Complex influence of rice variety, fertilization timing, and insecticide on population dynamics of Sogatella furcifera (Horvath) , Nilaparvata lugens (St�l) (Homoptera: Delphacidae) and their natural enemies in rice in Hangzhou, China

2004 ◽  
Vol 77 (2) ◽  
pp. 65-74 ◽  
Author(s):  
Zeng-Rong Zhu ◽  
Jiaan Cheng ◽  
Ming-Xing Jiang ◽  
Xiao-Xi Zhang
2016 ◽  
Vol 107 (3) ◽  
pp. 369-381 ◽  
Author(s):  
G. Hu ◽  
M.-H. Lu ◽  
H.A. Tuan ◽  
W.-C. Liu ◽  
M.-C. Xie ◽  
...  

AbstractRice planthopper (RPH) populations of Nilaparvata lugens and Sogatella furcifera periodically have erupted across Asia. Predicting RPH population dynamics and identifying their source areas are crucial for the management of these migratory pests in China, but the origins of the migrants to temperate and subtropical regions in China remains unclear. In particular, their early migration to China in March and April have not yet been explored due to a lack of research data available from potential source areas, Central Vietnam and Laos. In this study, we examined the population dynamics and migratory paths of N. lugens and S. furcifera in Vietnam and South China in 2012 and 2013. Trajectory modeling showed that in March and April in 2012 and 2013, RPH emigrated from source areas in Central Vietnam where rice was maturing to the Red River Delta and South China. Early migrants originated from Southern Central Vietnam (14–16°N), but later most were from Northern Central Vietnam (16–19°N). Analysis of meteorological and light-trap data from Hepu in April (1977–2013) using generalized linear models showed that immigration increased with precipitation in Southern Central Vietnam in January, but declined with precipitation in Northern Central Vietnam in January. These results determined that the RPH originate from overwintering areas in Central Vietnam, but not from southernmost areas of Vietnam. Winter precipitation, rather than temperature was the most important factor determining the number of RPH migrants. Based on their similar population dynamics and low population densities in Central Vietnam, we further speculated that RPH migrate to track ephemeral food resources whilst simultaneously avoiding predators. Migrations do not seem to be initiated by interspecific competition, overcrowding or host deterioration. Nevertheless, S. furcifera establishes populations earlier than N. lugens South China, perhaps to compensate for interspecific competition. We provide new information that could assist with forecasting outbreaks and implementing control measures against these migratory pests.


2015 ◽  
Vol 17 (1) ◽  
pp. 9 ◽  
Author(s):  
Martua Suhunan Sianipar ◽  
Luciana Djaya ◽  
Entun Santosa ◽  
RC Hidayat Soesilohadi ◽  
W Darajat Natawigena ◽  
...  

Kemampuan Indonesia dalam memenuhi kebutuhan beras nasional sangat penting. Akan tetapi, usaha pemenuhan kebutuhan beras ini tidak selamanya berjalan dengan lancar karena terganggunya produktivitas padi. Salah satu penyebab turunnya produktivitas padi di Indonesia karena adanya serangan serangga hama. Beberapa kendala yang menyebabkan gagalnya petani dalam mengendalikan serangga hama karena petani masih belum melakukan identifikasi serangga hama dan gejala serangan dengan baik. Penelitian yang dilaksanakan akhir tahun 2012 ini yang berlokasi di Lahan Persawahan Padi Dataran Tinggi Desa Sukawening, Kecamatan Ciwidey, Kabupaten Bandung, Jawa Barat bertujuan meng inventarisasi dan mendapatkan nilai keragaman jenis serangga hama pada tanaman padi. Penangkapan serangga hama yang dilakukan dengan menggunakan perangkap kuning, perangkap jaring dan perangkap cahaya. Hasil penangkapan serangga diidentifikasi di laboratorium. Indeks keragaman serangga dianalisis dengan menggunakan perhitungan Shannon- Weinner. Serangga hama yang dominan diperoleh pada fase vegetative yaitu Scirpophaga incertulas, Thaia oryzivora, dan Orselia oryzae. Serangga hama minor diperoleh yaitu Dicladispa armigera, Leptispa pygmaea, dan Melanitis ledaismene. Serangga hama yang dominan diperoleh pada fase generative yaitu Leptocorisa acuta, Scirpophaga incertulas, dan Thaiaoryzivora. Serangga hama minor diperoleh yaitu Nilaparvata lugens, Sogatella furcifera, dan Cofana spectra. Indeks keragaman serangga hama yang diperoleh pada ketiga lahan percobaan ada diantara sedang hingga tinggi.Pada fase vegetatif indeks keragaman tertinggi sebesar 4,74 pada pengamatan ke 6 dan terendah pada pengamatan ke 1 sebesar 2,22. Pada fase generatif indeks keragaman tertinggi pada pengamatan ke 9 sebesar 4,86 dan terendah pada pengamatan ke 12 sebesar 1,37.   Kata kunci :indeks keragaman, serangga hama, padi, Kabupaten Bandung.


2020 ◽  
pp. 120-125
Author(s):  
K. Elango ◽  
S. Jeyarajan Nelson

The rugose spiralling whitefly, Aleurodicus rugioperculatus Martin is a new exotic pest occurring in several crops including coconut since 2016 in India. Due to variation in the agro-climatic conditions of different regions, arthropods show varying trends in their incidence also in nature and extent of damage to the crop. Besides, abiotic factors also play a key role in determining the incidence and dominance of a particular pest and their natural enemies in a crop ecosystem. The population dynamics of new exotic whitefly species, A. rugioperculatus and their associated natural enemies was assessed on five-year-old Chowghat Orange Dwarf coconut trees at Coconut Farm of Tamil Nadu Agricultural University. The study indicated that RSW was found throughout the year on coconut and the observation recorded on weekly interval basis shows that A. rugioperculatus population escalated from the first week of July 2018 (130.8 nymphs/leaf/frond) reaching the maximum during the first week of October (161.0 nymphs/leaf/frond) which subsequently dwindled to a minimum during April. The parasitisation by E. guadeloupae on RSW ranged from 31.60 percent in Aug. 2018 to 57.60 percent in December 2018. The association of biotic and abiotic factors with A. rugioperculatus population showed a negative correlation with E. guadeloupae and C. montrouzieri. There was a significant positive correlation between maximum temperature and minimum temperature as well as relative humidity. However, rainfall showed a negative correlation with A. rugioperculatus population.


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