遗传算法在储粮害虫特征选择中的应用

介绍了遗传算法在储粮害虫特征选择中的应用,对遗传算法的思想、实现步骤、参数选择分析及具体实现等进行了重点阐述.该算法有效地将粮虫的17维原始形态学特征降为10维,提高了分类的效率.在粮库现场系统能以86.5%的正确率将12种常见的粮虫区别开来.     

Stored product pests as models for trapping entomopathogenic fungi from olive tree orchards in Western Greece

We used the following new range of insect species as baits for trapping entomopathogenic fungi: Plodia interpunctella, Rhyzopertha dominica, Tribolium confusum, Trogoderma granarium, Ephestia kuehniella and Tenebrio molitor, which constitute important stored product pests. Soil samples were collected from random points in olive tree orchards in Western Greece using Geographical Information Systems (GIS) and sample point coordinates were located with the Global Positioning System (GPS). Entomopathogenic fungi were identified by sequencing the ITS4 and ITS5 regions of the genomic DNA. Among the isolated fungal species, Beauveria bassiana and Metarhizium anisopliae showed the highest frequency, at 33.8% and 25.4% respectively. They also caused the most infestations of R. dominica and T. confusum whose mortality reached 33–97% and 87–100% respectively. We have also isolated various other fungal taxa such as Aspergillus alliaceus, Aspergillus insuetus, Aspergillus sp., Apophysomyces ossiformis, Chaetomium acropullum, Chaetomium sp., Chaetomium globosum, Chaetomium truncatulum, Trichoderma gamsii and Purpureocillium lilacinum. Our study confirms that T. confusum and R. dominica may be further utilized as baits for entomopathogenic fungi.     

Life cycle of Ulomoides dermestoides (Fairmaire, 1893) (Coleoptera: Tenebrionidae) under laboratory conditions

Ulomoides dermestoides (Fairmaire, 1983) is a beetle that feeds on stored grains such as peanuts, oats and corn. It is widely used in traditional medicine for the treatment of various respiratory diseases such as bronchial asthma. The aim of this study was to assess the life cycle of U. dermestoides using the peanut (Arachis hypogaea L) as food, under laboratory conditions. Twenty-five adult pairs were put together in glass vials for mating, employing broken peanut kernels as substrate. After the adults mated, 30 eggs were selected and monitored until the adult stage. The length of time each life stage took was recorded, including adult fecundity. The life cycle of U. dermestoides from egg to adult stage lasts for about 67.6 ± 0.2 days and consists of four stages: egg, larva, pupa and adult. Adult females laid eggs during 135 days after their emergence, and the average fecundity was 261 eggs per female. The duration of the larval stage was 60 ± 0.10 days and it passed through seven instars, and finally the semi-mobile pupae stage lasted 3–5 days.     

基于扩展Shearlet变换、Krawtchouk矩和SVM的储粮害虫分类

为了进一步提高储粮害虫的识别精度,以便更有效地防治储粮害虫,提出了一种基于纹理和形状综合特征及全局混沌蜂群优化支持向量机(SVM)的储粮害虫分类方法。首先对储粮害虫图像进行扩展Shearlet变换,利用变换系数得到能量分布均值,加权后的能量分布均值构成纹理特征向量,用Krwtchouk矩不变量描述储粮害虫的形状特征;然后将纹理特征向量和形状特征向量分别归一化,两者结合构成储粮害虫的综合特征向量;最后用全局混沌蜂群算法优化SVM的核参数与惩罚因子,并应用参数优化的SVM进行分类。结果表明:与基于Gabor小波和支持向量机方法、基于Krawtchouk不变矩和支持向量机方法相比,本方法提取的储粮害虫特征信息更加完整,识别率更高。     

Damage characteristics produced by insect pests in packaging film

This study investigated the morphology of damage produced by three important stored-product pest species, Rhyzopertha dominica, Sitophilus oryzae and Lasioderma serricorne, in food packaging film. Three different types of plastic film (polypropylene 25 μm, polyethylene 50 μm and polyester 12 μm), a multilayer film (paper, polyethylene 15 μm, aluminium 7 μm and polyethylene 30 μm), and cigarette paper were compared. Damage was examined using a stereomicroscope at 20× to 40× magnification and a scanning electron microscope. All three species produced several different types of damage on the surface of the side where insects perforated the plastic film. This damage consisted of scratches and tears on the contours of the holes. In comparison, damage around the holes was much less pronounced on the exit side. In polypropylene, holes produced by adults of S. oryzae and R. dominica and larvae of L. serricorne could be identified by the large damaged area, the small scratches produced and the deep scars left around the holes. Scratches on polyethylene produced by R. dominica were deeper and more marked than damage produced by the other two species. Holes covered with filaments were characteristic of the damage produced by S. oryzae. Conversely, in polyester it was difficult to differentiate between holes produced by S. oryzae and R. dominica: the easiest way to distinguish between damage by these species was on the basis of hole size. Larvae of L. serricorne did not produce holes in polyester. In cigarette paper the presence of filaments differentiated the holes produced by S. oryzae from those produced by the other two species. All three species were able to produce holes in multilayer film with a 7 μm thickness of aluminium foil. In this film, the morphology of damage was similar to that produced in paper because the first layer of this film was made of paper. The diameter of the perforations, including the damaged area around the holes, ranged from 0.58 to 1.86 mm for all three species.     

析影响熏蒸杀虫效果的原因及解决的对策

储粮害虫对粮食安全保管与储存造成很大损失,通过分析影响熏蒸杀虫效果的原因及解决的对策,以切实减少或避免储粮害虫造成的损失,提高储粮害虫防治水平。     

黄色花蝽模拟仓捕食储粮害虫及应用效果评价

为了明确黄色花蝽在模拟仓内对害虫的控制效果及黄色花蝽在高温高湿地区实仓条件下对储藏害虫的控制效果。通过控制模拟仓控制温度为(28±1)℃、湿度(50±10)%条件下接入黄色花蝽和在实仓投放一定数量的黄色花蝽。结果表明,不同数量黄色花蝽在模拟仓内下,3个月后对4种储藏害虫控害效果均达到70%以上,益害比对储藏害虫并无显著影响,黄色花蝽对4种害虫的控害效果为锯谷盗嗜卷书虱锈赤扁谷盗赤拟谷盗。在高温高湿地区,投放黄色花蝽对实仓内害虫的控制效果显著,能够有效控制害虫爆发。仓储害虫生物防治具有低成本、无污染等优点,可为研究一种新型储藏害虫防治提供有效方法。     

粮虫视觉检测技术的现状与展望

针对我国粮情测控发展所面临的技术需求,本文以分析粮虫视觉检测技术研究现状及其存在的问题为基础,结合粮储要求和粮仓实际情况,立足研究粮虫实时检测问题。并以此为目标围绕粮虫图像特征的多样性获取,欠观测条件下粮虫快速分类、多约束条件下粮虫的虫口密度估计等进行研究并做出展望,力求探讨粮虫视觉检测技术的创新点与突破点。为粮虫的实时检测的关键技术提供支撑从而达到提高粮虫防治水平的根本目的,这将对完善粮虫实时检测技术和实现粮食安全管理具有重要意义。     

10％溴氰虫酰胺可分散油悬浮剂对蔬菜害虫的防治效果、使用技术和推广前景

2009～2012年,对10％溴氰虫酰胺可分散油悬浮剂进行大田示范试验,结果表明该药剂对小菜蛾、豆荚螟、烟粉虱、蚜虫、黄曲条跳甲和美洲斑潜蝇等蔬菜害虫有优良的防治效果.当该药剂用量为有效成分15～27g/hm2时,其对小菜蛾、美洲斑潜蝇幼虫（若虫）药后7～10d的校正防效可达95％以上,持效期可达20～30 d.当用量为有效成分21～27 g/hm2时,药后9d对豇豆豆荚螟的荚校正防效80％以上,虫校正防效90％以上.当用量为有效成分30～42 g/hm2,对黄曲条跳甲成虫、幼虫无明显的防效,但药后10 d作物保护效果可达90％以上,并对黄曲条跳甲有良好的驱避和拒食作用.用量为有效成分40～60 g/hm2时对烟粉虱若虫、成虫药后10 d的校正防效达90％以上,持效期可达20 d以上,对烟粉虱若虫的防效优于成虫;对蚜虫药后10d的校正防效为99％以上,持效期20 d以上.同时对该药剂的使用技术和推广前景作了客观的评价.     

Synthesis Method for Thiosulfonate and Report of Its Insecticidal Activity in Anagasta kuehniella (Lepidoptera: Pyralidae)

Insect pests have caused economic losses valued at billions of dollars in agricultural production. Anagasta kuehniella (Zeller), the Mediterranean flour moth, is of major economic importance as a flour and grain feeder and is often a severe pest in flourmills. This study provides a suitable route for the direct preparation of thiosulfonates 2 and 3 from thiols, under mild conditions, with good yields; these thiosulfonates were tested for their regulatory effect on insect growth. The chronic ingestion of thiosulfonates resulted in a significant reduction in larval survival and weight. In addition, the tryptic activity of larvae was sensitive to these thiosulfonates. Results suggest that thiosulfonates 2 and 3 have a potential antimetabolic effect when ingested by A. kuehniella. The use of AgNO₃/BF₃·OEt₂ and Al(H₂PO₄)₃/HNO₃ provides a suitable route for the direct preparation of thiosulfonates from thiols under mild conditions with good yields. These thiosulfonates were toxic for A. kuehniella larvae, suggesting their potential as biotechnological tools.