Genetic and environmental influences on the cuticular hydrocarbon profiles of Goniozus wasps

The cuticular hydrocarbon (CHC) profiles of insects are well known to be variable. This variation may be due to genetic influences, environmental influences, or both. Most prior studies have focused on social insects, mainly those in the Hymenoptera, and have shown that hydrocarbons play an important role mediating social behaviour, particularly via kin recognition. Here, we assess the CHC profiles of three species of parasitoid wasps in the genus Goniozus (Hymenoptera: Bethylidae), some of which are known to attune their behaviour according to both environmentally based and genetically based recognition of kin. We find that CHC profiles vary according to both the genetic background (wasp species) and the developmental environment (host species) of individual parasitoids. This indicates that kin recognition could be based on CHC profiles in these parasitoids, as it is in social Hymenoptera. Because the CHC profiles of species within the genus Goniozus are dissimilar, we also conclude that chemical analysis could be used as a taxonomic tool alongside morphological and molecular genetic identification for Goniozus and other species.     

Influence of cabbage resistance and colour upon the diamondback moth and its parasitoid Oomyzus sokolowskii

Host plant resistance and biological control are vital integrated pest management tools against the diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), but to date no study has investigated this system including the DBM parasitoid Oomyzus sokolowskii (Kurdjumov) (Hymenoptera: Eulophidae). We examined oviposition and development of P. xylostella exposed to two commercial cabbage cultivars (green ‘Chato de quintal’ and red ‘Roxo’) and possible effects upon O. sokolowskii. Under free‐choice tests, DBM females laid significantly more eggs on plants of the green cabbage, even though several population growth parameters showed that DBM developed better on the red cabbage. Furthermore, a laboratory free‐choice test with artificially green‐ and red‐painted kale leaf discs demonstrated a similar oviposition preference pattern, with green colour being preferred over red colour. The preference was apparently visually mediated; olfactometer tests showed similar attraction of moths to both green and red cultivars in choice and non‐choice tests. Host plant cultivar had no statistically significant effect on female parasitoid behaviour towards DBM larvae, nor on parasitoid numbers or longevity. Moreover, wasps parasitizing DBM larvae reared on the green cultivar developed more quickly and in larger numbers per parasitized larva. Thus, feeding on green cabbage rather than red does not hinder, and potentially even enhances, control of DBM by O. sokolowskii. On a practical level, these results suggest that intercalating green cabbage cultivars as a trap crop might help protect more profitable red cultivars in growing fields.     

Host feeding experience affects host plant odour preference of the polyphagous leafminer Liriomyza bryoniae

Herbivorous insects use highly specific volatiles or blends of volatiles characteristic to particular plant species to locate their host plants. Thus, data on olfactory preferences can be valuable in developing integrated pest management tools that deal with manipulation of pest insect behaviour. We examined host plant odour preferences of the tomato leafminer, Liriomyza bryoniae (Kaltenbach) (Diptera: Agromyzidae), which is an economically important agricultural pest widespread throughout Europe. The odour preferences of leafminers were tested in dependence of feeding experiences. We ranked host plant odours by their appeal to L. bryoniae based on two‐choice tests using a Y‐tube olfactometer with five host plants: tomato, Solanum lycopersicum Mill.; bittersweet, Solanum dulcamara L.; downy ground‐cherry, Physalis pubescens L. (all Solanaceae); white goosefoot, Chenopodium album L. (Chenopodiaceae); and dead nettle, Lamium album L. (Lamiaceae). The results imply that ranking of host plant odours by their attractiveness to L. bryoniae is complicated due to the influence of larval and adult feeding experiences. Without any feeding experience as an adult, L. bryoniae males showed a preference for the airflow with host plant odour vs. pure air, whereas females did not display a preference. Further tests revealed that adult feeding experience can alter the odour choice of L. bryoniae females. After feeding experience, females showed a preference for host plant odour vs. pure air. Feeding experience in the larval stage influenced the choice by adults of both sexes: for males as well as females reared on bittersweet the odour of that plant was the most attractive. Thus, host feeding experience both in larval and/or adult stage of polyphagous tomato leafminer L. bryoniae influences host plant odour preference by adults.     

A test of fruit varieties on entry rate and development by neonate larvae of the codling moth,Cydia pomonella

The rate of entry by neonate larvae of the frugivorous codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), into fruit material was investigated. We used no‐choice bioassays in climate‐controlled rooms to assay larval entry across four host plant species (apple, pear, quince, walnut) and three varieties within a single fruit species (apple). Larvae successfully entering apples were reared to adulthood, and we collected tissue samples from apples which were successfully colonized in order to determine sucrose concentrations. This information was used to evaluate differences in adult moth size, development time, and pulp sucrose concentration due to apple variety. Four important findings emerged: (1) neonate larvae had the highest frequency of entry (86% of larvae) into apple fruits, compared with pear (78%), quince (56%), and walnut (32%); (2) the frequency of larval entry into immature apples differed across apple varieties, and larval entry rate was highest in variety Golden Delicious (72%), compared with Granny Smith (46%) and Red Delicious (64%); (3) on average, adult moths were larger and development times were shorter on the variety with the highest entry frequency (Golden Delicious); and (4) apple pulp sucrose concentrations were higher for Golden Delicious (17.5 μg mg^?1) than for either Granny Smith (15.9 μg mg^?1) or Red Delicious (15.1 μg mg^?1) varieties, which correlates positively with entry and development data. We conclude that host fruit species and varietals within a species affect the entry rate of neonate codling moth larvae in no‐choice assays. We hypothesize that larval development is influenced by mean sucrose concentrations or other phytochemical differences associated with host fruit varieties.     

Visualizing the effect of tumor microenvironments on radiation-induced cell kinetics in multicellular spheroids consisting of HeLa cells

In this study, we visualized the effect of tumor microenvironments on radiation-induced tumor cell kinetics. For this purpose, we utilized a multicellular spheroid model, with a diameter of ∼500 μm, consisting of HeLa cells expressing the fluorescent ubiquitination-based cell-cycle indicator (Fucci). In live spheroids, a confocal laser scanning microscope allowed us to clearly monitor cell kinetics at depths of up to 60 μm. Surprisingly, a remarkable prolongation of G2 arrest was observed in the outer region of the spheroid relative to monolayer-cultured cells. Scale, an aqueous reagent that renders tissues optically transparent, allowed visualization deeper inside spheroids. About 16 h after irradiation, a red fluorescent cell fraction, presumably a quiescent G0 cell fraction, became distinct from the outer fraction consisting of proliferating cells, most of which exhibited green fluorescence indicative of G2 arrest. Thereafter, the red cell fraction began to emit green fluorescence and remained in prolonged G2 arrest. Thus, for the first time, we visualized the prolongation of radiation-induced G2 arrest in spheroids and the differences in cell kinetics between the outer and inner fractions.     

Campbellenchinae (Nematoda: Tylodoridae), a new subfamily from campbell Island,with a description of two new species

The first paragraph of the Introduction serves as an Abstract.

Specimens of an undescribed subfamily of Tylodoridae Paramonov, 1967 were found in each of 50 soil samples collected since 1951 from around the roots of native plants on Campbell Island, New Zealand. This taxon, Campbellenchinae n.subfam., its type‐genus, Campbellenchus n.gen., and 2 new species, C. poae and C. filicauda, are described. The diagnostic characters of the new subfamily include a lip region without a labial disc, a stylet of moderate length, a characteristic zone of cuticular annulation anterior to the stylet knobs, a slit‐like amphidial opening, a single ovary, and a filiform tail.     

The potential for controlling Megalurothrips sjostedti (Thysanoptera: Thripidae) on cowpea,Vigna unguiculata (L.) Walp flowers using extracts of cashew (Anacardium occidentale L.) products

Abstract

The efficacy of aqueous extracts of cashew, Anacardium occidentale L. products was tested on Legume flower bud thrips on field cowpea in the 1999 and 2000 seasons using nutseed and nutshell at 10% w/v, bark and leaf at 20% w/v. Aqueous extract of cashew nutshell was superior to other cashew products in reducing thrip populations in cowpea flowers and compared favourably with cypermethrin + dimethoate. Pod density per plant was significantly enhanced on cowpea plants sprayed with aqueous extract of cashew nutshell compared to other extracts. Cashew extract contains cardole (a caustic substance) and anacardic acid, which may have been responsible for its insecticidal effect on thrips. This result indicates the potential of cashew products especially the nutshell for integrated management of thrips in legume crops.     

Management of pests and diseases of castor (Ricinus communis L.) in India: current status and future perspective

Abstract

Castor (Ricinus communis L.) cultivation is generally cost-effective and profitable for small and marginal farmers in India. However, crop productivity is affected by the damage from pests and plant pathogens. From seedling till capsule harvesting, leaf sap-sucking insects and mites, defoliators, capsule feeding insects; bacterial and fungal diseases and root-knot nematodes attack the crop at various stages of growth and deteriorate plant health. Currently, synthetic pesticides are being applied extensively. Considering side effects of chemicals, other control measures are considered in this review. Findings of greenhouse and the field trials are discussed, and the efficient, economic and eco-friendly management has been elaborated.     

基于综合生物标志物响应指数法评估近岸海洋环境压力——以广西西部沿海为例

2011-2012年,在广西西部沿海设置5个站点,以野生文蛤作为指示生物进行3次采样监测.从个体、细胞和分子水平选择了钻沙所需时间、吞噬能力、溶酶体膜稳定性、血浆三价铁还原力、乙酰胆碱酯酶活性及彗星率6项指标,利用综合生物标志物响应指数模型(IBR),整合上述生物标志物指标,并转化为形象直观的星状图,对调查站点的环境状况进行风险评估.结果表明: 各站点的综合生物标志物响应指数值(IBR/n)介于2.30~8.68,茅尾海的环境压力最大,北仑河口最小.虽然不同的生物标志物对污染压力的响应存在差异,但利用IBR可以有效区分文蛤所在区域的环境压力状况.利用生物标志物的监测结果与化学监测结果基本吻合.     

High plant species richness indicates management-related disturbances rather than the conservation status of forests

There is a wealth of smaller-scale studies on the effects of forest management on plant diversity. However, studies comparing plant species diversity in forests with different management types and intensity, extending over different regions and forest stages, and including detailed information on site conditions are missing. We studied vascular plants on 1500 20 m × 20 m forest plots in three regions of Germany (Schwäbische Alb, Hainich-Dün, Schorfheide-Chorin). In all regions, our study plots comprised different management types (unmanaged, selection cutting, deciduous and coniferous age-class forests, which resulted from clear cutting or shelterwood logging), various stand ages, site conditions, and levels of management-related disturbances. We analyzed how overall richness and richness of different plant functional groups (trees, shrubs, herbs, herbaceous species typically growing in forests and herbaceous light-demanding species) responded to the different management types. On average, plant species richness was 13% higher in age-class than in unmanaged forests, and did not differ between deciduous age-class and selection forests. In age-class forests of the Schwäbische Alb and Hainich-Dün, coniferous stands had higher species richness than deciduous stands. Among age-class forests, older stands with large quantities of standing biomass were slightly poorer in shrub and light-demanding herb species than younger stands. Among deciduous forests, the richness of herbaceous forest species was generally lower in unmanaged than in managed forests, and it was even 20% lower in unmanaged than in selection forests in Hainich-Dün. Overall, these findings show that disturbances by management generally increase plant species richness. This suggests that total plant species richness is not suited as an indicator for the conservation status of forests, but rather indicates disturbances.