scholarly journals Relative abundance of insect pests and their predators on boro rice

2018 ◽  
Vol 43 (1) ◽  
pp. 81-88
Author(s):  
MA Bakar ◽  
MMH Khan

The study was conducted to know the relative abundance of insect pests and their predators on 5 boro rice varieties namely Arize tez, Teea, Sakti, Sathi and BRRI Dhan 28. In Arize Tez variety, short horned grasshopper revealed the highest percent relative abundance (87.25%) at tillering stage and green rice leafhopper was only at panical initiation stage. Among insect predators, wasp showed the highest percent relative abundance (33.33%) both at tillering and panical initiation stages. In Teea variety, the highest percent relative abundance of short horned grasshopper was recorded at tillering (80.21%) and panicle initiation (86.03%) stages while spider and lady bird beetle had 21.05% at tillering stage, wasp (21.05% and 40.00%), damselfly (21.05% and 40.00%) at tillering and panical initiation stages, respectively. In Sakti variety, short horned grasshopper had the highest percent relative abundance (72.54% and 69.05%) at tillering and panicle initiation stages while dragonfly had 30.77% at tillering, wasp had 30.77% and 66.66% at tillering and panicle initiation stages. In Shathi variety, the highest percent relative abundance of short horned grasshopper was recorded at tillering (59.46%) and panicle initiation (52.27%) stages while wasp (41.67%) at panical initiation stage. In variety BRRI dhan 28, the highest percent relative abundance of insect pests was recorded in short horned grasshopper (76.73% and 86.05%) both at tillering and panicle initiation stages while in insect predators, wasp had 40% at tillering and 50% at panicle initiation stages but dragonfly had 50% only at panicle initiation stage.Bangladesh J. Agril. Res. 43(1): 81-88, March 2018

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Mohd Fitri Masarudin ◽  
Maisarah Mohamad Saad

The diversity of arthropod consists of pests and predators in rice fields were contribute to the biological control of crop pests at different stages of growth. The rice fields in Batang Lupar, Sarawak has diverse ecological conditions as well as presence of arthropod too. The study in MARDI research plot Batang Lupar in Sri Aman, Sarawak had been done on traditional rice varieties, Bubuk, Bali and Mamut by using sweeping net. The entire specimens were sorted out and classified into the smallest possible taxa. Statistical analysis were analysed by using Shanon-wiener Diversity Index, Evenness Shannon Index and Margalef Richness Index. A total of 272 individual arthropods had been collected and it consists of 7 order, 18 families and 23 species. Among of that 3 species are spiders, 9 species are insect pests and 11 species are insect predators. Analysis data for the diversity of arthropod has shown that there were no significantly different between three varieties, Bubuk, Bali and Mamut (P > 0.05). Besides that, diversity of the arthropod in Bali is higher than Bubuk and Mamut. 


2020 ◽  
Vol 17 (2) ◽  
pp. 97
Author(s):  
Andi Nurdaaniyah ◽  
Dadang Dadang ◽  
I Wayan Winasa

<p>Brown planthopper (<em>Nilaparvata lugens</em> (Stål)) is one of the major rice insect pests that is known to cause high loss of rice production. One of the strategies to control this pest is by using resistant rice varieties. The aim of this research was to study the resistance of IPB 3S variety to BPH by measuring BPH fecundity, sex ratio, feeding activity as well as population increase compared to Ciherang variety against brown planthopper (<em>N. lugens</em>). Fecundity test used a pair of BPH adult infested on 21 days after planting (DAP) of rice plants. Eggs laid in rice stalks and the rest of eggs in the ovary were counted. In order to know the change of sex ratio, a pair of BPH adults was infested on 30 DAP rice plants and allowed to lay eggs. The calculation of sex ratio was conducted at adult stage of BPH by segregation between male and female adults. Feeding activity of BPH was evaluated using ninhydrin and analyzed qualitatively using spectrophotometer. Ten fourth instar nymphs of BPH was infested on 30 DAP old of rice seedlings. Honeydew secreted by BPH was collected to filter paper sprayed with ninhydrin. Population increased test was conducted by infesting five pairs of BPH adults on 35 DAP old rice plants. Observations was conducted on nymph and adult stages. Each test was replicated 10 times. In general, IPB 3S is slightly resistant to BPH, compared to Ciherang variety. The feeding activity of BPH is higher in Ciherang compared to IPB3S. However, the fecundity and population increased of BPH in Ciherang is similar to IPB3S.</p>


2020 ◽  
Vol 17 ◽  
pp. 39-46
Author(s):  
S.K. Ajao ◽  
K.O. Popoola ◽  
S Mande ◽  
A Togola

The need to screen new rice genotypes for resistance to stored product insect pests is important to boost production and availability of rice for food security. Therefore, thirteen rice genotypes and varieties included ten interspecific rice genotypes from two crossed parents Oryza sativa (WAB 56-104) and Oryza barthii (IRGC 106107), the two parents and NERICA8 variety were collected from Africa Rice Center, International Institute of Tropical Agriculture (IITA) Ibadan, to examine their resistance level to infestation by Sitophilus oryzae L. and Rhyzopertha dominica F. The resistance of the varieties were assessed by artificial infestation with 12 unsexed adults each in 10 g of the rice varieties in four replicates under laboratory conditions of 26 ± 2oC temperature and 75 ± 5% relative humidity in a completely randomized design. Number of adult insect emergent, per cent grain damage, percent weight loss of infested samples and index of susceptibility were determined. Correlation analysis between nutritional contents of the varieties and infestation variables were also obtained. Results indicate differential responses of the two insects on the rice genotypes/varieties. The O. barthii parent was resistant, while the O. sativa parent was moderately resistant using the susceptibility index. Of the ten rice genotypes, G4, G3, G1, G7, G2, G10 and G9 were resistant in descending order, while G5 and G6 were moderately resistant, whereas only G8 was susceptible. NERICA8 was also found to be susceptible to infestation. In addition, the resistant grains had lower ash content. Modification in genetic variations and nutritional contents of new rice varieties may be a critical factor in insect resistant genotype pro-grammes to reduce post-harvest losses incurred by farmers. Keywords: Rice resistant genotypes; Rhyzopertha dominica; Oryzae sativa; Oryzae barthii; Sitophilus oryzae; susceptibility index


2016 ◽  
Vol 07 (03) ◽  
pp. 1650008 ◽  
Author(s):  
M. MEHEDI HASAN ◽  
Md. ABDUR RASHID SARKER ◽  
JEFF GOW

Despite substantial volumes of research on the impacts of climate change on rice productivity little attention has been paid in evaluating how these impacts differ between traditional varieties (TVs) and high yielding varieties (HYVs). In this study, Aman and Boro rice yields are examined, as respective examples. Cross-sectional time series data over 41 years for four climatic regions of Bangladesh has been used to explore this issue. Each region was examined individually and then across region comparisons were made to try to understand the impacts of major climate variables: average temperature, temperature range, and seasonal rainfall. Using both linear regression and panel data regression models, the major findings are that HYVs for both Aman and Boro rice varieties have less capacity to cope with changing climate conditions in contrast to TVs. Therefore, government should help to promote research and development aimed at developing more climate tolerant varieties, particularly temperature tolerant HYVs which have the potential to solidify the country’s food security situation at least in terms of food availability.


1960 ◽  
Vol 50 (4) ◽  
pp. 711-716 ◽  
Author(s):  
K. G. Smith

Walnuts grown and shelled in the Dordogne and adjacent regions of France are exported to Britain and other countries. The inspection of cargoes arriving at Liverpool between July 1955 and July 1958 has shown that they may frequently be infested by a number of species of insect pests. Of the 20 species recorded, six occurred regularly. These were Oryzaephilus surinamensis (L.), Aphomia gularis (Zell.), Plodia interpunctella (Hb.), Cryptophagus subfumatus Kraatz, Nemapogon granella (L.) and Enarmonia sp. During that period, changes occurred in the levels of infestation on parcels and the relative abundance of the species. In particular, there was a considerable increase in the occurrence of O. surinamensis. Though the general levels of infestation were light, parts of 58 per cent, of the cargoes had to be fumigated to prevent pests being distributed to factories, bakeries and shops in Britain and on transhipped parcels to Canada, U.S.A. and the Eepublic of Ireland. Though many of the species found are already established in those countries where conditions are suitable for their development some are still limited in their distribution. These include A. gularis, a serious pest of nuts, dried fruit and cereals. If the further spread of this and the other pests is to be prevented there is need for a more general application of control measures in the country of origin with strict control and possibly fumigation of cargoes before shipment.


1992 ◽  
Vol 61 (4) ◽  
pp. 568-575 ◽  
Author(s):  
Junko YAMAGISHI ◽  
Tsuneo YAJIMA ◽  
Kunio ETOH ◽  
Haruo SUZUKI ◽  
Shinobu INANAGA

Sign in / Sign up

Export Citation Format

Share Document