Main Insect Research Articles

INSECT PESTS OF RICE IN PAKISTAN: A COMPREHENSIVE REVIEW OF BIOLOGY, DAMAGE, AND MANAGEMENT

Rice is one of the most significant food crops in the world. It is predominantly a subsistence crop because half of it is consumed where it is grown. The main insect pests of rice in Pakistan include Stem borers, Plant-hoppers, Leafhoppers, rice grass-hopper, leaf-folder, African pink borers, and many others. There have been noticeable changes in Pakistan’s insect pest complex with the introduction of high-yielding cultivars. Many species that work earlier thought to be minor pests are now regarded as serious pests in Pakistan. In traditional Basmati growing regions, stem borers remain a serious issue. From ancient times, the Pakistani farming community used different management strategies to deal with the insect pests of rice. The management strategies involved are cultural, biological, physical, and chemical. Cultural practices have changed, such as the use of greater fertilizers rates in high-yielding varieties, and the leaf folder complex. Rice growers throughout Pakistan are strongly reliant upon traditional cultural practices. But this tendency has slowly changed towards chemical methods. Chemical pesticides are now used more frequently as a primary method of control in Pakistan. Biological control or the use of living organisms as pest control agents is a common natural process in which insects population in crops are continuously decreased by predators, parasites, and pathogens of the pests. Pakistan now has a problem with insect pests, thus utilizing an integrated pest management (IPM) strategy that is effective, affordable, and safe for the environment. Other techniques for pest control include the use of pheromones as attractants, insect growth regulators, insect growth inhibitors, repellents, and sterile insect release systems.

Reproductive potential of the black bean aphid (Aphis fabae Scop.) on a range of faba bean (Vicia faba L.) accessions

AbstractThe black bean aphid is one of the main insect pests of faba bean, leading to yield losses in many countries. The aphid inflicts damage to faba bean through direct phloem feeding and indirectly by transmission of several viruses. Sources of genetic resistance or tolerance to the aphid have been hard to identify and to use in breeding because of the high environmental variability of the attack, the weak and partial nature of the resistance when found, and the low repeatability of experiments. A range of molecular genotyping tools is now available for identifying the genes underlying key traits in faba bean. Hence, we screened the responses of eight inbred lines (Columbo, Albus, Closed‐flower, Diana, Hedin/2, Icarus, ILB938/2, and Mélodie/2) of faba bean, derived from commercial cultivars and experimental germplasm, to aphid infestation in controlled (no‐choice‐test) and field (preference test) conditions. In the controlled environment, aphid performance was assessed by measuring fecundity and determining the intrinsic rate of natural increase (rm). In the field experiment, population growth was examined on Columbo, Closed‐flower, Hedin/2, and ILB938/2 during June and July. Each week, 10 plants in each plot, randomly chosen at the start, were screened for aphid colonization and number of plants attacked. For each plant, an index number was given reflecting the severity of aphid presence. Our results demonstrate a clear conformity between the results obtained from the indoor pot experiments and the field experiments. In both experiments, ILB938/2 showed partial resistance with significantly lower fecundity, rm, and field infestation when compared with the known susceptible line Columbo. The consistently strong performance of ILB938/2 against the black bean aphid suggests that it carries a factor or factors rendering it unconducive to aphid landing, feeding, and/or reproduction. Further investigation into the resistance mechanisms of ILB938/2 is planned.

Insects as a potential source of chitin and chitosan: Physicochemical, morphological and structural characterization. -A review

Insects are mega-diverse species. Structurally, insects are composed of the polysaccharide known as chitin and its deacetylated derivative, chitosan. Actually, exist few studies regarding to the physicochemical and structural characterization of these biopolymers in the main insect orders. The present study shows a review of chitin and chitosan obtained from insect sources; it was carried out on the similarities and differences between these biopolymers and those obtained from conventional sources. X-ray diffraction, infrared spectroscopy with Fourier transform, and thermogravimetric analysis are presented which are important to determine how the structural, morphological and physicochemical properties of chitin and chitosan are affected depending on the source taxonomy of insects. The main techniques used for the isolation and the yields obtained are shown. Future research will be conducted to expand chitin and chitosan applications from insect in areas as diverse as food, biotechnology and biomedicine, emphasizing that insects can represent a potential raw material.Keywords: Biopolymeric materials; Physicochemical characterization; Insect order; Insect species; Chitin yield

Effective Phytosanitary Treatment for Export of Oriental Melons (Cucumis melo var L.) Using Ethyl Formate and Modified Atmosphere Packaging to Control Trialeurodes vaporariorum (Hemiptera: Aleyrodidae).

Trialeurodes vaporariorum (Hemiptera: Aleyrodidae), commonly known as greenhouse whitefly, is one of the main insect pests of Oriental melon (Cucumis melo var L.) in South Korea. T. vaporariorum is of concern as a quarantine pest for the exportation of C. melo in Southeast Asian countries. Due to future restrictions on the use of methyl bromide (MB) during quarantine, ethyl formate (EF) represents a potential alternative. In this study, we evaluated EF for its efficacy (probit-9 values) in enabling the export of Oriental melons. The probit-9 value of EF for controlling T. vaporariorum was 3.02 g·h/m3 after 2 h of fumigation. We also assessed the phytotoxicity of EF on melons when using modified atmosphere packaging (MAP) under low-temperature conditions, which is required for export and trade, to extend shelf-life. In scaled-up trials, we found 8 g/m3 EF for 2 h at 5 °C to be suitable as a new phytosanitary treatment against greenhouse whitefly for exported Oriental melons when using MAP. No phytotoxic damage was found 28 d after fumigation at 5 °C in terms of five quality parameters (firmness, sugar content, mass loss, color change, and external damage).

Investigation of Rhodnius prolixus head anatomy using microtomography.

In the last years, microtomography has proved to be a powerful technique on insects' studies, allowing a detailed view of the structures' internal with a high resolution. One of the most important advantages about the use of microtomography in these studies is the fact that the dissection is not necessary, which decreases considerably the number of samples used on the insects' research. Some insects are used constantly in studies about morphology, metamorphosis, and reproduction, because they work as a model for others, and Rhodnius prolixus is one of the most studied in this group. This insect is also one of the main insect vectors of Chagas disease that kills around 12,000 people every year in Latin America. Some studies using laboratory microtomography conventional scanners combining with the correct staining methods have proved that it could be a powerful tool in biological research, allowing the visualisation of low-density tissues. The main goal of the present work was to use staining protocols to study Rhodnius prolixus with laboratory microtomography conventional scanners. The experiments were carried out at the imaging lab in the Theoretical Biology Department, University of Vienna, using an Xradia MicroXCT and at the University of Oslo, using a Skyscan 2211.

Evaluation of a neonicotinoid alternative to phorate for the management of soil insects in Florida sugarcane

Wireworms (Coleoptera: Elateridae) are the main soil insect pests of sugarcane (Saccharum spp. hybrids) in Florida. Melanotus communis (Gyllenhal) is the most abundant wireworm in Florida sugarcane fields, reducing stalk populations by feeding on buds of sugarcane seed pieces and on young sugarcane plants. At-planting use of the organophosphate insecticide phorate is the main wireworm management tactic in Florida; however, phorate is a hazardous and relatively expensive insecticide. Thiamethoxam is a neonicotinoid insecticide that has potential to become registered for use on sugarcane in the United States. Previous studies suggested that thiamethoxam decreases wireworm injury to sugarcane seed pieces but does not increase wireworm mortality. The present study conducted between 2018 and 2022 aimed to comprehensively evaluate thiamethoxam for wireworm control under laboratory, outdoor, and field conditions. In two laboratory bioassays, M. communis mortality associated with thiamethoxam (3–20%) was not different than mortality for the non-treated check (0–7%), whereas mortality associated with phorate attained 93–100%. In three large container experiments conducted outdoors with controlled M. communis infestations, thiamethoxam and phorate generally protected young sugarcane plant populations at comparable levels. Insecticide efficacy was mainly associated with the protection of seed-piece buds. However, the number of recovered live wireworms was 2.7–8.0 times greater in thiamethoxam treatments than in phorate treatments. In three field experiments, young sugarcane plant populations in thiamethoxam- and phorate-treated plots were not different than those in non-treated plots. However, the at-planting application of thiamethoxam decreased the number of sugarcane thrips, Fulmekiola serrata (Kobus), by 67–89% in two experiments with thrips infestations 12 weeks after planting. Although the evaluation of insecticide efficacy under natural wireworm infestations was inconclusive, this study confirmed that thiamethoxam should be considered as an alternative to phorate if registered. However, the long-term effects of low wireworm mortality associated with thiamethoxam use should be studied.

Egg Parasitoid Complex of Helicoverpha armigera (Hübner) and Conopomorpha cramrella Snellen in North Sulawesi

Backround: Helicoverpa armigera is major maize pest, while Conopomorpha cramerella is cocoa is main insect pest. Their larvaes lie in corn cob and cocoa pulp which can be controlled using egg parasitoids. Methods: Exploring H. armigera eggs on female flowers on a corn plant along the 50 m line at 10 points with a 4 m distance to obtain parasitoids. C. cramrella. Egg parasitoids were obtained by taking eggs from cacao pod, while Corcyra cephalonica from egg traps along a straight line with 10 points with 3 m distance. Result: H. armigera egg parasitoids include Trichogramma sp. and Trichogrammatoidea armigera. Corn grown in between coconut palms has higher parasitism than without coconut palm shade and highest parasitism was in Bolaang (60.91±2.52 %). Parasitoids of Trichogaramma sp. produce unrearable female offsprings in C. cephalonica eggs. Dominant Trichogrammatoidea sp. were found in egg traps while only two C. cramerella parasitized eggs were found in cacao pod. Dominant Trichogaramma sp. Parasitoids in egg traps were found in Tombariri. C. cephalonica egg trap is the latest method for monitoring Trichogrammatoidea sp parasitoid The parasitism of Trichogrammatoidea sp. on C. cramerella eggs and C. cephalonica egg traps is low.

Climate mediates roles of pollinator species in plant–pollinator networks

AbstractAimUnderstanding how climate conditions influence plant–pollinator interactions at the global scale is crucial to understand how pollinator communities and ecosystem function respond to environmental change. Here, we investigate whether climate drives differences in network roles of the main insect pollinator orders: Diptera, Coleoptera, Lepidoptera and Hymenoptera.LocationGlobal.Time period1968–2020.Major taxa studiedDiptera, Coleoptera, Lepidoptera and Hymenoptera.MethodsWe collated plant–pollinator networks from 26 countries and territories across the five main Köppen–Geiger climate zones. In total, we compiled data from 101 networks that included >1500 plant species from 167 families and >2800 pollinator species from 163 families. We assessed differences in the composition of plant–pollinator interactions among climate zones using a permutational ANOVA. We calculated standard network metrics for pollinator taxonomic groups and used Bayesian generalized mixed models to test whether climate zone influenced the proportion of pollinator network links and the level of pollinator generalism.ResultsWe found that climate is a strong driver of compositional dissimilarities between plant–pollinator interactions. Relative to other taxa, bees and flies made up the greatest proportion of network links across climate zones. When network size was accounted for, bees were the most generalist pollinator group in the tropics, whereas non‐bee Hymenoptera were the most generalist in arid zones, and syrphid flies were the most generalist in polar networks.Main conclusionsWe provide empirical evidence at the global scale that climate strongly influences the roles of different pollinator taxa within networks. Importantly, non‐bee taxa, particularly flies, play central network roles across most climate zones, despite often being overlooked in pollination research and conservation. Our results identify the need for greater understanding of how global environmental change affects plant–pollinator interactions.

Environmental factors driving the abundance of Philaenus spumarius in mesomediterranean habitats of Corsica (France)

Philaenus spumarius (Ps) is considered the main insect vector of the bacterium Xylella fastidiosa (Xf) in Europe. As such, it is a key actor of the Xf pathosystem on which surveillance and management strategies could be implemented. Although research effort has increased in the past years, the ecological factors shaping Ps abundance and distribution across landscapes are still poorly known in most regions of Europe. We selected 64 plots of 500m2 in Corsican semi-natural habitats in which we sampled nymphs and adults of Ps during three years. While local or surrounding vegetation structure (low or high scrubland) had little effect on Ps abundance, we highlighted a positive relationship between Ps abundance and the density of Cistus monspeliensis in the plots. We also found larger populations of Ps in cooler and moister plots. The pattern of host association highlighted here is unique, which calls for more studies on the ecology of Ps in Europe, to help designing surveillance and management strategy for Xf.

The Impact of Various IPM Modules on the Management of Major Insect Pests of Sesame in Madhya Pradesh's Bundhelkhand Zone

The All India Coordinated Research Project Sesame Centre, College of Agriculture, JNKVV, Tikamgarh (M.P.) conducted a field experiment in 2017 kharif season using a Randomised block design to examine the effects of several IPM modules on the control of the main sesame insect pest. The experiment was set up using a Randomized Block Design with three replications, six treatments, and 21.6 M2 plots for each, using the sesame variety modrate resistant TKG -22 as the test variety. All of the plots' seeds were treated with imidacloprid 600 (5g/kg seed), and all plots except for the control were intercropping with black gram (3:3) and yellow sticky trap (1 trap/plot). Profenofos 50EC (2ml/L), NSKE5% (T1 and T2), two sprays of NSKE5% + NSKE 5%, Profenofos 0.1% (2ml/l)+ NSKE 5%, and Profenofos 0.1% were used as the treatment, with the untreated control side receiving no treatment. The results showed that treated areas with insecticides outperformed untreated areas by a significant margin. Of the treatments, treatment T5 (imidacloprid 600FS (5g/kg seed) foliar spray of NSKE5% at 30 & profenofos 0.11% (2ml/l)45 DAS) was the most effective and recorded the lowest population of Antigashtra (0.17) larvae/5plant). Bud flies were greatly diminished, and the populations of the three main sucking pests—mirid bugs (0.24 bugs per three leaves/plant), white flies (0.48 Nymphs per three leaves/plant were at their lowest. In T5 (imidacloprid 600FS (5g/kg seeds + intercropping with black gram 3:3) foliar srpray of NSKE5% at 30, & profenofos 0.1% (2ml/l), the seed equivalent yield was also greatly increased. 45 DAS had the highest seed equivalent yield of 1176 kg/ha, the highest net profit of Rs. 78667, and the highest B:C ratio (6.11); T4 had the highest seed equivalent yield of 1075 kg/ha, the net profit of Rs.70297, and the highest B:C ratio (5.48).

Impact of Some Foliar Applications on The Yield and its Components of Some Pea Cultivars and their Tolerance to Infestation by Main Insect Pests

Impact of Some Foliar Applications on The Yield and its Components of Some Pea Cultivars and their Tolerance to Infestation by Main Insect Pests

Supressão populacional de fase galícola e radícola da filoxera em videira com a utilização de inseticidas sintéticos

ABSTRACT: The grapevine phylloxera Daktulosphaira vitifoliae (Fitch, 1856) is the main insect pest of viticulture globally. Infestations can occur in the aerial part of the plant (gallicolae form) and roots (radicicolae form). In this study, the effect of insecticides on the populations suppression of the gall and root forms of phylloxera one vine was evaluated. For the gallicolous form, the thiamethoxam (Actara 250 WG®, 40g c.p./100L-1), flupyradifurone (Sivanto® Prime 200 SL, 75mL c.p./100L-1), and sulfoxaflor (Closer® SC, 40mL c.p./100L-1) were evaluated in the field, under natural infestation, using rootstock plants ‘Paulsen 1103’ (Vitis berlandieri x V. rupestris). For the root stage, an experiment was carried out in a greenhouse using rooted seedlings of ‘Cabernet Sauvignon’ (Vitis vinifera) grown in pots artificially infested with 200 phylloxera eggs per plant. After 80 days of infestation, the thiamethoxam (0.2g p.c./plant), flupyradifurone (0.8mL p.c./plant), sulfoxaflor (0.3mL/plant) and imidacloprid (Proved 200 SC, 0.7 mL/plant) were applied via drench. For the gallicolae form, an application of the flupyradifurone provided a gall reduction of 90% at 28 days after the first application (DAFA). While for thiamethoxam, 3 applications were needed at weekly intervals to maintain the same level of control. For sulfoxaflor, a second application at 14 DAFA was necessary to provide a level of control above 90%. For the root stage, the insecticides sulfoxaflor and imidacloprid showed the best results, with 96 and 89% of control over nymphs and adults, respectively. The insecticides flupiradifurone and sulfoxaflor are suitable for the chemical control of phylloxera in the vine.

Contribution of UDP-glycosyltransferases to chlorpyrifos resistance in Nilaparvata lugens

As a multigene superfamily of Phase II detoxification enzymes, uridine diphosphate (UDP)-glycosyltransferases (UGTs) play important roles in the metabolism of xenobiotics including insecticides. In this study, 5-nitrouracil, an inhibitor of UGT enzyme activity, effectively increased the toxicity of chlorpyrifos to the chlorpyrifos-resistant strain of Nilaparvata lugens, one of the most resistant rice pests. The enzyme content of UGT in the resistant strain was significantly higher than that in the susceptible strain. Among 20 identified UGT genes, UGT386H2, UGT386J2, UGT386N2 and UGT386P1 were found significantly overexpressed in the resistant strain and can be effectively induced by chlorpyrifos. These four UGT genes were most highly expressed in the midgut and/or fat body, two main insect detoxification tissues. Amino acid sequence alignments revealed that these four UGTs contained a variable N-terminal substrate-binding domain and a conserved C-terminal sugar donor-binding domain. Furthermore, homology modeling and molecular docking analyses showed that these UGTs could stably bind to chlorpyrifos and chlorpyrifos oxon, with the binding free energies from −19.4 to −110.62 kcal mol−1. Knockdown of UGT386H2 or UGT386P1 by RNA interference dramatically increased the susceptibility of the resistant strain to chlorpyrifos. These findings suggest that overexpression of these two UGT genes contributes to chlorpyrifos resistance in N. lugens.

Comparison of Droplet Distribution and Control Effect of Wheat Aphids under Different Operation Parameters of the Crop Protection UAV in the Wheat Flowering Stage

Aphid is one of the main insect pests of wheat in the flowering stage, so timely and effective control of wheat aphids plays an important role in ensuring wheat yield. The crop protection Unmanned Aerial Vehicle (UAV) is widely used in the control of wheat pests and diseases nowadays. In order to screen out the suitable operation parameters of the crop protection UAV to control the wheat aphids, this study conducted wheat aphid distribution investigation tests and droplet distribution tests. With the P20 electric four-rotor crop protection UAV (Guangzhou Jifei Technology Co., Ltd., Guangzhou, China) as the test equipment, four levels of flight speed (FS: 3, 4, 5, 6 m/s) and three levels of flight height (FH: 1.5, 2, 2.5 m) were combined as operation parameters, tests were carried out to compare the density and uniformity of droplet coverage, and the wheat aphid control tests were carried out by using the optimized operation parameters. The results of the wheat aphid distribution investigation test showed that aphids mainly distributed in the lower layer of the wheat plant canopy, accounting for more than 90.61%. The results of the droplet distribution test showed that with the increase in FS and FH, the coverage density and the droplet distribution uniformity in the upper and lower layers of wheat showed a downward trend under the condition of considering the boundary overlap of spraying width (SW) in multi-routes. Through the comparison of operation efficiency and droplet distribution quality, two combinations of parameters A1 (FS: 3 m/s, FH: 1.5 m) and B1 (FS: 4 m/s, FH: 1.5 m) were selected for the aphid control effect test. The results of the control test showed that the average control effect of A1 (92.05%) on aphids was 10.3% higher than that of B1 (81.75%) 7 days after pesticide application, which indicated that improving the droplet distribution uniformity in the lower layer of wheat could significantly improve the control effect of aphids. This study result could provide reference for the same type of crop protection UAV to control the same type of wheat diseases and insect pests in the same growing stage.

Innovation in Alternative Food Sources: A Review of a Technological State-of-the-Art of Insects in Food Products.

Insects present great potential for the food industry due to their easier rearing conditions and high nutritional value, in comparison with traditional livestock. However, there is a lack of evaluation of the technological status of food products developed with edible insects. Therefore, this study aims to analyze the emergent technological and scientific applications of edible insects in the food industry through a prospective study of patent documents and research articles. Espacenet was used as a research tool, applying the terms Insect, Pupa, Larva, or Nymph and the codes A23L33 and A23V2002. A total of 1139 documents were found-341 were related to the study. Orbit® was used to evaluate technological domains and clusters of concepts. Scopus database research was performed to assess the prevalence of insect research, with the term "edible and insect*". The main insects used were silkworms, bees, beetles, mealworms, crickets, and cicadas. Protein isolates were the predominant technology, as they function as an ingredient in food products or supplements. A diverse application possibility for insects was found due to their nutritional composition. The insect market is expected to increase significantly in the next years, representing an opportunity to develop novel high-quality/sustainable products.

Extrafloral nectar as entrée and elaiosomes as main course for ant visitors to a fireprone, mediterranean-climate shrub.

Thousands of plants produce both extrafloral nectaries (EFNs) on their leaves and nutrient-rich appendages on their diaspores (elaiosomes). Although their individual ecology is well-known, any possible functional link between these structures has almost always been ignored. Here, we recognized their co-presence in the shrub, Adenanthos cygnorum (Proteaceae), and studied their function and interaction. We observed that the same ants frequently visit both structures, seeds are attractive to vertebrate granivores but are released into a leafy cup from where they are harvested by ants and taken to their nests, from which seeds, lacking elaiosomes, germinate after fire. We showed that juvenile plants do not produce EFNs and are not visited by ants. We conclude that EFNs are not just an indirect adaptation to minimize herbivory via aggressive ant visitors (the role of a minority) but specifically enhance reproductive success in two ways: First, by inducing ants to visit the plant as a reliable food source throughout the year. Second, by promoting discovery of the seasonally available, elaiosome-bearing seeds for transport to their nests (the majority of visitors), so avoiding the risk of granivory should seeds instead fall to the ground. Parasitoid wasps play a supporting role in controlling the main insect herbivore whose larvae devour the reproductive apices. Thus, the EFN-elaiosome relationship has three components that enhance species fitness: foliage protection, seed transport, and granivore escape. A similar system has been described only once before (in an unrelated biome) and, consistent with the objectives of ecology as an integrative science, deserves wider study.

ANALYSIS OF ASPECTS OF THE CONVENTIONAL AND ORGANIC COCOA PRODUCTION SYSTEM AND PRODUCERS PERCEPTION OF THE USE OF BOTANICAL PESTICIDES FOR THE MANAGEMENT OF COCOA MIRIDS IN TOGO

Cocoa mirids are the main insect pests of the crop in Togo. In order to contribute to a sustainable management of these pests, the present study aimed at analyzing some aspects of the cocoa production system in conventional and organic farming and evaluating the perception of producers on the use of botanical pesticides as a means of control. Thus, a survey questionnaire was administered to 178 producers, including 96 conventional cocoa producers and 82 organic cocoa producers. The producers surveyed occured in 27 villages in the prefectures of Agou, Akebou, Kloto and Wawa. The results showed that about 98% of conventional cocoa farmers and 100% of organic cocoa farmers mentioned mirids as major pests of the crop. The average infestation rate of the plantations was estimated at 40.79 ± 25.72% in conventional cocoa production and 44.93 ± 26.92% in organic cocoa production. The related average losses are respectively 13.09 ± 8.58% and 17.39 ± 10.93% in conventional and organic cocoa production. As a means of control, 98.93% of producers in conventional cocoa production versus 65.06% in organic cocoa production use at least one insecticide. Three (3) classes of chemical insecticides are used in conventional cocoa production: Neonicotinoids (48.15%), pyrethrinoids (41.66%) and organophosphates (10.18%). In organic cocoa production, Azadirachtaindica is the plant most used for mirid control. 31.71% of producers use Neem oil against 17.05% and 15.85% who use its leaves and seeds respectively. Regarding producer adherence, 81.96% of conventional and 91.46% of organic cocoa farmers believe that local plant-based bioinsecticides can help to control cocoa mirids 68.75% and 71.95% of these two respective groups are willing to use them if they are effective and affordable.

Population Dynamics on The Main Faba Bean Insect Pests in Relation to Certain Ecological Factors in Kafr El-Sheikh Region, Egypt.

Population Dynamics on The Main Faba Bean Insect Pests in Relation to Certain Ecological Factors in Kafr El-Sheikh Region, Egypt.

Integrated management of the main tomato pest insects in the market garden areas of Niayes in Senegal

Integrated management of the main tomato pest insects in the market garden areas of Niayes in Senegal

Preliminary Assessment of Repellency and Toxicity of Essential Oils against Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) on Stored Organic Corn Grains

Insect infestation of cereal grains during post-harvest storage not only causes significant grain loss, but also reduces grain quality and makes grains more susceptible to mold infection. Synthetic pesticides are banned from being used in organic grain storage setting due to their high toxicity. The main insect damaging stored corn grains is maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae). The purpose of this study was to evaluate insect repellency and insecticidal potentials of some generally recognized as safe (GRAS) essential oils (EOs) (including cinnamon, clove, thyme, oregano, and orange terpene oils) at concentrations of 1–20% against the maize weevil using an olfactometer and a simulated fumigation method, respectively. The olfactory tests show that cinnamon oil had the highest repellency (90%) to the weevils among the EOs tested. The insecticidal activity study indicates that maize weevil mortality increased with EO concentration and storage time with cinnamon, clove, and thyme oils being more effective. No weevil death was observed at 1% EOs; weevil mortality was 3.3–36% at 5%, which varied with the type of EO and storage time. At 10% or higher concentrations, all tested EO showed comparable or higher insecticidal activity than pirimiphos methyl-positive control at its recommended concentration (5 mg/kg corn). No significant increase in weevil mortality was observed with further increase in EO concentration, with exceptions of oregano oil and thyme oil. The highest weevil mortality levels were observed at week 7 for 15% cinnamon oil (100%) and eugenol (100%), followed by 20% thyme oil (93%). The study indicates that some EOs have great potential to serve as synthetic insecticide alternatives to protect organic corn grains from maize weevil damage during storage. This is important to food security, safety and environmental health.