Effects of plant feeding on the development,survival and reproduction of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae)

Diets consisting of leaves of cotton and/or water were insufficient to promote the complete development and survival of Podisus nigrispinus (Dallas) to the adult stage. However, nymphs fed leaves lived longer than those provided with only water. Addition of Alabama argillacea (Huebner) larvae to the diet of P. nigrispinus added a substantial increment to the survival during the nymphal stage. The addition of cotton leaves to the diet of P. nigrispinus nymphs promoted an increase in the weight of newly eclosed adults, independent of predator sex. In addition, diets supplemented with cotton leaves promoted an increase in the duration of the oviposition period, the number of egg clutches per female, and the number of eggs per female. No effects were noted on either the duration of the pre-oviposition period, the number of eggs of the first clutch, the number of eggs per clutch, the interval between egg clutches, or sex ratio. Feeding on plant material by P. nigrispinus is a potentially positive attribute in biological control against cotton leafworm.     

Predatory potential of eleven native Moroccan adult ladybird species on different stages of Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae)

Dactylopius opuntiae is an insect pest of cactus which is currently causing severe damage to cactus crops in Morocco. It was first observed in 2014 in the Sidi Bennour region 120 km northwest of Marrakech, and has spread very quickly to destroy the prickly pear cactus crops (Opuntia ficus‐indica (L.) Miller) in several regions of country, causing very heavy economic losses. To control this pest, the predatory potential of eleven species of native Moroccan ladybird predators was investigated under laboratory conditions at 26 ± 2°C, 60 ± 10% RH and a 12 h light:12 h dark regime. The experiments were conducted in no‐choice feeding tests (only eggs, first instar or second instar of mealybugs were offered at one time) and free‐choice feeding tests (eggs and first and second instar larvae were offered simultaneously). In the no‐choice feeding tests, Exochomus nigripennis, Chilocorus bipustulatus and Chilocorus politus consumed the highest mean number of mealybug eggs and first instars, and the highest mean number of second instars was consumed by Hippodamia convergens. In the free‐choice feeding tests the highest mean number of mealybug eggs was eaten by Chilocorus bipustulatus and Chilocorus politus and Hippodamia convergens consumed the highest mean number of first and second instars of the mealybug.     

水稻孕穗期稻茎毛眼水蝇经济阈值的研究

试验表明，水稻孕穗期每丛水稻茎毛眼水蝇卵数（Ｘ_１）、被害穗数（Ｘ_２）与产量损失（Ｙ）的关系符合下列方程：Ｙ＝－２．０１＋４．５２４Ｘ_１±２．２，ｒ＝０．９９１４；Ｙ＝－０．０７６＋４．９１２Ｘ_２±２．７８，ｒ＝０．９８６３。产量损失的主导因素是水稻受害后，早稻实粒数减少，晚稻总粒数和实粒数减少。根据防治费用，稻谷价格等，导出孕穗期稻茎毛眼水蝇的经济阈值为每丛禾１．９粒卵或１．３４株受害穗。经大田验证，与实际基本相符。     

Life table and some feeding features of Nephus kreissli fed on Planococcus ficus

In this study certain biological and prey consumption features of the predator of mealybug, namely Nephus kreissli Fürsch & Uygun (Coleoptera: Coccinellidae), fed on vine mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), were determined under the laboratory conditions. Experiments were performed in the acclimatized room under 28?±?1°C, 60?±?10% r.h. and a photoperiod of 16:8 h(L:D) conditions. To determine the biological features of the coccinellid, predator individuals were continuously observed from egg stage to end of adult stage. The development, survival and fecundity of N. kreissli were determined and all the measured data were recorded daily. The total development time from egg to the eclosion of adult stage was determined as 31.6?±?0.4 days. The lifespan of males and females was 66.0?±?3.8 and 65.8?±?3.5 days, respectively; and a single female laid 122.6 eggs. The raw data related to life history were analyzed by using the age-stage, two-sex life table. The intrinsic rate of increase, the net reproductive rate, and the mean generation time were 0.0709?±?0.0036 d^?1, 53.1?±?9.5 offspring and 55.8?±?1.3 days, respectively. The first and second instars of N. kreissli preferred egg stages of P. ficus to other stages of mealybug. On the other hand, third and fourth instars and adult predators preferred the second and third instar nymphs and adult females of the prey. It was determined that the egg consumption of N. kreissli increased with the development of larval stages, and that the highest consumption was recorded in its fourth instar.     

中黑盲蝽人工饲料的初步研究

利用鸡蛋、黄豆粉、啤酒酵母、蜂蜜等配制了中黑盲蝽的半人工饲料,在每天光照16 h(30℃、RH80%)和黑暗8 h(25℃、RH90%)的光周期条件下连续饲养中黑盲蝽3代,其中第3代平均每雌产卵量达172粒。在人工饲养条件下,中黑盲蝽的卵期为(10.92±0.37)d、若虫期(19.83±0.31)d、成虫期(22.42±0.42)d、产卵前期(7.83±0.31)d。     

氯虫苯甲酰胺对桃小食心虫生长发育的亚致死效应

为明确亚致死浓度的氯虫苯甲酰胺连续处理对第4代桃小食心虫生物学特性的影响,本研究用LC10、LC30和LC50的氯虫苯甲酰胺处理的苹果分别继代饲养桃小食心虫（简称LC10、LC30和LC50种群）。以第4代初孵幼虫为起点记录其各阶段发育历期、存活率和繁殖力等数据,研究氯虫苯甲酰胺对桃小食心虫的亚致死效应。结果表明,LC30和LC50种群桃小食心虫的卵期与对照（CK）种群相比明显延长; LC50种群桃小食心虫的蛀果率、脱果率、幼虫存活率、世代存活率以及单雌平均产卵量均显著低于CK种群; CK、LC10、LC30和LC50种群单雌平均产卵量分别为(183.67±10.39)、(177.66±14.81)、(147.83±14.54)粒和(126.33±11.29)粒。桃小食心虫LC30和LC50种群与CK种群相比,内禀增长率、净生殖率和周限增长率显著降低,平均世代周期和种群加倍时间延长,相对适合度降低。     

Clutch size decisions of <Emphasis Type="Italic">Cotesia glomerata</Emphasis>, a gregarious parasitoid of <Emphasis Type="Italic">Pieris brassicae</Emphasis>

This work investigated the ability of the gregarious larval endoparasitoid Cotesia glomerata L. (Hymenoptera: Braconidae) to adjust the progeny sex ratio and clutch size with repeated oviposition experience and the effect of a honey-based diet on the clutch size. In the field-collected clusters many clusters were female-biased but some clusters (3.8%) produced only male wasps, suggesting that there is a low percentage of unmated females in the field. Superparasitism was common in the field, and females were believed to increase progeny sex ratio when attacking previously parasitized hosts. In the laboratory, the number of eggs laid in a day tended to decrease with increasing female age. For females that were offered two hosts per day and for those offered three hosts per day, this value became nearly the same at 9 days after the start of oviposition. Old females which attacked many hosts tended to lay fewer eggs in a day than young ones. However, the degree of this tendency was not the same for all the parasitoid females of all three groups because sperm remained viable throughout a female’s lifetime. The amount of sperm used in a single oviposition bout seemed fixed and was not dependent on the number of eggs laid. Over the 2 days of the clutch size response experiment, the number of hosts a female attacked per day was not affected by the presence or absence of honey.     

Allelopathic effect of Pluchea lanceolata on growth and yield components of mustard (Brassica juncea) and its influence on selected soil properties†

Pluchea lanceolata (DC.) C.B. Clarke (Asteraceae) is a rapidly spreading perennial weed in semiarid areas of north‐west India. While preparing fields for cultivation, farmers incorporate Pluchea plant debris into the soil. In the present study, mustard grown in plots with soil‐incorporated Pluchea had significantly reduced shoot height (61 ± 8.8 cm), number of pods per plant (7 ± 3.2), number of seeds per pod (4.1 ± 3.9) and weight per seed (0.08 ± 0.03 g) of mustard compared to mustard growing in Pluchea‐free soils. Pluchea‐infested and Pluchea‐free soils were analyzed for pH, electrical conductivity, organic matter, soluble chloride, exchangeable phosphate, copper, zinc, sodium, potassium, magnesium, calcium and water‐soluble phenolics. Pluchea‐infested soils had different values for electrical conductivity, Cl, K and total phenolics when compared to Pluchea‐free soils. Data on yield reduction of mustard due to soil‐incorporated Pluchea leaves have been reported for the first time. The reduced mustard growth and yield is proposed to be partly due to water‐soluble phenolic compounds contributed by Pluchea leaves into soil.     

In vitro and in planta nematicidal activity of Fumaria parviflora (Fumariaceae) against the southern root‐knot nematode Meloidogyne incognita

Root and stem extracts of Fumaria parviflora showed strong nematicidal activity against Meloidogyne incognita in in vitro and in planta experiments. Phytochemical screening of F. parviflora revealed the presence of seven classes of bioactive compounds (alkaloids, flavonoids, glycosides, tannins, saponins, steroids and phenols). Quantitative determination of the plant extracts showed the highest percentages of alkaloids (0·9 ± 0·04) and saponins (1·3 ± 0·07) in the roots and total phenolic contents in the stem (16·75 ± 0·07 μg dry g^?1). The n‐hexane, chloroform, ethyl acetate and methanol extracts of roots and stems at concentrations of 3·12, 6·24, 12·5, 25·0 and 50·0 mg mL^?1, significantly inhibited hatching and increased mortality of second‐stage juveniles (J2s) compared with water controls. Percentage J2 mortality and hatch inhibition were directly related to exposure time. In pot trials with tomato cv. Rio Grande, root and stem extracts at concentrations of 1000, 2000 and 3000 ppm, applied as soil drenches, significantly reduced the number of galls, galling index, eggs masses, eggs and reproduction factor compared with the water control. Regardless of concentration, all the extracts significantly increased the host plant growth parameters studied. The n‐hexane extracts from the roots and stem were the most active, followed by the methanol ones, at all concentrations. The in vitro and in planta results suggest that extracts from the roots and stem of F. parviflora may be potential novel nematicides.     

水稻苗期稻茎毛眼水蝇经济阈值的研究

接虫试验表明，水稻苗期每丛稻茎毛眼水蝇卵数（Ｘ_１）、为害株数（Ｘ_２）与产量损失（Ｙ）的关系符合下列方程：Ｙ＝－７．３１＋３．０１６ｘ１±２．１５，ｒ＝０．９８０４；Ｙ＝－６．７＋３．５３ｘ２±２．１９，ｒ＝０．９８０２。早稻产量损失的主要原因是受害后千粒重和实粒数减少；晚稻为千粒重下降。根据当前的稻谷价格、防治费用等，导出水稻苗期稻茎毛眼蝇的经济阈值为每丛４．６粒卵或３．７４株受害。经大田验证，与实际基本相符     

松褐天牛肿腿蜂的产卵模式：雄性先产的有利原则

本研究分别设计了去除松褐天牛肿腿蜂Sclerodermus alternatusi母蜂第1 d所产的卵（处理1）和在松褐天牛肿腿蜂产卵1 d后去除母蜂（处理2）,并统计其子代性别构成和比例这2组数据来明确其产卵行为特征,进而来验证松褐天牛肿腿蜂在一次产卵行为中是否会优先产出未受精的卵。研究发现,在处理2中仅保留了肿腿蜂第1 d所产的卵后,24例有效重复中仅有1例无雄性后代;对照组（接蜂后无处理）中所有重复均有雄性后代。然而,在处理1去除了肿腿蜂第1 d所产的卵后,25例有效重复中子代无雄蜂的样本数达到了10例,其雄蜂缺失的比例显著高于处理2和对照组。处理1和处理2均羽化出26头雄蜂,其平均单雌产雄量分别为1.04和1.08头,显著低于对照组的1.98头。以上研究结果表明,松褐天牛肿腿蜂的群体构成是显著的偏雌性,母蜂一次产卵行为中会在最初的时间内将雄性后代产出,而随后再陆续地产出雌性后代。这种雄性后代先产的行为特征对肿腿蜂控制其较高的子代雌性比和子代雌蜂在羽化后可第一时间完成交配是有利的。     

Transovarial biotransference of etoxazole through a terrestrial trophic web

BACKGROUND: Transovarial transport is defined as the passage of chemicals from the maternal body to eggs within the ovaries. Little is known about the effects of transovarial transport on non‐target species. This study evaluates etoxazole (a transovarial acaricidal compound) on a terrestrial trophic web consisting of a ubiquitous phytophagous mite, Tetranychus urticae Koch, and three species of predatory mites. RESULTS: Predatory mite females that consumed eggs laid by etoxazole‐treated T. urticae also produced infertile eggs. There was a negative relationship between the proportion of etoxazole‐treated T. urticae females and the instantaneous rate of predatory mite increase at the population level (r² = 0.86). Reduced fertility of etoxazole‐treated T. urticae females continued for 18 days following application. Eggs laid by etoxazole‐treated T. urticae females remained toxic to predatory mite females for 42 days after treatment. CONCLUSIONS: Transovarial transport could lead to magnification in the ecosystem by enhancing both bioavailability and movement of an active ingredient. The potential for enhancement of residual activity by terrestrial organisms and its significance once reaching the food web should be taken into account for new classes of acaricides and insecticides. Copyright © 2012 Society of Chemical Industry     

Laboratory studies on the effect of temperature and humidity on the life table of the whitefly,Aleurotuberculatus takahashi David & Subramaniam (Hom., Aleyrodidae) from southeastern China

The present paper deals with developmental duration, emergence, longevity and fecundity ofAleurotuberculatus takabashi David & Subramaniam at different temperatures and humidity levels. The developmental time from egg to adult was 81.8, 56.9, 39.6, 29.9, 20.6 days at 15±1, 20±1, 25±1, 30±1, 35±1°C under constant relative humidity (RH) of 70±5%, respectively. At 25±1°C, the total developmental time was slightly affected by humidity, ranging from 46.4 days at 40±5% RH to 39.2 days at 90±5% RH. The developmental threshold and the thermal constant for the stage from egg to adult were 10.1°C and 542.8 day-degrees. It was estimated that the whitefly has about 10 generations a year in Fuzhou region in southeastern China. Lowest mortality rates of 12.4% for the egg, 6.8% for the nymph and 3.1% for the puparium were obtained at 15±1°C, while they were highest with 92.1% for the egg, 48.2% for the nymph and 36.3% for the puparium at 35±1°C. The mortality rates were slightly affected by humidity, ranging from 17.6% at 40±5% RH to 27.9% at 90±5% RH for the egg, 11.2% at 40±5% RH to 19.6% at 90±5% RH for the nymph, and 6.4% at 40±5% RH to 11.6% at 90±5% RH for the puparium. The emergence rate of adults decreased as temperature increased, ranging from 89.1% at 15±1°C to 21.5% at 35±1°C, so did the longevity of adults, ranging from 9.6 days at 15±1°C to 2.9 days at 35±1°C. The number of eggs per female was significantly affected by temperature (P.01), valuing 29.4 eggs per female at 15±1°C, 36.7 at 20±1°C, 52.4 at 25±1°C, 42.9 at 30±1°C, and 6.1 at 35±1°C. The optimal temperature for reproduction was about 25°C.     

Sprinkling irrigation enhances production of oospores of phytophthora infestans in field-grown crops of potato

ABSTRACT Two field experiments were conducted to study the effect of overhead sprinkling irrigation on oospore formation by the late blight fungus Phytophthora infestans in potato. Total rain (natural + sprinkling) accumulated in treatments of experiment 1 (winter 1997 to 1998) were 765, 287, and 219 mm and treatments of experiment 2 (winter 1999 to 2000) were 641, 193, and 129 mm. Sporangia from 11 isolates of P. infestans were combined in eight pairs, seven of A1 and A2 and one of A2 and A2 mating type, and were sprayed on field-grown potato crops (42 plants per plot at 7 m(2) each) and examined for their ability to form oospores in the host tissues. In experiment 1, oospores were recorded in a total of 132 of 1,680 leaflets (7.9%), 24 of 105 stems, and 2 of 90 tubers. In experiment 2, oospores were recorded in 40 of 519 leaflets (7.7%), but not in any of the 90 stems or the 45 tubers examined. Both the proportion of leaflets containing oospores and the number of oospores per leaflet increased with time after inoculation and were dependent on the rain regime, the position of leaves on the plant, and the isolate pair combination. In both field trials, increasing the rainfall significantly enhanced oospore production in leaves. Leaf samples collected from the soil surface had significantly more oospores than those collected from the midcanopy. Two pairs in experiment 1 were more fertile than the others, whereas the pair used in experiment 2 was the least fertile. The total number of oospores per leaflet usually ranged from 10 to 100 in experiment 1, but only from 2 to 10 in experiment 2. Maximal oospore counts in the field were 200 and 50 in experiments 1 and 2, respectively, but ranged from approximately 2,000 to 12,000 oospores per leaflet in detached leaves in the laboratory. We concluded that P. infestans can produce oospores in the foliage of field-grown potato crops, especially when kept wet by regular overhead sprinkling irrigation, but production was far below that in the laboratory.     

中药材储藏害虫优势种药材甲形态及生活史

药材甲[Stegobium paniceum(L.)]是中药材储藏期害虫优势种,对我国储藏中药材造成极大危害。此虫卵小,椭圆形,长径296.80～380.80μm,短径224.00～313.60μm。幼虫有4个龄期,1～2龄体小,3～4龄体长迅速增加,整个幼虫期蛀食生存于药材中。蛹被蛹室,长5～10 mm,发育过程中伴随颜色变化。成虫体长2～6 mm,羽化后2～3 d交配产卵,单雌卵量(55.78±3.01)粒,寿命(22.22±1.39)d。1年发生3～4代,世代重叠明显,多以当年第4代幼虫越冬。     

Aqueous solubilities,photolysis rates and partition coefficients of benzoylphenylurea insecticides

The aqueous solubilities and octanol–water partition coefficients (K_OW) of the benzoylphenylurea (BPU) insecticides teflubenzuron, chlorfluazuron, flufenoxuron and hexaflumuron were determined in comparison with the more extensively studied diflubenzuron. Both teflubenzuron and hexaflumuron were substantially less water‐soluble (9.4 (± 0.3) µg litre⁻¹ and 16.2 (± 0.5) µg litre⁻¹ in water, respectively) than the value previously reported for diflubenzuron (89 (± 4) µg litre⁻¹ in water). Log K_OW values for diflubenzuron, teflubenzuron, hexaflumuron, flufenoxuron and chlorfluazuron were 3.8, 5.4, 5.4, 6.2 and 6.6, respectively, as determined using reverse‐phase HPLC. Photodegradation of hexaflumuron, teflubenzuron and diflubenzuron in water indicated hexaflumuron to be the most rapidly degraded of the three compounds at pH 7.0 (t_1/2 = 8.6 (± 0.4) h) and pH 9.0 (t_1/2 = 5 (± 1) h); diflubenzuron was the slowest of the three pesticides to degrade in pH 7.0 (17 (± 4) h) and pH 9.0 (8 (± 2) h) buffered water. In a solar simulator using river water buffered to pH 9.0, teflubenzuron, hexaflumuron and diflubenzuron half‐lives were 20 (± 4), 15 (± 2) and 12 (± 1) h, respectively; dark controls showed no loss of parent BPU over similar time periods. © 2000 Society of Chemical Industry     

沙芥田节肢动物群落多样性分析

为了解沙芥田节肢动物群落的结构组成及其多样性,于2013年5月至2013年8月采用目测法和网捕法对沙芥田节肢动物群落进行了系统研究。记录了该田节肢动物共10目44科74种,共计4 080号。其中半翅目和鳞翅目个体数量较多,占个体总数的70%以上,膜翅目和双翅目的丰富度较高。沙芥田节肢动物季节动态变化和多样性指数的变化说明,6月节肢动物个体数量和物种数最多,8月多样性指数和均匀度最大。将沙芥田节肢动物划分为不同的功能集团,并对其进行了多样性分析,结果表明,天敌集团在时间上的多样性指数较高,而害虫集团的个体数量在沙芥生长期各阶段均比其他集团高。其中,小菜蛾、黄曲条跳甲、桃蚜、萝卜蚜和甘蓝蚜为沙芥田的主要害虫,并在不同时期分别成为该田的优势种。本研究对了解沙芥田生态系统以及沙芥田害虫的综合治理具有重要作用。     

Characterization and Inhibitor Studies of Chitinases from a Parasitic Blowfly (Lucilia cuprina), a Tick (Boophilus microplus), an Intestinal Nematode (Haemonchus contortus) and a Bean (Phaseolus vulgaris)

The molecular weight pattern and the stage-specific activities of chitinases from the blowfly Lucilia cuprina, the tick Boophilus microplus and the intestinal nematode Haemonchus contortus were examined. Chitinolytic enzymes could be detected in all parasite species tested, but the activity was different between the stages. Highest chitinolytic titers were found in blowfly pupae (83 kDa, 118 kDa), hatching larvae of ticks (58 kDa, 94 kDa) and nematode eggs (43 kDa). Leaves from ethylene-treated bean plants Phaseolus vulgaris expressed two basic Class I chitinases (Ia, Ib) of 34 kDa, differing in their amino acid sequences at residue 33 and 34 (Ia: glycine, proline; Ib: lysine, aspartic acid). Inhibitor studies with blowfly pupae revealed that allosamidin (IC₅₀=0·32 (±0·02) μM ) was by far the best inhibitor when compared with various amino sugar derivatives. This compound also inhibited chitinases from tick larvae (IC₅₀=0·69(±0·10) μM ) and nematode eggs (IC₅₀=0·048(±0·0045) μM ) specifically. Whereas Class Ia chitinase from bean leaves was inhibited only up to 18% by 10 μM allosamidin, it had an IC₅₀ of 1(±0·14) μM for the Ib type, which is the first plant chitinase described to be highly sensitive to allosamidin.     

Synthesis and structure–activity relationships of carbohydrazides and 1,3,4‐oxadiazole derivatives bearing an imidazolidine moiety against the yellow fever and dengue vector,Aedes aegypti

BACKGROUND

1,3,4‐Oxadiazole and imidazolidine rings are important heterocyclic compounds exhibiting a variety of biological activities. In this study, novel compounds with oxadiazole and imidazolidine rings were synthesized from 3‐(methylsulfonyl)‐2‐oxoimidazolidine‐1‐carbonyl chloride and screened for insecticidal activities. The proposed structures of the 17 synthesized compounds were confirmed using elemental analysis, infrared (IR), proton nuclear magnetic resonance (¹H‐NMR), and mass spectroscopy.

RESULTS

None of the compounds showed larvicidal activity at the tested concentrations against first‐instar Aedes aegypti larvae. However, nine compounds exhibited promising adulticidal activity, with mortality rates of ≥80% at 5 µg per mosquito. Further dose–response bioassays were undertaken to determine median lethal dose (LD₅₀) values. Compounds 1 , 2b , 2c , 2d , 2 g , 3b , 3c , 3 g, and 3 h were effective, with typical LD₅₀ values of about 5 ? 10 µg per mosquito against female Ae. aegypti. Compounds 2c (bearing a nitro group on the aromatic ring; LD₅₀ = 2.80 ± 0.54 µg per mosquito) and 3 h ( double halogen groups at 2,4 position on the phenyl ring; LD₅₀ = 2.80 ± 0.54 µg per mosquito) were the most promising compounds.

CONCLUSION

Preliminary mode of action studies failed to show consistent evidence of either neurotoxic or mitochondria‐directed effects. Further chemical synthesis within this series may lead to the development of new effective insecticides. © 2017 Society of Chemical Industry