Effect of Streptomyces melanosporofaciens strain EF-76 and of chitosan on common scab of potato

The efficiency of Streptomyces melanosporofaciens strain EF-76, a geldanamycin producer, and of chitosan, a polymer derived from chitin that elicits plant defense mechanisms, to protect potato tubers against common scab was evaluated under both controlled and field conditions (years 2000 and 2001). S. melanosporofaciens EF-76 reduced disease incidence in the greenhouse assay and in the 2001 field assay. EF-76 also reduced symptom severity on potato tubers grown under field conditions. Chitosan provided a protective effect against S. scabies,the causal agent of potato common scab during the 2000 field assay by reducing both disease incidence and symptom severity. Combination of S. melanosporofaciensEF-76 and chitosan ensures a level of protection that was at least equivalent to the protection conferred by one of the two products used alone. In some instances, an additive effect of protection was observed when both products were used in combination. Combination of S. melanosporofaciensEF-76 and of chitosan thus represents a promising method of biocontrol against common scab.     

Does feeding on Bt-maize affect the slug Arion vulgaris (Mollusca: Arionidae)?

Via expression of Cry-proteins, toxic for specific insect groups, genetically modified Bacillus thuringiensis (Bt) maize offers an effective protection against insect pests. In a laboratory experiment with two transgenic and two non-transgenic maize varieties, a potential impact of Bt-maize was examined for the non-target slug Arion vulgaris. Lifetime after field collection, weight change and oviposition was examined for slugs fed with Bt-maize, non Bt-maize or dandelion (Taraxacum officinale). Test parameters were neither significantly different between transgenic and non-transgenic varieties nor among the maize varieties overall. Slugs fed with dandelion showed a significantly longer lifetime after field collection, gained significantly more weight and laid eggs. The results did not show a Bt-effect but indicated the general poor quality of maize as food resource for slugs.     

The interaction of protectants with EPTC on field bean, and tri-allate on wheat

Protectants (antidotes) were tested for their potential to protect field beans (Vicia faba L.) from EPTC damage, or wheat (Triticum aestivum L.) from triallate damage. For both crops there was considerable variation in the degree of protection shown from similar treatments in different experiments. For field bean, a seed treatment of 1,8-naphthalic anhydride (NA) at 5 mg/g seed gave some protection from EPTC applied pre-planting at 4–8 kg a.i./ha but not in all experiments. NA also caused marked chlorosis of the foliage. N, N-diallyl-2, 2-dichloroacetamide (R25788) at 20 mg/g seed severely damaged field bean in the absence of herbicide but 5 mg/g gave comparable protection from EPTC to that given by NA and did not cause chlorosis. Mixing R25788 with EPTC in the spray tank gave reduced protection. In a single experiment R4115 (chemistry undisclosed) gave some protection against EPTC damage. For wheat, a seed treatment of 5–20 mg/g NA sometimes countered damage from tri-allate applied pre-planting at 1 kg a.i./ha but not generally from higher doses. R25788 sometimes protected from weight loss due to tri-allate at 1 kg a.i./ha but not from damage symptoms, whereas R4115 at 20 mg/g seed alleviated these symptoms but did not prevent weight loss. R25788 at 4 kg a.i./ha mixed in the spray tank with the herbicide partially reduced weight loss and damage symptoms from a dose of 2 kg a.i./ha. Some treatments of R29148 gave complete protection from tri-allate at 1 kg a.i./ha. The results are discussed in the context of the full data from the two series of experiments.     

Comparing methods of weed seed exposure to predators

Several methods of seed exposure are used in seed predation studies, but how these methods influence the results remains poorly studied. In this article, two commonly used methods of seed exposure – seed cards and plasticine trays – were compared in the field and in the laboratory using three species of weed seeds. In the field, cards or trays with seeds were exposed either with or without cages to keep vertebrates out and either with or without impermeable roofs to provide protection from the weather. The overall seed retrieval from the control stands varied significantly between the methods of seed exposure, roof treatment and the species of seeds, and the scatter in the seed retrieval increased or decreased monotonically with the temperature or precipitation for some species of seeds. This indicates that the controls were more or less relevant depending on the weather conditions and species. The seed removal from cards varied between the species of seeds. The effect of exclosure cages indicated that invertebrates were the dominant seed predators of Capsella bursa‐pastoris, while in Poa annua and Stellaria media both vertebrates and invertebrates were important. Higher seed removal from plasticine trays compared to seed cards was found for all three species of seeds, and placing roofs over the seeds affected seed removal in C. bursa‐pastoris and P. annua. In the laboratory, seed consumption varied with the method of exposure in 10 out of 12 combinations of seed species and predator (two species of carabids and two species of isopods). The overall tendency was the opposite of the field observations: seed consumption was higher for seeds on filter paper and cards compared to seeds on tin trays. We conclude that seed cards are more convenient for short term studies in the field, while tin trays are useful in laboratory multi‐choice experiments. To measure the realistic consumption of invertebrate predators in the laboratory, filter paper seems to be the best option as it does not present an obstacle to predators eating the seed. Using roofs introduced further bias regarding the estimates of seed removal in the field and thus should be avoided.     

Studies in vitro and in vivo with powdery mildew fungicides

Droplets of 4-(i-cycloalkylalkyl)-2,6-dinitrophenols often protect areas of leaf very much greater than that of the initial deposit against powdery mildew. For a given alkyldinitrophenol, this type of protection is greater on apple than on marrow leaves. This zonal protection is not correlated with vapour activity in vitro or in vivo, or with inhibition of conidial germination in vitro, but is correlated with the degree of protection obtained when leaves are sprayed to give good cover. By contrast, crotonic esters of these alkyl-dinitrophenols do not show zonal activity, but nevertheless often exhibit protectant activity comparable with that of the parent phenols. These results suggest that exploitation of favourable hydrogen bonding characteristics in the fungicide molecule may lead to better control of fungal diseases in the field as a result of enhanced movement of fungicide in or on the leaf cuticle (zonal movement) or easier penetration of the fungal conidium.     

Mini‐plot field experiments using the rhabditid nematode Phasmarhabditis hermaphrodite for biocontrol of slugs

The nematode Phasmarhabditis hermaphrodita, a parasite of slugs, was cultured in vitro and applied as a drench in two outdoor mini‐plot field experiments to test the capacity of the nematode to protect Chinese cabbage seedlings and wheat seeds from damage by the field slug Deroceras reticulatum. The first experiment compared a single dose of nematodes (2 X 10¹⁰ ha^‐1) with methiocarb pellets added at the recommended field rate (5.5 kg.product ha^‐1 ) and untreated plots. Plots treated with either nematodes or methiocarb pellets had significantly less slug damage than untreated plots and, from the third week onwards, there was significantly less slug damage on plots treated with nematodes than on methiocarb‐treated plots. At the end of the experiment, 6 weeks after treatment, both slug numbers and biomass were significantly higher in untreated plots than in either methiocarb‐treated or nematode‐treated plots. In the second experiment, six nematode doses ranging from 1 X 10 ⁸ to 2 X 10¹⁰ ha^‐1 were compared with a standard rate application of methiocarb pellets and untreated plots. Plant protection improved with increasing nematode dose between 1 X10⁸ and 8 X 10⁸ha^‐1, but showed little or no further improvement at higher doses. Plant protection similar to that given by methiocarb pellets was provided by nematode doses of 8 X 10⁸ ha^‐1 and above.     

Attitude to Animals and Empathy: Comparing Animal Protection and General Community Samples

ABSTRACT

Although a number of studies have examined a range of demographic and personality variables that may impact upon attitudes towards the treatment of non-human species, little consensus has been reached within the literature. The aim of the current study was to evaluate and assess levels of human-directed empathy and attitudes towards the treatment of animals in two diverse populations, namely the general community (n = 543) and those within the animal protection field (n = 389). Both groups of participants completed the Attitude Towards the Treatment of Animals Scale (AAS) and the Davis Interpersonal Reactivity Index (IRI), a measure of human-directed empathy. Comparisons between the two samples indicated that those within the animal protection community scored more highly on both the animal attitude and human-directed empathy measures. Correlational analyses revealed a positive relation between AAS and IRI scores for both samples, whilst the strength of the correlation was greater for those within the animal protection sample. These findings are discussed.     

Green tea extracts as ultraviolet protectants for the beet armyworm,Spodoptera exigua,nucleopolyhedrovirus

The addition of a caffeinated green tea, Camellia sinensis L., filtrate (1%) to the nucleopolyhedrovirus (SeMNPV) of the beet armyworm, Spodoptera exigua (Hübner), provided almost complete protection following UVB irradiation (30 min) in laboratory tests. There were few differences in UV protection when extracts were prepared at 27 or at 90°C. Moreover, few differences in UV protection were demonstrated following infusion times of 5, 15, 30, and 60 min at 90°C. At a 1% concentration, decaffeinated and caffeinated green teas were equally effective as UV protectants. At lower concentrations (0.1, 0.01, and 0.001%) caffeinated green tea provided greater UV protection (UVB/UVB 30, 60 min). Virus/tea extracts (caffeinated), under field conditions at 1 and 5%, were ineffective as UV screens. At a 10% concentration, some UV protection was provided and UV protection further increased in a concentration-dependent manner.     

The role of selenium in protecting plants against prairie dog herbivory: implications for the evolution of selenium hyperaccumulation

Some plants can hyperaccumulate the element selenium (Se) up to 10,000 mg Se kg⁻¹ dry weight. Hyperaccumulation has been hypothesized to defend against herbivory. In laboratory studies high Se levels protect plants from invertebrate herbivores and pathogens. However, field studies and mammalian herbivore studies that link Se accumulation to herbivory protection are lacking. In this study a combination of field surveys and manipulative field studies were carried out to determine whether plant Se accumulation in the field deters herbivory by black-tailed prairie dogs (Cynomys ludovicianus). The Se hyperaccumulator Astragalus bisulcatus (two-grooved milkvetch) occurs naturally on seleniferous soils in the Western USA, often on prairie dog colonies. Field surveys have shown that this Se hyperaccumulator is relatively abundant on some prairie dog colonies and suffers less herbivory than other forb species. This protection was likely owing to Se accumulation, as judged from subsequent manipulative field experiments. When given a choice between pairs of plants of the Se hyperaccumulator Stanleya pinnata (prince’s plume) that were pretreated with or without Se, prairie dogs preferred to feed on the plants with low Se; the same results were obtained for the non-hyperaccumulator Brassica juncea (Indian mustard). Plants containing as little as 38 mg Se kg⁻¹ DW were protected from herbivory. Taken together these results shed light on the functional significance of Se hyperaccumulation and the possible selection pressures driving its evolution. They also have implications for the use of plants in Se phytoremediation, or as Se-fortified crops.     

Synergistic effects of Trichoshield on enhancement of growth and resistance to downy mildew in pearl millet

Trichoshield, a talc formulation consisting of spores of Trichoderma harzianum, Trichoderma lignorum, Gliocladium virens and Bacillus subtilis was tested, following different application methods, for its ability to promote growth of pearl millet plants and to induce resistance to downy mildew of pearl millet. Under laboratory conditions, trichoshield seed treatment enhanced seed germination and seedling vigor of pearl millet significantly over the control; under greenhouse conditions vegetative growth parameters like height, fresh and dry weight, leaf area and number of tillers were significantly enhanced over the control: Trichoshield formulation offered greater protection against downy mildew in comparison with individual strains of T. harzianum, T. lignorum, G. virensand B. subtilis. Among the methods of application, foliar spray was found to be a more efficient delivery method than seed treatment or slurry treatment. Combinations of foliar spray with seed treatment and slurry treatment produced the same effect as foliar spray alone. Under field conditions, trichoshield treatment enhanced reproductive parameters like number of earheads, length and girth of earheads, 1000 seed weight and yield significantly over the control. Days required for 50% flowering was reduced by 4 days compared to the control. Yield enhancement of 28% over the control was highly significant. Trichoshield treatment offered protection ranging from 52 to 71% under field conditions, depending on the application method. However, the chemical fungicide metalaxyl Apron provided the highest protection against downy mildew, both under greenhouse and field conditions.     

Synergies between site protection and agri‐environment schemes for the conservation of waders on lowland wet grasslands

Two conservation strategies have been put in place in Europe to address precipitous population declines of wading birds that breed on lowland wet grasslands. These are site protection and agri‐environment schemes (AESs) and the two are rarely compared, or their synergy assessed. Increasingly, efforts to recover populations of previously widespread species follow a landscape‐scale approach whereby habitat improvement takes place at key sites through partially overlapping protected area management and AESs. To investigate whether site protection and AESs improve the conservation status of breeding waders and how these interact, we partially repeated a 2002 survey of breeding waders on protected areas (nature reserves and Sites of Special Scientific Interest) and sites with wader‐specific AES options in England in 2009 and 2010. We then assessed the individual and combined effects of these delivery mechanisms on field occupancy, breeding density and population change of four species of declining wader (Northern Lapwing Vanellus vanellus, Common Snipe Gallinago gallinago, Eurasian Curlew Arquata numenius and Common Redshank Tringa totanus). Although results for Curlew differed from the other species, in general field occupancy was positively influenced by conservation delivery mechanisms, with the highest occupancy and breeding densities on land where site protection was combined with wader‐specific AES options. Field occupancy varied between different types of AES, with higher occupancy associated with higher‐level options in fields, particularly those on nature reserves. Outside nature reserves, the history of AES management did not influence wader populations, but within nature reserves and on fields that gained AES management between 2002 and 2009–2010, populations of Curlew and Snipe were more likely to have persisted and population change in Snipe and Lapwing was more positive. We conclude that the conservation of breeding waders will be most effective when site protection and AES management are combined on the same land. Using limited AES money to support management for breeding waders on, around and between the existing network of protected sites will protect remaining populations while presenting opportunities for population expansion in future.     

液体植物保护膜防治瓜实蝇的效果评价

【背景】瓜实蝇是一种重要的世界性检疫害虫,广泛分布在我国的热带、亚热带地区。在室内和田间测定了液体植物保护膜对瓜实蝇的控制效能,并初步探索了该保护膜的作用方式,以期为瓜实蝇的绿色防控提供一定的技术支撑。【方法】测定了应用保护膜后瓜实蝇的产卵、存活以及对苦瓜的为害率。【结果】保护膜显著影响了瓜实蝇产卵、存活以及选择性。随着保护膜浓度的升高,瓜实蝇的存活率和在供试苦瓜段上的产卵量逐渐下降,但300和400倍保护膜之间的差异不显著。当浓度达到400倍时产卵量最低,为0.33粒,死亡率最高,约为50%;室内研究发现保护膜可持续影响瓜实蝇产卵5 d;此外,通过将保护膜应用在损伤的苦瓜上,发现保护膜并没有抑制瓜实蝇产卵。在田间,研究发现苦瓜的果长影响了保护膜的应用效能,2种果长的苦瓜应用保护膜后12~14 cm苦瓜的被害率显著低于6~8 cm苦瓜的被害率。【结论与意义】400倍的植物液体保护膜是防治瓜实蝇的最佳浓度,应用时间建议每4 d一次。保护膜最合适的应用时期为果长发育至12~14 cm时,即生长后期。施用保护膜时一定均匀,且在寄主果实受到损伤时不宜喷施保护膜。     

Lethal and repellent effects of transfluthrin and metofluthrin used in portable blowers for personal protection against Ochlerotatus togoi and Aedes albopictus (Diptera: Culicidae)

The lethal efficacy of three vaporizing insecticides – 0.6% transfluthrin and 0.6% metofluthrin in portable battery‐powered blowers and 2.5% bioallethrin in electric mats – was assessed in unventilated and ventilated screened room conditions against Ochlerotatus togoi (Theobald) females. The mosquitoes were highly susceptible to transfluthrin and metofluthrin. Mean mortality rates of mosquitoes exposed to transfluthrin and metofluthrin in portable blowers ranged from 95 to 100% at a distance of 10 cm from mosquito cages in both room conditions; this was a >2.4‐fold greater mortality rate than for mosquitoes exposed to bioallethrin in electric mats under the same conditions (mean 40%). The three insecticides showed a decrease in mortality rate at a distance of 70 cm: rates were <5.0, 32.5, 85.0 and 90.0% for 10, 30, 60, and 120 min after exposure, respectively, for the same exposure periods in a closed room. In semi‐field repellent tests with human volunteers, 0.6% concentrations of transfluthrin and metofluthrin provided mean biting protection of 76.1 and 59.9% on legs, 68.5 and 52.1% on arms, 63.4 and 63.1% on the chest, and 87.1 and 52.9% on the face, respectively. In field tests, 0.6% transfluthrin effectively repelled Armigeres subalbatus and Aedes albopictus, with mean biting protection of 85.4 and 89.3% on exposed legs and arms, respectively, of the human volunteers. Metofluthrin at 0.6% also effectively repelled Ar. subalbatus, with mean biting protection levels of 71.8 and 73.5% on the legs and arms, respectively. There was no significant difference of repellent activity between the two vaporizing insecticides in the field.     

Rhizobacterially induced protection of watermelon against Didymella bryoniae

Aims: To identify rhizobacteria from the Mekong Delta of Vietnam, which can systemically protect watermelon against Didymella bryoniae and elucidate the mechanisms involved in the protection conferred by isolate Pseudomonas aeruginosa 23_1‐1. Methods and Results: Bacteria were isolated from watermelon roots and their antagonistic ability tested in vitro. Of 190 strains, 68 were able to inhibit D. bryoniae by production of antibiotics. Four strains were able to reduce foliar infection by D. bryoniae when applied to watermelon seeds before sowing. Strain Ps. aeruginosa 23_1‐1 was chosen for investigations of the mechanisms involved in protection and ability to control disease under field conditions. In the field, the bacterium was able to significantly reduce disease in two consecutive seasons and increase yield. Furthermore, it colonized watermelon plants endophytically, with higher numbers in plants infected by D. bryoniae than in noninoculated plants. To elucidate the mechanisms involved in protection, the infection biology of the pathogen was studied in bacterially treated and control plants. Pseudomonas aeruginosa 23_1‐1 treatment inhibited pathogen penetration and this was associated with hydrogen peroxide accumulation, increased peroxidase activity and occurrence of new peroxidase isoforms, thus indicating that resistance was induced. Conclusions: The endophytic bacterium Ps. aeruginosa 23_1‐1 can control D. bryoniae in watermelon by antibiosis and induced resistance under greenhouse and field conditions. Significance and Impact of the Study: These findings suggest that rhizobacteria from native soils in Vietnam can be used to control gummy stem blight of watermelon through various mechanisms including induction of resistance.     

Use of lichen secondary metabolites as antifeedants to protect higher plants from damage caused by slug feeding

Extracts of 15 species of lichen were tested for antifeedant properties against the field slug Deroceras reticulation (Müller) (Mollusca: Pulmonata). All but three showed some activity and two of these were from endolithic species. The most effective extract was from Letharia vulpina. The major active compound from this species, vulpinic acid, was tested for dose response, applied as a foliar spray to turnip plants and as a dressing to wheat seeds in laboratory experiments. It provided effective protection against slug feeding under these conditions.     

Responses of a sterile red fungus to soil types,wheat varieties and the presence of certain isolates ofStreptomyces

The biological activities of a sterile red fungus (SRF) capable of plant growth promotion and suppression of take-all disease were investigated in soils collected from Lancelin, Newdegate and Mt. Barker regions of Western Australia. Further, the effects of three wheat cultivars and the presence of two isolates ofStreptomyces on the biological activities of the SRF were tested using the Lancelin soil. The biological activities of the SRF were greatest in the Lancelin and Newdegate (wheat field) soils and with the wheat cultivar Gutha. In in vitro studies the soil streptomycetes tested showed either a significant increase in the exudate production by the SRF, which had antifungal and growth promoting properties, or an inhibition of growth of the fungus. Streptomycete A63 which stimulated the exudate production by the SRF in vitro, however, did not enhance disease protection in vivo. On the other hand, protection from root rot by the SRF in vivo was reduced in the presence of the streptomycete isolate Ax which is capable of inhibiting the growth of the SRF in vitro.     

Extrafloral nectary-bearing plant Mallotus japonicus uses different types of extrafloral nectaries to establish effective defense by ants

Extrafloral nectary (EFN)-bearing plants attract ants to gain protection against herbivores. Some EFN-bearing plants possess different types of EFNs, which might have different effects on ants on the plants. Mallotus japonicus (Thunb.) Muell. Arg. (Euphorbiaceae) bears two types of EFNs, including a pair of large EFNs at the leaf base and many small EFNs along the leaf edge. This study aimed to determine the different roles of the two types of EFNs in biotic defense by ants. A field experiment was conducted to investigate the effect of leaf damage on EFN production and on the distribution pattern of ants. After leaf damage, the number of leaf edge EFNs increased in the leaves first-produced. The number of ants on the leaves also increased, and the foraging area of ants extended from the leaf base to the leaf tip. An EFN-covering field experiment revealed that leaf edge EFNs had a greater effect than leaf base EFNs on ant dispersal on leaves. The extended foraging area of ants resulted in an increase of encounter or attack rate against an experimentally placed herbivore, Spodoptera litura. These results suggest that M. japonicus plants control the foraging area of ants on their leaves using different types of EFNs in response to leaf damage, thus achieving a very effective biotic defense against herbivores by ants.

     

Factors affecting crop damage by wild boar and methods of mitigation in a giant panda reserve

In China, following the introduction of protection measures, wild boar (Sus scrofa) are returning to forested mountains they previously inhabited and conflict in villages near or within areas under protection has intensified. We studied this phenomenon around a giant panda nature reserve in the Qinling Mountains, China to determine the incidence and frequency of wild boar damage and methods of mitigation. Over a 3-year period, we found that almost half of households in the local village sustained crop damage, that wild boar frequently raided maize (Zea mays), potato (Ipomoea batatas), and wheat (Triticum aestivum) adjoining the reserve, and that boar usually raided croplands at night and preferred the actual crops. The distance between maize fields and mountains or a stream predicted the probability of a field being raided and also the severity of the damage. Local farmers used many methods to protect their crops; however, all were ineffective except increasing the presence of humans in fields.     

Spatial proximity between two host plant species influences oviposition and larval distribution in a leaf beetle

Everything else being equal, insect herbivores can be expected to oviposit on host plants that provide the qualitatively and quantitatively best food for larvae. However, the selection of a plant for oviposition may be influenced by such ecological factors as natural enemies, host distribution, host patch size or host patch density. We performed a field study to test whether spatial proximity between two host plant species influences the oviposition patterns and larval distribution of the alpine leaf beetle Oreina elongata. In the population studied, O. elongata oviposits and feeds on two host plants, that belong to the same family (Asteraceae): Adenostyles alliariae and Cirsiumspinosissimum. The first species contains pyrrolizidine alkaloids that are sequestered by the beetle as a chemical defence, whereas the second plant does not contain any alkaloids but has hairy and spiny leaves that might give some mechanical protection to beetle larvae.
During two consecutive summers, we quantified oviposition and larval distribution on randomly chosen C. spinosissimum that grew spatially isolated from A. alliariae, on C. spinosissimum that grew in leaf contact with A. alliariae and on A. alliariae that grew in leaf contact with C. spinosissimum (isolated A. alliariae was not considered, because it is rare in the study population). In both years, more eggs were laid on C. spinosissimum than on A. alliariae and more on those C. spinosissimum that were growing close to A. alliariae than on those growing isolated. Large numbers of larvae moved from C. spinosissimum to A. alliariae during the season. Patch size did not influence egg and larval numbers. Eggs survived better on C. spinosissimum than on A. alliariae in the field. The data suggest that C. spinosissimum may provide eggs with better protection against stormy weather. In a separate study of the same population, we found that larval performance was better on A. alliariae than on C. spinosissimum. Our present data suggest that O. elongata preferentially oviposits on plants of the species that maximizes egg survival and that grow in close proximity to plants of the species that provides better food and chemical defence.     

Effect of seed depth on slug damage to winter wheat

In a field experiment drilled at two depths on three dates in autumn 1988, with or without methiocarb pellets broadcast on the soil surface immediately after drilling, 26% of seeds of winter wheat sown at c. 20 mm depth were killed by slugs compared with only 9% of seeds sown at c. 40 mm. The protection from slug damage provided by this additional 20 mm of depth was comparable with that provided by methiocarb pellets. The effects of seed depth and pellet application did not interact and were consistent on all drilling dates. Thus, fewest seeds and seedlings were killed where methiocarb pellets were broadcast on a seed-bed with seeds sown at 40 mm depth. Intermediate damage was recorded where seeds were sown at 40 mm depth without pellets, or where pellets were broadcast on seeds sown at 20 mm depth. Most seeds and seedlings were killed where seeds were sown at 20 mm depth without pellets. Sublethal damage to seedlings was not affected by sowing depth but was reduced where pellets were broadcast immediately after sowing.