Comparative biology of Mallada desjardinsi (navas) and Chrysoperla congrua (walker) (Neuroptera: Chrysopidae), predators of Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) and aphis gossypii (glover) (Homoptera: Aphididae) on cotton in eastern Tanzania

The developmental biology of Mallada desjardinsi (Navas) and Chrysoperla congrua (Walker) on the American bollworm, Helicoverpa armigera and the cotton aphid, Aphis gossypii was studied in the laboratory at 28–32°C. Total larva! periods of M. desjardinsi and C. congrua on H. armigera eggs were 14.4 and 14.8 days respectively. However, when reared on A. gossypii larval periods of M. desjardinsi and C. congrua were 14.9 and 13.5 days respectively. When reared on H. armigera 52.9% and 25% respectively of third instars of M. desjardinsis and C. congrua sp. died before pupation. However, when reared on A. gossypii 82.6% and 46.9% respectively of third instars of M. desjardinsi and C. congrua died before pupation. Thus, H. armigera eggs and A. gossypii nymphs were both adequate but not optimal diets for chrysopid larval development. The number of prey consumed by M. desjardinsi and C. congrua increased with instar. Total larval consumption of H. armigera by M. desjardinsi and C. congrua was determined to be 135.5 and 169.8 eggs respectively. However, total larval consumption of A. gossypii by M. desjardinsi and C. congrua was found to be 189.0 and 171.8 nymphs respectively. Because of its longer larval period, and higher consumption of A. gossypii, M. desjardinsi would be better suited for use against A. gossypii than C. congrua. In contrast, C. congrua whose consumption of H. armigera was higher than that of M. desjardinsi although their larval periods were similar, would appear promising for control of H. armigera.     

Base-catalysed hydrolysis of (E)- and (Z)-mevinphos

The rates at which (E)- and (Z)-mevinphos are hydrolysed in aqueous solutions in the pH range 8.7–11.5, and in the temperature range 30–50°C, have been measured. The overall activation parameters have been calculated, and equations to allow calculation of the rates in any basic conditions are given. The complicated routes by which (E)- and (Z)-mevinphos are hydrolysed to simple molecules have been deduced. The rates for the individual steps in each route have been either measured experimentally, or have been calculated through analogue simulation of all the reactions, by matching the calculated to the observed ultraviolet spectral changes during hydrolysis. It is proposed that (Z)-2-carboxyl-1-methylvinyl dimethyl phosphate is not observed as a hydrolysis product of (Z)-mevinphos because it decomposes by an extremely fast intramolecular reaction. The reasons for the greater lability of (E)-mevinphos are also discussed.     

胡瓜新小绥螨对B型烟粉虱的控制能力

为明确胡瓜新小绥螨Neoseiulus cucumeris Oudermans对烟粉虱Bemisia tabaci Gennadius的控害潜能,在（26±1）℃、相对湿度65%±5%、光周期16L：8D条件下,研究了各螨态胡瓜新小绥螨对不同发育阶段烟粉虱的捕食作用。结果表明,胡瓜新小绥螨幼螨期较短,不取食烟粉虱,其他不同螨态的胡瓜新小绥螨可捕食除4龄若虫和成虫以外的其他各虫态的烟粉虱,捕食功能反应符合HollingⅡ型;胡瓜新小绥螨雌成螨对烟粉虱卵的日捕食量最大（8.5粒/雌）,对烟粉虱3龄若虫的日捕食量最小（2.1头/雌）;雌成螨对烟粉虱卵具有较高的瞬间攻击率（0.038）和寻找效应（0.025）。研究表明,胡瓜新小绥螨对烟粉虱卵及低龄若虫的捕食能力较强,是烟粉虱发生初期的有效天敌。     

检疫性害虫南亚果实蝇生物学及控制技术

南亚果实蝇[Bactrocera(Zeugodacus)tau(Walker)]是黄瓜、南瓜、丝瓜、冬瓜和苦瓜等多种果蔬作物上的一种重要检疫性害虫。近年来在我国多个省市发生危害,发生程度呈加重和扩大蔓延的趋势,对瓜果作物造成了严重的经济损失。本文概述了南亚果实蝇的发生危害规律、生物学特性,提出了加强植物检疫、农业防治、诱集灭虫、雄性不育技术和保护天敌等防治措施。     

首次发现我国柑橘小实蝇沃尔巴克氏体的共生

沃尔巴氏体(Wolbachia)是广泛分布于节肢动物体内的一类共生细菌,它们可以调控宿主的生殖活动.本研究利用沃尔巴克氏体wsp基因的一对通用引物(81F,691R),成功地从我国柑橘小实蝇雄成虫的总DNA中扩增到一段400bp左右的wsp基因片段,通过wsp基因的特异性扩增首次证实了沃尔巴克氏体在我国柑橘小实蝇雄虫体内的共生.     

Tuta absoluta (Meyrick) (Lepidoptera,Gelechiidae) in the Republic of Srpska (Bosnia and Herzegovina)

Pheromone traps were placed in the market place in Banja Luka, and in greenhouses and open field tomato crops, on 13 September 2010 to determine the presence of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) in Banja Luka region. Based on examination of traps, the presence of T. absoluta was confirmed for the first time in the Republic of Srpska. Only mines of Liriomyza species were found by examining leaves under a stereomicroscope. In 2011, pheromone traps were placed in greenhouses at several locations (Banja Luka, Prijedor, Novi Grad, Kozarska Dubica, Ljubinje and Trebinje) at the beginning of June, and in open fields in Bijeljina and Trebinje at the beginning of September. Examination of the traps was carried out at intervals of 15 days. A sample of 100 leaves, taken from 20 randomly selected plants, was examined in order to evaluate the intensity of the attack. The first adults were caught in greenhouses in Ljubinje and Trebinje on 18 June 2011; in open field crops in Bijeljina on 9 September 2011 and in Banja Luka on 5 October 2011. Adults were not captured in Prijedor, Novi Grad or Kozarska Dubica, and no mined leaves were observed. The intensity of attack was evaluated on the basis of active infestation (percentage of leaves with active mines compared with all mined leaves). The strongest intensity of active infestation was recorded in the open field crops in Trebinje, where 19% of leaves with active mines were found.     

The occurrence of thrips (Thysanoptera) on food legumes (Fabaceae)

Journal of Plant Diseases and Protection - The occurrence, quantity and population fluctuations in thrips (Thysanoptera) on various food legume crops (Leguminosae or Fabaceae) in southern Poland...     

多异瓢虫对豆无网长管蚜捕食作用研究

在实验室内测定了多异瓢虫成虫,各龄幼虫对豆无网长管蚜的捕食作用,结果表明,多异瓢虫成虫及4龄幼虫对豆无网长管蚜有较强的捕食作用;多异瓢虫成虫及各龄幼虫对豆无网长管蚜密度的功能反应符合Holling-Ⅱ型;多异瓢虫成虫自身密度的功能反应能用Hassell数学模型较好地反映。     

引诱剂对蜜柑大实蝇的诱捕效果

本文报道了采用国际通用的监测技术,利用橘小实蝇、瓜实蝇、地中海实蝇引诱剂和水解蛋白诱饵,在广西凭祥市确定存在蜜柑大实蝇的果园开展了针对性的诱捕;诱捕结果表明,瓜实蝇引诱剂和水解蛋白诱饵能够诱捕到蜜柑大实蝇成虫,且水解蛋白诱饵比瓜实蝇引诱剂诱捕效果好.     

伪钝绥螨对二斑叶螨的捕食作用

室内条件下研究了伪钝绥螨对二斑叶螨的捕食作用。结果表明：伪钝绥螨雌成螨对二斑叶螨卵、幼螨、若螨和雌成螨的功能反应均符合HollingⅡ型方程,搜寻效率a′与处理时间Th值分别为0.5902、1.0025、0.9697、0.3146和0.0150、0.0240、0.0520、0.1681。伪钝绥螨的雌成螨喜食二斑叶螨的卵、幼螨和若螨,而对二斑叶螨雌成螨的捕食能力较弱。伪钝绥螨捕食率随着自身密度的增加而下降。捕食者密度低时,捕食率下降较快;随着捕食者密度进一步增加,捕食率下降缓慢,干扰反应方程拟合为E=0.3101P~（-0.412）。     

异色瓢虫对桃大尾蚜的捕食作用研究

测定了异色瓢虫 2龄、4龄幼虫和成虫对桃大尾蚜捕食功能反应及自干扰作用 ,结果表明其功能反应属于Holling-Ⅱ型圆盘方程式 ,寻找效应与自身密度的关系可用Hassell数学模型描述。异色瓢虫对桃大尾蚜具有较强的捕食能力 ,对猎物的寻找效应随着自身密度的增大而下降。模拟后的各方程理论值与实测值经X² 检验差异不显著     

Phytotoxic potential of Chrysopogon aciculatus (Retz.) Trin. (Poaceae)

The creeping weed, Chrysopogon aciculatus (Retz.) Trin., is widely known for its use as folk medicine, while its phytotoxic potential has not been examined. Therefore, we carried out an investigation into the phytotoxic potential of C. aciculatus to identify phytotoxic substances. C. aciculatus extracts showed inhibitory effects on shoot and root growth of cress, lettuce, rapeseed, and Italian ryegrass. Inhibition was both species‐dependent and concentration‐dependent. Two substances, (9S,10E,12Z)‐9‐hydroxyoctadeca‐10,12‐dienoic acid (9‐HO‐ODDEA) and rhizopycnin A, were isolated using chromatographies and characterized by spectral analysis. 9‐HO‐ODDEA retarded shoot and root growth of cress at concentrations higher than 1.0 and 0.3 mM, respectively, while on cress seedling by rhizopycnin A, the inhibition began from 1.0 mM. The concentrations needed for 50% inhibition of the shoot and root growth of test plants ranged from 1.71–2.31, and 0.71–0.72 mM for 9‐HO‐ODDEA and rhizopycnin A, respectively. These results indicate that these substances may contribute, to a certain extent, to the phytotoxic activity of C. aciculatus.     

黏虫和劳氏黏虫形态特征比较

黏虫和劳氏黏虫往往混合发生,给小麦、玉米和水稻等造成严重的产量损失。本文从卵、幼虫、蛹和成虫4个虫态分别描述了这两种黏虫在形态特征上的差异。两种黏虫卵无差异。低龄幼虫中黏虫刚毛基部的毛片色深,2龄幼虫前胸背板上各条背线较明显;劳氏黏虫毛片色浅,2龄幼虫各背线不明显。高龄幼虫中黏虫头部有"八字纹",气门近圆形,气门筛黑色有光泽;劳氏黏虫头部除"八字纹"外唇基还有一黑褐色斑,气门椭圆形,气门筛黄褐色。黏虫蛹腹部背面5~7节有刻点,臀棘着生近于平行;劳氏黏虫蛹4~7节有刻点,臀棘呈"八"字形。黏虫成虫前翅有环纹、肾形纹,劳氏黏虫则无。本研究旨为两种黏虫的田间调查提供技术支撑。