CABI

About: CABI is a nonprofit organization based out in Wallingford, United Kingdom. It is known for research contribution in the topics: Population & Introduced species. The organization has 789 authors who have published 1759 publications receiving 73843 citations. The organization is also known as: Centre for Biosciences and Agriculture International.

Recruitment of native parasitoids by an exotic leaf miner, Cameraria ohridella: host-parasitoid synchronization and influence of the environment

Abstract: 1The horse-chestnut leaf miner, Cameraria ohridella, is a moth of unknown origin that has recently invaded Europe and severely defoliates the European horse-chestnut, an important ornamental tree. 2Several indigenous parasitoids have colonized this new host, but parasitism remains low. One of the hypotheses suggested to explain the low parasitism is that candidate parasitoids emerge too early in spring to attack the first host generation and, thus, need early-occurring leaf miners as alternate hosts. This hypothesis was tested by observing the synchronization between the phenology of the moth and that of its main parasitoids, and by comparing parasitism rates and parasitoid richness in different environments with various levels of biological diversity. 3In spring, the bulk of the parasitoids emerge at least 5 weeks before the occurrence of the first suitable larvae of C. ohridella whereas most parasitoid adults reared outdoors die within 5 weeks after emergence. 4Parasitism rates and parasitoid richness do not increase with biological diversity, suggesting that most parasitoids attacking the first generation of C. ohridella do not come from alternate hosts. Parasitism does not increase later in the year in the subsequent generations, when host-parasitoid synchronization becomes less critical. 5We conclude that, although the spring emergence of parasitoids is not synchronized with the phenology of C. ohridella, the parasitoids attacking the first generation are probably old or late-emerging adults of the overwintering generation. The lack of synchronization is probably not the only reason for the poor recruitment of native parasitoids by C. ohridella.

Roles of stolbur phytoplasma and Reptalus panzeri (Cixiinae, Auchenorrhyncha) in the epidemiology of Maize redness in Serbia

Abstract: Maize redness (MR), a disease causing midrib, leaf and stalk reddening and abnormal ear development in maize, has been reported from Serbia, Romania and Bulgaria for 50 years. Recent epiphytotics reduced yields by 40%–90% in southern Banat, Serbia. MR was recently associated with the presence of the stolbur phytoplasma, although the epidemiology of the disease remained unknown. Diseased fields in southern Banat were surveyed for potential vectors of the phytoplasma during 2005 and 2006, and high populations of Reptalus panzeri were found. In affected fields, 20% of the R. panzeri individuals and 85% of symptomatic maize plants carried the stolbur phytoplasma. When stolbur phytoplasma-infected R. panzeri were introduced into insect-free mesh cages containing healthy maize plants, midrib and leaf reddening developed on 48% of plants and stolbur phytoplasma was detected in 90% of the symptomatic plants. No symptoms or phytoplasma-positive plants were found in cages without insects. These data indicate that MR symptoms are associated with the stolbur phytoplasma. Reptalus panzeri is both abundant in affected fields and can transmit the stolbur phytoplasma, indicating the insect is likely to be a major vector of MR.

Comparative efficacy assessment of fungi, nematodes and insecticides to Control western corn rootworm larvae in maize

Abstract: All three larval instars of Diabrotica virgi- fera virgifera LeConte (western corn rootworm, Coleoptera: Chrysomelidae) feed on the roots of maize, Zea mays (L.). We assessed the efficacies of the following four agents in controlling these larvae: (1) the entomopathogenic fungus Metarhizium anisopliae (Metsch.) Sorokin (Hypocreales: Clavicipitaceae), (2) the nematode Heterorhabditis bacteriophora Poinar (Nematoda: Rhabditida), (3) a tefluthrin-based soil insecticide and (4) clothianidin-coated seeds. The agents were applied in field plot experiments in southern Hungary in 2006 and 2007. Efficacy was assessed by comparing the number of emerging D. v. virgifera adults and corresponding root damage among treatments and untreated controls. All agents significantly reduced D. v. virgifera numbers and root damage, but the relative success of each treatment was variable. On average across fields and years, the nematode and the two insecticides reduced D. v. virgifera by 65 ± 34% SD, while the fungus reduced D. v. virgifera by 31 ± 7%. According to the node injury scale, the agents prevented 23-95% of potential root damage. Large-scale commer- cialisation of these biological agents could offer viable and practical control options against D. v. virgifera.

Going Public: A New Extension Method

Abstract: Contemporary agricultural extension uses intensive face-to-face communication, especially for teaching farmers about pest and disease management. Development scholars are increasingly concerned about the cost of these programmes, and some are trying to reach more farmers through mass media. Small media is another recent option. We have developed a novel method of face-to-face extension, which we call Going Public. It makes use of places where farmers meet spontaneously, such as markets, bus terminals and other public places, to create a two-way learning channel. Going Public allows scientists, extensionists and farmer experts to show things to people, answer questions, run short experiential learning exercises and potentially to distribute material, as in any other face-to-face method, but it is quick and it allows contact with people from many areas at once. It also allows scientists to gather feedback from farmers in a social setting where the farmers are comfortable, surrounded by their friends and nei...

The role played by invasive species in interactions with endangered and threatened species in the United States: a systematic review

Abstract: Invasive species are considered to be a leading cause of the decline of threatened species. However, this view has been disputed because much of the evidence base is anecdotal. This systematic review, through an extensive, repeatable search using agreed selection criteria, examined the available scientific evidence on invasive species’ interactions with the 1363 endangered and threatened species protected under the United States Endangered Species Act (ESA). The review found scientific evidence available for 116 endangered or threatened species (8.5% of the ESA list). Of these, 85 species (6.2%) were reported as being negatively impacted by invasive species: 39 located on the continental US and 39 on islands, with seven marine species. The relative percentages of species impacted differed according to location: 4.3% (n = 906) on the continental US, 9.3% (n = 420) on islands. It was found that predation by invasive vertebrates on birds on islands and competition between invasive plants and endangered or threatened plants on the mainland were the main mechanisms of impact. The results of this study contrast markedly with a previous study which found that 49% of imperilled species in the United States were threatened by invasive species. Further research is essential in order to evaluate the impact of invasive species on imperilled species on the ESA list; this would help to reduce the high degree of uncertainty regarding the threat of invasive species due to the lack of empirical information.