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

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.

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 804 ◽  
Author(s):  
Frank Arthur ◽  
W. Robert Morrison

In evaluating insecticides, progeny production on grain commodities can be evaluated by either exposing adults on a commodity for a given time period, then removing them and assessing mortality and progeny production, or by leaving the adults on the commodity continuously, and then assessing progeny production. Little research directly compares these methodologies. Thus, our aims were to: (1) determine residual efficacy of Diacon IGR+ (methoprene+deltamethrin) and Gravista (methoprene+deltamethrin+piperonyl butoxide) on wheat, corn, and brown rice over the course of a year, using bioassays with select stored product insects at different time intervals, and (2) directly compare the two different methods of parental adult exposure on progeny production. Adults were either exposed for 7 d, then removed and assessed for survival, and the commodities were held for 6–7 weeks to assess progeny production, or adults were continuously exposed on the commodities for 6–7 weeks. Commodities were aged and sampled every 3 months for 12 months. Afterwards, samples were examined for progeny, sample weight loss, and insect feeding damage. Each insecticide killed exposed adults and prevented progeny of Rhyzopertha dominica on wheat and brown rice, and Tribolium castaneum on corn. There was extensive survival of Sitophilus spp. on all commodities, though Gravista did initially suppress S. oryzae on wheat and S. zeamais on corn compared to Diacon IGR+. Progeny, weight loss, and insect feeding damage were positively correlated in the 7 d exposure compared with continuous parental exposure. Both insecticides will control R. dominica and externally-feeding insects, but may exhibit reduced effectiveness for Sitophilus spp., especially S. oryzae. Food managers can utilize these data to more effectively plan management programs.


1991 ◽  
Vol 26 (3) ◽  
pp. 339-344 ◽  
Author(s):  
J. E. Baker ◽  
F. H. Arthur ◽  
P. L. Bruckner

Population development by the rice weevil, Sitophilus oryzae (L.) and feeding damage caused by the lesser grain borer, Rhyzopertha dominica (F.), were assessed on twelve triticale (X Triticosecale Wittmack) genotypes maintained at 25°C and at 11.7 or 14.2% moisture content. Among genotypes at 14.2% moisture content, total progeny production by the rice weevil ranged from 7.1 (GA82014) to 8.8 (87AB13541) weevils per female-day; mean time to adult emergence ranged from 35.5 (GA82014) to 36.9 days (87AB13541 and CT4699); and rate of emergence (a measure of the slope of the cumulative emergence curve at the average emergence day) ranged from 0.59 (87AB 13541) to 0.72 (‘Morrison’). Although there were some statistical differences among these population growth parameters on different triticale genotypes, all genotypes were at least as susceptible as the long grain brown rice (Oryza sativa L.) and soft red winter wheat (Triticum aestivum L., cultivar ‘Florida 302’) controls tested concurrently. Development time of rice weevils was significantly delayed and total progeny production after 65 days was reduced about 17-fold on triticale genotypes at 11.7% moisture content. About 3-fold more frass was produced by lesser grain borers feeding for 7 days at 25°C on triticale genotypes at 14.2% moisture content compared to that obtained on genotypes at 11.7% moisture content. Significantly more feeding and frass production by lesser grain borers occurred on triticale and wheat than occurred on rice.


Insects ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 95 ◽  
Author(s):  
Frank Arthur

Rhyzopertha dominica (Fab.), the lesser grain borer, and Sitotroga cerealella (Olivier), the Angoumois grain moth, are internally feeding stored product insects that can infest raw grains. In this test, brown rice was treated with 0.5 and 1.0 ppm of a new emulsifiable concentrate (EC) formulation of the pyrethroid deltamethrin and stored for 12 months. One day after treatment, and every 3 months for 12 months, treated rice was mixed with untreated brown rice in the following ratios: 0:100 (untreated controls), 10:90, 25:75, 50:50, 75:25, and 100:0 (all treated). Bioassays were conducted by exposing 10 parental adults of each species on the rice mixtures and assessing progeny production, feeding damage, and weight loss. The progeny of S. cerealella ranged from 105.6 F1 adults on untreated brown rice to 69.4 F1 adults on 100% treated rice, but there was little feeding damage or weight loss. The progeny production of R. dominica declined from 177.4 F1 adults on untreated rice to 9.8 F1 adults on 100% treated rice. Weight loss and feeding damage were correlated with progeny production. The results show that the new deltamethrin formulation could be used for protection of brown rice, but S. cerealella may be less susceptible to deltamethrin compared to R. dominica.


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


2017 ◽  
Vol 9 (2) ◽  
pp. 736-743
Author(s):  
Usha Yadav ◽  
Ruchira Tiwari

he laboratory experiments were conducted to study the efficacy of some indigenous products such as plant products (chopped neem leaves ajwain seed powder, garlic capsules, saw dust), animal derivedproducts ( cow dung cake powder, cow urine) and inert materials ( ash powder, sand, talcum powder, salt) @ 2g/100g of wheat grains against rice weevil, Sitophilus oryzae (Linn.) and lesser grain borer, Rhyzoper thadominica (Fab.) on stored wheat by undertaking various parameters viz., percent adult emergence, percent seed damage, per cent weight loss and per cent germination after six months of storage during April to October 2015. After 180 days of treatments, the minimum number of adults weevils of S. oryzae( 4.00, 6.00,7.67, 9.00, 9.67 and 10.33) were emerged in wheat grains treated with ash powder, sand, cow dung powder, talcum powder, ajwain seed powder and neem leaf powder, respectively with minimum grain damage (7.33 %, 8.67 %,11.67 % and 12.00 %) was observed on ash powder, sand, ajwain seed powder and talcum powder, respectively, whereas minimum weight loss (2.67 %, 3.67 %, 5.67 % and 6.67 %) was recorded on ash powder, sand, cow dung powder, talcum powder and ajwain seed powder, respectively. Similarly, the minimum number of adult beetles of R. dominica were emerged (2.00,2.33, 6.67,7.00 and 8.33) in ash power, sand, talcum powder, cow dung cake powder and ajwain seed powder, respectively with minimum grain damage (4.00 %,8.00 %. 8.67 % and 12.67 % and weight loss (1.33 %, 4.00 %, 7.33 % and 11.67 %) in sand, ash powder, talcum powder and cow dung cake treated wheat grains, respectively. It has been clearly observed that seed germination was not affected adversely in any treatment during six months of storage. The present study clearly revealed that these naturally occurring indigenous products could be used to manage the storage insect pests in wheat.


Author(s):  
Subash Singh ◽  
D.K. Sharma

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. 


2011 ◽  
Vol 74 (8) ◽  
pp. 1288-1299 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
ANN N. HATZIKONSTANTINOU ◽  
HELEN N. KAVALLIERATOU

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.


2020 ◽  
Vol 83 (12) ◽  
pp. 2167-2172
Author(s):  
VASU MEHTA ◽  
SURJEET KUMAR

ABSTRACT Sitophilus oryzae (L.) is the most widespread and destructive insect of stored wheat throughout the world. The main aim of the study was to find ecofriendly alternatives to chemical fumigants and synthetic insecticides for the control of weevils in stored wheat. The leaf powder of Ageratum conyzoides proved to be the best treatment against the weevil that resulted in maximum mean cumulative mortality (96.67%), the lowest monthly population increase (18.33), and the least grain damage (12.61%) and weight loss (1.75%) during 6 months of storage. The next best treatments were the drupe powder of Melia azedarach, followed by Vitex negundo and Ocimum sanctum. A. conyzoides, Melia azedarach, and O. sanctum were found effective even 3 months after preparation. The leaf powder of Murraya koenigii resulted into the lowest mean cumulative adult mortality (14.23%), the highest monthly population increase (132.78), and the highest grain damage (47.50%) and weight loss (11.07%), thus proving to be the least effective. HIGHLIGHTS


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