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In JoVE (2)
- Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example
- Establishing Fungal Entomopathogens as Endophytes: Towards Endophytic Biological Control
Other Publications (4)
Articles by Soroush Parsa in JoVE
Characterizing Herbivore Resistance Mechanisms: Spittlebugs on Brachiaria spp. as an Example
Soroush Parsa, Guillermo Sotelo, Cesar Cardona
International Center for Tropical Agriculture, CIAT
This video explains mechanisms of host plant resistance to herbivory and demonstrates a no-choice test that estimates the relative contributions of antibiosis and tolerance to spittlebug resistance in Brachiaria spp.
Establishing Fungal Entomopathogens as Endophytes: Towards Endophytic Biological Control
Soroush Parsa1, Viviana Ortiz1, Fernando E. Vega2
1Entomology, International Center for Tropical Agriculture (CIAT), Cali, Colombia, 2Sustainable Perennial Crops Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, Maryland, USA
This protocol demonstrates two inoculation methods to introduce the fungal entomopathogen Beauveria bassiana as an endophyte in the common bean (Phaseolus vulgaris), in preparation for subsequent evaluations of endophytic biological control.
Other articles by Soroush Parsa on PubMed
Journal of Economic Entomology. Apr, 2011 | Pubmed ID: 21510177
Experimentation has been the cornerstone of much of integrated pest management (IPM) research. Here, we aim to open a discussion on the possible merits of expanding the use of observational studies, and in particular the use of data from farmers or private pest management consultants in "ecoinformatics" studies, as tools that might complement traditional, experimental research. The manifold advantages of experimentation are widely appreciated: experiments provide definitive inferences regarding causal relationships between key variables, can produce uniform and high-quality data sets, and are highly flexible in the treatments that can be evaluated. Perhaps less widely considered, however, are the possible disadvantages of experimental research. Using the yield-impact study to focus the discussion, we address some reasons why observational or ecoinformatics approaches might be attractive as complements to experimentation. A survey of the literature suggests that many contemporary yield-impact studies lack sufficient statistical power to resolve the small, but economically important, effects on crop yield that shape pest management decision-making by farmers. Ecoinformatics-based data sets can be substantially larger than experimental data sets and therefore hold out the promise of enhanced power. Ecoinformatics approaches also address problems at the spatial and temporal scales at which farming is conducted, can achieve higher levels of "external validity," and can allow researchers to efficiently screen many variables during the initial, exploratory phases of research projects. Experimental, observational, and ecoinformatics-based approaches may, if used together, provide more efficient solutions to problems in pest management than can any single approach, used in isolation.
Ecological Applications : a Publication of the Ecological Society of America. Mar, 2011 | Pubmed ID: 21563583
Modern restructuring of agricultural landscapes, due to the expansion of monocultures and the resulting elimination of non-crop habitat, is routinely blamed for rising populations of agricultural insect pests. However, landscape studies demonstrating a positive correlation between pest densities and the spatial extent of crop monocultures are rare. We test this hypothesis with a data set from 140 subsistence farms in the Andes and find the inverse correlation. Infestations by the Andean potato weevil (Premnotrypes spp.), the most important pest in Andean potato agriculture, decrease with increasing amounts of potato in the landscape. A statistical model predicts that aggregating potato fields may outperform the management of Andean potato weevils by IPM and chemical control. We speculate that the strong pest suppression generated by aggregating potato fields may partly explain why indigenous potato farmers cluster their potato fields under a traditional rotation system common in Andean agriculture (i.e., "sectoral fallow"). Our results suggest that some agricultural pests may also respond negatively to the expansion of monocultures, and that manipulating the spatial arrangement of host crops may offer an important tool for some IPM programs.
Explaining Andean Potato Weevils in Relation to Local and Landscape Features: a Facilitated Ecoinformatics Approach
PloS One. 2012 | Pubmed ID: 22693551
Pest impact on an agricultural field is jointly influenced by local and landscape features. Rarely, however, are these features studied together. The present study applies a "facilitated ecoinformatics" approach to jointly screen many local and landscape features of suspected importance to Andean potato weevils (Premnotrypes spp.), the most serious pests of potatoes in the high Andes.
The Cassava Mealybug (Phenacoccus Manihoti) in Asia: First Records, Potential Distribution, and an Identification Key
PloS One. 2012 | Pubmed ID: 23077659
Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae), one of the most serious pests of cassava worldwide, has recently reached Asia, raising significant concern over its potential spread throughout the region. To support management decisions, this article reports recent distribution records, and estimates the climatic suitability for its regional spread using a CLIMEX distribution model. The article also presents a taxonomic key that separates P. manihoti from all other mealybug species associated with the genus Manihot. Model predictions suggest P. manihoti imposes an important, yet differential, threat to cassava production in Asia. Predicted risk is most acute in the southern end of Karnataka in India, the eastern end of the Ninh Thuan province in Vietnam, and in most of West Timor in Indonesia. The model also suggests P. manihoti is likely to be limited by cold stress across Vietnam's northern regions and in the entire Guangxi province in China, and by high rainfall across the wet tropics in Indonesia and the Philippines. Predictions should be particularly important to guide management decisions for high risk areas where P. manihoti is absent (e.g., India), or where it has established but populations remain small and localized (e.g., South Vietnam). Results from this article should help decision-makers assess site-specific risk of invasion, and develop proportional prevention and surveillance programs for early detection and rapid response.