Stored grain pests of corn (Zea mays L.) in Mardin province, Türkiye

Observations on behavioural activity involved in the host selection by secondary pests of stored grains, Oryzaephilus surinamensis (Linnaeus), Tribolium castaneum (Herbst) and Tribolium confusum J. du Val, with respect to intact and mechanically or naturally damaged kernels are reported. Our results indicate that the attraction of secondary pests is facilitated by broken grain kernels, which resulted from either mechanical damage during harvesting and/or binning procedures, or the feeding activity of primary insect pests. Insect damaged kernels were more attractive to O. surinamensis, T. castaneum and T. confusum than whole kernels; in addition insect damaged kernels elicit more attractiveness than mechanically split kernels. The damage caused by primary pests, such as Rhyzopertha dominica (Fabricius) and Sitophilus oryzae (Linnaeus), on whole kernels may facilitate colonization by secondary pests, which continue damaging the cereals. O. surinamensis, T. castaneum and T. confusum utilize the grain volatile odours to distinguish whether the grain kernels of the stored cereals are damaged mechanically or by insects.

Pulses and Cereals have great nutritional value in the daily human diet. Infestation of Stored grain is a serious issue since different life stages of several types of insects can cause it. Insect degrade the quality of stored grains and product, resulting in economic losses. The storage of grains has been linked to a high number of insect infestations. Almost all stored grain insect pests have remarkably high multiplication rates and may destroy 10-15 % of grains. The major pest of stored grains includes Weevil (Sitophilus oryzae, Sitophilus zeamais, Sitophilus granaries), Tribolium species (Tribolium castaneum and Tribolium confusum), Khapra beetles (Trogoderma granarium), lesser grain borer (Rhyzopertha dominica), Pulse beetles (Callosobruchus maculatus), Rice moth (Corcyra cephalonica), etc. Continuous and indiscriminate over use of insecticides are responsible for the development of resistance against these insect pesticides. Accumulation of synthetic chemical pesticide residues on pulses and cereals are unfortunately consumed by human. Recently, in agricultural practices in different areas of the world, attention has been given towards the exploitation of plant biochemical as a new approach in stored grain protection. Various scientific literature already documented the efficacy of plant derivatives against storage grain pests. Biopesticides kill and repel the insect pests, affect insect growth, development and metamorphosis. Farmers have used higher plants, medicinal plants, various herbs and traditional spices for stored grain insect pest management, but majority of farmer use chemical insecticide to increase productivity but it causes adverse effect on environment and non-target animal including human also, so there is more need for scientific research regarding the plant Biopesticides efficacy against stored grain pests.

Sitophilus oryzae L. produces serious damage to stored grains. The use of chemical products in the control of this pest, have led to the emergence of resistance, accumulation of waste in the environment, intoxications and increased production costs, which requires the search for effective and less toxic alternatives such as dust of plants.
\nObjective: To evaluate the effect of different concentrations of Syzygium jambos (L.) Alston powder on Sitophilus oryzae L. in stored corn grains.
\nConfiguration and Design: A completely randomized design trial was conducted with the following treatments: 0 (control), 1.5; 2.0; 2.5; 3.0; 3.5 and 4.0% of the powder of the leaves of the botanical species / weight of corn seeds, with 15 repetitions.
\nMaterials and Methods: Adults of S. oryzae fed corn (Zea mays, L.) were used in the trials. The percentage of mortality was determined at 15 and 30 days after the treatment with the powders and the weight loss of the grains at 55 days after the start of the treatment.
\nStatistical analysis used: The data was transformed into √% / 100 and processed by analysis of variance. The means were compared by the Tukey test for P <0.05. Conclusions: Although of Syzygium jambos (L.) Alston powder show a marked insectistatic effect on adults of Sitophilus oryzae L and reduce affectations in stored corn grains, any studied powder proportions archives mortalities over 25 % in laboratory conditions.
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Sitophilus species are major pests of stored grain and their control is achieved mainly with the use of chemical insecticides, but the indiscriminate use of these products is resulting in several undesirable factors to man and to the environment. Thus, the use of natural insecticides comes as an option to control the insects, while lessening risks to the environment. The study was conducted at the Institute of Agricultural Sciences and Technologies, Rondonópolis campus of the Federal University of Mato Grosso, in the period from March to September 2012. The experiment was conducted under three different storing conditions. Aqueous extracts were obtained by the addition of Allium sativum L, Azadirachta indica A. Juss. and Cymbopogon winterianum Jowitt vegetable powders in distilled water, at a ratio of 5 g per 100 ml, and the levels of chemical insecticides were of 0.04 and 0.15 ml/100 ml of water for deltamethrin and chlorpyrifos, respectively. Treatments were added to the corn grains, which were placed in a 2.5 L glass container, mixed by manual shaking and infested with 20 adults of unsexed Sitophilus zeamais. Grains were stored for 60 days. At 30 and 60 days, the following items were analyzed: bugs count, water content in grains and electrical conductivity. The data were submitted to analysis of variance, and means were compared by Tukey test at 5% probability. At 30 days, the efficiency of chemical insecticides in the control of Sitophilus zeamais was observed in the three storage environments. Vegetal extracts were not effective in controlling insects. The larger number of insects increased the electrical conductivity and humidity values in the grains.n.

In recent years, limited research works has been reported on the use of integrated pest management to control the insect and pests in stored grain. Management of stored grain insects and pests using essential oils either in combination or alone will be of great importance as it is economical and eco-friendly. Tests were conducted to evaluate the toxicological impact of essential oils on stored product beetles in wheat and chickpea storage, as well as their influence on germination characteristics. The impact of essential oils was assessed for their fumigant toxicity, mortality, repellent properties, and effects on germination against storage pests such as Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum, and Collasobruchus chinensis in wheat and chickpea. During the fumigant toxicity test the selected essential oils either alone at 0.4 percent or in combination at 0.2 percent each were highly effective against Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum, Collasobruchus chinensis. All the essential oils at 0.4% concentration demonstrated complete mortality within twenty-four hours of treatment against Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum, and Collasobruchus chinensis, compared to untreated samples. The evaluated essential oils exhibit the greatest repellent activity against Sitophilus oryzae, Rhyzopertha dominica, Tribolium castaneum, Collasobruchus chinensis. Whether applied individually at a concentration of 0.4% or in combinations at 0.2%, they show no impact on the percentage of germination, vigour index, and viability significance after eight and ten months of storing wheat, respectively.

Our recent work on applications of near infrared spectroscopy (NIRS) to entomological problems is reviewed. Using an automated NIRS system to scan individual wheat kernels at the rate of 15 per minute, we were able to differentiate between uninfested kernels and kernels infested with late instar larvae of Rhyzopertha dominica, Sitophilus oryzae, or Sitotroga cerealella. The ability to rapidly scan individual kernels indicates potential for automated segregation of infested kernels from bulk grain. The automated NIRS system was used to differentiate uninfested wheat kernels, kernels infested with rice weevils, and kernels that contained rice weevils that were parasitized by Anisopteromalus calandrae. Being able to distinguish kernels containing parasitoids would be useful for quality control in commercial insectaries that rear biological control agents, and would be useful for research on natural enemies. The NIRS system was used to segregate samples of transgenic maize that contain low and high levels of the protein avidin. Avidin is toxic to a number of insect pests, and transgenic maize that contains a level of avidin that is toxic to insect pests of stored grain has been developed. A manual NIRS system was used to quantify insect fragments in flour. Although the sensitivity is not sufficient to detect insect fragments at the US Food and Drug Administration defect action level (75 fragments per 50 grams of flour), the technique is accurate at an action level of 130 fragments per 50 grams of flour and could be useful for prescreening large numbers of flour samples to select samples for more expensive and labour intensive chemical analyses. A manual NIRS system was used to identify stored product insect pests to species level. We were able to identify insects to genus with greater than 95% accuracy and to identify insects as being primary or secondary pests with greater than 99% accuracy. Ability to identify insects to species depended on the genus. This technology could be useful to pest managers who may not be familiar with insect taxonomy. The manual NIRS system was used to determine chronological age of two primary pests and one secondary pest of stored products.

Controlled atmospheres (CA) are used as periodic treatments to control pests (insects and mites) in stored grain or, less frequently, as long-term storage environments to prevent pest occurrence (insects, mites, and molds) or spontaneous combustion, as in poppy seeds that must be stored in nitrogen gas (Mills, 1989). The CAs contain either high levels of carbon dioxide (CO2), or high levels of nitrogen (N2), with virtual elimination of oxygen (O2). Grain in bulk storage is an immature ecosystem (Sinha, 1995) consisting of the living grain itself, numerous species of insects, mites, and molds, both on and in the seed. The nonliving part of the system includes humidity and grain moisture, temperature, and intergranular gases. When the grain is warm ( 25° C) or becomes moist, owing to bin leakage or to moisture migration by convection currents, the biological organisms begin to respire. Oxygen is consumed and heat, moisture, and carbon dioxide are produced. Canada has a legally defined zero-tolerance for insect pests in stored grain; hence, they must be controlled whenever detected. Dozens of insects are found in stored grain (Sinha and Watters, 1985) in low numbers, and many are fungus feeders that do not directly feed on the grain (White et al., 1995a). The most common grain-feeding insects in western Canada are the rusty grain beetle, Cryptolestes ferrugineus (Stephens) and the red flour beetle, Tribolium castaneum (Herbst), often being detected in up to 46% of farm granaries (Madrid et al., 1990). The whole-seed feeders—the rice weevil Sitophilus oryzae

Tribolium castaneum and Sitophilus oryzae are listed among the most destructive pests of stored grains. Although synthetic insecticides and fumigants are commonly employed for their control, plant-based formulations offer safer, and eco-friendly alternatives. The aim of the current study was to explore the insecticidal potential of three aromatic plants against stored grain pests. Artemisia scoparia , Seriphidium brevifolium , and Salvia yangii were extracted using steam distillation and macerated in hexane and methanol, and their chemical compositions were investigated using gas chromatography-mass spectrometry. The insecticidal activity of plant essential oils (EOs) and solvent extracts was evaluated against laboratory-reared T. castaneum and S. oryzae using a fumigation bioassay. A. scoparia EO showed the highest insecticidal activity with LC 50 of 7.4 mg/L and 5.3 mg/L against T. castaneum and S. oryzae , respectively, after 12 h exposure. The LC 50 of S. brevifolium was 21.1 mg/L and 2.9 mg/L against T. castaneum and S. oryzae , respectively, after 12 h exposure. Compared to their respective EOs, plant solvent extracts exhibited lower bioactivity; however, the methanolic extract of S. brevifolium showed notable insecticidal activity against T. castaneum and S. oryzae . The major constituents found in A. scoparia EO were capillene (38.3%), γ-terpinene (19.3%), and β-myrcene (17.2%). The EO of S. brevifolium comprised camphor (31.6%), eucalyptol (29.3%), and thujone (9.9%). EOs and methanolic extracts of A. scoparia and S. brevifolium demonstrated the highest fumigant toxicity against T. castaneum and S. oryzae , highlighting their potential as botanical pest control agents to protect stored grains.

Stored grain pest prevalence and insecticide resistance in Egyptian populations of the red flour beetle Tribolium castaneum (Herbst) and the rice weevil Sitophilus oryzae (L.)

Stored product pests gain access to the grain storage from the standing crop in the field to various stages of grain processing and storage. Although, about one thousand species of insects have been associated with stored products in different parts of the world, a few pests are considered as pests causing severe damage to the stored grains. The stored grain insect pests can be categorized on the basis of their feeding behaviour as internal and external feeder or as major and minor pests based on the severity of damage, they cause. This paper gives an overview of damage symptoms and biology of some of the major pests of stored grains viz., rice weevil, Sitophilus oryzae, lesser grain borer, Rhyzopertha dominaca, khapra beetle, Trogoderma granarium, red flour beetle, Tribolium castaneum, cigarette beetle, Lasioderma serricorne, drug store beetle, Stegobium paniceum, pulse beetles Callosobruchus spp., Angoumois grain moth, Sitotroga cereallela, rice moth Corcyra cephalonica, saw toothed grain beetle Oryzaephilus surinamensis, long headed flour beetle, Latheticus oryzae, and almond moth Cadra cautella.

Mycotoxigenic fungi and pests are responsible for quality losses during medium to long-term storage of grain. Since gas composition is considered one of the most important abiotic conditions that influence fungal and pest growth, the use of a controlled atmosphere with a very high N2 concentration is a valid tool to control grain quality in post-harvest. Aim of the present work is to evaluate the use of a highly purified N2 controlled atmosphere – generated in situ by a Membrane Nitrogen Separator (Eurosider s.a.s) – for safely storage of corn and wheat grains. Two different parallel lab-scale experiments were performed in order to assess the effect of N2 atmosphere on: (1) the growth of Fusarium graminearum, Fusarium langsethiae, Aspergillus flavus and Fusarium verticillioides on agar and the production of aflatoxins on corn grains; (2) the populations of the most important post-harvest pests such as Sitophilus oryzae and Tribolium confusum on wheat grains and flour, respectively. When exposed to highly purified N2 controlled atmosphere (98.5%±0.5), growth and sporulation of all the four pathogens and aflatoxins production by Aspergillus were significantly reduced. In addition, atmosphere containing 98.5%±0.5 N2 caused the complete mortality of adults of S. oryzae after 3 days on wheat and of T. confusum after 7 days on flour. Results herewith reported suggest that N2 controlled atmosphere represents an eco-friendly tool that could be transferred to a large-scale system for grain storage in order to avoid or reduce chemical treatments.

This study describes the spatial distribution of stored product insects captured biweekly using foodbaited cage traps in a large rice storage and processing facility, in the state of Rio Grande do Sul, Brazil. Monitoring started in August 2009 and will be carried out for 1 year, the first 5 months of sampling being presented in this study. From end of August 2009 until the end of December 2009, a total of 9893 insects were captured in the 99 cage traps. The most abundant species were: Carpophilus spp. (76%), Typhaea stercorea (8.6%), Ahasverus advena (5.5%), Tribolium castaneum (2.3%), Sitophilus oryzae (2%), Sitophilus zeamais (1.5%), Ephestia spp. (1.2 %), Cryptolestes ferrugineus (1%), Rhyzopertha dominica (0.64%), Oryzaephilus surinamensis (0.6%), Anthicus floralis (0.4%), Lasioderma serricorne (0.25%). The first two species, which make up for 84.6% of the insects collected, are not considered pests in stored grain, rather are attracted by moldy material present in residues or even in the bait material. The other insects, including primary and secondary species, comprised about 15% of the total trapped. The spatial distribution of the most important species infesting rice grain and of the total insect number was analyzed using Surfer 6.04 (Golden software, Golden, CO, USA) and contour maps were constructed to target areas for sanitation. Except for trap 66, located by the rice hulk storage box, the spatial distribution we observed using the contour maps showed that the greatest number of insects was mostly captured in cages placed in the receiving area, around the dryers, as well as outside of the structure where grain residues frequently accumulate. As indicated on the maps for total number of insects, a few isolated infested spots were detected. The parboiled rice area had the least amount of insects, except for trap 61, placed outside the structure. The population of primary and the most important secondary insect species, as well as the overall number of insects, decreased after sanitation and physical control measures were applied. Our observations confirm that insect monitoring is an essential tool for targeting and evaluating the control measures adopted in the quality program of rice storage and processing facilities. Keywords : Insect monitoring; Spatial distribution; Stored grain pests; Stored rice

The potential for using imidacloprid (a neonicotinoid) and indoxacarb (an oxadiazine) as grain protectants was investigated in bioassays against resistant strains of five stored grain beetles. The species investigated were Rhyzopertha dominica (F.) (the lesser grain borer), Sitophilus oryzae (L.) (the rice weevil), Tribolium castaneum (Herbst) (the rust‐red flour beetle), Oryzaephilus surinamensis (L.) (the saw tooth flour beetle), and Cryptolestes ferrugineus (Stephens) (the flat grain beetle). Each of these species has developed resistance to one or more protectants, including organophosphorus insecticides, synthetic pyrethroids and the juvenile hormone analogue methoprene. Mortality and reproduction after a 2‐week exposure of adults to treated wheat depended on species, dose and insecticide. Imidacloprid had no effect on S. oryzae at any dose, but none of the other species produced any live progeny at 10 mg/kg. Indoxacarb had no effect on T. castaneum at any dose, but none of the other species produced any live progeny at 5 mg/kg. The results show that although both imidacloprid and indoxacarb can control at least four of the five key pests tested at doses comparable to those used for organophosphorus protectants, more potent neonicotinoid or oxadiazine insecticides would be needed than either of these to provide broad spectrum protection of stored grain.

Rice weevils, Sitophilus oryzae (L.), and maize weevils, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), are important pests of stored grain. We have observed that rice weevil adults have a greater propensity than maize weevils to climb upward after physical disturbance of stored grain. Our objective was to quantify this climbing behavior in both species under a variety of environmental conditions to assess whether our anecdotal observations were correct. We confirmed that, after a disturbance, significantly more rice weevils climb than maize weevils when reared on fresh wheat, Triticum aestivum L., and corn, Zea mays L., and at relatively low and high population density. This greater climbing tendency is apparently exclusively due to S. oryzae males, which climb significantly more often than females. This work not only elucidates the divergent evolutionary histories of these sibling species but also may provide useful information for the monitoring and control of these stored grain pests.

Comparative insecticidal activity of different plant materials from six common plant species against Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)