利用电子鼻区分羊奶中不同浓度抗生素

采用电子鼻方法,利用主成分分析(PCA)和线性判别分析(LDA)进行数据采集,对添加硫酸土霉素、盐酸链霉素、硫酸庆大霉素的羊奶进行快速检测与识别.结果表明,PCA只能区分盐酸链霉素样品,LDA的区分效果明显优于PCA.电子鼻能够有效的区分添加以上3种不同浓度抗生素的羊奶.     

小麦受蛀食性害虫侵害后其粉质特性动态变化

为探讨玉米象、米象和谷蠹3种蛀食性害虫不同感染程度对小麦出粉率和粉质特性的影响及其变化规律。选用河南产储藏2 a的商用小麦为材料,按不同虫种分组,设定不同的虫口密度,检测不同感染时间小麦的出粉率和制粉后面团的稳定时间和粉质指数,并与虫口密度和感染时间之间作相关性分析。结果表明:玉米象,米象和谷蠹侵害后样品出粉率与虫口密度和感染时间均呈极显著负相关;且随虫口密度增加和感染时间延长,出粉率总体呈下降趋势,样品的稳定时间和粉质指数呈下降趋势。     

Feasibility of detection of infested rice using an electronic nose

Electronic nose (E-nose) technology has a potential to be used for detecting insects in stored rice. It may provide a new method to detect the insect activity by providing smell prints for the headspace volatiles in rice mass. The objective of this research was to study the feasibility of using E-nose to detect infested rice during the storage process. An E-nose instrument (Cyranose 320) consisting of 32 sensors for detecting the volatile components produced in infested rice was used for this study. Storage rice with moisture content of 11.8 ± 0.3% was used for conducting the tests. The rice samples were infested with different numbers of adult insects, including rice weevil (Sitophilus oryzae), lesser grain borer (Rhyzopertha dominica) and red flour beetle (Tribolium castaneum), in containers containing 1 kg of rice. The samples were stored at temperatures of 15 °C and 30 °C for four weeks. Air samples in the containers were taken for measurements every five days. The data were analyzed using the principal component analysis (PCA) method. The results revealed that the E-nose was not able to distinguish the clean rice and infested rice with lesser grain borer. While the E-nose had high response ability to the volatile components produced by rice weevil and red flour beetle after four weeks of storage. Consequently, the E-nose could discriminate the clean and infested rice with above insects after four weeks of storage at temperature of 30 °C. Additionally, under the aforementioned conditions, the E-nose could not distinguish the clean and infested rice during the first, second and third weeks of storage. The classification accuracy of E-nose for clean and infested rice was low at storage temperature of 15 °C for the tested insets. It can be concluded that the E-nose has the capability to detect infested rice after four weeks of storage.     

Physical and chemical properties of flour products affect the development of Tribolium castaneum

The rust-red flour beetle, Tribolium castaneum, is a polyphagous pest of cereal grains and many other stored products. The presence of this pest causes contamination and economic losses by reducing the quality and quantity of commodities in storage. This research was aimed to study the development of T. castaneum on different flour products and investigate the factors affecting the survivorship and development time of T. castaneum. We used 16 flour products differentiated by production process (commercial vs. non-commercial) and commodity types. We conducted experiments on the development of T. castaneum in the laboratory by placing 15 mating pairs of T. castaneum into a treatment jar and allowing them to feed on different flour products. The results showed that T. castaneum adults laid eggs in all flour products. The larvae could live and survive, although the population density was found to be significantly lower in the commercial products. The pupae and adult (F₁ progeny) were only found in all non-commercial products and three commercial products. In addition, the total development time of T. castaneum was shown to be significantly faster in commercial products and did not differ among commodity types. We found that particle size variation and protein content of flour products affected the survivorship and development time of T. castaneum. In conclusion, understanding the particle size and chemical composition of flour products is a pivotal step in developing a pest management strategy for T. castaneum.     

基于图像处理的储粮低密度虫害监测系统的设计与验证

为解决高害虫密度储粮处理成本昂贵和现有监测系统实时性和移动性不足等问题,采用Web技术,结合自主设计的粮虫诱捕器,建立了储粮低密度虫害实时监测系统。树莓派控制诱捕器采集害虫图像并进行图像处理得到图像中害虫的数量,再将数据传至云端服务器,用户通过Web客户端获取历史以及实时的害虫图像和害虫数量。在实验室用该系统监测了赤拟谷盗密度为0.5、1、2、3、4、5头/kg的稻谷,通过系统捕获第一只害虫的时间来评价其灵敏度,24 h内对害虫的捕捉率验证系统用于低密度虫害监测的可行性,并以人工直接计数结果为参考计算了系统计数的准确率,结果表明：系统灵敏度高,在低密度害虫条件下对害虫的捕捉率高于61.98%且诱捕器捕捉的害虫数与稻谷中的害虫总数存在显著线性关系,系统计数准确率为90.26%。因此,该系统可用于低密度虫害的实时监测。     

Corcyra cephalonica: A serious pest of stored products or a factitious host of biocontrol agents?

The rice moth, Corcyra cephalonica, is an economically significant stored product pest (SPP). It is widely distributed and causes severe damage to grains and products in storage under varying environmental conditions. However, compared to other Lepidopterous pests like Ephestia kuehniella and Plodia interpunctella, the pest potential of C. cephalonica is often underestimated. While farmers typically rely on chemical control to manage insect pests, recent studies suggest that non-chemical control methods can be used successfully as alternatives for their management. Therefore, in-depth knowledge of rice moth biology and its current pest status is essential for developing integrated management systems. Besides being a pest under natural conditions, Corcyra cephalonica also serves as a factitious host of natural enemies. It has a short life cycle and can be easily mass-reared on a variety of feeding media, making it a preferable alternative host with year-round availability, which can help in the cost-effective production of beneficial insects such as biocontrol agents and, as a result, in better management of other harmful agricultural insect pests. In the second part of this review, we examine the suitability of the rice moth as a laboratory host and conclude by determining whether Corcyra is best addressed as a serious pest of stored products or as a factitious host of biocontrol agents.     

Comparison in vitro and in vivo efficiencies of three attractant products against webbing clothes moth Tineola bisselliella (Hummel) (Lepidoptera: Tineidae)

Moth pests belonging to the Tineidae attack clothing and other animal products, during the processing or manufacturing stage as well as in storage. The insects cause considerable loss or damage to the commodity in terms of quantity, quality and market value. Insect control measures in these products differ depending on the conditions of storage or processing and the relevant cost factor. Fumigation products play an important role in insect pest elimination for the majority of stored animal products. The need of detailed studies on alternatives methods involving the exploitation of insect traps for pest management has been highlighted. In the past years test systems for the evaluation of attractant products have been developed and further refined in our laboratory. In this study, a standardized test system for the evaluation in vitro of commercial traps for Tineola bisselliella, the webbing clothes moth (WCM), was validated. Three sticky traps baited with female-produced sex pheromone were tested in the laboratory and in vivo at the “Mobilier National”, a repository of valuable artefacts. In both types of experiment the number of individuals captured was closely linked with the kinetic release of volatile organic compounds (VOCs) from the sticky traps. The test system allowed clear discrimination of the products according their efficiency in a reliable manner but none of the traps tested were effective enough to reduce the damage potential of the pest.In the light of these results, the characteristics needed for an effective trap in warehouse conditions is discussed.     

Potential for widespread application of biological control of stored-product pests—the European perspective

“Biological control of stored product pests has substantial potential in Europe”. This is essentially the conclusion of the activities of a European working group funded by the COST system, an intergovernmental networking system. Working group 4 of COST action 842 (2000-2005) focussed on biological control of stored-product pests and has considered a number of existing and potential fields for application of biological control. Three situations were identified where biological control would be a valuable component of integrated pest management: (1) Empty room treatment against stored-product mites, beetles and moths; (2) Preventative treatment of bulk commodities against weevils (Sitophilus spp.) and storage mites; (3) Preventative application of egg-parasitoids against moths in packaged products. Development of methods for biological control and of mass production of natural enemies for these situations will contribute to ensuring that stored food products are protected from insect and mite pests using techniques that are safe for consumers, workers and the environment.     

Insect infestation in stored animal products

Published information about insect pest infestation in dried or preserved animal products comprising food items like dried fish and milk powder and non-food materials such as hides and skins, silkworm cocoons, wool and woollen materials, honeybee combs, fishmeal and museum collections/exhibits and control measures has been summarised in this review. Beetle and moth pests belonging to the Dermestidae and Tineidae, respectively, attack the animal products, during the processing or manufacturing stage as well as in storage. The insects cause considerable loss or damage to the commodity in terms of quantity, quality and market value. Silk, apiculture and leather industries are particularly affected by the pests. Data on the extent of losses due to insect pests in various preserved animal products are lacking. Insect control measures in these products differ depending on the conditions of storage or processing and the relevant cost factor. Phosphine fumigation plays an important role in insect pest elimination in the majority of the stored animal products. For disinfesting museum objects and honeycombs, freezing (for artefacts) or modified atmosphere application of CO₂ or nitrogen is preferred. Commodities such as woollen materials, dried fish, fishmeal and feeds containing animal products and their storage premises are sometimes treated with residual contact insecticides such as deltamethrin, pirimiphos-methyl, permethrin and synergised pyrethrins. For protecting animal products, especially dried fish, different countries have examined alternatives including plant extracts and vegetable oils.The need for detailed studies on (i) fumigation with alternatives to methyl bromide such as sulphuryl fluoride, ethyl formate and ozone, (ii) disinfestation methods involving the active principles from natural products and (iii) exploitation of insect traps for pest management in museums has been highlighted.     

Toxicity and repellency of dimethoate,pirimiphos-methyl and deltamethrin against Tribolium castaneum (Herbst) using different exposure methods

Tribolium castaneum, the red flour beetle, is one of the major pests of cereal grains and their products. Infestation of raw food products by T. castaneum can be tackled by use of insecticides which offer a rapid and effective control method for different insect pests. In the present study, toxicity and repellency of three widely used insecticides was assessed on adult red flour beetles to investigate how a flour substrate affects the results of the standard laboratory toxicity and repellency test methods. The red flour beetles were exposed to the organophosphates dimethoate and pirimiphos-methyl and the pyrethroid deltamethrin, following the original and two modified residual film methods (toxicity assessment) and by the area preference method to assess repellency. Since the conditions of exposure (glass and filter paper surfaces as exposure substrates) in the original methods are quite different compared to the exposure carried out in stored-product protection, methods were modified to include flour as an exposure substrate. The results showed that according to the LC₅₀ values, toxicity of the investigated insecticides could be arranged in the following order: pirimiphos-methyl > dimethoate > deltamethrin. Also, both mortality and repellency were dependent on the exposure methods, i.e. presence and treatment of flour substrate. Mortality was significantly reduced in comparison to the original method. Repellency was recorded when beetles were exposed to deltamethrin using flour as a substrate, whereas using the filter paper surface (original method) repellency was not obtained. The results of the present study clearly indicate that there is an influence of substrate on the susceptibility of T. castaneum to insecticides and that the efficacy of different insecticides is affected by exposure substrate.     

Influence of different diets on some biological parameters of the Mediterranean flour moth,Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)

The Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), is one of the most important pests of stored products, especially damaging cereals. Besides pest status, its eggs and larvae are commonly used for mass rearing of many natural enemies. Different diets are suggested for the production of E. kueniella, but the influence of diet supplements, such as yeast and glycerine on the performance of E. kuehniella diets are not clearly understood. In the present study, we investigated the effects of several diet ingredients on some major biological parameters of E. kuehniella. Ten diets based on different combinations of wheat flour, cornmeal, wheat bran, glycerine and yeast were tested in the experiments. Twenty eggs of E. kuehniella were added into 5 g of each diet within separate plastic cylindrical containers (5 cm height × 3 cm diameter) and incubated in climate rooms at 25 ± 1 °C and 60 ± 10 Relative Humidity (R.H) on a 14 h light: 10 h dark photoperiod. Pupal weight, developmental period, emergence ratio, fecundity and fertility were determined. The diet containing wheat flour, wheat bran, glycerine and yeast in a percentage of 53.33, 26.67, 15 and 5%, respectively, resulted in shorter development time and higher fertility, and could be used as an alternative to the standard diets currently used in insectaries.     

基于深度学习的储粮害虫检测研究进展

储粮害虫检测与预警对保障粮食储存安全具有重要意义。目标检测是计算机视觉研究领域的核心问题之一，近年来深度学习在目标检测领域的应用研究取得了重大突破，储粮害虫目标检测也取得了较大进展，并逐步在粮库智能化建设中推广与应用。本文从储粮害虫数据集的获取与预处理、储粮害虫目标检测算法研究、储粮害虫检测结果应用等三个方面，总结了近年来基于深度学习的储粮害虫检测研究进展，通过对比研究，提出了该研究领域存在的问题及未来研究方向。     

Electronic nose and GC–MS analysis of volatile compounds in Tuber magnatum Pico: Evaluation of different storage conditions

The characteristic aromatic composition of white truffles (Tuber magnatum Pico) determines its culinary and commercial value. However modifications of truffle organoleptic proprieties occur during preservation. A study of headspace of white truffles by using Electronic nose (E-nose), gas chromatography–mass spectrometry (GC–MS) and sensory analyses was performed. Truffles were stored at different conditions for 7 days: +4 and +8 °C wrapped in blotting paper or covered by rice or none of the above. Headspace E-nose measurements and sensory analyses were performed each day. Statistical multivariate analysis of the data showed the capability of E-nose to predict sensorial analysis scores and to monitor aroma profile changes during storage. Truffle’s volatile molecules were also extracted by headspace solid phase microextraction technique and separated and identified by GC–MS. Partial Components Analysis of data was performed. E-nose and GC–MS results were in agreement and showed that truffle storage in paper at +8 °C seemed to be the best storage condition.     

粮仓中小麦的声学检测方法研究进展

小麦的贮藏品质关系到粮食的数量安全和质量安全,对小麦品质的声学检测技术的应用研究进行了综述,首先对农产品的声学特性的概念进行了简述,然后从以下几个方面综述了声学检测技术的研究进展:通过采集并分析小麦粉调制面团过程中的声学特性测定不同小麦粉的品质;或采集并分析小麦籽粒在特定装置中的声音信号来达到测定小麦品质的目的;或通过声学方法测定粮食的密度或采集分析粮仓中害虫的声信号来监测粮仓中小麦的贮藏状态。     

Detection of age and insect damage incurred by wheat, with an electronic nose

Wheats of five storage ages and with 15 degrees of insect damage were evaluated and classified by the static-headspace sampling method using an electronic nose (E-nose). A commercial E-nose (PEN2) comprising 10 metal-oxide semiconductor (MOS) sensors was used to generate a typical chemical fingerprint of the volatile compounds present in the samples. Principal-component analysis (PCA) and linear-discriminant analysis (LDA) were applied to the generated patterns to achieve classification into the five groups of different storage-age wheats and the 15 groups of different degrees of insect-damaged wheat. The results obtained indicated that the E-nose could discriminate successfully among wheats of different age and with different degrees of insect damage.     

Geostatistical analysis of adult Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) in wheat stored at constant temperatures

Insect monitoring and sampling programmes are used in the stored grains industry for the detection and estimation of insect pests. At the low pest densities dictated by economic and commercial requirements, the accuracy of both detection and abundance estimates can be influenced by variations in the spatial structure of pest populations over short distances. Geostatistical analysis of Rhyzopertha dominica populations in 2-dimensions showed that, in both the horizontal and vertical directions and at all temperatures examined, insect numbers were positively correlated over short (0–5 cm) distances, and negatively correlated over longer (≥10 cm) distances. Analysis in 3 dimensions showed a similar pattern, with positive correlations over short distances and negative correlations at longer distances. At 35 °C, insects were located significantly further from the grain surface than at 25 and 30 °C. Dispersion metrics showed statistically significant aggregation in all cases. This is the first research using small sample units, high sampling intensities, and a range of temperatures, to show spatial structuring of R. dominica populations over short distances. This research will have significant implications for sampling in the stored grains industry.     

The efficacy of sieving, filth flotation and Tullgren heat extraction for detecting various developmental stages of Tribolium castaneum and Ephestia kuehniella in samples of wheat grain, flour and semolina

A prerequisite for effective pest risk management in food is the unbiased interpretation of results obtained by various detection methods. In this study we compared the sensitivity of filth flotation tests, sieving and heat extraction in Tullgren–Berlese funnels for detecting insect contaminants. Samples of wheat grain, flour and semolina were contaminated with eggs, juveniles and adults of Tribolium castaneum, and eggs or larvae of Ephestia kuehniella. Calibration methods were applied for every detection method, and total and sample recoveries and detection limits were calculated for each method, food substrate and contaminant type. The tested contaminants were not detected on a qualitative level by any single technique, instead a combination of techniques was necessary for detection. Sieving was the method with the highest total recoveries, ranging from 90 to 100%. Filth flotation was a uniquely effective for egg detection, with total recoveries ranging from 65 to 95%. The extraction of adults and larvae of both species in Tullgren–Berlese funnels failed in semolina and flour, and was of very limited success in grain. The detection limits for sieving were from 1 to 16 contaminants/kg commodity. The detection limits for filth flotation were from 224 to 508 eggs, and 58 to 507 adults or larvae/kg commodity. The sample recoveries were usually influenced by sample size, species, stadium and their interactions, and indicated how to optimize method protocols. The calibration of methods provided estimates of contaminant densities different from those obtained without calibration. Our work revealed that some currently used methods are not sensitive enough to detect all stages of insect pests, or in some cases, low levels of pest infestation. This lack of sensitivity potentially enables the infested cereal food product to continue down the food processing chain even after laboratory inspection.     

Rapid molecular diagnosis of the stored-product psocid Liposcelis corrodens (Psocodea: Liposcelididae): Species-specific PCR primers of 16S rDNA and COI

Psocids of the genus Liposcelis (Psocodea: Liposcelididae) are common economically important pests in storage facilities all over the world. Stored-product psocids have small bodies and are difficult to identify to species using external morphological characteristics. Quick and accurate identification methods for psocid species serve as the foundation for pest management, quality control of food products, and settling of legal disputes from quarantine inspection. Liposcelis corrodens (Heymons) is a common stored-product pest distributed in European, American, and Oceania countries but has not been reported as established in China. To facilitate pest management and quarantine inspection to prevent importation and establishment of L. corrodens in China, methods for accurate and rapid identification need to be developed. Based on the sequencing and alignment of mitochondrial 16S rDNA and COI gene of 10 common Liposcelis species, two pairs of species-specific primers were designed according to the variation regions among species. PCR cycling parameters were developed for the amplification of specific fragments of 16S rDNA and COI genes of L. corrodens with lengths of 261 bp and 243 bp, respectively. Both primer sets have high sensitivity in target species detection and successfully identified psocids found by quarantine personnel in China as L. corrodens. The diagnostic method we have developed is reliable for identification of L. corrodens for quarantine and pest management purposes.     

Patch exploitation by Tribolium castaneum: movement patterns, distribution, and oviposition

Stored-product insects often live in an environment of spatially separated food patches that vary considerably in size, quality, and persistence. The movement of individuals among patches of food influences the probability that stored products will become infested and pest populations will persist within storage facilities, thus affecting many aspects of pest management. We examined how a major stored-product pest, the red flour beetle, Tribolium castaneum (Herbst), exploits patches of food. Individuals are often inactive, periods of inactivity are often outside of food patches, males are more likely to be inactive outside of flour patches than females, and there is considerable variation among individuals in the time spent outside of patches. Beetles outside of food patches tend to be observed near edges due to a tendency to be inactive at edges, to move along edges, and to move more slowly when moving along edges. This tendency to move along edges makes beetles more likely to infest flour patches near the edges than patches further from the edge. A better understanding of the influence of landscape on pest behavior, spatial distribution, and population dynamics is needed to develop effective stored-product pest IPM programs.     

The repellent effect of plants and their active substances against the beetle storage pests

This review compares research techniques, plant species and forms of their application in worldwide studies on the repellent activity of plant material against storage pests, such as Sitophilus oryzae, Sitophilus granarius, Tribolium castaneum, Rhyzopertha dominica and Oryzaephilus surinamensis. Over 300 plant extracts, essential oils and powders were tested against these five insect species with various methods. The intensity of repellency of the examined plant products against each considered pest species was presented. Evaluation of the repellency potential of particular plant extracts, oils and powders showed that insect repulsion increased with their concentration. Duration of exposure was also an important factor affecting repellent activity.