Insects In Grain Research Articles

Use of Microwave Heating Technology for Disinfestation of Stored Green Gram (Vigna radiata) against Cowpea Bruchid Callosobruchus maculatus (Fabricius)

Background: Pulses are an integral component of food in India which acts as major source of protein required for growth and maintenance of body. But during their storage they suffer heavy losses resulting in depletion of their quality and edibility. The present studies focused on disinfestation of green gram grains using microwaves as an alternative approach to chemical methods for controlling insects in grains and pulses. Methods: In this laboratory studies during 2017-18, the grains of green gram were infested with different life stages of the cowpea weevil and exposed to 200, 400, 600 and 800 W microwave power levels, each at an exposure period of 10, 20, 30 and 40 s. Result: Eggs were the most susceptible, while pupal and adults were the least susceptible life stages to microwave treatments. Complete mortality of eggs was achieved with microwave treatments (400, 600 and 800 W), each at an exposure period of 30 and 40 s. Complete inhibition of larval stage was attained with 400 and 600 W (30 and 40 s) and 800 W (20, 30 and 40 s exposure) while for pupal stage it was observed at the higher wattages of 600 (40 s exposure) and 800 (30 and 40 s exposure). Microwave wattage of 600 W for 40 sand 800 W for 30 and 40 s exposure caused 100% mortality of 2d old adults of cowpea bruchid.

Influence of Moisture of Wheat on Acoustic Wave Propagation Characteristics

HighlightsA novel measuring device was developed for the propagation constant of acoustic waves in grain.Increase in moisture of wheat from 1.1% to 7.8% (wet basis) decreased the wave velocity and increased the attenuation coefficient.Increase in moisture of wheat from 7.8% to 21.2% increased the wave velocity and decreased the attenuation coefficient.Using the Johnson-Champoux-Allard (JCA) model and particle swarm optimization (PSO) algorithm, the influence of moisture on the pore structure in wheat was characterized.Abstract. Acoustic methods have been widely used for the measurement of grain moisture content and temperature as well as for detecting the presence of insects in grain. Therefore, this study was conducted to understand the influence of wheat moisture content on acoustic wave propagation characteristics. A novel device was developed for measuring the acoustic wave propagation constant. The propagation constants of 12 samples of wheat were measured, with each sample having a different moisture content in the range from 1.1% to 21.2% (wet basis). The results showed that the acoustic wave velocity decreased slightly with an increase in moisture from 1.1% to 7.8%, while the attenuation coefficient increased slightly. When the moisture increased from 7.8% to 21.2%, the velocity increased gradually, while the attenuation coefficient decreased. A quadratic equation described the results well. In addition, a Johnson-Champoux-Allard (JCA) model was adopted to study the influence of moisture on the pore structure of wheat samples. With the increase in moisture from 1.1% to 21.2%, the average radius of interconnection between two adjacent pores decreased from 0.275 to 0.262 mm at moisture below 7.8% and then increased to 0.304 mm, and the average radius of the pores decreased from 0.773 to 0.481 mm at moisture below 7.8% and then increased to 1.2 mm. Keywords: Acoustic standing wave tube, JCA model, Moisture content, Propagation constant, PSO algorithm, Wheat.

Recent developments in the global application of ECO2FUME ® and VAPORPH3OS ® phosphine fumigants:

ECO2FUME® (2% phosphine, 98% CO2 by weight) and VAPORPH3OS® (99.3% phosphine average by weight) are cylinderized gas formulations of phosphine that have achieved significant growth in commercial applications for the disinfestation of food and non-food commodities in the last two decades. The expansion in the global application of these two cylinderized phosphine fumigants is driven by increasing concern for safety, efficacy, unreacted powdered residue and disposal associated with aluminium phosphide tablets, which are promoted as alternatives to methyl bromide, and the concern of insect resistance to phosphine in both developed and developing countries. This paper describes recent developments in the global application of ECO2FUME® and VAPORPH3OS® in terms of commercial in-transit fumigation of grains and logs in ships, fumigation of export distiller’s dried grain with solubles (DDGS) in containers and shiphold, best practices in the management of phosphine resistance of insects in grains, and establishment and application of quarantine and preshipment (QPS) phosphine fumigation protocols for selected fresh fruits, vegetables, dried fruits and cut flowers as an alternative to methyl bromide. The growing issue of powdered residue from unspent aluminium phosphine tablets and the use of cylinderized phosphine as an effective solution are discussed.

A compact microwave device for monitoring insect activity in grain samples

We designed and fabricated a novel microwave device capable of detecting a single insect in grain samples. A test set-up was constructed by combining a planar active microwave resonator, a Peltier cell, and an insect cage. With the integration of a regenerative element, the active resonator had a quality factor as high as 21,600 even when placed in grain, an electrically lossy medium. The high sensitivity of the device allowed the characterisation of the activity of single adult insects Tribolium castaneum or Cryptolestes ferrugineus at different temperatures, as well as the reliable detection of single adult insects in grain samples. Our approach demonstrated the non-contact sensing technique that could assist in decision making for integrated pest management programs to monitor insects in stored grain.

Detection and analysis of the stored grain insect creeping sound

With the random acoustic source model as the theory model of the stored grain insects creeping, the sounds, of 20 Alphitobius diaperinus Panzer in wheat and 20 Tribolium castaneum Herbst adults in corn, are detected, respectively. By using Matlab, the original sound signals are reproduced and the de-noised signals are obtained. The power spectrums characteristics analysis are made. It is shown that the random acoustic source model is effective for the stored grain insect creeping sound detection, and their power spectrums are all discrete, where the highest frequency is 1600 Hz, the main frequency 205 Hz in the former, and the highest frequency is 800 Hz, the main frequency 350 Hz the latter, which may be used to distinguish different types insects in grain.

Investigation of the Feasibility of Radio Frequency Energy for Controlling Insects in Milled Rice

Many studies showed that radio frequency (RF) holds great potential to control insects in grains, while a few more technical issues need to be addressed to further make this technology ready for industrial application. Therefore, the effect of RF heating rate on rice fissure ratio and broken rate, RF heating lethality on immature rice weevils, and RF disinfestation treatment on cooking and eating quality of milled rice was investigated in this study. Results indicated that RF heating rate had no significant influence on rice broken rate, while fast RF heating rate (>7.2 °C/min) had adverse effects on rice fissure ratio, and mild RF heating rate (<5.8 °C/min) had no significant influence on fissure ratio of milled rice. RF treatment (50 °C, 5 min) could completely control immature rice weevils in rough, brown, and milled rice. Even though RF disinfestation treatment (50 °C, 5 min) influenced the cooking quality (water absorption, adhesive strength) of milled rice, it had no significant effect on overall sensory quality. This study provided valuable information for considering the application of RF energy in milled rice process to control insects.

Chemical Composition of Essential Oils from SixZanthoxylumSpecies and Their Repellent Activities against Two Stored-Product Insects

The objective of this study was to analyze six essential oils fromZanthoxylumgenus (family Rutaceae) in China and evaluate their repellent activities againstTribolium castaneumandLasioderma serricorneadults. Six essential oils fromZanthoxylumgenus, includingZ. armatum,Z. dimorphophyllum,Z. dimorphophyllumvar.spinifolium,Z. piasezkii,Z. stenophyllum,andZ. dissitum,were obtained by hydrodistillation and their yields were ranging from 0.02% to 0.53%. Totally, there were 39 chemical components revealed by GC-MS. Among them, some components with high relative content existed in more than threeZanthoxylumspecies. For instance, bothδ-cadinene (1.21%–17.15%) and spathulenol (0.36%–10.19%) appeared in essential oils ofZ. dimorphophyllum,Z. piasezkii,Z. stenophyllum,andZ. dissitumwhich were found to have higher content of sesquiterpenoids. The repellent activities of six essential oil samples againstT. castaneumandL. serricorneadults were investigated for the first time. Data demonstrated that sixZanthoxylumspecies had much stronger repellent activities againstT. castaneumthanL. serricorneadults, especially in 2 hours after exposure. The results indicate that these six essential oils fromZanthoxylumhave significant potential to be developed into natural repellents to control insects in grains, food, and traditional Chinese medicinal materials.

Resistance in cowpea cultivars to Bruchidius atrolineatus (PIC) (Coleoptera: Chrysomelidae: Bruchinae)

ABSTRACT: This study aimed to assess the resistance in cowpea cultivars to Bruchidius atrolineatus (Pic) attack. The experiment was conducted at the Faculdade de Ciências Agrárias e Veterinárias of Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Jaboticabal (SP). The following cultivars were used: BR17 Gurgueia, BR3 Tracuateua, BRS Novaera, Sempre Verde, BRS Milênio, and BRS Urubuquara. The non-preference test without choice evaluated the number of viable eggs, unviable and total posed by insects in grains, after 25 days of confinement. In addition, it was observed, in a daily basis, the total dry matter consumed and dry matter consumed per insect; male and female mass; male, female and total egg-adult cycle length; male and female longevity; sex ratio; number of emerged insects and percentage of emerged insects. The non-preference test with free choice evaluated the number of viable, unviable and total eggs and adult attractiveness after 24 hours and seven days of release. Sempre Verde cultivar was the least preferred for oviposition in the test without choice and showed lower number and percentage of emerged insects. BRS Milênio had the lowest total dry mass consumed and dry mass consumed per insect.

Continuous-wave Terahertz Imaging Applied to Detect Infestations Caused by Insects in Grain

Detection infestations caused by insects in grain are important control measures for ensuring storage longevity, seed quality and food safety. The efficiency of the continuous wave terahertz imaging method to detect infestations caused by insects in wheat kernels was determined in this study. A continuous wave terahertz experimental setup was designed for recording of THz images corresponding to different infestations caused by different life stages of insects. The experimental results indicate that the absorbance is generally highest for un- infested wheat kernels and decreased at later growth stages from THz pseudo-color images. Our study intended to demonstrate how the method of continuous wave Terahertz imaging could be applied to detect Infestations Caused by Insects in Grain.

Microwaves to control Callosobruchus maculatus in stored mung bean (Vigna radiata)

Disinfestation of stored grains using microwaves can be an alternative to chemical methods for controlling insects in grains and pulses. Mung bean of 12% moisture content (m.c.) was infested with different life stages of the cowpea weevil (Callosobruchus maculatus) and exposed to 200, 300 or 400 W microwave power levels for 14, 28 and 42 s. One hundred percent insect mortality for all life stages (egg, young larva, old larva, pupa and adult) was achieved with exposure to 400 W power level for 28 s, which caused a surface temperature of mung bean of 68.1 °C. Eggs were the most susceptible and adults were the least susceptible life stages to microwave treatments. No significant difference was observed between mortality of larvae and pupae stages and their mortality was between eggs and adults. Mung bean temperatures increased and germination decreased with increased power level or exposure time.

Detection of infestation by Callosobruchus maculatus in mung bean using near-infrared hyperspectral imaging

Mung bean (Vigna radiata (L.) R. Wilczek) is one of the major pulse crops grown in India. Cowpea weevil (Callosobruchus maculates F.) is the major insect that causes qualitative and quantitative losses of mung bean kernels during storage. There is an increasing demand from grain buyers and consumers toward zero-tolerance to contamination by insects in grains and grain products. Uninfested mung bean kernels and kernels infested with different stages of C. maculatus were imaged using a near-infrared (NIR) hyperspectral imaging system within the wavelength region of 1000–1600 nm at 10 nm intervals. The wavelengths corresponding to the highest principal components (PC) factor loadings (1100, 1290 and 1450 nm) were considered to be significant. Six statistical features (maximum, minimum, mean, median, standard deviation, and variance) and ten histogram features from images at the significant wavelengths were extracted and given as input to non-parametric statistical classifiers. Average classification accuracies of more than 85% and 82% were obtained using statistical classifiers for identifying uninfested and infested mung bean kernels, respectively. Mung beans kernels with pupal and adult stages of infestation had higher classification accuracies than the egg and larval stages of infestation using both the classifiers.

Microwave technology for disinfestation of cereals and pulses: An overview.

Contamination of stored grain with insects, insect fragments, fungi, and mycotoxins is a major concern of the grain industry. The stored-grain insects affect the grains not only quantitatively but also qualitatively. Disinfestation of grains can be achieved by physical, chemical and thermal methods. Microwaves may be an alternate to chemical methods of killing insects in grain as their application do not leave any undesirable residues and thus might be very effective for controlling insect infestation compared to other available methods. Microwave disinfestation can provide a continuous process to allow large quantities of products to pass in a shorter period of time. Microwave disinfestation is considered safe and competitive alternative method to fumigation as it avoids environmental pollution. The aim of this review is to examine how the use of microwave treatment benefits grain producers, handlers, and processors seeking to use non-chemical methods for preventing and controlling insect infestation and fungal growth during storage.

Survey of Insects Pest Stored and Biological Control of Trogoderma Granarium Everts in Setifian Region (North-East of Algeria)

Cereal grains are the major source of food for humans and most domesticated animals. In many developing countries like Algeria, overall post-harvest losses of cereals and legums of about 10–15% are fairly common. The study was conducted in Setif high plains in the north east of Algeria. The Setif region is one of the important areas for the production of cereal crops. The objective of this work was to survey the insects pests stored in different stored products in Setifian region. Using different methods: manual samples, traps, and probes have been used to determine the presence of insects and manual inspection, sieving, cracking-floatation and Berlese funnels are used at present to detect insects in grain. We recorded seven species (6 Coleoptera: Trogoderma granarium, Tribolium castaneum, Rhyzopertha dominica, Tribolium confusum, Sitophilus granarius, Tenebrio molitor and 1 Lepidoptera: Ephestia kuehnielle). The relative abundance of the different species was discussed. Trogoderma granarium was the dominant species (82,10%) of insect pests recorded from cereals grains. So, biological control on Trogoderma granarium is described. The stored conditions for these species are also discussed.

Novel use of a micro‐computed tomography scanner to trace larvae of wood boring insects

AbstractTracing the tunnels of wood boring larvae in wood or other plant material is generally a difficult and destructive process. Here we present a novel non‐destructive method using an in vivo micro‐CT scanner to obtain tomograms of small tunnels. The tunnels were formed by larval xiphydriid woodwasps in the branches of the Tasmanian tree Anodopetalum biglandulosum (Cunoniaceae) and show that, as the larvae develop, the tunnels become progressively larger until pupation occurs just below the surface of the bark. The adult then chews its way through the remaining wood and bark before emerging. This non‐destructive method is discussed more broadly in regard to its application for tracing the tunnels of wood boring insects, for detecting insects in grain and other plant material for quarantine purposes, and for tracking the tunnelling behaviour and development of live insects in wood.

Thermal imaging to detect infestation by Cryptolestes ferrugineus inside wheat kernels

Canada's zero tolerance for live insects in grain received from farmers, and shipped to domestic and export buyers, has necessitated the development of an accurate insect detection method. An infrared thermal imaging system was developed to detect infestation by six developmental stages (four larval instars, pupae and adults) of Cryptolestes ferrugineus under the seed coat on the germ of the wheat kernels. The artificially infested wheat kernels were removed from the incubation room (30 °C), refrigerated (5 °C) for 60 s, maintained at ambient conditions for 20 s, and imaged using a thermal camera to identify each developmental stage ( n=283). The means of the highest 5% and 10% of all temperature values on the surface of the grain were significantly higher ( α=0.05) for grains having young larvae inside and lower for grains having pupae inside. Temperature distribution on the surface of the infested kernels with different stages of C. ferrugineus was highly correlated with the respiration rate of each developmental stage ( r=0.83–0.91). The overall classification accuracy for a quadratic function was 83.5% and 77.7% for infested and sound kernels, respectively, and for a linear function, it was 77.6% and 83.0% for infested and sound kernels, respectively, in pairwise discriminations. Thermal imaging has the potential to identify whether the grain is infested or not, but is less effective in identifying which developmental stage is present.

Agricultural applications of dielectric measurements

A brief historical perspective on dielectric properties of agricultural products is presented, including their use for rapid measurement of moisture content in grain and in considering potential dielectric heating applications. General principles are discussed as they relate to dielectric properties of materials and energy absorption from radio-frequency and microwave electric fields. Measurement principles and techniques for determining the dielectric properties of agricultural materials are described, and appropriate references are cited for detailed information. Dielectric properties data for some grain, insects, fruits, and vegetables are presented that relate to applications for selective heating of insects in grain and potential maturity and quality sensing in fresh fruits and vegetables. Principles are discussed for the use of microwave dielectric properties for sensing moisture content in grain, and relationships between dielectric properties of granular and powdered materials and their bulk densities are described

Detection techniques for stored-product insects in grain

Cereal grains are the major source of food for humans and most domesticated animals. In many developing countries, overall post-harvest losses of cereals and legumes of about 10–15% are fairly common. Consumption of cereals and legumes by pests such as insects during storage and microbial spoilage or contamination may make these totally inedible. On farms, manual samples, traps, and probes have been used to determine the presence of insects. Manual inspection, sieving, cracking-floatation and Berlese funnels are being used at present to detect insects in grain handling facilities. These methods are not efficient and are time consuming. Acoustic detection, carbon dioxide measurement, uric acid measurement, near-infrared spectroscopy, and soft X-ray method have the potential for use at the industry level to detect insects in grain samples as their usefulness has been demonstrated in the research laboratories. Researchers have developed image analysis programs to automatically scan X-ray images to detect insect infestations. The use of near-infrared (NIR) spectroscopy has been investigated to detect hidden insects in wheat kernels. X-ray and NIR spectroscopy methods are cost prohibitive and current NIR instrumentation requires complex operating procedures and calibrations. The advantages and limitations of these insect detection methods are evaluated and the advantages of one technique over the other are described in this paper.

X‐ray Image Analysis to Detect Infestations Caused by Insects in Grain

ABSTRACTInsect infestations in stored wheat affect the chemical characteristics and baking qualities of wheat flour, and insect‐infested flours are unacceptable in the baking industry. The efficiency of the soft X‐ray method to detect infestations caused by Cryptolestes ferrugineus (Stephens), Tribolium castaneum (Herbst), Plodia interpunctella (Hübner), Sitophilus oryzae (L.), and Rhyzopertha dominica (F.) in wheat kernels was determined in this study. Wheat kernels infested by different insects were prepared by artificial implantation of insect eggs or by introducing adult insects in wheat samples. Kernels infested by different stages of the insects were X‐rayed until the adults emerged from the kernels. A total of 57 features using histogram groups, histogram and shape moments, and textural features were extracted from the X‐ray images and a linear‐function parametric classifier was used to identify the insect‐infested kernels. The parametric classifier identified more than 84% of infestations due to C. ferrugineus and T. castaneum larvae. The infestations by C. ferrugineus pupae‐adults and P. interpunctella larvae were identified with &gt;96% accuracy. Kernels infested by different stages of S. oryzae and R. dominica larvae were identified with &gt;98% accuracy. Using the Berlese funnel method, 67, 51, and 81% of first, second, and third instars of C. ferrugineus, respectively, were extracted in 6 hr. The same infested kernels were all categorized as infested by the parametric classifier. When kernels infested by different insects were pooled together, the parametric classifier correctly identified 74% of uninfested and 94% of infested kernels by the internal and external grain feeders. The 26% false positives identified from the independent test was caused by one sample infested by T. castaneum. When that sample was removed from the training set, the false positives were reduced to 16%, and 92.7% of infested kernels by different insects were correctly identified.

Wheat in bins and discharge spouts, and grain residues on floors of empty bins in concrete grain elevators as habitats for stored-grain beetles and their natural enemies.

Wheat stored in upright concrete bins at seven grain elevators in central Kansas was sampled intermittently for insects over a 2.5-yr period by collecting samples from the upper half of the grain mass, from the discharge spout at the base of the bins, and from residue remaining in empty bins before the 2000 wheat harvest. Samples were taken from the grain mass with a power vacuum sampler (PV) and from the discharge spouts (DS) by dropping grain onto the reclaim belt beneath the bins. The density and species distribution in the residue samples were compared with those found in the DS samples and samples from the grain mass (PV). Cryptolestes spp. dominated the insect populations in all types of samples, constituting >40% of all insects in the PV samples in three of five time periods and >60% of all insects in DS samples in four of the five time periods. Cryptolestes spp. was an early colonizer, being found in the grain mass shortly after new grain was added. Rhyzopertha dominica appeared to be slower to colonize grain and grain residue, but sometimes developed large populations (i.e., 2.4 +/- 0.7 adults/kg between July and December 2000). Sitophilus spp. weevils often were present in grain masses, were often abundant in grain in the discharge spouts (i.e., 11.1 +/- 2.9 adults/kg between July and December 2000), and were abundant in grain residue in empty bins in May/June 2000 (5.3 +/- 0.7 adults/kg). Differences in density and species distribution of insects in grain in the upper part of the grain mass and those in the discharge spouts indicated that the populations were not closely related. Grain in discharge spouts usually was densely infested, and parasitic wasps, natural enemies of several of the beetles, were found when the density of the pest insects was greater than approximately 10/kg. The population of natural enemies appeared to increase when the density of pest insects increased after a lag of about one month, and decreased when the population of pest insects decreased. Grain in discharge spouts appeared to provide an incubation chamber for pest insects, and removing this grain periodically should reduce the resident populations. Residue in empty bins often was densely infested compared with samples from the grain masses. Cleaning the empty bins before refilling with newly-harvested wheat resulted in a significantly-reduced density of pest insects in discharge spouts later, and the effect lasted at least 12 wk after filling.

Remote-sensing, telemetric and computer-based technologies for investigating insect movement: a survey of existing and potential techniques

This paper provides an overview of the recent literature on electronic, remote-sensing and computer-based techniques for observing and monitoring insect movement in the field and in the laboratory. Topics (such as entomological radar) which are covered in detail elsewhere in this Special Issue are deliberately omitted. Techniques which have been used, or which have potential for use, in monitoring insects in the field, include optical and opto-electronic devices, videography, thermal imaging, radio frequency identification (RFID), radio-telemetry, X-ray radiography and computed tomography, sodar and sonar. The discussion includes optical sensors and insect trapping, instrumented beehives, acoustic detection of insects in grain, fruit and soil, and various laboratory methods for studying insect movement, such as actographs, treadmills, automatic flight mills, and the video recording and analysis of movement in wind tunnels and in indoor arenas. Airborne and satellite imaging of insect habitats is mentioned, but only in the context of the use of these techniques to deduce changes in population distribution in some migratory species. Finally, some of the main constraints to progress in the sensing of insect movement, and areas where rapid advances seem possible, are discussed.