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.     

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。     

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.     

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.     

具条实蝇研究综述

具条实蝇[Bactrocera(Zeugodacus)scutellata(Hendel)]是我国对外重要检疫害虫,地理分布广,危害程度重,使我国果蔬生产遭受了严重经济损失。文章综述了具条实蝇的形态特征、分类地位、寄主范围、地理分布、种群数量动态以及分子生物学等方面的研究进展,并提出未来研究展望。     

Powdery mildews on borage (Borago officinalis) and evening primrose (Oenothera biennis)

The powdery mildews Erysiphe cynoglossi and E. howeana, causing disease on borage (Borago officinalis) and evening primrose (Oenothera biennis), respectively, are reported for the first time in Britain.     

Aphis (Toxoptera) citricidus (Kirkaldy) [Hemiptera: Aphididae] and Chile

As there was no consensus on the presence or absence of Aphis (Toxoptera) citricidus (Kirkaldy) in Chile, a meticulous literature survey has been carried out to clarify the issue. From this survey, it can be concluded that A. (T.) citricidus is not present in Chile, that it has never been cited as present from first‐hand information/observations in this country, and that all available Chilean records of this species are due to old (and now abandoned) taxonomic interpretations or poor transmission of information.     

进口大豆中菌核和麦角的鉴别

进口大豆中不断检出的黑色鼠粪状物质,究竟是大豆菌核病菌的菌核还是麦角,是目前困扰口岸检验检疫人员的一个问题。本文对大豆菌核病菌的菌核和麦角的分类地位、寄主及为害症状、形态特征、检疫鉴定方法等方面进行了介绍和比较,以期对今后大豆检疫工作有所帮助。     

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。     

Bioactivity of extracts and isolated compounds from Vitex polygama (Verbenaceae) and Siphoneugena densiflora (Myrtaceae) against Spodoptera frugiperda (Lepidoptera: Noctuidae)

The effects of crude extracts, fractions and isolated compounds from Vitex polygama Cham. and Siphoneugena densiflora Berg were evaluated on the development of Spodoptera frugiperda JE Smith, a destructive insect pest of corn and several other crops. The extracts and fractions were incorporated into an artificial diet at 1 mg g(-1) and offered to the insect during its larval stage. Length and viability of larval and pupal stages as well as pupal weight were assessed. Isolated compounds were tested through superficial contamination of the diet at 0.1 mg g(-1). Weight and viability of ten-day-old larvae were determined. Methanolic and hydroalcoholic S. densiflora extracts caused 100% larval mortality, while leaf and fruit hydroalcoholic extracts from V. polygama were the most active. Among the isolated compounds, flavonoids presented the best insecticidal results, and tannins the best larval growth inhibition.     

Arrowleaf sida (Sida rhombifolia) and prickly sida (Sida spinosa): germination and emergence

Maximum arrowleaf sida (Sida rhombifolia L.) germination occurred at 35°C, whereas prickly sida (Sida spinosa L.) germinated to the same extent at 35 or 40°C. Arrowleaf sida germinated better than prickly sida at 20 and 25°C, but did not germinate at 40°C. Less than 50% of seed from both species were viable at 45°C after 21 days of exposure. Both species exhibited more than 75% germination at a range of pH from 5.0 to 8.0. Arrowleaf sida germinated to a greater extent than prickly sida from 0 to —800 kPa, and an osmotic stress of —200 kPa reduced prickly sida germination, whereas —400 kPa was necessary to reduce arrowleaf sida germination. Prickly sida emergence was optimal at a planting depth of 0.5 cm, and declined rapidly at deeper planting depths. However, arrowleaf sida emergence was equivalent at planting depths of 0.5–2.0 cm, with declining emergence below 2.0 cm. Neither species emerged from depths exceeding 5.0 cm. Light did not influence the germination of arrowleaf sida or prickly sida. Sida rhombifolia et Sida spinosa: germination et levee Le maximum du germination pour Sida rhombifolia L. a été atteint à 35°C tandis que Sida spinosa L. a germé de facon équivalente à 35 ou 40°C. S. rhombifolia a mieux germé que S. spinosaà 20 et 25°C, mais n'a pas germéà 40°C. Moins de 20% de graines des deux espèces étaient encore viables à 45°C après 21 jours dèxposition. Les deux especes ont germéà plus de 75% dans des niveaux de pH allant de 5 à 8. S. rhombifolia a mieux germe que S. spinosa de 0 à 800 kPa, et un stress osmotique de —200 kPa a réduit la germination de S. spinosa, tandis que —400 kPa ont été nécessaires pour réquire la germination de S. rhombifolia. La levée de S. spinosaétait optimale à une profondeur de semis de 0,5 cm, et décroissait rapidement à des profondeurs plus élevées. Cependant la levée de S. rhombifoliaétait équivalente pour des profondeurs de 0,5 à 2 cm, avec une baisse à partir de 2 cm. Aucune des deux espèces n'a levéà des profondeurs supérieurs à 5 cm. La lumière n'a pas d'influence sur la germination des 2 espèces. Keimung und Auflaufen der Sidafaserpflanze (Sida rhombifolia L.) und der Stacheligen Samtmalve (Sida spinosa L.) Die stärkste Keimung lag bei der Sidafaserpflanze (Sida rhombifolia L.) bei 35 °C vor, während Samen der Stacheligen Samtmalve (Sida spinosa L.) bei 35 oder 40 °C gleich gut keimten. Samen der Sidafaserpflanze keimten bei 20 und 25 °C besser als die der Stacheligen Samtmalve, keimten jedoch nicht bei 40 °C. Nach Lagerung bei 45 °C für 21 Tage waren die Samen beider Arten zu < 20% keimfähig. Bei pH-Werten zwischen 5 und 8 keimten beide Arten zu >75%. Bei osmotischen Drücken zwischen 0 und —800 kPa keimte die Sidafaserpflanze besser als die Stachelige Samtmalve, deren Keimung ab —200 kPa gehemmt wurde, wahrend bei der Sidafaserpflanze —400 kPa erforderlich waren, die Keimung zu verringern. Samen der Stacheligen Samtmalve keimten am besten in 0,5 cm Tiefe, in gröβerer Ablagetiefe schnell schlechter. Bei der Sidafaserpflanze jedoch waren Aussaattiefen zwischen 0,5 und 2,0 cm gleich gut, erst bei Tiefen unter 2 cm ging der Auflauf zurück. Aus Tiefen unter 5 cm keimte keine der beiden Arten. Durch Licht wurde die Keimung der beiden Sida Arten nicht beeinflußt.     

Distribution and tephritid hosts (Diptera) of braconid parasitoids (hymenoptera) in Brazil

Tephritid parasitoids reared from 26 different host fruit species showed remarkably little diversity across 21 Brazilian counties. The majority of the parasitoids (81.4%) belonged to the braconid subfamily Opiinae, with Doryctobracon areolatus (Szépligeti) the most commonly encountered species. Four other opiines, namely D. brasiliensis (Szépligeti), Opius bellus Gahan, Optus sp. and Utetes (Bracanastrepha) anastrephae (Viereck) were also reared, but in much smaller numbers. Asobara anastrephae (Muesebeck), an alysiine braconid parasitoid of tephritids, accounted for an additional 18–6% of the individuals reared from tephritids. The hosts and distribution patterns of the braconid parasitoids of Brazilian fruit‐infesting Tephritidae are summarized.     

Competition for light between velvetleaf (Abutilon theophrasti) and soybean (Glycine max)

We examined factors affecting conversion of light into dry matter of velvetleaf (Abutilon theophrasti) and soybean (Glycine max) grown in a replacement series near Ames, Iowa, U.S.A. in 1986 and 1987. Velvetleaf was taller than soybean over most of the growing season and had more branches, especially at the top of the canopy. Velvetleaf had greater light interception than soybean in the upper part of the canopy, particularly early and late in the day, although total light interception by canopies of the two species was similar on most sample dates. Velvetleaf had higher light utilization efficiency, or conversion of intercepted light into dry matter, in the middle and later part of the growing season. This combination of traits appears to give velvetleaf an advantage over soybean in competition for light.     

Gyrodactylus bohemicus sp. n. (Monogenea: Gyrodactylidae) from Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) in Czechoslovakia.

Gyrodactylus bohemicus sp. n (Gyrodactylidae: Monogenea) is described from the fins, skin and gill filaments of Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) from a trout farm in Czechoslovakia. G. bohemicus sp. n. is most closely related to G. thymalli Zitnan, 1960 and G. magnus Konovalov, 1967 in the shape of the anchors, the ventral and the dorsal bar, but can be distinguished from both these species by the shape of the marginal hook proper.     

红星盘瓢虫取食烟粉虱和桃蚜的生物学特性研究

本文研究了取食烟粉虱Bemisia tabaci（Gennadius）和桃蚜Myzus persicae（Sulzer）对红星盘瓢虫Phrynocaria congener（Billberg）生物学特性的影响,结果表明,取食不同虫态的烟粉虱时,红星盘瓢虫从卵到成虫不同虫态的发育历期和存活率差异不显著;取食不同虫态的桃蚜时,红星盘瓢虫一、三和四龄幼虫的发育历期和四龄幼虫的成活率差异显著。分别取食烟粉虱的混合种群（卵、各龄若虫和蛹）和桃蚜的混合种群（卵和各龄若虫）时,瓢虫从卵到成虫的发育历期和存活率差异显著,分别为13.3d和15.7d、81.1%和70.0%。红星盘瓢虫取食烟粉虱和桃蚜的产卵前期差异不显著;但成虫寿命和平均单雌产卵量差异显著,分别为64.6d和86.0d、389.4粒和960.4粒。红星盘瓢虫捕食烟粉虱和桃蚜的内禀增长率（rm）分别为0.0967和0.0964;净增殖率（R0）分别为118.7573和355.3586;世代平均历期（T）分别为49.4d和60.9d;周限增长率（λ）分别为1.1015和1.1012。     

两种麦蚜对杀虫剂的敏感性测定

用浸叶法测定了麦长管蚜和禾谷缢管蚜对 7种杀虫剂的敏感性。结果表明 ,麦长管蚜对 7种杀虫剂的分布均匀度呈以下规律 :辛硫磷 <毒死蜱 <吡虫啉 <抗蚜威 <啶虫脒 <氧乐果 <甲基对硫磷 ;LC₅₀按以下次序增大 :啶虫脒 ,辛硫磷 ,毒死蜱 ,抗蚜威 ,甲基对硫磷 ,吡虫啉 ,氧乐果。禾谷缢管蚜对 6种杀虫剂敏感性分布均匀度呈以下规律 :吡虫啉 <毒死蜱 <啶虫脒 <抗蚜威 <甲基对硫磷 <氧乐果 ;LC₅₀按以下次序增大 :啶虫脒 ,毒死蜱 ,吡虫啉 ,抗蚜威 ,甲基对硫磷 ,氧乐果。麦长管蚜和禾谷缢管蚜对 7种杀虫剂的敏感性依次为 :啶虫脒 <甲基对硫磷 <抗蚜威 <毒死蜱 <氧乐果 <吡虫啉。