Resistance levels of selected rice genotypes to Sitophilus oryzae L. and Rhyzopertha dominica F. infestations

2020 ◽  
Vol 17 ◽  
pp. 39-46
Author(s):  
S.K. Ajao ◽  
K.O. Popoola ◽  
S Mande ◽  
A Togola
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
International Institute ◽  
Rice Varieties ◽  
Resistance Level ◽  
Susceptibility Index ◽  
Grain Damage ◽  
Rice Genotypes ◽  
Moderately Resistant

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

scholarly journals Efficacy of Combinations of Methoprene and Deltamethrin as Long-Term Commodity Protectants

Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 50 ◽  
Author(s):  
Frank H. Arthur
Keyword(s):  
Weight Loss ◽  
Sitophilus Oryzae ◽  
Brown Rice ◽  
The United States ◽  
Rhyzopertha Dominica ◽  
Insect Damage ◽  
Ambient Conditions ◽  
Progeny Production ◽  
Grain Damage ◽  
Sample Weight Loss

Wheat, corn, and brown rice were treated with different combinations of a deltamethrin suspension concentrate (SC) formulation and a new emulsifiable concentrate (EC) formulation, at rates of either 0.5 or 1.0 ppm alone or in combination with 1.25 and 2.5 ppm methoprene (10 treatments in all, including an untreated control). Treated commodities were stored at ambient conditions on the floor of an empty grain bin in Manhattan, KS, USA, in 5-kg lots for individual replicates. The commodities were sampled and bio-assayed every three months for 15 months by exposing 10 mixed-sex parental adults of selected adult stored product insects on 70–80 g of the commodity. For all treatments, there was no regression of declining efficacy with respect to the month. Therefore, the data were combined for analysis. On wheat and brown rice, there was no reproduction of Rhyzopertha dominica (Fabricius) in any of the treatments, and there was no weight loss in either commodity that was caused by feeding of the parental adults or developing progeny. There was reproduction of Sitophilus oryzae (L.) on wheat but, for several combinations, the EC formulation gave better suppression of progeny compared to the standard SC. However, on brown rice, only the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene was different than other treatments with respect to progeny development, sample weight loss caused by feeding, and weight of the feeding damage itself. Progeny production was correlated with grain damage. No progeny of Tribolium castaneum (Herbst) developed on the treated corn, but there was some variation in insect damage, with less damage in those treatments involving the EC formulation. Progeny production of Sitophilus zeamais (Motschulsky) was at the lowest in the combination of 1.0 ppm deltamethrin EC and 2.5 ppm methoprene. The resulting insect damage was the lowest in this combination as well. Results of this study were used by the registrant (Central Life Sciences) in the United States (US) to modify the commercial formulation to replace the deltamethrin SC with the EC, at label rates of either 0.5 ppm EC+ 1.25 ppm methoprene, or 1.0 ppm EC + 2.5 ppm methoprene, on wheat, corn, and rice.

scholarly journals Detection of Phosphine Resistance in Field Populations of Four Key Stored-Grain Insect Pests in Pakistan

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 288
Author(s):  
Waqas Wakil ◽  
Nickolas G. Kavallieratos ◽  
Muhammad Usman ◽  
Sehrish Gulzar ◽  
Hamadttu A. F. El-Shafie
Keyword(s):  
Insect Pests ◽  
Probit Analysis ◽  
Rhyzopertha Dominica ◽  
Laboratory Population ◽  
Stored Grain ◽  
Resistance Level ◽  
Granary Weevil ◽  
Maximum Resistance ◽  
Phosphine Resistance ◽  
Susceptible Populations

In Pakistan, the control of stored-product insect pests mainly relies on the use of phosphine gas along with other control tactics. The aim of this study was to determine the level of phosphine resistance among ten differently located populations of the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the granary weevil, Sitophilus granarius (L.) (Coleoptera: Curculionidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae). Laboratory-susceptible populations of all insect species were also considered in the experiments. Concentration–response bioassays were conducted for each species. All of the tested populations (10 out of 10) of each species were found to be resistant to phosphine, but varied in their level of resistance. Probit analysis estimated LC50 at 2.85, 1.90, 2.54 and 2.01 ppm for laboratory-susceptible populations of R. dominica, S. granarius, T. castaneum and T. granarium, respectively. Against R. dominica, the highest and lowest resistance levels were observed in the Rahim Yar Khan (LC50 at 360.90 ppm) and Rawalpindi (LC50 at 210.98 ppm) populations, respectively. These resistant populations were 126.67- and 74.02-fold more resistant than the laboratory population. The Multan and Lahore populations of S. granarius exhibited the maximum (LC50 at 122.81 ppm) and minimum (LC50 at 45.96 ppm) resistance levels, respectively, i.e., they were 64.63- and 24.18-fold more resistant than the laboratory population. The Layyah population of T. castaneum showed the maximum resistance level (LC50 at 305.89 ppm) while the lowest was observed in the Lahore population (LC50 at 186.52 ppm), corresponding to 120.42- and 73.43-fold more resistant than the laboratory population, respectively. Regarding T. granarium, the Layyah population showed the maximum resistance level (LC50 at 169.99 ppm) while the Lahore population showed the minimum resistance (LC50 at 74.50 ppm), i.e., they were 84.57- and 37.06-fold more resistant than the laboratory population, respectively. Overall, R. dominica presented the highest resistance level, followed by T. castaneum, T. granarium and S. granarius. The current study suggests that the application of phosphine may not be an adequate control strategy for the management of the above tested insect pests in Pakistan.

scholarly journals Could biorational insecticides be used in the management of aflatoxigenic Aspergillus spp. and their insect vectors in stored wheat?

2015 ◽  
Author(s):  
Tiyyabah Khan ◽  
Ahmad Ali Shahid ◽  
Hafiz Azhar Ali Khan
Keyword(s):  
Insect Pests ◽  
Fungal Infections ◽  
Fungal Spores ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
Stored Wheat ◽  
Stored Grains ◽  
Subsequent Effect ◽  
Infection Inhibition ◽  
Reduced Risk

Insect pests in stored wheat cause significant losses and play an important role in the dispersal of viable fungal spores of various species including aflatoxin producing Aspergillus spp. The problems of insecticide resistance in stored insects and environmental hazards associated with fumigants and conventional grain protectants underscore the need to explore reduced risk insecticides to control stored insects and the ultimate effect on fungal infection inhibition. The purpose of this study was to investigate the insecticidal potential of four biorational insecticides: spinosad, thiamethoxam, imidacloprid and indoxacarb on wheat against Rhyzopertha dominica and Sitophilus oryzae and the subsequent effect of insects’ mortality on Aspergillus flavus and A. parasiticus infection in grains. Spinosad and thiamethoxam were the most effective insecticides against R. dominica compared to S. oryzae followed by imidacloprid. Spinosad applied at 0.25, 0.5 and 1ppm and thiamethoxam at 2 and 4ppm concentrations resulted in complete mortality of R. dominica and >90% infection inhibition of A. flavus and A. parasiticus. However, indoxacarb was more toxic against S. oryzae compared to R. dominica. The mortality of R. dominica was directly related to the percent infection inhibition of A. flavus and A. parasiticus in all the treatments. Whereas, mortality of S. oryzae was only related to the percent infection inhibition of A. parasiticus in all the treatments. The results show that although both spinosad and thiamethoxam can provide protection against R. dominica and fungal infections in stored grains, more potent reduced risk insecticides and/or their combinations would be needed than either of these to provide broad spectrum protection of stored grains. In conclusion, the results of the present study provide baseline data for the management of aflatoxigenic fungi by controlling stored insects using biorational insecticides .

scholarly journals Abundance and diversity of insects associated with stored grains and tamarind in Nigeria

2021 ◽  
Vol 90 (3 - Ahead of print) ◽  
pp. 119-129
Author(s):  
James Adebayo Ojo ◽  
Adebayo Amos Omoloye
Keyword(s):  
Species Richness ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
Cereal Grains ◽  
Storage Pests ◽  
Maize Weevil ◽  
Ecological Zones ◽  
Anisopteromalus Calandrae ◽  
Stored Grains

Detailed information on insect pests of stored grains in Nigeria is lacking. A two-year survey was conducted to determine the species composition and abundance of insects associated with maize, millet, rice, sorghum and tamarind in eighteen locations across five agro-ecological zones in Nigeria. Sixteen coleopteran, lepidopteran and hymenopteran species were associated with stored products, with high species richness on cereal grains but low species richness on tamarind. Most of these insects are polyphagous on cereal grains, whereas the tamarind weevil Sitophilus linearis (Herbst, 1797) (Curculionidae), and Caryedon serratus (Oliver, 1790) (Chrysomelidae) were found only on tamarind in this study. The maize weevil Sitophilus zeamais (Motschulsky, 1758), rice weevil Sitophilus oryzae (Linneaus, 1763), lesser grain borer Rhyzopertha dominica (Fabricius, 1792) (Bostrichidae), rusty grain beetle Cryptolestes ferrugineus (Stephens, 1831) (Laemophloeidae) and red flour beetle Tribolium castaneum (Herbst, 1797) (Tenebrionidae) were most abundant on stored grains. The tamarind weevil, C. serratus and the sawtoothed grain beetle Oryzaephilus surinamensis (Linneaus, 1758) (Silvanidae) were most abundant on tamarind. The hymenopterans Theocolax elegans (Westwood, 1874) (Pteromalidae), Anisopteromalus calandrae (Howard, 1881) (Pteromalidae) and Cephalonomia waterstoni (Gahan, 1931) (Bethylidae) were the dominant parasitoids of larvae and pupae of the storage pests. Simpson index of diversity of insect species across locations ranged from low (0.63) to high (0.89).

scholarly journals Screening of rice genotypes for leaf blast resistance under field condition

2020 ◽  
Vol 3 (2) ◽  
pp. 276-286
Author(s):  
Pratiksha Sharma ◽  
Prem Bahadur Magar ◽  
Suraj Baidya ◽  
Ram Baran Yadaw
Keyword(s):  
Field Experiment ◽  
Blast Resistance ◽  
Blast Disease ◽  
Disease Assessment ◽  
Research Centre ◽  
Leaf Blast ◽  
Rice Varieties ◽  
Rice Genotypes ◽  
Moderately Resistant ◽  
Resistant Genotypes

Blast, caused by Pyriculariagrisea (Sacc.) is the most destructive disease of rice in Nepal. To identify the sources of leaf blast resistance in rice genotypes, a field experiment was conducted under natural epiphytotic condition at National Plant Pathology Research Centre (NPPRC), Khumaltar, Lalitpur, Nepal during summer season in 2018 and 2019.A total of 128 rice genotypes in 2018 and 291during 2019 including resistant check (Sabitri) and susceptible check (Shankharika/Mansuli) were tested. Field experiment was conducted in single rod row design. Leaf blast disease assessment was done according to 0-9 scale. During 2018, 59 entries were highly resistant (Score 0), 34 resistant (Score 1), 26 moderately resistant (Score 2-3), 5 were moderately susceptible (Score 4-5), 4 susceptible (Score 6-7) and none of them were highly susceptible (Score 8-9) to leaf blast. Similarly, in 2019, 6 lines were highly resistant, 70 resistant, 196 moderately resistant, 15 lines were moderately susceptible, 4 susceptible and none of them were highly susceptible to the disease. Only, one genotype NR2179-82-2-4-1-1-1-1 (Score 1) was found resistant in both years. Similarly, genotype NR2182-22-1-3-1-1-1 (Score 2-3) was found moderately resistant. Some of the genotypes were found resistant in 2018 which become moderately resistant in 2019, they were NR2180-20-2-5-1-1-1-1, IR97135-8-3-1-3, IR98786-13-1-2-1, NR2181-139-1-3-1-1-1-1, and IR13F402. So, findings of these resistant and moderately resistant genotypes could be used in resistant source for the development of leaf blast resistant rice varieties through hybridization in future.

scholarly journals An Appraisal of Insect Pests Associated with Cereal Grains Traded in Maiduguri, Borno State, Nigeria

2014 ◽  
Vol 19 ◽  
pp. 76-83
Author(s):  
D.M. Mailafiya ◽  
Z. Dauda ◽  
M.M. Degri ◽  
B.G.J. Kabir ◽  
Y.T. Maina
Keyword(s):  
Insect Pests ◽  
Insect Pest ◽  
Sitophilus Oryzae ◽  
Rhyzopertha Dominica ◽  
Wheat Grains ◽  
Pest Infestation ◽  
Randomized Design ◽  
Cereal Grain ◽  
The Mean ◽  
Completely Randomized Design

This study investigated insect pest infestation of maize, millet, sorghum, rice and wheat grains traded in the three main markets namely Monday, Baga-Road and Custom-Park markets in Maiduguri, Borno state, Nigeria. Sampling lasted from January to June 2012. Samples per grain type, each weighing one kilogram, were obtained every two weeks from ten randomly selected traders per market. Each sample was sieved in the laboratory to recover all adult insects present, both at sampling and also after one month stay (laid out in a completely randomized design). In each market, Sitophilus zeamais Motschulsky and Rhyzopertha dominica (F.) followed by Tribolium castaneum Herbst, Sitophilus oryzae (Linnaeus), Trogoderma granarium (Everts) or Cryptolestes sp. were the insect pests commonly found attacking more (between two to five) grain types. Observed highest and lowest mean insect numbers were respectively by S. zeamais in maize grains (12.13 individuals in Monday market) and T. granarium in wheat grains (0.13 individuals in Baga-Road market). Results unveil that among three markets, higher mean total numbers of insects were present in maize, rice or wheat (18-33). For all grain types, the mean numbers of damaged grains were significantly higher in Monday (53-357) and Custom-Park (46-302) than in Baga-Road (17-109) markets. Furthermore, the mean total number of damaged grains across markets was significantly higher maize, followed by rice and wheat (55-231) than in other grain types (37-41). The implications of all these results on insect infestation of different cereal grain types sold in these markets are discussed.

scholarly journals Survey of insects and Mites Associated with Stored Rice in Nigeria

2021 ◽  
Vol 4 (1) ◽  
pp. 194-201
Author(s):  
IB Ezeobiora ◽  
KA Kemabonta ◽  
WA Makanjuola
Keyword(s):  
Species Composition ◽  
Pest Management ◽  
Insect Pests ◽  
Insect Pest ◽  
Sitophilus Oryzae ◽  
Mite Species ◽  
Insect Species ◽  
Rhyzopertha Dominica ◽  
Percentage Occurrence ◽  
Rice Samples

Insect pest infestation causes quantitative or qualitative losses in stored Rice. Proper identification of the insect species infesting stored Rice is critical for making pest management decisions. This study assesses the species composition and abundance of insect pests of stored Rice in Nigeria. Imported and Local Rice samples each weighing one kilogram were obtained every 6 months from three randomly selected vendors in randomly selected markets in 14 towns in 14 states in Nigeria. 50g were weighed from each sample and kept in vials, covered, strapped with rubber band and kept in the laboratory. The Rice samples were sieved to collect all adult insects present after Six months in storage. Sampling lasted for two years (2016-2017). There were 11 species of insect pests and one Mite species in the stored Imported and Local Rice samples. Most of the species were from the order Coleoptera with the percentage occurrence of 80.9% in Imported Rice and 82% in Local Rice. The insect species composition includes Sitophilus oryzae, Cryptolestes ferrugineus, Sitophilus zeamais, Psocids, Sitotroga cerealella, Ahasverus advena, Tribolium castaneum Oryzeaphilus surinamensis, Oryzaephilus mercator and Rhyzopertha dominica. The Psocid and mite species could not be identified. Sitophilus oryzae was the main insect pest of Rice with the percentage occurrence of 39.23% in Imported Rice and 26.87% in Local Rice. The outcome of this study is very important in planning control measures as the knowledge of the species composition and abundance of insect pests is an important component of pest management in stored Rice in Nigeria.

scholarly journals Deterioration of Grain Quality of Wheat by Rice Weevil, Sitophilus oryzae (L.) during Storage

2021 ◽  
Author(s):  
Subash Singh ◽  
D.K. Sharma
Keyword(s):  
Durum Wheat ◽  
Sitophilus Oryzae ◽  
Biochemical Properties ◽  
Rice Weevil ◽  
Rhyzopertha Dominica ◽  
Wheat Cultivars ◽  
Storage Pests ◽  
Granary Weevil ◽  
Stored Wheat ◽  
Grain Damage

Background: A number of storage pests viz., Rhyzopertha dominica (F.), rice weevil, Sitophilus oryzae (L.), granary weevil, Sitophilus granarius (L.) and Khapra beetle, Trogoderma granarium (Evert.) damage stored wheat. However, S. oryzae is considered a primary pest of stored wheat and has been reported to prefer soft textured wheat cultivars.Methods: The grains of three bread (soft textured) viz., HD2967, PDW314, PBW658 and three durum wheat (hard textured) cultivars viz., WHD943, PBW621, PDW291 were screened for feeding response by rice weevil, Sitophilus oryzae L. in the laboratory. Each cultivar seed was properly cleaned and disinfested before its use. A 100g seed sample of each cultivar was taken into the plastic jars. Of the pure culture, ten 1-2 week young one insects (1:1 sex ratio) were released into the jars each containing different cultivar grains. The jars were covered with white muslin as three separate storage sets, i.e., 30, 60 and 90 days after storage to record data observations. Result: Durum wheat cultivars being low in protein contents were comparatively less preferred for pest feeding and cultivar PDW291 was found highly resistant based on low insect emergence, grain damage and weight loss. The bread wheat cultivars due to high protein contents were highly preferred by the pest and cultivar HD2967 showed maximum preference. The biochemical properties like ash contents and crude fibres showed positive while crude fats and protein a negative correlation with the pest infestation. 

Migration of stored-grain insect pests from a small wheat bulk

1984 ◽  
Vol 24 (125) ◽  
pp. 260 ◽  
Author(s):  
ER Sinclair ◽  
J Alder
Keyword(s):  
Food Source ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Red Flour Beetle ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
Grain Beetles ◽  
Grain Bulks ◽  
Source Populations ◽  
Cryptolestes Pusillus

One hundred unsexed adults of each of the following coleopterous species were added to 27 .3 kg of clean wheat: Sitophilus oryzae (L.) (rice weevil), Rhyzopertha dominica (F.) (lesser grain borer), Tribolium castaneum (Herbst) (rust-red flour beetle), and the flat grain beetles Cryptolestes pusillus (Schonherr), C. ferrugineus (Stephens), and C. pusilloides (Steele and Howe). For 15 months, measurements were made of population size and emigration from this wheat bulk. The highest populations recorded for each species were: 138 850, 65 680, 9 060, 47 000, 15 530, 11 940, respectively, and total emigrant numbers during the period were: 774 682, 278 094, 123 784, 335 588, 39 070, 9 352, respectively. Such high numbers of emigrants in relation to relatively low source populations emphasize the significance of small amounts of infested grain as sources of infestation of large grain bulks, and hence the importance of grain hygiene. The proportion of females in the populations of four species changed significantly from 0.50 as populations developed. Emigration behaviour was influenced most commonly by temperature, insect numbers, and wheat age, but these factors did not act uniformly on all species. Negligible numbers of emigrants returned to the food source. Low numbers caught in food traps away from the source were consistent with these not being attractive but traps near the shed walls caught greater numbers than expected.

Abiotic and Biotic Factors Affect Efficacy of Chlorfenapyr for Control of Stored-Product Insect Pests

2011 ◽  
Vol 74 (8) ◽  
pp. 1288-1299 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
ANN N. HATZIKONSTANTINOU ◽  
HELEN N. KAVALLIERATOU
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Adult Emergence ◽  
Paddy Rice ◽  
The Other ◽  
Rhyzopertha Dominica ◽  
Prostephanus Truncatus ◽  
Progeny Production ◽  
Abiotic And Biotic Factors ◽  
Grain Protectant

Laboratory bioassays were conducted to assess pyrole chlorfenapyr as a potential grain protectant against adults of Rhyzopertha dominica, Sitophilus oryzae, Prostephanus truncatus, Tribolium confusum, and Liposcelis bostrychophila. Factors such as dose (0.01, 0.1, 0.5, 1, 5, and 10 ppm), exposure interval (7 and 14 days), temperature (20, 25, and 30°C), relative humidity (RH; 55 and 75%), and commodity (wheat, maize, barley, and paddy rice) were evaluated. Progeny production was assessed after 74 days of exposure. For L. bostrychophila and T. confusum the increase of dose increased mortality. After 7 or 14 days of exposure, mortality was low at doses of ≤1 ppm and did not exceed 23 or 36%, respectively, for L. bostrychophila or 13 or 58%, respectively, for T. confusum. After 14 days of exposure, mortality of S. oryzae at 30°C and 75% RH was 82.2%. Mortality of P. truncatus was considerably higher than that of the other species. At 0.5 ppm, mortality exceeded 81% after 7 days of exposure and 91% after 14 days of exposure. Progeny production of L. bostrychophila was extremely high. Very few progeny were found for T. confusum. For S. oryzae, offspring emergence was high, except at 20°C and 55% RH. For P. truncatus, progeny production in the treated maize was not avoided, even at 10 ppm. In the case of S. oryzae, at 0.1 ppm and after 14 days of exposure, mortality in wheat was higher than in the other three commodities. For R. dominica, mortality was low at 0.1 and 1 ppm for paddy rice but reached 74.4% in barley after 14 days of exposure. For T. confusum, mortality was low at 0.1 and 1 ppm in all commodities. For progeny production counts, for S. oryzae or R. dominica, adult emergence was higher in paddy rice than in the other three commodities. Finally, overall T. confusum progeny was low. Chlorfenapyr efficacy varied remarkably among the combinations tested, and it may be a viable grain protectant in combination with other insecticides.

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