Toxicity,repellent and oviposition deterrent effects of select essential oils against the house fly Musca domestica

Essential oils from plants may provide environment-friendly alternatives to conventional synthetic insecticides. Here, toxic, repellent, and oviposition deterrent effects of essential oils of six plants: Allium sativum L. (Alliaceae), Azadirachta indica A. Juss. (Meliaceae), Cinnamomum cassia (L.) (Lauraceae), Eucalyptus camaldulensis Dehnh. (Myrtaceae), Piper nigrum L. (Piperaceae), and Thevetia peruviana (Pers.) (Apocynaceae), were evaluated against different life stages of Musca domestica. Bioassays revealed that the essential oils of A. indica, T. peruviana and E. camaldulensis exhibited: a) the highest toxicity on larvae (LC₅₀ = 169.72, 182.23 and 277.01 ppm, respectively), pupae (LC₅₀ = 150.56, 164.84 and 164.87 ppm, respectively) and adults (LC₅₀ = 166.69, 139.15 and 302.75 ppm, respectively) of M. domestica; b) the highest repellency (91.44, 72.19 and 72.80%, respectively) and oviposition deterrent (90.36, 88.82 and 89.13%, respectively) effects on adults of M. domestica, as compared to the other essential oils. Moreover, the speed of mortality caused by essential oils of A. indica (LT₅₀ = 16.85 and 17.06 h for larvae and adults, respectively) and T. peruviana (LT₅₀ = 16.46 and 18.58 h for larvae and adults, respectively) was faster than the rest of the essential oils. On the whole, it might be expected that the essential oils of A. indica, T. peruviana and E. camaldulensis could be developed into a new type of environment-friendly insecticides and/or repellents for the management of M. domestica.     

Gene flow and population structure of a common agricultural wild species (Microtus agrestis) under different land management regimes

The impact of landscape structure and land management on dispersal of populations of wild species inhabiting the agricultural landscape was investigated focusing on the field vole (Microtus agrestis) in three different areas in Denmark using molecular genetic markers. The main hypotheses were the following: (i) organic farms act as genetic sources and diversity reservoirs for species living in agricultural areas and (ii) gene flow and genetic structure in the agricultural landscape are influenced by the degree of landscape complexity and connectivity. A total of 443 individual voles were sampled within 2 consecutive years from two agricultural areas and one relatively undisturbed grassland area. As genetic markers, 15 polymorphic microsatellite loci (nuclear markers) and the central part of the cytochrome-b (mitochondrial sequence) were analysed for all samples. The results indicate that management (that is, organic or conventional management) was important for genetic population structure across the landscape, but that landscape structure was the main factor shaping gene flow and genetic diversity. More importantly, the presence of organically managed areas did not act as a genetic reservoir for conventional areas, instead the most important predictor of effective population size was the amount of unmanaged available habitat (core area). The relatively undisturbed natural area showed a lower level of genetic structuring and genetic diversity compared with the two agricultural areas. These findings altogether suggest that political decisions for supporting wildlife friendly land management should take into account both management and landscape structure factors.     

Selective toxicity of some pesticides to Pullus mediterraneus Fabr. (Coleoptera: Coccinellidae), a predator of Saissetia oleae Bern. (Homoptera: Coccoideae)

• 1 To contribute to the development of IPM strategies in olive groves, the selectivity of several insecticides to Pullus mediterraneus Fabr. (Coleoptera: coccinellidae) was investigated in the laboratory. The study assessed the toxicity of seven chemical pesticides and one bacteriological insecticide to adult P. mediterraneus.
• 2 The LC₅₀ was estimated by applying the pesticides on the dorsal side of adults. Lambda‐cyhalothrin, methomyl and cypermethrin resulted in the highest toxicity followed, in decreasing order of toxicity, by malathion, fenthion and dimethoate. Parathion had the least effect on the coccinellid.
• 3 Consumption of Bacillus thuringiensis bacteria (applied as a commercial formulation), over a period of 10 consecutive days, resulted in low mortality of adult P. mediterraneus.
• 4 The results of these laboratory experiments indicate that the most widely used chemical pesticides were toxic to P. mediterraneus. Their use in olive groves must take account of the activity period of this predator. In contrast, B. thuringiensis seemed to be a suitable candidate to be included in pest management systems.

     

Out of the Neotropics: Late Cretaceous colonization of Australasia by American arthropods

The origins of tropical southwest Pacific diversity are traditionally attributed to southeast Asia or Australia. Oceanic and fragment islands are typically colonized by lineages from adjacent continental margins, resulting in attrition of diversity with distance from the mainland. Here, we show that an exceptional tropical family of harvestmen with a trans-Pacific disjunct distribution has its origin in the Neotropics. We found in a multi-locus phylogenetic analysis that the opilionid family Zalmoxidae, which is distributed in tropical forests on both sides of the Pacific, is a monophyletic entity with basal lineages endemic to Amazonia and Mesoamerica. Indo-Pacific Zalmoxidae constitute a nested clade, indicating a single colonization event. Lineages endemic to putative source regions, including Australia and New Guinea, constitute derived groups. Divergence time estimates and probabilistic ancestral area reconstructions support a Neotropical origin of the group, and a Late Cretaceous (ca 82 Ma) colonization of Australasia out of the Fiji Islands and/or Borneo, which are consistent with a transoceanic dispersal event. Our results suggest that the endemic diversity within traditionally defined zoogeographic boundaries might have more complex evolutionary origins than previously envisioned.     

Prospects of botanical pesticides for the future in integrated pest management programme (IPM) with special reference to neem uses in Egypt

Botanically derived insecticides have gained favour in recent years. They are more safe or natural. Also, they are comparatively safe to natural enemies and higher organisms. Neem, pyrethrum, rotenone, nicotine, sabadilla, ryania and a number of different available botanicals were used to protect agricultural crops from the ravages of insects, mites and nematodes in different parts of the world. In Egypt, experiments were carried out on the efficacy of neem seed kernel extract fractions and formulations against different pests. Promising results were obtained showing feeding deterrency, repellency, toxicity, sterilant and growth disruptive activities. However, few of these can be exploited as crop protectants. Those that are proven to have sufficient efficacy against pests in the field and can be produced in adequate quantities are suitable candidates for commercial development.     

Non-target effects of kaolin and coppers applied on olive trees for the predatory lacewing Chrysoperla carnea

Kaolin clays and copper salts might be considered as alternative chemical control products for controlling olive pests in the contexts of both organic farming and integrated pest management programmes. Chrysoperla carnea (Stephens) (Neur. Chrysopidae) represents one of the most significant generalist predators of olive grove pests. In this study, we evaluated the side effects of these compounds on the predatory lacewing. First, kaolin and two copper salts (copper oxychloride and Bordeaux mixture) were tested on C. carnea eggs to determine their effects on egg viability and larval hatching suppression by topical application. Second, L₃ larvae were exposed to the pesticide residues on treated olive tree leaves. Third, a series of three residual tests in adults were sequentially performed as follows: residues on glass surfaces, on olive tree leaves and on small olive trees. Finally, kaolin- and water-treated eggs of Ephestia kuehniella Zeller (Lep. Pyralidae) were offered to L₃ larvae in both dual- and no-choice tests. C. carnea egg hatching was reduced by the kaolin treatment compared to the control treatment. Residual treatments were harmless to larvae and adults, without any deleterious effects on reproduction. L₃ larvae consistently preferred to feed on water-treated E. kuehniella eggs compared to kaolin-treated eggs. The larvae from the no-choice test that had fed ad libitum until pupation on kaolin-treated E. kuehniella eggs, pupated and emerged as healthy adults in reduced proportions compared with those that fed on water-treated eggs. In conclusion, our data suggest that both kaolin and copper products appeared to be largely harmless or only slightly harmful to the predator.     

Notch-mediated segmentation of the appendages is a molecular phylotypic trait of the arthropods

Arthropod limbs are arguably the most diverse organs in the animal kingdom. Morphological diversity of the limbs is largely based on their segmentation, because this divides the limbs into modules that can evolve separately for new morphologies and functions. Limb segmentation also distinguishes the arthropods from related phyla (e.g. onychophorans) and thus forms an important evolutionary innovation in arthropods. Understanding the genetic basis of limb segmentation in arthropods can thus shed light onto the mechanisms of macroevolution and the origin of a character (articulated limbs) that defines a new phylum (arthropods). In the fly Drosophila limb segmentation and limb growth are controlled by the Notch signaling pathway. Here we show that the Notch pathway also controls limb segmentation and growth in the spider Cupiennius salei, a representative of the most basally branching arthropod group Chelicerata, and thus this function must trace from the last common ancestor of all arthropods. The similarities of Notch and Serrate function between Drosophila and Cupiennius are extensive and also extend to target genes like odd-skipped, nubbin, AP-2 and hairy related genes. Our data confirm that the jointed appendages, which are a morphological phylotypic trait of the arthropods and the basis for naming the phylum, have a common developmental genetic basis. Notch-mediated limb segmentation is thus a molecular phylotypic trait of the arthropods.     

Using soil and litter arthropods to assess the state of rainforest restoration

Summary The present study investigated recolonization patterns of selected soil and litter arthropods following replanting of pasture with rainforest species in the Mary River catchment of eastern subtropical Australia. While extensive research has been conducted in rehabilitated mined sites in Australian dry sclerophyll forests, very little attention has been paid to rainforest restoration on previously pastoral land. We examined the utility of soil and litter arthropod groups for monitoring the progress of restoration, and the relationship between arthropod assemblage patterns and environmental factors potentially under the control of those doing the replanting. Leaf litter was extracted from 20 sites: five remnant rainforest, five pasture, and 10 sites that had been revegetated (from 1 to 12 years previously) with a diversity of indigenous species. Ants (identified to genus), centipedes, millipedes, isopods, amphipods and mites were enumerated and their assemblages described with multi- and univariate methods. Ant genera alone proved unable to distinguish pasture from rainforest, and mites (identified only to oribatid or non-oribatid) proved of limited use because these two groups were present in all samples in extremely high numbers that overwhelmed the contributions of other arthropod groups. However, a coarse taxonomic approach using five arthropod groups (ants, centipedes, millipedes, isopods, amphipods) clearly discriminated between pasture and rainforest, and also arranged the revegetated sites between these two extremes. Simple frequency scores based on the presence/absence of these arthropod groups in each of three replicate subplots were sufficient to achieve this separation of site types. Habitats created by close planting of trees and mulching may accelerate invertebrate colonization and, thus, promote the rapid establishment of processes and functions characteristic of developing rainforests.     

Efficacy of a physical method for control of direct pests of apples and peaches

Two studies were conducted to test the feasibility and efficacy of using physical barriers (Maggot Barrier^® nylon mesh bags) for control of three internal pests of tree fruit (codling moth (Cydia pomonella L.), apple maggot (Rhagoletis pomonella (Walsh)) and peach twig borer (Anarsia lineatella Zeller)) and three groups of external direct pests (stink bugs (Pentatomidae), plant bugs (Miridae) and birds). Two types of Maggot Barrier^® were tested (regular and heavy duty), and two methods of securing the bags: knotting the bag on itself (‘self‐ties’) and using plastic‐coated wire ‘twist‐ties’. Bags were applied to eight cultivars of both apples and peaches, selected to give a range of maturity dates. Apples were bagged when fruit was approximately 27 mm in diameter, and peaches when the fruit was approximately 36 mm in diameter. Unbagged fruits served as controls. On apples, bagging had no effect on damage due to birds, stink bugs or apple maggot (which was present only in very low numbers), but reduced codling moth damage by 20–25% compared with unbagged controls; there were no significant differences due to bag type or tie type. In apples, a significantly higher proportion of the heavy duty bags were reusable after harvest, but on peaches, which were bagged for a shorter time, there was no difference between bag types in this respect. Bagging significantly reduced the percentage of peach fruits damaged by twig borer, birds and stink bugs, but increased the percentage of fruit with skin marks; there were no significant differences between bag or tie types. In peaches, there were significant effects on the time taken to apply bags due to both tying method and differences between individual operators. Cultivar affected pest‐related damage in both fruit types, underlining the importance of appropriate cultivar choice in pest management, particularly for organic growers and home gardeners.     

Investigating the effects of crop type, fertility management and crop protection on the activity of beneficial invertebrates in an extensive farm management comparison trial

The activity of 11 groups of invertebrates, mainly predators and parasites, was investigated in 2005 and 2006 in a plot trial system on a farm in northern England, where the effects of organic and conventional fertility and crop protection management were separated within different crop types. Invertebrate activity was assessed using pitfall traps and suction sampling. Mixed effects models indicated that crop type significantly affected activity in all 11 groups. Crop protection applications had only a limited impact on activity but fertility management had considerable effects in some crops. Most differences were in barley, wheat and grass/clover, with less in vegetable and bean plots. Carabidae, Lycosidae, Staphylinidae, Linyphiidae and Braconidae gave consistent responses to fertility management, with more activity of the first two groups in organic plots and more of the other three in conventional plots. However, Coccinellidae and Ichneumonidae were not consistent in their activity between crops. After the effects of crop type had been partialled out, a constrained ordination showed that the novel combination of organic fertility and conventional crop protection had the most influence on group activity, with the combination of organic fertility and organic crop protection also significant. Maximising the activity of beneficial invertebrates in organic and sustainable farming systems requires a basic understanding of the effects of both crop type and fertility management, as well as crop protection.     

A macro-scale perspective on within-farm management: how climate and topography alter the effect of farming practices

Organic farming has the potential to reverse biodiversity loss in farmland and benefit agriculture by enhancing ecosystem services. Although the mixed success of organic farming in enhancing biodiversity has been attributed to differences in taxa and landscape context, no studies have focused on the effect of macro-scale factors such as climate and topography. This study provides the first assessment of the impact of macro-scale factors on the effectiveness of within-farm management on biodiversity, using spiders in Japan as an example. A multilevel modelling approach revealed that reducing pesticide applications increases spider abundance, particularly in areas with high precipitation, which were also associated with high potential spider abundance. Using the model we identified areas throughout Japan that can potentially benefit from organic farming. The alteration of local habitat-abundance relations by macro-scale factors could explain the reported low spatial generality in the effects of organic farming and patterns of habitat association.     

Laboratory pesticide screening method for the aphid predatory midge Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae)

A laboratory pesticide screening method is described for the aphid predatory midge Aphidoletes aphidimyza. Four acaricides, 10 fungicides, 11 insecticides and one herbicide, all of which are in common usage, were evaluated against both the adult and larval stages of the predator. The acaricide dienochlor, the fungicides benomyl, bupirimate, chlorothalonil, iprodione and hexaconazole, the herbicide tralkoxydim and the insecticides Bacillus thuringiensis and diflubenzuron were all safe to both adult and larval A. aphidimyza. Adults were more susceptible to the pesticides than larvae. Pesticide was exposed to adults as a residue on glass plates and to larvae on a leaf section mounted on agar. The leaf material remained healthy and supported host aphids for several days without deteriorating. The method and apparatus have potential for use with many other pests and beneficial organisms required to be caged for several days on detached leaf material.     

Explaining diversity of livestock-farming management strategies of multiple-job holders: importance of level of production objectives and role of farming in the household

We characterised the livestock-farming management strategies of multiple-job holders and identified which variables contributed most to the differentiation of these strategies. We hypothesised that they would mainly be differentiated by the contribution of the farming income to the total household income and the availability of the household members for farming. The multiple-job holding livestock-farmer's motivations, decisions and actions about both multiple-job holding and livestock farming were obtained in semi-directed interviews of 35 sheep farmers who held multiple jobs, on farm and off farm. They were synthesised into six variables characterising the diversity of the livestock-farming objectives and management guidelines. Thanks to a multiple factorial analysis, we showed that the diversity of the sheep-farming management strategies of multiple-job holders was better explained by two factors 'level of motivation of the farmer to get high technical results' and 'more personal fulfilling v. the family business conception of farming', than the factors we hypothesised. Within our sample, the performances ranged from 0.7 to 1.4 weaned lambs per ewe per year. Six sheep-farming management strategies were identified. They illustrated the importance of the level of production objectives and of farming income expectation, which were found to be independent, in explaining diversity. No direct relationship between farm work organisation and sheep-farming management strategy was identified. Explaining the diversity of the livestock-farming management strategies of multiple-job holders appears to require that all the benefits expected from farming and their hierarchy be identified before analysing how they are translated into production objectives and management guidelines.     

抗虫转基因植物对非靶标节肢动物生态影响的研究进展

重组DNA技术的发展为培育高效的抗虫作物提供了前所未有的便利条件。通过转基因技术,全世界已培育出众多转基因抗虫植物品系。其中,表达苏云金芽孢杆菌(Bt)基因的作物品系如Bt棉花和Bt玉米已在很多国家大规模种植,在害虫控制方面发挥了重要的作用。转基因抗虫作物可能带来的生态风险问题,如对农田非靶标节肢动物的潜在影响,一直受到相关研究者及民众的广泛关注。至今,已有大量研究论文发表。本文在总结、归纳前人研究的基础上,阐述了从实验室到田间多层次评价转基因抗虫作物对非靶标生物影响的一般研究程序和方法,并简要综述了Bt玉米和Bt棉花2种已商业化种植的转基因抗虫作物对农田非靶标节肢动物生态影响的研究进展。现有研究表明:当前种植的Bt作物所表达的Cry蛋白杀虫专一性非常强,对农田非靶标节肢动物没有毒性;且Bt作物的利用降低了广谱化学杀虫剂的施用量,从而提高了非专一性害虫天敌的种群密度,加强了对害虫的控制,并有效地保护了生态环境和农民健康。因此,Bt作物可以作为害虫综合防治(IPM)的一个策略,结合其他防治措施可加强对害虫的有效控制。     

有机稻田内不同生态措施对褐稻虱种群的控制作用

应用害虫生态控制理论和方法,以抗性品种、施用有机肥、种植对天敌具有助迁或保护作用的植物为基础,将稻田放鸭、薇甘菊(MikaniamicranthaKunth)乙醇提取物、现代苦楝油(MeliaazedarachL.)等各项生态措施,科学、合理地组配成褐稻虱Nilaparvatalugens(Stl)种群生态控制系统,研究其对褐稻虱种群的控制作用。结果表明稻田放鸭对褐稻虱若虫具有60.92%的控制效果,现代苦楝油200倍对褐稻虱种群的作用优于薇甘菊乙醇提取物1gDW·100mL-1,不同生态措施组合对褐稻虱自然种群的控制作用显著,但其联合作用效果与组合组分不成正比例增长。所组建的生态措施组合可将褐稻虱种群数量降至经济阈值以下,完全可达到持续控制褐稻虱种群的目的。     

Evaluation of organic,conventional and intensive beef farm systems: health,management and animal production

The overall aim of the present study was to analyse and compare organic beef cattle farming in Spain with intensive and conventional systems. An on-farm study comparing farm management practices and animal health was carried out. The study also focussed on a slaughterhouse analysis by comparing impacts on the safety and quality of the cattle products. Twenty-four organic and 26 conventional farms were inspected, and farmers responded to a questionnaire that covered all basic data on their husbandry practices, farm management, veterinary treatments and reproductive performance during 2007. Furthermore, data on the hygiene and quality of 244, 2596 and 3021 carcasses of calves from organic, intensive and conventional farms, respectively, were retrieved from the official yearbook (2007) of a slaughterhouse. Differences found between organic and conventional farms across the farm analysis did not substantially reflect differences between both farm types in the predominant diseases that usually occur on beef cattle farms. However, calves reared organically presented fewer condemnations at slaughter compared with intensive and to a lesser extent with conventionally reared calves. Carcass performance also reflected differences between farm type and breed and was not necessarily better in organic farms.     

Effects of weed harrowing frequency on beneficial arthropods,plants and crop yield

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Comparative evaluation of composts and dried powdered biomass of botanicals for organic management of downy mildew of sorghum

The biomass of 10 selected botanicals was evaluated as soil amendments, in the form of composts and dry powder biomass, to compare their potential to suppress downy mildew disease caused by oosporic inoculum of Perenosclerospora sorghi. Eight botanicals (Allium cepa, Lantana camara, Polyalthia longifolia, Hyptis suaveolens, Azadirachta indica, Nerium oleander Eucalyptus globulus and Tamarindus indica) proved effectively in the form of dry biomass powder at 4% (w/w) rate to control infection by oospores, while two (Croton sparsiflorus and Tagetes erecta) promoted it. In the form of composts (2% rate), the efficacy of botanicals was generally found reduced with the appearance of more disease than negative control in case of all botanicals except one (A. cepa). At the 4% compost rate, only four botanicals namely, A. cepa, P. longifolia, H. suaveolens and L. camara were found to suppress the disease. At higher amendment rates of 6, 8 and 10%, six botanicals suppressed the disease. Dry powders are not only superior in disease suppression but confer additional benefits like reduced bulk, increased shelf life, consistent composition and results.