scholarly journals Insecticidal effect of from three Hypericum species extracts against Rhyzopertha dominica, Sitophilus oryzae and Tribolium confusum

2021 ◽  
Vol 45 ◽  
Author(s):  
Cennet Yaman ◽  
Şeyda Şimşek
Keyword(s):  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Tribolium Confusum ◽  
Rhyzopertha Dominica ◽  
Botanical Insecticides ◽  
Stored Grain ◽  
Leaf Extracts ◽  
Insecticidal Effect ◽  
Hypericum Species ◽  
Control Insect

ABSTRACT The search for new plant natural products with insecticidal properties to control insect pests in agriculture has gained relevance in the past decades. The aim of the study was to investigate the insecticidal activity of extracts derived from flower, leaf, and stem of three Hypericum species (Hypericum heterophyllum, Hypericum perforatum, Hypericum scabrum) against the adults of three important stored grain insect pests namely; Sitophilus oryzae (Curculionidae), Rhyzopertha dominica (Bostrichidae) and Tribolium confusum (Tenebrionidae). The insects were incubated with the food under 10% concentration of Hypericum extracts and the mortality was recorded after 24, 48 and 72 h of exposure. The extracts of the Hypericum species and exposure time were found to have statistically significant effective against the three insect pests. After 72 h exposure, the mortality ranged from 4.3 to 94.1 % for all insects. Among tested insects, R. dominica was more susceptible than T. confusum and S. oryzae. Although desirable insecticidal effect against the insects were recorded from all the three Hypericum species, the leaf extract of H. perforatum was more effective on R. dominica, while the flower and stem of H. scabrum displayed high toxic effect on T. confusum and S. oryzae, respectively. The leaf extracts, of H. perforatum, in particular, may be used as source of new potential botanical insecticides against R. dominica in stored grains.

Effect of Two Azadirachtin Formulations against Adults of Sitophilus oryzae and Tribolium confusum on Different Grain Commodities

2007 ◽  
Vol 70 (7) ◽  
pp. 1627-1632 ◽  
Author(s):  
NICKOLAS G. KAVALLIERATOS ◽  
CHRISTOS G. ATHANASSIOU ◽  
CONSTANTIN J. SAITANIS ◽  
DEMETRIUS C. KONTODIMAS ◽  
ALEXANDER N. ROUSSOS ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Abiotic Factors ◽  
Sitophilus Oryzae ◽  
Adult Mortality ◽  
Tribolium Confusum ◽  
Progeny Production ◽  
Stored Grain ◽  
Insecticidal Effect ◽  
Grain Beetles ◽  
Dosage Formulation

The insecticidal effect of two azadirachtin-based insecticides, NeemAzal-T/S and Oikos 32 EC, was examined against adults of the grain beetles Sitophilus oryzae and Tribolium confusum on wheat and maize under different temperature and humidity regimes. The insecticides were applied at three dosages, equivalent to 50, 100, and 200 mg of active ingredient per kg of grain. Adults of the above species were exposed to the treated grains at 20, 25, and 30°C and two relative humidity levels (55 and 75%), and mortality was assessed after 14 days of exposure. All adults were then removed, and the treated substrate remained under the same conditions for 45 more days. After this period, the grains were checked for progeny production. In both species and both commodities, mortality increased with insecticide dosage. For many dosage-formulation combinations, mortality increased with temperature at 55% relative humidity but the reverse was observed at 75% relative humidity. Comparing the two formulations, NeemAzal-T/S was more effective than Oikos 32 EC at all the combinations tested. NeemAzal-T/S was more effective at high relative humidity, but the efficacy of Oikos 32 EC was not much affected by the relative humidity. Survival was high, even at the higher dosages, in some of the temperature-humidity combinations. Progeny production of S. oryzae in the treated grains was considerably higher than that of T. confusum. The results of the present study indicate that further dosage increases and longer exposure times are needed to obtain a complete (100%) adult mortality in all combinations tested. However, the feasibility of using higher azadirachtin dosages (>200 mg/kg grain) is questionable for cost reasons. Consequently, the use of these substances is not comparable to the use of traditional grain protectants, which are usually used at dosages of <5 mg/kg grain. Although azadirachtin-based insecticides can be used with success for protection of stored grain, our study demonstrated that under certain circumstances such an application may not be effective. Abiotic factors (formulation, temperature, and relative humidity) had a more serious impact on the efficacy of these insecticides than did biotic factors (target species and commodity).

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.

scholarly journals Prevalence of Insects in Traditionally Stored Rice at Farmhouses in Bangladesh

2021 ◽  
pp. 34-44
Keyword(s):  
Storage Time ◽  
Insect Pests ◽  
Sitophilus Oryzae ◽  
Small Farmers ◽  
Plastic Bags ◽  
Rice Moth ◽  
Plastic Bag ◽  
Meal Worm ◽  
Storage Structures ◽  
Control Insect

A survey was conducted to investigate rice storage practices at the farmer’s level and the prevalence of insects’ status through a pretested questionnaire in Mymensingh and Jashore districts, Bangladesh. For seed purposes, large, medium, and small farmers store about 40, 10, and 5 kg, respectively in the Aman season for 7 months whereas in the Boro season large and medium farmers keep about 80 and 20 kg for 5 months. Average storage time was the highest (7 months) for Boro and Aman rice by large and small farmers, respectively for consumption. Eleven storage items namely, Dole, Motka, Tin, Plastic Drum, Gunny Bag, Bamboo Gola, Dhari, Bamboo Auri, Berh, Steel Drum, and Plastic Bag were found. About 57 and 74% of farmers stored rice, among them 47 and 58% used traditional Dole in Jashore and Mymensingh, respectively. Tin and Berh (1%) were the least used storage structures. About 11 and 17%; 3 and 4% of farmers used neem leaf and chemicals especially phostoxin in storage as an insect repellent in these areas, respectively. The use of Plastic Bags increased sharply due to lightweight, availability, and low price, whereas Bamboo Gola, Berh, Motka users decreased remarkably. Relative abundance of the insect species was: Rice Moth Sitotroga cerealla, Rice Weevil Sitophilus oryzae, Red Flour Beetle Tribolium castoreum, and Lesser Meal Worm Alphitobious diaperinus. Maximum insect infestation was found in stored paddy in Dole followed by Motka, and Plastic Bag; and the least amount was observed in Plastic Drum in both regions. Three fourth of the respondents took no measures to control insect pests in stored rice.

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

Control of Main Stored-Grain Insects with New Formulations of Entomopathogenic Fungi in Diatomaceous Earth Dusts

2008 ◽  
Vol 4 (1) ◽  
Author(s):  
Yacoub Ahmad Batta
Keyword(s):  
Entomopathogenic Fungi ◽  
Diatomaceous Earth ◽  
Sitophilus Oryzae ◽  
Germination Percentage ◽  
Fungal Species ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
High Loss ◽  
Mortality Percentage ◽  
Stored Grain Insects

The present research is aimed at a formulation of the entomopathogenic fungi, Beauveria bassiana (Bal.) Vuillemin and Metarhizium anisopliae (Metch.) Sorokin, in two types of diatomaceous earth dusts, fossil shield and Silico-Sec, are then applied against the adults of three species of stored-grain insects: Sitophilus oryzae L., Rhyzopertha dominica Fab. and Tribolium castaneum Herbs. Effect of the treatment was assessed by comparing the mortality percentage of the adults of the three insect species exposed to the formulated fungi with that of the adults exposed to the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. Results obtained from these exposures have indicated that treatment of the adults with the formulated fungi resulted in a significantly higher mean mortality percentage compared to the treatment with the unformulated fungi or the diatomaceous earth dusts or the undisturbed control. A synergistic interaction between the effect of fungal species and the diatomaceous earth dusts was shown. Viability of conidia of both fungal species in diatomaceous earth dusts was assessed by calculating the germination percentage of the conidia over time. Results indicated a small loss of mean germination percentage for formulated conidia of both fungal species versus a high loss of mean germination percentage for the unformulated conidia, thus the diatomaceous earth dusts used in the formulation of both fungi demonstrated a negligible effect on the viability of formulated conidia compared to the unformulated.

The frequency of Cryptolestes spp. in grain in south-east Queensland

1980 ◽  
Vol 20 (103) ◽  
pp. 234 ◽  
Author(s):  
ER Sinclair ◽  
M Bengston
Keyword(s):  
Sitophilus Oryzae ◽  
Common Species ◽  
Red Flour Beetle ◽  
Rhyzopertha Dominica ◽  
Stored Grain ◽  
Grain Beetles ◽  
Farm Survey ◽  
Stored Grain Pests ◽  
Grain Protectant ◽  
Grain Farms

In a survey of 60 grain farms on the Darling Downs, Queensland, during 1977-78, the flat grain beetles Cryptolestes spp., which are germ feeders in stored grains, were found on 39 of the farms and in 15% of the 483 samples taken. Ninety percent of infestations involving Cryptolestes spp. were found in bag or bulk stores of seed and feed grain, where they were usually associated with heavy infestations of the three more common stored grain pests, the rice weevil Sitophilus oryzae (L.), the lesser grain borer Rhyzopertha dominica (F.), and the red flour beetle Tribolium castaneum (Herbest.). Three species of Cryptolestes were detected: C. pusillus (Schonherr) (45.6% of farms surveyed), C. ferrugineus (Steph.) (28.1 %), and C. pusilloides (Steel and Howe) (15.8%). During the farm survey, samples were also collected from 8 of the 11 central storages reported infested with Cryptolestes spp. C. ferrugineus was present in each of these samples, C. pusillus in only one, whilst C. pusilloides was not found. The three species were tested for resistance to malathion and fenitrothion, the most commonly used grain-protectant chemicals, by exposing adults to treated wheat. C. pusillus and C. pusilloides were susceptible to both malathion and fenitrothion (LC99.9 < 1 mg kg-1). C. ferrugineus, whilst susceptible to fenitrothion (LC99.9 < 1 mg kg-1) was resistant to malathion, with LC99.9 of 300-400 mg kg-1 compared with the recommended dose of 18 mg kg -1. Although C. pusillus was the most common species on farms, it was concluded that C. ferrugineus was the most important overall because it is biologically better suited to the grain in central storages, which is typically hot (>30�C) and of low moisture content (< 12% for wheat).

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