ◽  
Author(s):  
Lihong Sun ◽  
Changchao Su ◽  
Chunming Wang ◽  
Huqu Zhai ◽  
Jianmin Wan
Keyword(s):  
Resistance Gene ◽  
Brown Planthopper ◽  
Rice Cultivar ◽  
Major Resistance Gene ◽  
Rathu Heenati
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