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Maize weevil

The maize weevil, Sitophilus zeamais (Motschulsky), is a small cosmopolitan beetle belonging to the family Curculionidae, recognized as one of the most destructive primary pests of stored cereal grains worldwide, particularly maize (corn), where it infests both whole kernels and processed products.^[1]^[2]^[3] Adult maize weevils measure 3–4.5 mm in length, with a reddish-brown to black body featuring a distinctive elongated snout (rostrum) that houses chewing mouthparts at its tip, elbowed antennae, and four pale spots on the wing covers (elytra); the pronotum (thorax) is marked by deep, nearly round pits, distinguishing it from similar species like the rice weevil (Sitophilus oryzae).^[1]^[4] Larvae are legless, creamy-white, C-shaped grubs that develop internally within grain kernels.^[1]^[2] The life cycle is holometabolous, typically spanning 28–40 days under optimal conditions of 25–30°C and 60–75% relative humidity, beginning when females chew a cavity in a grain kernel to deposit 300–400 eggs over their 5–8 month lifespan, sealing each with a gelatinous plug; eggs hatch in 3–7 days, larvae feed voraciously on the endosperm for 16–24 days, pupate within the kernel, and adults emerge by boring an exit hole, often leaving behind frass and hollowed grains.^[1]^[5] Adults are capable of flight, facilitating rapid spread from field to storage, and the sex ratio is approximately 1:1, with peak fecundity of up to 6–7 eggs per female per day.^[1]^[5] Development ceases below 15°C or above 35°C, limiting infestations in temperate regions without heated storage.^[5] Native to the Americas, S. zeamais has spread globally through international trade, infesting stored grains in over 100 countries, especially in tropical and subtropical areas of Africa, Asia, and Latin America, where it attacks not only maize but also wheat, rice, sorghum, barley, and derived products like pasta and cereals.^[3]^[1] Its economic impact is severe, causing 12–36% weight loss in stored maize through direct feeding and secondary fungal contamination, with losses reaching up to 80% in poorly managed tropical storage, exacerbating food insecurity and contributing to billions in annual agricultural damages.^[1]^[3]

Taxonomy and Identification

Taxonomy

The maize weevil, Sitophilus zeamais, belongs to the kingdom Animalia, phylum Arthropoda, class Insecta, order Coleoptera, family Curculionidae, subfamily Dryophthorinae, genus Sitophilus, and species S. zeamais.^[6]^[7] The species was originally described by Victor Motschulsky in 1855 as Calandra zeamais and later transferred to the genus Sitophilus, reflecting its close relation to other grain-infesting weevils in the Dryophthorinae subfamily, which includes pests adapted to stored products.^[8]^[3] It is commonly known as the greater rice weevil or maize weevil, with synonyms including Calandra chilensis Philippi.^[8] Taxonomic distinction from the closely related rice weevil (S. oryzae) relies on subtle morphological traits, particularly pronotal punctures and genitalia. In S. zeamais, the pronotum features punctures along the midline, whereas S. oryzae typically has a puncture-free midline.^[4] Additionally, male genitalia differ, with S. zeamais exhibiting two longitudinal grooves on the dorsum of the phallus, in contrast to the smooth and evenly convex phallus of S. oryzae.^[9] These features, along with slight size differences, confirm their status as sibling species.^[10]

Morphological Description

The maize weevil, Sitophilus zeamais, is a small beetle belonging to the family Curculionidae, characterized by distinct physical traits that aid in its identification. Adults typically measure 2.3–4.9 mm in length, with body size varying based on the larval host; for instance, individuals emerging from maize kernels are generally larger, ranging from 3.9–4.9 mm.^[11]^[12] The adult body is cylindrical and reddish-brown, often appearing darker and shinier than related species, with four distinctive reddish spots on the elytra (wing covers). A prominent feature is the long rostrum, or snout, which can extend up to one-third of the body length and houses the mouthparts. The antennae are geniculate (elbowed) with a total of eight segments, typically held in an extended position during movement. Unlike the flightless granary weevil (Sitophilus granarius), maize weevil adults possess fully developed hind wings beneath the elytra, enabling flight.^[8]^[13]^[14] Immature stages develop internally within host kernels, making them rarely observable without dissection. Eggs are white, measure 0.2–0.3 mm in diameter, and are individually deposited in a small cavity sealed by a gelatinous plug. Larvae are white, legless, C-shaped, and grow to 2–3 mm in length before pupation. The pupa is exarate, with free appendages including legs, wings, and the developing rostrum, and remains enclosed within the kernel.^[15]^[12]^[16]^[8] For diagnostic purposes, maize weevils can be distinguished from the rice weevil (Sitophilus oryzae) by their rounder pronotal punctures (versus more elongated in the rice weevil) and generally larger size, while differing from the granary weevil by their flight capability and presence of elytral spots.^[16]^[13]

Distribution and Habitat

Global Distribution

The maize weevil (Sitophilus zeamais) is closely associated with the domestication of maize (Zea mays) in Mesoamerica around 9,000 years ago. Genetic evidence suggests its emergence may have been in Southeast Asia or the Indian subcontinent, but the pest's range expansion accelerated with human agriculture, particularly through the global dissemination of maize as a crop starting in the 16th century via colonial trade routes.^[17] Genetic analyses indicate an ancient divergence within the genus Sitophilus approximately 8.7 million years ago, but the pest's range expansion accelerated with human agriculture, particularly through the global dissemination of maize as a crop starting in the 16th century via colonial trade routes.^[17] This human-mediated dispersal, intensified by 19th-century grain commerce, transformed the weevil from a regional pest into a cosmopolitan invader, with low genetic differentiation across populations reflecting rapid, trade-driven colonization.^[18] Today, S. zeamais exhibits a pantropical and subtropical distribution, thriving in warm climates conducive to grain storage. It is widespread in sub-Saharan Africa, where it infests stored maize across countries like Ghana and Nigeria; South America, notably Brazil and other Andean nations; Asia, including India, China, and Southeast Asian rice-growing regions; and Oceania, such as Australia, Fiji, and Pacific islands.^[19]^[3] In North America, populations are established in the southern United States, from Texas to Florida, but the species remains rare in temperate zones; in Canada, for instance, it is frequently intercepted in imported shipments but has not formed self-sustaining populations due to unsuitable cold conditions.^[20]^[6] Invasion patterns of S. zeamais are overwhelmingly anthropogenic, driven by international grain shipments that inadvertently transport adults and larvae hidden within kernels, enabling establishment wherever suitable storage conditions exist.^[3] As of 2017, the pest had been detected in 112 countries, with continued spread through international trade.^[1] Recent expansions have been observed in Europe, particularly Mediterranean regions like Greece, where warming temperatures and imported grains have facilitated sporadic outbreaks and potential foothold populations, signaling broader risks from climate change.^[21]^[22]

Preferred Habitats

The maize weevil, Sitophilus zeamais, thrives in warm, humid environments, with optimal development occurring at temperatures between 25°C and 35°C; the life cycle completes in approximately 26 days at 30°C and 75–76% relative humidity.^[16] Relative humidity above 60% is essential for reproduction and survival, with peak performance at 75–76% RH; development halts below 15°C or above 35°C, limiting activity in cooler or excessively hot conditions.^[16]^[23] These preferences align with its prevalence in tropical and subtropical regions globally.^[3] Preferred habitats include agricultural fields with standing maize, where adults infest developing ears, as well as post-harvest storage facilities such as warehouses, silos, and traditional granaries containing bulk grains.^[16] In tropical areas, populations can persist on wild grasses and natural vegetation, serving as reservoirs between crop cycles.^[24] The species favors undisturbed, enclosed spaces that maintain stable warmth and moisture, facilitating migration from fields to storage post-harvest.^[3] Within these settings, S. zeamais exhibits microhabitat preferences for dark, undisturbed accumulations of whole, intact grains, where females oviposit directly into kernels for larval protection and development inside the endosperm.^[16] Initially, it avoids heavily processed or broken grains, prioritizing uncompromised seeds that offer seclusion from predators and environmental fluctuations.^[16] Adaptations enhancing habitat suitability include strong flight capability, enabling dispersal to new fields or storage sites over distances up to several kilometers in search of suitable conditions.^[16] In milder tropical climates, adults and larvae overwinter within grain kernels, entering dormancy to survive seasonal dips in temperature without seeking alternative shelters.^[16]

Life History

Life Cycle

The maize weevil, Sitophilus zeamais, undergoes complete metamorphosis, consisting of four distinct developmental stages: egg, larva, pupa, and adult.^[16] The egg stage lasts 2–7 days, during which the female deposits a single egg within a small cavity chewed into a grain kernel and seals it with a gelatinous plug; incubation shortens at higher temperatures within the viable range of 15–35°C.^[12] Upon hatching, the legless, creamy-white larva bores tunnels through the kernel, feeding primarily on the endosperm and creating frass as it consumes the grain's interior contents over 14–20 days.^[25]^[16] The pupal stage follows, lasting 5–8 days, as the mature larva constructs a frass-lined chamber within the kernel for transformation into the exarate pupa, which remains immobile and protected inside the grain.^[16] The adult emerges by chewing an exit hole through the kernel wall, typically after the full pre-imaginal development; adults measure 2.5–4 mm in length, are reddish-brown to black, and possess functional wings for dispersal.^[25] The adult lifespan ranges from 5–8 months under favorable conditions, during which they feed on grain and initiate new infestations.^[16] The complete life cycle from egg to adult emergence spans 28–40 days under optimal conditions of 27–30°C and approximately 70% relative humidity, though it can extend to over 110 days at lower temperatures like 18°C.^[16]^[12] Higher temperatures accelerate the cycle by reducing stage durations, with no evidence of diapause interrupting development across seasons.^[16]^[12]

Reproduction

Mating in the maize weevil, Sitophilus zeamais, typically begins shortly after adult emergence, with males and females engaging in copulation to initiate reproduction. Females remain receptive to mating throughout their adult lives, allowing for multiple matings that can enhance reproductive output. No elaborate courtship rituals have been observed, with mating often proceeding directly upon encounter, though a brief refractory period of approximately 2-3 days post-emergence may precede initial copulation in some individuals.^[26]^[27] Oviposition follows mating, during which the female uses her elongated rostrum to chew a small cavity (approximately 0.5–1 mm in diameter) into an individual grain kernel. A single egg is deposited within this cavity, and the female seals the entry hole with a gelatinous plug to protect the egg from desiccation and predation. Females preferentially select undamaged kernels for oviposition, as these provide optimal conditions for larval development without competition from prior infestations.^[28]^[29] The fecundity of S. zeamais females ranges from 300 to 400 eggs over their lifetime, which can span up to a year under favorable conditions. Egg production peaks during the first 4–5 weeks of adulthood, accounting for the majority of total output, after which the rate declines. Fecundity is influenced by host grain quality, with higher egg numbers observed on maize compared to other cereals due to its nutritional suitability.^[30]^[19]^[1] The sex ratio in S. zeamais populations is approximately 1:1, with no evidence of parthenogenesis, ensuring biparental reproduction and genetic diversity.^[31]

Hosts and Ecology

Primary Hosts

The maize weevil, Sitophilus zeamais, primarily targets maize (Zea mays) as its preferred host, infesting developing ears in the field and stored kernels post-harvest, where it causes significant damage by feeding internally and laying eggs within the grain.^[3] This pest is particularly destructive in tropical and subtropical regions, where maize serves as the staple crop most vulnerable to its attacks.^[16] In addition to maize, the maize weevil readily infests a variety of other cereal grains, including rice, wheat, sorghum, barley, oats, rye, and buckwheat, as well as peas and cottonseed.^[3] These hosts support complete development, though suitability varies; for instance, the weevil produces larger adults when reared on maize compared to rice or millet.^[12] The pest also attacks non-cereal products such as pasta, stored apples and other dried fruits, yam products, and cassava flour, but it shows limited or no reproductive success on legumes alone.^[16] Host suitability is highest on maize, where the developmental cycle from egg to adult completes in approximately 34.7 days under optimal conditions (27–30°C and 60–75% relative humidity); volatiles emitted by these hosts attract adult weevils, facilitating host location.^[12]^[32]

Ecological Interactions

The maize weevil, Sitophilus zeamais, exhibits complex chemical ecology, primarily through its response to host plant volatiles and aggregation pheromones. It is attracted to odors emitted by suitable hosts such as maize and other cereals, using olfactory cues to discriminate between preferred and non-preferred plant species during host location. These volatiles, including those from stored grains, guide foraging behavior, with immature rice plants showing particularly strong attraction compared to mature ones.^[32] Additionally, male-produced aggregation pheromones facilitate both intraspecific and interspecific attraction among Sitophilus species, promoting clumping in storage environments; the pheromone is identified as sitophilure ((4R*,5S*)-5-hydroxy-4-methyl-3-heptanone).^[33] Bacterial volatile organic compounds from grain-associated microbes further modulate these interactions, influencing weevil orientation and potentially enhancing pest aggregation in humid conditions.^[34] Symbiotic associations play a key role in the maize weevil's ecology, particularly with fungi and gut microbiota. S. zeamais acts as a vector for mycotoxigenic fungi such as Aspergillus spp. and Fusarium verticillioides, disseminating spores during feeding and movement within storage facilities, which exacerbates mycotoxin contamination like fumonisins in maize.^[3] This mutualistic or commensal relationship benefits fungal propagation while potentially aiding weevil nutrition through fungal metabolites, though high toxin levels can deter feeding. Gut microbiota, including endosymbionts like Sodalis pierantonius and bacteria capable of digesting cellulose and starch, support nutrient acquisition and host survival, with community composition shifting based on grain type and environmental factors.^[35] Predation and parasitism exert significant pressure on S. zeamais populations in storage settings. Natural predators include lizards and geckos that consume adults in warehouses, as well as birds that forage on exposed weevils, and invertebrate predators like the mite Acaropsellina docta targeting larvae and pupae, and the beetle Tilloidea notata (formerly Tillus notatus).^[36] Parasitoids, predominantly pteromalid wasps such as Anisopteromalus calandrae and Lariophagus distinguendus, oviposit into weevil larvae, reducing host fitness; A. calandrae shows preference for S. zeamais over other stored-product pests.^[3] S. zeamais also competes with species like Rhyzopertha dominica for resources, influencing community dynamics in grain stores.^[3] Population dynamics of S. zeamais are shaped by genetic structure and environmental factors, with trade-mediated gene flow facilitating widespread dispersal despite localized differentiation. Genomic studies reveal fine-scale genetic structure among populations, indicating limited isolation by distance but ongoing connectivity through human-mediated transport of infested grains.^[37] Densities increase in humid storage conditions (above 70% relative humidity), where optimal development rates support rapid proliferation, contrasting with lower populations in drier environments.^[3]

Economic Impact

Damage to Crops and Storage

The maize weevil (Sitophilus zeamais) infests developing maize ears in the field, particularly during grain drying and pre-harvest stages, where larvae bore into kernels, hollowing them out and causing structural weakening that leads to premature ear drop and reduced yield. Pre-harvest infestations by maize weevils can contribute to yield losses, with pest-related field damage reported up to 30% in tropical regions under high infestation.^[38] Such pre-harvest attacks not only diminish harvestable grain but also facilitate secondary infections by facilitating entry points for pathogens.^[39] In storage, maize weevil infestations cause substantial quantitative losses, with weight reductions of 20–30% commonly reported in tropical environments due to larval feeding and frass production over extended periods. Under typical smallholder storage conditions, weight losses can reach up to 6.9% within just three months, escalating rapidly as populations multiply. Globally, these storage pests contribute to annual post-harvest losses of approximately 112 million tons of maize, representing a significant portion of the crop's economic value in developing countries where storage infrastructure is limited. These losses translate to an estimated $1–2 billion USD annually in global agricultural damages, particularly in developing countries.^[40]^[41]^[39]^[42] Beyond direct weight loss, maize weevil damage severely impacts grain quality through frass contamination, which introduces debris and elevates moisture levels, promoting fungal growth and mycotoxin production such as aflatoxins and fumonisins. These contaminants reduce the nutritional value of the grain by degrading carbohydrates, proteins, and essential micronutrients, while also posing health risks from toxicity. Infested maize often experiences a significant market value drop, with discounts of 5–30% for damaged grain and potential rejection of heavily infested lots, leading to forced early sales or disposal.^[43]^[44]^[45] The cumulative effects of maize weevil infestations exacerbate food insecurity and malnutrition in developing regions, where maize constitutes a dietary staple for millions, amplifying poverty through lost income and reduced food availability. In sub-Saharan Africa and other tropical areas, these losses compound vulnerabilities, with 2025 analyses indicating that climate-driven range expansions for major maize insect pests, including weevils, could intensify proliferation and associated damages.^[46]^[47]

Detection Methods

Detection of maize weevil (Sitophilus zeamais) infestations relies on identifying visual signs of damage and employing targeted monitoring techniques to enable early intervention in both field and storage settings. Visual indicators include the presence of adult weevils, which are reddish-brown to black beetles approximately 3-4 mm long with elongated snouts, often observed crawling on the surface of grain or ears when disturbed.^[13] Emergence holes, typically 1-2 mm in diameter with irregular edges, appear on kernels or ears as adults exit after development inside.^[3] Frass, consisting of fine grain dust and insect excrement, accumulates around damaged areas, signaling active feeding.^[48] In storage, infested kernels become hollow and lightweight, floating when placed in water, while in the field, scouting reveals damaged maize ears with entry holes near the base and frass at the tips.^[49] Monitoring tools facilitate proactive detection, particularly in bulk storage. Probe traps inserted into grain bins and pitfall traps placed on the surface capture adult weevils, providing estimates of population density.^[13] Pheromone lures, often combined with food attractants, are used in traps to draw and monitor adult activity, though they are more effective for presence/absence than precise quantification.^[50] Sieving grain samples separates adults and larvae for counting, while temperature probes detect hot spots—localized areas exceeding ambient grain temperature by 5-10°C (often >35°C in active infestations)—caused by insect respiration and metabolic heat.^[49] Acoustic detection systems record sounds of larval feeding within kernels, offering non-invasive early warning with sensitivity of 75-95% for later developmental stages.^[51] Quantitative assessments involve systematic sampling to evaluate infestation levels. Grain probes collect samples from multiple depths and locations within bins (e.g., surface to base, center to walls), which are then sieved to count adults or larvae per kilogram; warming samples to 15-20°C stimulates hidden insects to emerge for accurate enumeration.^[13] In field settings, scouts examine ears for damage indicators, counting visible holes or frass per plant. One study noted emergence rates reaching 100 adults per kg per day after five weeks of infestation, underscoring the rapid population growth that necessitates frequent monitoring.^[52] Economic thresholds guide management decisions to balance costs and benefits. In stored maize, action is recommended at 2-5 adults per kg, as this level signals potential for significant damage without immediate economic loss exceeding control costs.^[53] For field infestations, regular scouting detects ear damage exceeding 10-20% affected plants, prompting protective measures before harvest.^[49] These thresholds vary by region and storage conditions but emphasize early detection to prevent proliferation.

Management Strategies

Cultural and Physical Controls

Cultural controls for maize weevil (Sitophilus zeamais) emphasize farm practices that disrupt the pest's life cycle and reduce infestation risks during crop growth and post-harvest handling. Timely harvest at physiological maturity minimizes field exposure, as weevils often infest maturing maize ears, potentially reducing initial populations by limiting the window for oviposition.^[54] Sanitation is critical, involving the removal, burning, or burial of crop residues from previous seasons to eliminate overwintering sites, alongside thorough cleaning of storage facilities to remove old grain, dust, and debris that harbor pests.^[55]^[54] Drying harvested grain to below 13% moisture prevents weevil development, as populations rarely establish in low-moisture environments.^[55] Breeding and selection for resistant maize varieties form another key cultural strategy, focusing on traits like hard endosperm and tight husk cover that hinder weevil penetration and larval feeding. Organizations such as ICRISAT and CIMMYT have advanced recurrent selection programs to develop tropical maize lines with enhanced post-harvest resistance, including varieties exhibiting low progeny emergence and minimal grain damage under weevil pressure.^[56] Intercropping maize with non-host plants like cowpeas can create physical barriers and alter microenvironments, reducing field infestation levels by up to 50% in some systems through companion crop effects that deter oviposition.^[57] Physical controls target direct suppression of weevil populations through environmental manipulation and barriers during storage. Hermetic storage systems, such as Purdue Improved Crop Storage (PICS) bags, create low-oxygen atmospheres (dropping to 3-10%) that suffocate insects, achieving 100% mortality of maize weevils within 21 days and preventing re-infestation for up to 150 days while preserving grain quality.^[58]^[59] Aeration systems cool stored grain to below 20°C, slowing metabolic rates and reproduction, with regular monitoring every two weeks in warm conditions to maintain efficacy.^[55] Fine mesh screens and elevated platforms serve as barriers, excluding flying adults and reducing moisture buildup that favors weevils. Periodic physical disturbance, such as sieving or tumbling grain in storage, can achieve 81% mortality by dislodging and exposing insects.^[60] Solarization, involving exposure of infested grain to direct sunlight for 2-6 hours, leverages heat to kill weevils, with studies showing up to 90% mortality in surface layers after repeated sessions, though full penetration requires agitation for uniform effect. These methods, when integrated, offer sustainable, non-chemical options particularly suited for smallholder farmers in tropical regions.

Chemical and Biological Controls

Chemical controls for the maize weevil (Sitophilus zeamais) primarily involve fumigants and contact insecticides applied during post-harvest storage. Phosphine (PH₃) remains the most widely used fumigant, achieving high mortality rates—often exceeding 90%—in sealed storage environments by penetrating grain bulks and targeting all life stages of the pest.^[61] However, resistance to phosphine has been documented in some populations, necessitating proper sealing and dosage to maintain efficacy. Contact insecticides, such as pyrethroids (e.g., deltamethrin), provide rapid knockdown of adult weevils but are less effective against hidden larvae and eggs, with efficacy rates around 70-85% in surface treatments; resistance is prevalent, and the use of synergists like piperonyl butoxide (PBO) is recommended to enhance performance.^[62] As of 2025, regulatory frameworks from agencies like the EPA emphasize low-residue options to minimize environmental impact and food contamination, promoting integrated approaches over sole reliance on synthetic chemicals.^[63] Biological controls leverage natural enemies to suppress maize weevil populations without synthetic residues. Parasitoids, particularly Lariophagus distinguendus (Hymenoptera: Pteromalidae), have shown promising results, with progeny emergence rates leading to 70-100% host mortality in stored maize under controlled conditions.^[64] Predators such as certain spiders (e.g., Theridion spp.) and ground beetles (e.g., Pterostichus spp.) contribute to suppression in storage ecosystems, though their impact is more variable and density-dependent. Entomopathogenic fungi like Beauveria bassiana offer effective mycoinsecticide options, reducing weevil populations by up to 80% over six months when applied as conidial suspensions, especially when combined with inert carriers like kaolin for improved adhesion and persistence.^[65] Botanical and integrated pest management (IPM) strategies provide eco-friendly alternatives, often incorporating plant-derived repellents and toxins. Extracts from neem (Azadirachta indica) and garlic (Allium sativum) exhibit 80-95% repellency and up to 100% mortality against adults and juveniles at concentrations of 5-10% (w/w), acting as antifeedants and oviposition deterrents. Spice powders, such as clove (Syzygium aromaticum) at 10 g/kg grain, achieve complete (100%) adult mortality within weeks by disrupting respiratory and nervous systems. These botanicals are frequently integrated into IPM programs, combining with monitoring thresholds from detection methods to apply treatments only when weevil densities exceed economic injury levels, thereby reducing overall chemical inputs.^[66]^[67] Emerging research focuses on advanced biotechnologies and natural volatiles as sustainable fumigation alternatives. RNA interference (RNAi)-based biopesticides, targeting essential genes like those for chitin synthesis in S. zeamais, have demonstrated 70-90% mortality in 2025 laboratory trials, offering species-specific control without broad environmental effects. Essential oils from plants like wild mustard (Sinapis arvensis) and others (e.g., citrus and eucalyptus) show fumigant efficacy comparable to phosphine, with 80-100% mortality at low doses (1-5 µL/L air) and strong repellency, positioning them as viable low-residue options in ongoing field validations.^[68]^[69]

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Observations on grain weevils Calandra (Col Curculionidae) I ...
Aug 5, 2025 · ... sex ratio of Sitophilus spp including S. zeamais is approximately, 1: 1 (Richards, 1947; Evans, 1977;Danho et al., 2002). Following the ...
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Attraction of Sitophilus zeamais (Coleoptera: Curculionidae) to Four ...
Sep 23, 2021 · Sitophilus spp. have a long history as a crop pest; Chinese, Greek, and Roman societies all have records of these weevils infesting wheat ...Missing: etymology | Show results with:etymology
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Identification of Resistance to the Corn Weevil (Sitophilus zeamais ...
S. zeamais infests ears in the maize field during grain drying and before harvest or when the grain is stored. The greatest damage to the grain is caused by ...
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[PDF] Effects of insect population density and storage time on grain ...
The losses include weight loss, nutritional loss and economic loss such as income foregone as a result of early sale or costs incurred for having to purchase ...
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Sep 27, 2022 · Hermetic storage minimizes insect damage and weight loss (max 4.1% and 2.2%) compared to polypropylene bags (61.4% and 23.4%), and maintains ...
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(PDF) Measuring the nutritional cost of insect infestation of stored ...
Insect infestation decreased the carbohydrate content of the stored grains, causing a relative increase in the proportion of protein and fibre in the remaining ...Missing: frass | Show results with:frass
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Apr 16, 2019 · The most economically important and widely occuring postharvest losses due to insect pests of stored maize include the maize weevil (Sitophilus ...Missing: impact | Show results with:impact
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Our results show that aflatoxin levels were high in the market maize in Northern Region of Ghana and insects were prevalent, even though grain moisture tended ...
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Flint corn is extensively grown in Central and South America, Asia, some parts of Africa, and Southern Europe for human consumption and industrial purposes ( ...Missing: Oceania | Show results with:Oceania
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Grain traits and ozone exposure shape maize resistance to ... - Nature
Jul 4, 2025 · This study evaluated resistance in 15 maize genotypes, including sweet corn, popcorn, and non-transgenic and transgenic varieties, while exploring the ...Maize Genotypes · Results · Discussion
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Jul 1, 2014 · Pictures. Open in Viewer Adult weevil, Sitophilus zeamais (USDA, www.flickr.com). Open in Viewer Maize weevil ... frass from feeding. •. Act as ...Missing: threshold | Show results with:threshold
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Aug 25, 2020 · Monitor the grain regularly. · Use a grain probe to take samples in a pattern from the surface, and also from the base of the grain mass. · Take ...Missing: methods | Show results with:methods
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XLure R.T.U. Rice Weevil Kit | J.F. Oakes
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Mar 19, 2021 · ... weevil, Sitophilus oryzae, feeding behavior in maize seeds and the occurrence of supernumerary molts in low humidity conditions. Entomol ...
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Weevils on Stored Grain
### Life Cycle of the Maize Weevil (Sitophilus zeamais)
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Apr 6, 2018 · In this review, we report the current status and advances in maize kernel-pest interactions, the bases and mechanisms of kernel resistance and ...
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Intercropping maize with cowpeas, and not harvesting crops late ... Mixing seeds with 0.3% lime have given good results in weevil control. Sand. In ...
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Hermetic storage is the best among the researched methods to effectively control the maize weevils, followed by physical disturbance and then maize-amaranth ...
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Sep 29, 2016 · Sitophilus zeamais Motschulsky is the most important insect pest of stored maize in tropical regions. The objective of this study was to ...
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Apr 29, 2025 · different levels of efficacy to address pesticides with different levels of potential impacts to different species, and therefore different ...Missing: maize weevil
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Prospects for Use of Biological Control of Insect and Mites for ... - MDPI
Overall, for biological control of 19 stored product taxa evaluated by 13 natural enemies, 163 of 212 mortality estimates were between 70–100% [83]. Much ...
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Biocontrol of Maize Weevil, Sitophilus zeamais Motschulsky ... - NIH
May 11, 2023 · The maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae), is a serious pest of maize grain in Africa. The post-harvest ...
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... neem influenced juvenile mortality (100%) compared to untreated. More so ... Sitophilus zeamais Motschulsky) mortality. Agric. Res. 2016, 2, 90–94 ...
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Use of Neem and Garlic Dried Plant Powders for Controlling some ...
Neem and garlic powders effectively control storage pests of maize, rice, and beans, achieving up to 100% mortality. Prolonged exposure to treated grains ...
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Perspectives of RNAi, CUAD and CRISPR/Cas as Innovative ...
Apr 17, 2025 · Pest management has entered a new era with the emergence of three innovative antisense technologies: RNAi, CUAD, and CRISPR/Cas.
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(PDF) Toxic potential of wild mustard fruit essential oil against maize ...
Jun 18, 2025 · Toxic potential of wild mustard fruit essential oil against maize weevil (Sitophilus zeamais Motschulsky). May 2025. Authors: Samuel Adelani ...