Sitophilus Granarius Research Articles

Ancient DNA preservation, genetic diversity and biogeography: A study of houseflies from Roman Qasr Ibrim, lower Nubia, Egypt

The optimal preservation of many Egyptian archaeological sites provides unique opportunities in the research into the evolution of synanthropic species, wild animals or plants, which benefit from close association with man-made human habitats. In this study we extracted and analysed ancient mitochondrial DNA (mtDNA) from three synanthropic insect species, two storage pests, Sitophilus granarius (Coleoptera: Curculionidae) (N = 8) and Trogoderma granarium (Coleoptera: Dermestidae) (N = 14), and the housefly Musca domestica (Diptera: Muscidae), (N = 14), from Roman Qasr Ibrim, an Egyptian frontier site located in lower Nubia. The impact of different experimental variables on ancient DNA recovery was also evaluated, confirming that it is possible to extract endogenous ancient DNA from desiccated specimens while preserving the insect exoskeleton. A phylogenetic comparison of the Qasr Ibrim housefly mtDNA-COI (COI) with modern housefly sequences, revealed that they were genetically similar to modern Egyptian, Near Eastern, Indian, Japanese, and US/Canadian populations. As the now cosmopolitan houseflies were transported by human populations alongside domestic animals and crops and may have aided the spread of disease, these findings provide important information for these processes. While limited by the resolution of the comparative databases, our research suggests the existence of biological invasions and links across the Red Sea from Egypt to the Arabian Peninsula, and exchanges between India and Egypt. We demonstrate the great potential of fossil insect aDNA for reconstructing biogeographic and diachronic species distribution and for better understanding past environments.

Essential oil composition and insecticidal activity of Satureja boissieri against Sitophilus granarius (Coleoptera:Curculionidae) and Spodoptera littoralis (Lepidoptera: Noctuidae)

In the scope of this study, we have investigated fumigant and contact toxicity effects of Satureja boissieri Hausskn. ex Boiss. essential oil against Sitophilus granarius L. (Coleoptera: Curculionidae) and Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae). The fumigant and contact toxicity experiments were carried out with the adults of Sitophilus granarius whereas the contact toxicity experiment was carried out with the 3rd, 4th and 5th larvae of S. littoralis. Also, various fractions of S. boissieri essential oil were investigated for fumigant activity against S. granarius. In fumigant toxicity studies, the highest activity was obtained at 36 hours with a dose of 0.1 μl/ml with a 100% mortality rate. Fractions of the essential oil had significant fumigant activity on S. granarius (100% fumigant activity at 0.1 μl/ml). Contact toxicity of 100 μl/ml essential oil on the 3rd and 4th larval stage of S. littoralis, was determined to be 100%, however, on the 5th larval stage it was 90.17%. The activity at 25 μl/ml dose was 71.12% in the 3rd larval stage whereas the activity remained very low (6.39- 22.20%) in other larval stages. These results indicated that essential oil of S. boissieri have significant potential which merits to be studied further in possible applications as fumigant and contact insecticide in the control of S. granarius and S. littoralis.

Evaluation of three new insecticide formulations based on inert dusts and botanicals against four stored-grain beetles

Three new insecticide formulations were developed that combine diatomaceous earth (Celatom MN 23) with compounds with low mammalian toxicity. Sitophilus oryzae, Sitophilus granarius, Rhyzopertha dominica and Tribolium castaneum were held on wheat (13.5% moisture content) treated with different doses of the formulations at 28 ± 1 °C and 60 ± 5% RH for 2–7 days, and then held for progeny emergence. The three formulations were made up of: dill essential oil, bait, silica gel and DE (Dill-DE); pyrethrin, PBO, dill essential oil, silica gel and DE (Py-Dill-DE); and disodium octaborate tetrahydrate (DOT), pyrethrin, PBO, dill essential oil, silica gel and DE (DOT-PY-Dill-DE). They were applied either as powders or as slurries. Applying the formulations as powders over a range of concentrations showed that pure DE is the least effective insecticide, with 50% mortality ranging from 430 to 1000 ppm depending on the species after 2–3 days. Dill-DE formulation was the next least effective formulation. The Py-Dill-DE and DOT-Py-Dill-DE formulations had similar activity and being the most effective formulations with 50% mortality from 40 to 260 ppm depending on the species. Bioassays were also run at single doses. Dill-DE was applied at 300 ppm, Py-Dill-DE at 150 ppm and DOT-PY-Dill-DE at 200 ppm. After 3 days, Py-Dill-DE and DOT-PY-Dill-DE formulations there was 100% mortality for S. oryzae, S. granarius and R. dominica. After 7 days the mortality of T. castaneum was from 96 to 100%. Both formulations reduced the progeny almost by 100%. There was survival for all insects with Dill-DE formulation. The concentrations of 150 ppm of Py-Dill-DE, 200 ppm of DOT-PY-Dill-DE and 300 ppm of Dill-DE reduced bulk densities by 0.7, 0.8 and 5.7 kg/hL, respectively.

Characterization of chitinase from Shewanella inventionis HE3 with bio-insecticidal effect against granary weevil, Sitophilus granarius Linnaeus (Coleoptera: Curculionidae)

A 40 kDa chitinase from Shewanella inventionis HE3 was purified (ChiA-Si40) and characterized. Using fermentor with an optimized medium for 48 h at 37 °C, enzyme activity was enhanced by 10-times compared to those using shaking-flask-culture. Purified chitinase is a homogenous monomer with molecular mass of 40 kDa. Its N-terminal residues revealed significant identity with glycoside hydrolase family 18 (GH18) chitinases from Gammaproteobacteria. Using colloidal chitin as a substrate, its finest activity was accomplished at pH 4 and a temperature of 70 °C. Its catalytic efficiency (kcat/Km) was superior to that of some bacterial GH18 chitinases and commercial enzyme, Chitodextrinase®. For scale-up and with regards to the improvement of ChiA-Si40 with PEG 6000 storage stability (6 months), the atomizing process was more pronounced than that of lyophilizing. Bio-assay of ChiA-Si40 against grain weevil Sitophilus granarius, indicates that it had an efficient insecticidal effect. About 10–100 % mortality rates were obtained 1-h after insect came in contact with ChiA-Si40. Histological study clearly demonstrated that luxury larval mid-gut, peritrophic-membrane, and epithelial-cells have been affected considerably after ChiA-Si40 treatment. These properties make ChiA-Si40 a potential bio-insecticidal agent for the biological control of S. granarius that is popular among insect pests of stored grains in Algeria.

Acute Toxicity and Sublethal Effects of Lemongrass Essential Oil and Their Components against the Granary Weevil, Sitophilus granarius.

In the present work, we evaluate the toxic and repellent properties of lemongrass (Cymbopogon citratus (DC. ex Nees) Stapf.) essential oil and its components against Sitophilus granarius Linnaeus as an alternative to insecticide use. The lethal dose (LD50 and LD90), survivorship, respiration rate, and repellency on adults of S. granarius exposed to different doses of lemongrass oil and some of its components were evaluated. The chemical composition of the essential oil was found to have the major components of neral (24.6%), citral (18.7%), geranyl acetate (12.4%), geranial (12.3%), and limonene (7.55%). Lemongrass essential oil (LD50 = 4.03 µg·insect–1), citral (LD50 = 6.92 µg·insect–1), and geranyl acetate (LD50 = 3.93 µg·insect–1) were toxic to S. granarius adults. Survivorship was 99.9% in insects not exposed to lemongrass essential oil, decreasing to 57.6%, 43.1%, and 25.9% in insects exposed to LD50 of essential oil, citral, and geranyl acetate, respectively. The insects had low respiratory rates and locomotion after exposure to the essential oil, geranyl acetate, and citral. Our data show that lemongrass essential oils and their components have insecticidal and repellent activity against S. granarius and, therefore, have the potential for application in stored grain pest management schemes.

Durum Wheat Cultivars Express Different Level of Resistance to Granary Weevil, Sitophilus granarius (Coleoptera; Curculionidae) Infestation.

The granary weevil, Sitophilus granarius Linnaeus 1875, is a primary pest of stored grains worldwide. Feeding damage and progeny production of S. granarius was estimated to identify the levels of resistance of the insect on different durum wheat cultivars. Insect attack on four different durum wheat cultivars was investigated over a period of 20 weeks. Durum wheats were artificially infected with 20 individuals of S. granarius. Every two weeks the sample weight, hectoliter weight, moisture and the number of live weevils, including their number of progenies, were recorded. Overall findings revealed different levels of resistance of different durum wheat cultivars to S. granarius infestation. The Primadur cultivar had the highest resistance, followed by the Marco Aurelio and Cesare cultivars followed finally by the Tito Flavio cultivar which was highly susceptible to S. granarius. For all cultivars, apart from Primadur, S. granarius metabolism increased humidity and temperature, leading to grain degradation and resulting in the potential complete loss of market value if under field conditions. Evidently, durum wheat characteristics affect the life cycle of S. granarius, primarily their progeny, and thus the damage they undertake to the wheat itself. These findings are important because they enable the strategic selection of wheat cultivars that can be stored for a longer time period, while more sensitive wheat cultivars can be selected for shorter storage time and thus faster delivery to market.

Seasonal Effect on the Chemical Composition, Insecticidal Properties and Other Biological Activities of Zanthoxylum leprieurii Guill. & Perr. Essential oils.

This study focused, for the first time, on the evaluation of the seasonal effect on the chemical composition and biological activities of essential oils hydrodistillated from leaves, trunk bark and fruits of Zanthoxylum leprieurii (Z. leprieurii), a traditional medicinal wild plant growing in Côte d’Ivoire. The essential oils were obtained by hydrodistillation from fresh organs of Z. leprieurii growing on the same site over several months using a Clevenger-type apparatus and analyzed by gas chromatography-mass spectrometry (GC/MS). Leaf essential oils were dominated by tridecan-2-one (9.00 ± 0.02–36.80 ± 0.06%), (E)-β-ocimene (1.30 ± 0.50–23.57 ± 0.47%), β-caryophyllene (7.00 ± 1.02–19.85 ± 0.48%), dendrolasin (1.79 ± 0.08–16.40 ± 0.85%) and undecan-2-one (1.20 ± 0.03–8.51 ± 0.35%). Fruit essential oils were rich in β-myrcene (16.40 ± 0.91–48.27 ± 0.26%), citronellol (1.90 ± 0.02–28.24 ± 0.10%) and geranial (5.30 ± 0.53–12.50 ± 0.47%). Tridecan-2-one (45.26 ± 0.96–78.80 ± 0.55%), β-caryophyllene (1.80 ± 0.23–13.20 ± 0.33%), α-humulene (4.30 ± 1.09–12.73 ± 1.41%) and tridecan-2-ol (2.23 ± 0.17–10.10 ± 0.61%) were identified as major components of trunk bark oils. Statistical analyses of essential oil compositions showed that the variability mainly comes from the organs. Indeed, principal component analysis (PCA) and hierarchical cluster analysis (HCA) allowed us to cluster the samples into three groups, each one consisting of one different Z. leprieurii organ, showing that essential oils hydrodistillated from the different organs do not display the same chemical composition. However, significant differences in essential oil compositions for the same organ were highlighted during the studied period, showing the impact of the seasonal effect on essential oil compositions. Biological activities of the produced essential oils were also investigated. Essential oils exhibited high insecticidal activities against Sitophilus granarius, as well as antioxidant, anti-inflammatory and moderate anti-plasmodial properties.

Kütahya İli Üretici Depolarından Alınan Buğday Örneklerinde Bulunan Zararlı Böcek Türleri ve Doğal Düşmanları

Bu çalışma 2017 yılında Kütahya ili üretici depolarında bulunan buğdaylardaki zararlı ve yararlı böcek türleri ve bu türlerin yoğunluklarının tespiti ile depolarda sebep oldukları zarar oranlarının belirlenmesi amacı ile yapılmıştır. 24 farklı köyden alınan toplam 41 örneğin incelenmesi sonucunda, Sitophilus granarius (L.), Oryzaphilus surinamensis (L.), Tribolium castaneum (Herbst), Tenebroides mauritanicus (L.), Tenebrio molitor (L.), Anthrenus scrophulariae var. albidus (Reitter), Dienerella sp. (Reitter), Stegobium paniceum (L.), Plodia interpunctella (Hübner) ve Ephestia cautella (Walker) olmak üzere toplam 10 böcek türü zararlı olarak tespit edilmiştir. Ayrıca Lariophagus distinguendus (Förster), Anisopteromalus calandrae (Howard) ve Bracon hebetor (Say) türleri doğal düşman olarak bulunmuştur. Zararlı türlerden S. granarius ve O. surinamensis sırasıyla örneklerdeki yoğunluk (%52.6-%40.2) ve bulaşıklık (%56.1-%46.3) bakımından en fazla karşılaşılan türler olmuştur. Örneklerde zarar görmüş tane ortalaması en yüksek %10 olarak tespit edilmiş olup, il ortalaması %1.39 bulunmuştur. Tespit edilen 13 farklı böcek türünden, Anthrenus scrophulariae var. albidus’un Türkiye’de ilk kez buğday depolarındaki varlığı bu çalışmayla ortaya konulmuştur.

Chemical composition of Achillea millefolium L. (Asteraceae) essential oil and insecticidal effect against Sitophilus granarius (Coleoptera: Curculionidae) and Rhyzopertha dominica (Coleoptera: Bostrichidae)

Stored product pests are responsible for the quality and quantitative losses worldwide in stored products. Studies on the development of plant-based pest control strategies have been increasing in recent years. In this study, the insecticidal and behavioral effect of essential oil obtained from the Achillea millefolium L. (Asteraceae) plant were measured under laboratory conditions against two main stored product pests, Sitophilus granarius (Coleoptera: Curculionidae) and Rhyzopertha dominica (Coleoptera: Bostrichidae). Contact and fumigant activity tests were conducted at 0.10 (v/v) and 0.15 (v/v) concentration, and mortality rates were recorded at the end of the 24th and 48th hours. Pure acetone was used in the control group. Repellent activity tests were established at three different concentrations (0.025 µl/cm2, 0.06 µl/cm2 and 0.125 µl/cm2) and the effects of 2nd, 4th, 8th, and 12th hours were recorded. Additionally, the essential oil composition of A. millefolium was determined by using GC-MS. For both insects, essential oil did not demonstrate significant fumigant activity. At the end of 48 hours, the highest fumigant activity was determined with a mortality rate of 19.7% for R. dominica. This oil did not show any fumigant activity against Sitophilus granarius. At the end of 24 hours, the highest contact activity was determined against R. dominica at the dose of 0.15 (v/v) with a mortality rate of 99.2%. In the same period, the contact activity was determined as 83.4% for S. granarius. Consequently, the essential oil showed significant repellent activity against both pests.

Insecticidal Efficacy and Repellency of Trans-Anethole Against Four Stored-Product Insect Pests

In this study, it was investigated that repellency and insecticidal efficacy of trans-anethole of botanical origin on major stored product on pests species, namely Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Tribolium confusum Jacquelin du Val (Coleoptera, Tenebrionidae) and Tribolium castaneum (Herbst) (Coleoptera, Tenebrionidae). Repellency effect was evaluated by choice test in petri dishes, while the mortality effect was examined by exposure to wheat treated at different concentrations, such as 1, 2, 3, 4, and 8 μL trans anethole. In efficacy tests, after 72 hours exposure, the highest adult mortality was found on T. castaneum with a 60% mortality, while other test species showed no significant mortality. On the other hand, repellency tests revealed varying degree of repellency depending on the application dose of trans-anethole. It was determined that S. granarius belongs to repellent class III, while all of the other species fall under repellent class IV. F1 progeny decreased as trans-anethole concentration increased, and in this context 8 μL of trans-anethole is proved to be the optimal concentration causing maximum decrease in progeny production. Among the insect species tested, T. confusum was found to be the most sensitive to trans-anethole with 100% decrease in F1 progeny production. Our results indicate that trans-anethole can be used as a potential repellent for the control of major stored grain pests. Additionally, trans-anethole, by its contact efficacy, might be considered as a grain protectant against S. granarius, S. oryzae, T. confusum and T. castaneum.

Bioinsecticidal activity of Vitex negundo L. (Family: Verbenaceae) leaf extracts against Sitophilus granarius L. in stored maize grains

The insecticidal property of dry leaves of Vitex negundo against the Sitophilus granarius in the laboratory at (28±3) 0C and (78±3) % r. h. with Soxhlet extracted extracts of V. negundo leaves in ethanol, methanol, chloroform, acetone and n-Hexane were tested and found very effective to control the store grain insect pest. The biopesticidal effects of extracts in different solvents were compared by calculating LD10, LD50, LD90 and LD99 values for 96 hrs. The Probit analysis of data demonstrated that LD values for ethanol, methanol, chloroform, acetone and n-Hexane extracts were LD10 – 1.216, 1.141, 0.9298, 1.265, 0.5398 ml/Kg; LD50 – 2.997, 3.106, 2.490, 3.727, 1.302 ml/Kg; LD90 – 7.392, 8.457, 6.667, 10.98, 3.142 ml/Kg and LD99 –15.43, 19.14, 14.88, 26.50, 6.439 ml/Kg respectively, for 96 hrs. These results demonstrated that the mortality increased with increase in concentration of extract and exposure time. There was nearly zero fecundity and next generation was not observed in treated grains. The extracts of V. negundo leaf may be of high value in grain storage against S. granarius, especially in subsistence agriculture where the plants are locally available to local farmers. Hence, we conclude that the ethanol, chloroform and n-Hexane extracts from V. negundo leaf are more effective and useful. It served as being a potential insecticidal agent and could be applicable to the management of populations of stored-product insects particularly against the infestation by granary weevil, S. granarius after proper dose formulation.

Chemical composition and insecticidal potential of different Origanum spp. (Lamiaceae) essential oils against four stored product pests

This study was conducted to determine the contact and fumigant toxicity of plant essential oils extracted from four Origanum spp. against four stored product pests, Rhyzopertha dominica (F., 1792) (Coleoptera: Bostrichidae), Tribolium confusum Jacquelin Du Val, 1863 (Coleoptera: Tenebrionidae), Sitophilus granarius (L., 1875) and Sitophilus oryzae (L., 1763) (Coleoptera: Curculionidae). Chemical composition of the essential oils was determined using GC-MS. The trials were conducted under laboratory conditions in 2019 at Plant Protection Central Research Institute. Essential oils extracted from Origanum onites L. and Origanum vulgare L. var. hirtum caused 100% mortality of R. dominica and T. confusum . The computed LD50 value for O. vulgare var. verticium against R. dominica 24 h after application was 0.046 µl/insect. Single concentration fumigant study indicated that O. onites and O. vulgare var. hirtum essential oils cause high mortality (91 and 70%, respectively) of R. dominica within 24 h. Essential oils of O. vulgare showed the highest activity against R. dominica with LC50 and LC90 values of 0.0052 and 0.0144 µl/ml, respectively. The main components of O. onites essential oil were thymol (22.9%), γ-terpinene (13.0%), p-cymene (12.9%) and carvacrol (7.2%). Similarly, the essential oils of O. vulgare var. hirtum were composed of carvacrol (32.5%), thymol (16.1%), p-cymene (12.2%) and γ-terpinene (7.9%). Likewise, the essential oil of O. vulgare var. verticium had carvacrol (35.0%), p-cymene (11.6%), γ-terpinene (10.3%) and thymol (9.1%). Nonetheless, O. vulgare x O. onites essential oil had carvacrol (15.2%), cis-sabinene hydrate (14.6%), terpinen-4-ol (14.6%) and γ-terpinene (8.7%).

Neural Visual Detection of Grain Weevil (Sitophilus granarius L.)

A significant part of cereal production is intended for agri-food processing, which implies a necessity to search for and implement modern storage systems for this product. Stored grain is exposed to many unfavorable factors, particularly caryopsis macro-damage caused mainly by grain weevil (Sitophilus granarius L.). This triggers a substantial decrease in the value of the stored material, thus resulting in serious economic losses. Due to this fact, it is necessary to take steps to effectively detect this pest’s presence when grain is delivered to storage facilities. The purpose of this work was to identify the representative physical characteristics of wheat caryopsis affected by grain weevil. An automated visual system was developed to ease the detection of damaged kernels and adult weevils. In order to obtain the empirical data, a decision was made to take advance of SKCS 4100 (the Perten Single Kernel Characterization System). The measurements obtained were used to build the training sets necessary in the process of ANN (artificial neural network) learning with digital neural classifiers. Next, a set of identifying neural models was created and verified, and then the optimal topology was selected. The utilitarian goal of the research was to support the decision-making process taking place during grain storage.

Ompetition or cooperation? – the concurrent development of grain weevil (Sitophilus granarius L.) and lesser grain borer (Rhyzopertha dominica F.)on barley grain

ompetition or cooperation? – the concurrent development of grain weevil (Sitophilus granarius L.) and lesser grain borer (Rhyzopertha dominica F.)on barley grain

The insecticidal activity of some plant-seeds extracts against two coleopteran pest Granary Weevils Sitophilus Granarius (Linnaeus.) and the Lesser Grain Borer Rhyzopertha Dominica (Fabricius)

The insecticidal activity of some plant-seeds extracts against two coleopteran pest Granary Weevils Sitophilus Granarius (Linnaeus.) and the Lesser Grain Borer Rhyzopertha Dominica (Fabricius)

Evaluation of Carifend® for the control of stored-product beetles

In the present study, the effectiveness of Carifend® (BASF AG, Ludwigshafen, Germany), an alpha-cypermethrin-coated net, was evaluated in laboratory tests against major stored-product insects. The insecticide-treated net was adjusted at the bottom of plastic petri dishes, and adult insects were placed in each dish and exposed for different exposure intervals (1, 3, 5, 7 and 14 days), after which mortality and knockdown was measured. The tests were carried out against a wide spectrum of stored-product insects, i.e. Sitophilus oryzae, Sitophilus granarius, Sitophilus zeamais, Oryzaephilus surinamensis, Tribolium castaneum, Tribolium confusum, Prostephanus truncatus, Rhyzopertha dominica and Cryptolestes ferrugineus. The results showed that O. surinamensis, R. dominica and P. truncatus were highly susceptible to Carifend®, as complete control was achieved for all three species, after 5, 14 and 5 days, respectively. Regarding Sitophilus species, S. zeamais was the most tolerant species, as mortality levels did not exceed 46%, even after 14 days of exposure. In contrast, S. oryzae and S. granarius mortality was >98% after 14 days of exposure. So far, Carifend® has been registered in many parts of the world for the protection of stored tobacco against major tobacco pests, i.e. Lasioderma serricorne and Ephestia elutella. However, our results clearly indicate that this net can be used effectively for the control of other stored-product insects that infest durable food, such as grains and related amylaceous commodities.

Contact Toxicity and Repellency Evaluation of Rosmarinus eriocalyx Leaves Essential Oil (Lamiaceae) Against Adults Sitophilus granarius (Coleoptera/Beetle) and Anti-Free Radical DPPH Activity

Chemical control using synthetic products against pests of stored foods converted with restrictions such as the toxicity of living things and ecological risks. Today the world opinion is oriented towards a new fight against pests, among the alternative strategy, the use of natural insecticides of plant origin. This work aims to evaluate the insecticide effect of essential oils of Rosmarinus eriocalyx leaves against a wheat pest stored Sitophilus granarius and the evaluation of their antioxidant activity in vitro. The insecticide activity of essential oils of this plant was assessed by the filter paper contact test method and the repulsion test by the method of preference and determination of lethal doses DL50 and DL90, and the percentage of repulsion, measurement of anti-radical activity by trapping free radical DPPH and determining EC50. With regard to the chemical composition of the volatile oils of R. eriocalyx, 1.8-cineol (48.47%), camphor (17.04%), 'pinene' (7.58%), 'pinene' (6.99%) were the main compounds, the results showed that the essential oil of the R.eriocalyx leaves has a very high rate of repulsion PR= 96.25% at the dose of 20 µl/ml after 120 minutes of exposure, the mortality rates of the wheat weevil in the toxicity tests have increased with increased doses and over time. lethal doses for the dose 20 µl/ml has 50% DL50 = 0.306 µl/cm2 and 90% DL90 = 2.513 µl/cm2 for 72 hours of exposure, , in the test system DPPH one determines the trapping activity of radical free of essential oil 23.794% ± 2.908% EC50 = 8.585 ± 2,608 mg/ml. The activity of synthetic antioxidants of gallic acid, quercetin and ascorbic acid were also determined in parallel experiments as positive control. The essential oils of R.eriocalyx leaves can be used as a natural alternative to synthetic insecticides to control pests of stored foodstuffs.

THE EFFECT OF THE INFESTATION WITH THREE SITOPHILUS SPECIES ON THE WEIGHTS OF GRAINS STORED UNDER LABORATORY CONDITIONS FOR ONE YEAR

This article aimed to study the effect of the infestation of Sitophilus species on the average weights of wheat, maize, and rice grains stored under laboratory conditions for one year. The average weights of grains were gradually decreased along year months from 10 kg reaching 7 kg at the end of the experiment. The wheat weevil, Sitophilus granarius insects appeared in the wheat grains at the second month of storage with a few numbers (1 insect / kg grains) and gradually increased along year months recording 80 insect / kg grains at the end of the experiment. The average weights of maize grains were gradually decreased along year months from 10 kg reaching 6 kg at the end of the experiment. Results also indicated that there were no damage or infestation at the first month of storing, meanwhile the damage start to increase at the third month recording 5 % , and 7 % after 4 months , and continued in increase recording 65 % after 12 months of storing . The maize weevil, Sitophilus zeamais insects appeared in the maize grains at the second month of storing with a few numbers (2 insect / kg grains) and gradually increased along year months reaching 75 insect / kg grains at the end of the experiment. The average weights of rice grains were gradually decreased along year months from 10 kg reaching 6 kg at the end of the experiment. The rice weevil, Sitophilus oryzae insects appeared in the rice grains at the second month of storing with a few numbers (2 insects / kg grains) and gradually increased along year months recording 75 insects / kg grains at the end of the experiment.

Evaluation of four different methods of DNA extraction from wheat weevil Sitophilus granaries

Evaluation of four different methods of DNA extraction from wheat weevil Sitophilus granaries

Impact of essential oil from plants on migratory activity of Sitophilus granarius and Tenebrio molitor

Measures against pests should be performed in the context of integrated management of agricultural crops and complex control of pests. Therefore, use of ecologically safe approaches is the best option. Essential oils of plants can make an impact on the main metabolic, biochemical, physiological and behavioural functions of insects. We evaluated the effect of 18 essential oils and 18 dried plants on migratory activity of Sitophilus granarius (Linnaeus, 1758) and Tenebrio molitor Linnaeus, 1758 in conditions of laboratory experiment. Notable repellent activity against S. granarius was exhibited by Citrus sinensis and Picea abies. Repellent action against T. molitor was displayed by dried and cut leaves of Origanum vulgare and Eucalyptus globulus, and also essential oils from Juniperus communis, Р. abies, Pterocarpus santalinus, C. sinensis and C. aurantiifolia. Therefore, out of 18 studied essential oils, only two samples had a notable biological effect on migratory activity of S. granarius and five samples – on T. molitor. These data indicate a possibility of using essential oils or their main components as ecologically safe natural repellents against pests of stored wheat and products of its processing.