Sitophilus Zeamais Research Articles

Sweet corn seeds coating with hexane plant extracts for controlling maize weevil (Sitophilus zeamais Motschulsky) and their effect on seed qualities

Sweet corn seeds coating with hexane plant extracts for controlling maize weevil (<i>Sitophilus zeamais</i> Motschulsky) and their effect on seed qualities

Insecticidal and Repellent Activities of Four Essential Oils Against Sitophilus zeamais (Coleoptera: Curculionidae).

This study aimed to evaluate the efficacy of Corymbia citriodora, Melaleuca alternifolia (Myrtaceae), Mentha × piperita (Lamiaceae), and Schinus terebinthifolius (Anacardiaceae) essential oils as an alternative to manage Sitophilus zeamais (Coleoptera: Curculionidae) adults. Acute contact toxicity, acute toxicity on treated maize grain, fumigation toxicity, repellency bioassays, and GC-MS analysis of the essential oils were carried out. Corymbia citriodora, M. alternifolia, M. × piperita, and S. terebinthifolius oils were toxic at different levels to S. zeamais through residual contact, ingestion and via fumigation, and were also repellent to adults of this pest. Melaleuca alternifolia oil was the most active in contact (LC50 = 18.98μL.mL-1), ingestion (LC50 = 1.03μL.g-1), and fumigant (LC50 = 20.05μL.L-1 air) bioassays. Citronelal (53.6% in C. citriodora), terpinen-4-ol (46.9% in M. alternifolia), menthol (44.8% in M. × piperita), and β-caryophyllene (16.2% in S terebinthifolius) are the major constituents of these oils. Melaleuca alternifolia and M. × piperita essential oils can be used by residual contact, while those of C. citriodora, M. alternifolia, and M. × piperita by mixing with maize grains. Melaleuca alternifolia essential oil can be used as a fumigant, while those of C. citriodora and S. terebinthifolius as repellents for S. zeamais adults.

Efficacy of entomopathogenic fungi against three major stored insect pests, Rhyzopertha dominica, Sitophilus zeamais and Trogodermagranarium

The use of biological control agents such as pathogens and natural enemies could be helpful in reducing reliance on synthetic non-selective insecticides and environmental pollution. Entomopathogenic fungi act as pathogens for insect pests and could be a good alternative to insecticides. In the present work, control potential of six native entomopathogenic fungi: Aspergillus nidulans, Aspergillus fumigatus, Cladosporium cladosporioides, Metarhizium flavoviride, Penicillium citrinum and Trichoderma harzianum, was evaluated against three major stored insect pests, Rhyzopertha dominica, Sitophilus zeamais and Trogoderma granarium, under laboratory conditions. Four doses of each fungal isolate viz., 1 × 104, 1 × 106, 1 × 108 and 1 × 1010 conidia/kg wheat grains were evaluated in terms of adult mortality and progeny suppression of subsequent generation. Bioassays were performed in an incubator with 30 °C, 65% relative humidity and without lighting, and the vials were observed after 7, 14, and 21 d post exposure to calculate mortality of introduced adults. The results revealed that insects’ mortality was dose and time dependent. In most of the cases, M. flavoviride caused the highest mortality and progeny suppression of all tested insect species followed by T. harzianum and C. cladosporioides, while the lowest were observed against A. nidulans followed by A. fumigatus and P. citrinum. Overall, R. dominica was the most susceptible species to all fungal isolates followed by S. zeamais and T. granarium. In summary, the data of the present work indicate a significant potential of tested entomopathogenic fungi as biological control agents against R. dominica, S. zeamais and T. granarium. Further studies are recommended to evaluate control potential of these entomopathogenic fungi against stored insect pests under storage environment. Evaluation of more virulent strains of entomopathogenic fungi and their isolates, development of suitable formulation(s), and standardizing mode application will also be the questions for future research.

STUDIES ON THE MORPHOLOGY AND MOLECULAR CHARACTERIZATION OF STORED GRAIN WEEVILS SITOPHILUS (CURCULIONIDAE: COLEOPTERA) FROM KHAIRPUR, SINDH-PAKISTAN

In this paper, Sitophilus oryzae, Sitophilus zeamais, and Sitophilus granarius, three economically significant grain pests are thoroughly analyzed in terms of their morphological and molecular differences. The work provides critical insights into species identification, genetic differentiation, and adaptation by contrasting conventional morphological features and genetic approaches. The samples were collected from eight talukas of district Khairpur: Kingri, Kot Deji, Khairpur, Gamabat, Mirwah, Sobhodero, Nara, and Faizganj during the year 2018-2022. The samples were identified on the basis of morphology and extraction of DNA was done. The samples were sent for sequencing. The findings provide important evolutionary insights and aid in pest management. Additionally, the text describes the distinguishing physical characteristics of mature Sitophilus granarius, maize weevils, and rice weevils, emphasising size, colour, markings, and anatomical aspects. Understanding the differences among various weevil species is made easier by this information.

Effect of cumin seed (Cuminum cyminum L.) essential oil from Catamarca, Argentina, on the stored maize pests Sitophilus zeamais and Fusarium verticillioides

The essential oil composition of Cuminum cyminum L. from Catamarca province, Argentina, and its insecticide and antifungal activities were studied, with the major constituents detected by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) being: cuminaldehyde (20.58 %), ϒ-terpinene (20.43 %), p-cymene (17.35 %) and β-pinene (13.75 %). Insecticidal activity was tested against Sitophilus zeamais Motschulsky. The results showed that cumin oil lethal concentrations (LC) LC50 and LC95 values were 66.39 μL/L air and 370.14 μL/L air, respectively. Moreover, the essential oil had a repellent effect at 4 μL/L and 0.4 μL/L and an inhibition of acetylcholinesterase activity of 88.39 % and 47.75 % at concentrations of 9.2 and 2.3 mg/L, respectively. Antifungal activity against Fusarium verticillioides was tested at 250.500 and 1000 μL/L. For the highest concentration of cumin essential oil, the mycelia growth was inhibited by around 80 %. Lag phase and growth rate of F. verticillioides was affected considerably and showed concentration dependence. The results obtained in this study revealed the possible use of cumin oil as a natural alternative in controlling S. zeamais and F. verticillioides, the main pests of stored maize.

Efficacy of Neem and Eucalyptus Leaf Powders for the Management of Maize Weevil Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) in Dried Sweet Potatoes

Maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) is a polyphagous storage pest in many crops of economic and food security importance. Its management currently relies mainly on synthetic chemical pesticides. However, plant botanicals are known to exhibit insecticidal properties which can be used to manage the weevil in stored dry sweet potatoes. To study the effect of neem and eucalyptus leaf powders, an experiment was set up at Busitema University laboratory. Neem and eucalyptus leaves were processed into powders. 400g of dried sweet potato chips were weighed and placed in 4 different plastic buckets. Under laboratory conditions, buckets were inoculated with 30 unsexed newly emerged adult weevils. To each bucket, 40g of leaf powders were introduced as single powders and a combination. The experiment was replicated three times. Data on mortality, growth inhibition, produce damage and weight loss was collected over a period of 84 days. Analysis of variance showed that all plant powders showed significant (P&lt;0.001) increase in mortality and inhibition of maize weevil and a decrease in damage and weight loss of sweet potato compared to control. The combination showed superiority in all parameters measured. Effectiveness of the plant powders was in the order; combination (neem + eucalyptus) &gt; neem leaf powder &gt; eucalyptus leaf powder.

Evaluating Plant Leaf Tinctures against Maize Weevils (Sitophilus zeamais Motsch.) in Stored Maize (Zea mays L.) under Laboratory Conditions

Maize weevils (Sitophilus zeamais Motschulsky) are commonly stored grain pests of economic importance in several parts of Africa. A huge amount of synthetic pesticides is being used for the management of crop pests, which have many negative effects on the biotic and abiotic components of the environment. Plant-derived pesticides, on the other hand, are safe for the environment, affect only target insects, have a low application cost, and are easily biodegradable. The purpose of this research was to determine the effectiveness of ethanol leaf tinctures of four selected botanicals against S. zeamais: Brucea antidysenterica (J.) (Waginos), Croton macrostachyus (Hochst.) (broad-leaved croton), Nephrolepis exaltata (L.) (Boston fern), and Carica papaya (L.) (papaya). The experiment was carried out in a completely randomized design (CRD) with four different concentrations (0 mL, 2.5 mL, 5 mL, and 7.5 mL) and four plant leaf tinctures in three replicates. A random sample of 300 g of clean maize seed was treated with the four selected botanicals in plastic jars covered with a muslin cloth. Twenty adult maize weevils were introduced into each disinfected, treated, and untreated maize grain. The mortality rate, grain damage, and F1 progeny emergences were assessed and analyzed using SPSS software version 25. The highest (100%) mortality rate of S. zeamais was recorded for maize seeds treated with the leaf tincture of B. antidysenterica, followed by maize seeds treated with the leaf tincture of C. papaya (97.5%) at an application rate of 7.5 mL/300 g. The mean weight loss of the seeds showed a significant variation between the treatments. The mean weight loss of the seeds in the control (8.96%) was higher than the total mean weight loss treated by all plant leaf tinctures (3.66%). The emergence of F1 progeny of S. zeamais on maize grains showed significant differences among the treatments. The highest emergence (100%) of F1 progenies was recorded for the control treatment followed by C. macrostachyus (16.65%) at a rate of 2.5 mL/300 g maize grain treatment. The study concluded that B. antidysenterica and C. papaya tinctures had the potential to control the infestation of maize grains by S. zeamais.

Sitophilus zeamais (Motschulsky): the primary obstacles in the maize quality and quantity

One of the main obstacles to maize farming is the extensive loss of yields caused by the investment of the Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae) during the storage period. This pest attacks maize kernels in the active larval stage; they burrow, attack, and hide in seeds. Some research reports that this pest attack can cause damage between 18-20%; in conditions of high water content, the damage rate can reach 30-40%. In addition to direct damage, this pest attack can reduce product and nutritional quality, seed weight, and the percentage of germination, which will reduce market value. Besides being able to cause severe damage to maize kernels, this pest also attacks several other agricultural products in stockpiles, such as sorghum, rice, wheat, and processed food products such as pasta and biscuits. This paper reviews several significant research results on the insect pest Sitophilus zeamais Motsch. In the future, it is hoped that it will provide helpful information for researchers and academics everywhere.

Prospect of utilizing botanical pesticides for maize weevil Sitophilus zeamais (Motschulsky) management to preserve national maize production

Maize plays a strategic role in the national food map as well as a mainstay commodity in accelerating the realization of food self-sufficiency. It is because maize has wide adaptability and is relatively easy to cultivate. However, the attack of maize weevil obstructs the increase of maize productivity. This pest is the most destructive and reduces maize productivity as a national source of carbohydrates. The global policy of limiting the use of synthetic pesticides to control agricultural pests has become a topic of discussion in international forums today. It is due to the large number of deaths reported by synthetic pesticides. WHO reports that every year pesticide poisoning occurs between 44,000-2,000,000 people worldwide, and the highest poisoning rates occur in developing countries. In response to this, the government has made regulations through Government Regulation No.6 of 1995 concerning synthetic pesticides. It is contained in. Plant-based materials are very prospective to be used as active ingredients for environmentally friendly botanical pesticides. It has been identified that around 10,000 potential secondary metabolite components can be processed into active ingredients of botanical pesticides. This paper discusses the potential of botanical pesticides in Indonesia’s national plant treasures.

Effects of Harvest Time and Storage Form on Insect Population and Damage of Maize

The aim of this study was to determine the effects of harvest time and storage form on population levels of insect pests and their damage on stored maize. Maize was cultivated on a total land area of 19 x 23m2 during the major season (April to August 2020) and minor season (September to December 2020). Maize was harvested at three stages; early harvest, mid harvest and late harvest. Harvested maize was stored in three ways; husked, de-husked and shelled. Analysis of variance (ANOVA) was applied to the data through Sisvar version 5.6. Insect pests that were sampled during the study were Sitophilus zeamais, Cathartus quadricollis, Carpophilus dimidiatus and Tribolium castaneum. Carpophilus dimidiatus were sampled from treatments during the major season whereas Tribolium castaneum was sampled during the minor season. Sitophilus zeamais and Cathartus quadricollis were sampled in both seasons. In the major season, late harvest shelled maize (LHS) recorded 689% more S. zeamais numbers as compared to early harvest husked maize (EHH). Mid-harvest husked maize (MHH) had 307% less number of S. zeamais compared to LHS in the minor season. Late-harvest shelled maize (LHS) had the highest percentage insect damaged kernels (86.94%) in the major season.

Diversity of Storage Insect Pests of Maize (Zea mays L.), their Damage and Losses Causes to Maize in Gabilay District, Somaliland

Maize is one of the foremost cereals cultivated today, and it is a queen of cereals. Maize is threatened by a wide range of post-harvest insect pests. Therefore, a survey was conducted in Gabilay District, Somaliland in 2021 to determine the status of storage pests. During the survey a total of 60 maize storage structures were assessed in three villages of Gabilay District namely; Galloley, Ijaara, and Boqor. Data on storage structures, infestation status, grain damage, and weight loss were collected and analyzed by SPPS version 20 and interpreted using descriptive statistics. The result showed that a locally constructed bit was the major storage structure followed by sacks while iron tank is used at the lowest level. Results found also indicated that all storage structures were infested by two major insect pests, i.e., Maize weevil (S. zeamais) and Angoumois grain moth (S. cerealella) at the highest level and by molds and rats to a lesser extent. Galloley site was infested only by maize weevil, while Boqor and Ijaara sites were infested by both maize weevil and angoumois grain moth. Maize weevil accounted for the lion's share of the infestation compared to angoumois grain moth. The highest grain damage was recorded at the bottom position of the storage structure from the Ijaara area followed by Galloley and Boqor. Likewise, grain weight loss was also highest at the bottom position that showed 12.0%. These findings provide benchmark information for developing sustainable management methods for the storage of insect pests of maize in the study area. It is also recommended training on storage methods, management of storage pests and healthy maize preparation should be practiced.

Assessment of Colocasia esculenta leaf extract as a natural alternative for Sitophilus zeamais control: Toxicological, biochemical, and mechanistic insights

The present study assessed the toxicological, biochemical, and mechanism of action of Colocasia esculenta leaf extract (CELE) on Wistar albino rat and on cholinergic, antioxidant, and antiinflammatory enzymes in Sitophilus zeamais. This was with a view to assessing the potential benefits and safety profile of CELE as a natural alternative for insect control. The bioactivity of the fraction was evaluated using insecticidal and repellent activities against colonies of Sitophilus zeamais to obtain a VLC-chromatographed fraction which was spectroscopically characterized and investigated for enzyme inhibition. The results revealed the ethyl acetate fraction (EAF) as the most potent one with LC50 6.198 μg/ml and 6.6 ± 0.5 repellency. The EAF had an LD50 > 5000 mg/kg but repeated dose >800 mg/kgbw po administration caused significant (p < 0.05) increase in liver and kidney function biomarkers accompanied with elevated atherogenic and coronary indices. Also, renal and hepatomorphological lesions increased in a dose–dependent manner. The High-Performance Liquid Chromatography analysis profiled 7 unknown compounds while the GC-qMS revealed 103 compounds in the CC6 fraction allowing for their identification, quantification, and providing insights into the biological activities and its potentials application. The CC6 fraction inhibited glutathione S-transferase (IC50 = 2265.260.60 mg/ml), superoxide dismutase (IC50 = 1485.300.78 mg/ml), catalase (IC50 = 574.471.57 mg/ml), acetyl cholinesterase (IC50 = 838.280.51 mg/ml), butyryl cholinesterase (IC50 = 1641.76 ± 1.14 mg/ml) and upregulated cyclooxygenase-2 (IC50 = 37.89 ± 0.15 mg/ml). Based on the result of the study, it could be inferred that the unidentified compounds present in the EAF exhibit strong insecticidal properties. The study concluded that the acute toxicity of the potent fraction showed no abnormal clinical toxic symptoms while a repeated dose of the extract in sub-acute studies showed a toxic effect that is dose-dependent. The mechanism of action of the purified fraction could be said to be by inhibition of cholinergic and antioxidant enzymes. However, the potent fraction also upregulated the activity of anti-inflammatory enzymes. Hence, regulated amount of CELE at a repeated dose <800 mg/kgbw could be considered for use as an anti-pest agent in Integrated Pest Management of Sitophilus zeamais.

Diatomaceous earth against Ecuadorian populations of the maize weevil (Sitophilus zeamais)

Diatomaceous earth (DE) is an inert dust derived from unicellular algae, which is effectively used as an insecticide. The DE efficacy has been recognized against a range of stored grain insects including the maize weevil (Sitophilus zeamais, Motschulsky, 1885). However, little is known about the effect of DE among maize weevil populations exposed to different doses, particularly regarding its potential effects on mortality, repellence, progeny emergence, and grain consumption. Thus, we assessed DE (83.97% SiO2) effects of three Ecuadorian maize weevil populations (Buena Fe, Mocache, Quevedo) exposed to different DE doses (0, 1, 3, 5 g DE/kg of maize). As expected, the three DE doses were able to effectively control the insects (P = 0.05) with the median survival times (LT50) ranging from 5 to 9 days (120.00–216.00 h). No DE repellence was detected in the three maize weevil population, regardless of the dose used suggesting that DE is not recognized by the adult weevils. The DE doses applied against maize weevil led to reduction on the progeny production of S. zeamais (χ2 = 235.77, df = 1, P < 0.001) and compromised their grain consumption (F1,174 = 20.65, P < 0.001). However, no differences were found among the three weevil populations. These findings reinforce the use of DE as an alternative in management programs for S. zeamais populations.

Insecticidal potential of essential oil from inflorescences of Etlingera elatior and its major constituents against Sitophilus zeamais

The maize weevil, Sitophilus zeamais, is responsible for an estimated 15 to 40 % loss of corn kernels in the field and during storage. Phosphine-based fumigants and insecticides, such as pyretroids and organophosphates, have been employed excessively for the control of this pest, causing harm to the environment. Botanical products have been analyzed as safer, more viable alternatives. The present study investigated the insecticidal effect against S. zeamais of the essential oil from the inflorescences of Etlingera elatior (EeIEO) and its two major constituents. EeIEO was extracted by hydrodistillation and characterized using gas chromatography techniques (GC and GC/MS). Dodecanal (58.31 %), dodecanol (20.33 %), β-caryophylene (4.21 %), α-pinene (2.66 %), n-decanol (2.52 %) and β-farnesene (2.46 %) were the main compounds found in the oil. EeIEO, dodecanal (NAL) and dodecanol (NOL) exhibited toxicity by fumigation (LC50 = 0.83, 0.51 and 3.05 μL/L of air, respectively) and contact (LD50 = 1.42, 1.04 and 0.28 μg/adult, respectively) for adult forms of S. zeamais. All nutritional parameters of the insects were altered by the ingestion of an artificial diet mixed with EeIEO, NAL and NOL, which promoted insect mortality and had a strong deterrent action (feeding deterrent indices from 70.5 to 92.0 %). EeIEO, NAL, and NOL were also capable of inhibiting in at least 67 % amylase activity from the insect gut. The results indicate the insecticidal activity of EeIEO, NAL, and NOL as a natural option for the control of S. zeamais. NOL achieved the best results in terms of toxicity by contact and ingestion, whereas NAL was the most effective by fumigation.

Efficacy of Botanical Extract Formulations of Zanthroxylum usambarense and Warburgia ugandensis on Post-Harvest Management of Sitophilus zeamais in Maize

Sitophilus zeamais causes significant losses to maize produce worldwide. The use of biodegradable and environmentally friendly botanicals as an alternative to synthetic pesticides is increasingly becoming important. Therefore, we sought to determine the use of plant extract formulations to manage S. zeamais during storage. Crude Zanthroxylum usambarense and Warburgia ugandensis stembark extracts were used for contact toxicity and repellent bioassays against S. zeamais. The formulations that exhibited the highest repellence and mortality were tested for insecticidal activity during storage for six months. Phytochemical profiles of the extracts were determined using GC-MS, and molecular docking of active compounds against insect target proteins was done. Mortality analyses revealed LD50 values of 114.89 µg/mL and 197.19 µg/mL for Z. usambarense’s hexane and methanol organic extracts, respectively. Warburgia ugandensis extracts had LD50 values of 69.25 µg/mL and 163.52 µg/mL, respectively. Extract formulations achieved weevil perforation index values of &lt;50.00 in all treatments. The docking analysis showed the pesticidal potential of several compounds, and mortality could be attributed to Eugenol (19.28%), 1,8-cineole (5.78%) and Linalool (21.42%). The tested botanicals have demonstrated their ability to suppress S. zeamais development in stored maize and could be utilized to protect maize grains during storage.

Inventory of Warehouse Pests on Grain Samples at the Plant Quarantine Laboratory of the Makassar Agricultural Quarantine Center

This study aims to determine and record the types of warehouse pest insects found in several export grain commodities in the plant quarantine laboratory of the Makassar Agricultural Quarantine Center. Data on the types of warehouse pest insects on several grain commodities were obtained by sampling as much as 2 kg from each commodity. Grain commodities are taken in warehouses: rice, corn, green beans, coffee, and cocoa. Then take insects found on the surface or inside the grain. The types of warehouse pest insects found in grain samples were identified based on insect morphology. Then secondary data related to kinship relationships between insect species and data on optimal environmental factors for insect growth are taken from book and journal references. The number of warehouse pest insects found in several export grain commodities in the plant quarantine laboratory of BBPK Makassar is eight types. Insect pests are only found in rice, corn, and cocoa commodities. Types of insect pests found, namely &lt;em&gt;Sitophilus oryzae&lt;/em&gt;, &lt;em&gt;Sitophilus zeamais&lt;/em&gt;, &lt;em&gt;Tribolium castaneum&lt;/em&gt;, &lt;em&gt;Cryptolestes ferrugineus&lt;/em&gt;, &lt;em&gt;Araecerus fasciculatus&lt;/em&gt;, &lt;em&gt;Ahasverus advena&lt;/em&gt;, &lt;em&gt;Ephestia kuehniella,&lt;/em&gt; and &lt;em&gt;Sitotroga cerealella&lt;/em&gt;.

Susceptibility of pro-Vitamin A biofortified maize genotypes to Sitophilus zeamais (Mots) in Ghana

Pro-Vitamin A Biofortified maize is one of the crops with the cheapest and most sustainable option for preventing Vitamin A deficiency in humans in Ghana. It is also a key energy component of feed for layer chicken, forming about 60-70% of the total feed. Sitophilus zeamais is one of the most serious primary internal feeding pests of maize and other grains in sub-Saharan Africa. It causes both quantitative and qualitative grain losses. Two no - choice laboratory experiments in 112 days cumulative feeding of S. zeamais and 60 days susceptibility of six pro-Vitamin A Biofortified Maize (PVABM) genotypes to the insect were conducted. The experimental designs were Completely Randomized Design in four replications. Percentage grain damage and weight loss were significantly lower (P&lt;0.05) in Aburokokoo than the other genotypes. Significantly more S. zeamais emerged from Accession GH2354 which also had significant (P&lt;0.05) higher percentage grain damage than other genotypes. In the 60-day susceptibility experiment, grain hardness had significant (P&lt;0.05) negative correlation with F1 progeny, index of susceptibility and protein content but positive significant correlation with median development period. Large number of S. zeamais F1 progeny, high susceptibility index, high protein, low total carbohydrate content, short median development time with low grain hardness value were observed on accession GH2354. Aburokokoo had significantly (P&lt;0.05) small number of F1 progeny, low index of susceptibility, low protein and high total carbohydrate, long development period and intermediate value of grain hardness. The ascending order of grain hardness among the maize genotypes was GH2354&lt;Obatanpa &lt;Aburokokoo&lt;Abontem&lt;Honampa&lt;Ahoodzin. There was no relationship between grain length, width and thickness and grain susceptibility. A cluster dendrogram obtained from the maize genotypes with regard to resistance parameters to S. zeamais showed that accession GH2354 and Obatanpa-QPM were susceptible, Ahoodzin, Honampa and Abontem were moderately resistant, with Aburokokoo resistant to the maize weevil infestation. Key words: Biofortified maize, stored produce, insect pest, Vitamin A deficiency, grain damage

Medicinal Plants as a Natural Greener Biocontrol Approach to "The Grain Destructor" Maize Weevil (Sitophilus zeamais) Motschulsky.

According to the United Nations (UN), the global population may skyrocket to 9.8 billion people in 2050 and 11.2 billion in 2100, placing an overwhelming burden on food security as the world will have to meet this growing demand. Maize is the largest staple grain crop produced in developing countries. The maize weevil, Sitophilus zeamais, is one of the most destructive post-harvest pests of stored cereals and grains. The maize weevil contributes up to 40% of total food-grain losses during storage, mainly in developing countries. Current synthetic pesticides are ineffective, and, moreover, they raise serious environmental safety concerns as well as consumer health hazards. Drawing from past oversights and current environmental realities and projections, the global population has been switching to green living by developing sustainable strategies. In our context, these new greener strategies include the utilization of medicinal plants to control maize weevil infestation, which unlocks unlimited innovative possibilities, and, thus, improves the yield, quality, and safety of maize. Medicinal plants are less toxic, easily biodegradable, and capable of protecting grain from pests. This paper systematically outlines the literature on host plants as well as the feeding and associated diseases of the maize weevil. In light of this, we cement medicinal plants as excellent candidates in the pursuit of greener, sustainable, more potent, and cost-effective pesticides.

Effect of herbicides on the emergence of Sitophilus zeamais (Coleoptera: Curculionidae) in transgenic Bt maize

etically modified organisms (GMOs) are widespread in Brazil, especially those related to resistance to herbicides and insects. This work aimed to evaluate herbicides' effect on the emergence of maize weevil Sitophilus zeamais (Coleoptera: Curculionidae) in different maize genotypes. The experimental design was a 3 × 5 factorial experiment in a randomized complete block design with four replications. Genotypes of transgenic maize, Herculex® (TC1507) and PowerCore® (MON89034 × TC1507 × NK603) and an Isohybrid (non-transgenic) were used. The herbicides were Atrazine, Atrazine + Nicosulfuron, Ammonium Glufosinate, Nicosulfuron and a control treatment without herbicide application. The emergence of S. zeamais was observed in grains from each plot for 100 days, with 300 grams of maize grains. The Isohybrid was the most attractive to S. zeamais when no herbicide was applied. The application of Ammonium Glufosinate increased S. zeamais preference for Herculex® and Nicosulfuron for PowerCore®. The insertion of an exogenous gene and the application of herbicides in maize plants can alter components of the insect-plant interaction, changing the attractiveness to S. zeamais.

Development of the first high-density linkage map in the maize weevil, Sitophilus zeamais.

The maize weevil, Sitophilus zeamais, is a worldwide pest that disproportionately affects subsistence farmers in developing countries. Damage from this pest threatens food security in these communities as widely available and effective control methods are lacking. With advances over the last decade in the development of genetic pest management techniques, addressing pest issues at the ecosystem level as opposed to the farm level may be a possibility. However, pest species selected for genetic management techniques require a well-characterized genome and few genomic tools have been developed for S. zeamais. Here, we have measured the genome size and developed the first genetic linkage map for this species. The genome size was determined using flow cytometry as 682 Mb and 674 Mb for females and males, respectively. The linkage map contains 11 linkage groups, which correspond to the 10 autosomes and 1 X-chromosome found in the species and it contains 1,121 SNPs. This linkage map will be useful for assembling a complete genome for S. zeamais.