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Archive for the ‘biological control’ Category

Impact of the rosette weevil on yellow starthistle

March 13, 2017 Leave a comment

Yellow starthistle (Centaurea solstitialis L.) (YST) is an invasive weed native to the Mediterranean region with a geographical centre of diversity in Turkey. It is widely established in Chile, Australia, and western North America. It arrived in California as a contaminant in alfalfa seed in 1859 and, by 2002, had infested more than 7.7 million hectares in the U.S.A. Biological control of YST using capitula feeding weevils, picture wing flies and a foliar rust pathogen has been ongoing in the western U.S.A. for more than three decades with limited success. Modelling and field research suggest natural enemies that kill whole plants and/or reduce seed production of survivors are good candidates for successful biological control. A candidate species with some of these attributes is the rosette weevil Ceratapion basicorne (Illiger). In the present study, a model of the rosette weevil is added to an extant system model of YST and its capitula feeding natural enemies and, in a GIS context, is used to assess YST control in the Palearctic region and the weevil’s potential impact on YST in western U.S.A. The results obtained suggest densities of mature YST plants in western U.S.A. would be reduced by 70–80% in many areas.

Gutierrez A.P., Ponti L., Cristofaro M., Smith L., Pitcairn M.J., 2016. Assessing the biological control of yellow starthistle (Centaurea solstitialis L.): prospective analysis of the impact of the rosette weevil (Ceratapion basicorne (Illiger)). Agricultural and Forest Entomology, https://doi.org/10.1111/afe.12205

The rosette weevil Ceratapion basicorne.
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Invasion biology of Drosophila suzukii

May 11, 2016 Leave a comment

The Asian vinegar fly Drosophila suzukii [spotted wing Drosophila (SWD)] has emerged as a major invasive insect pest of small and stone fruits in both the Americas and Europe since the late 2000s. While research efforts have rapidly progressed in Asia, North America, and Europe over the past 5 years, important new insights may be gained in comparing and contrasting findings across the regions affected by SWD. In this review, common themes in the invasion biology of SWD are explored by examining (1) its biology and current pest status in endemic and recently invaded regions; (2) current efforts and future research needs for the development of predictive models for its geographic expansion; and (3) prospects for both natural and classical (=importation) biological control of SWD in invaded habitats, with emphasis on the role of hymenopteran parasitoids. The review concludes that particularly fruitful areas of research should include fundamental studies of its overwintering, host-use, and dispersal capabilities; as well as applied studies of alternative, cost-effective management techniques to complement insecticide use within the integrated pest management framework. Finally, we emphasize that outreach efforts are critical to effective SWD management by highlighting successful strategies and insights gained from various geographic regions.

Asplen M.K., Anfora G., Biondi A., Choi D-S., Chu D., Daane K.M., Gibert P., Gutierrez A.P., Hoelmer K.A., Hutchison W.D., Isaacs R., Jiang Z-L., Kárpáti Z., Kimura M.T., Pascual M., Philips C.R., Plantamp C., Ponti L., Vétek G., Vogt H., Walton V.M., Yu Y., Zappalà L., Desneux N., 2015. Invasion biology of spotted wing drosophila (Drosophila suzukii): a global perspective and future priorities. Journal of Pest Science, 88: 469-494. http://dx.doi.org/10.1007/s10340-015-0681-z

Drosophila suzukii (http://www.terraevita.it/drosophila-suzukii-danni-e-contromisure/).

Invasive species and climate change: the PBDM approach

September 12, 2014 Leave a comment

Assessing the geographic distribution and abundance of invasive species is critical for developing sound management and/or eradication policies. Ecological niche modelling approaches (ENMs) that make implicit assumptions about biology and mathematics are commonly used to predict the potential distribution of invasive species based on their recorded distribution. An alternative approach is physiologically based demographic modelling (PBDM), which explicitly incorporates the mathematics and the observed biology, including trophic interactions, to predict the temporal phenology and dynamics of a species across wide geographic areas. The invasive weed, yellow starthistle (YST) (Centaurea solstitialis), and its interactions with annual grasses and herbivorous biological control agents is used to demonstrate the utility of the PBDM approach for analysing complex invasive species problems. The PBDM predicts the distribution and relative abundance of YST accurately across the western USA, and the results are used to assess the effects of temperature, rainfall, competition from grasses and the efficacy of biocontrol efforts. Such an effort could also be used to include the direct effects of rising carbon dioxide on YST biology. A bioeconomic model could be developed to show how the YST PBDM analysis can also be used to assess the biological and economic effects of climate change on YST infestation levels regionally. Finally, this chapter discusses the need for a unified system for assessing invasive species problems at the field, regional and global levels, with the goal of enhancing the development of efficacious policy and management decisions.

Gutierrez A.P., Ponti L., 2014. Assessing and managing the impact of climate change on invasive species: the PBDM approach. In: Ziska L.H., Dukes J.S., (eds.), Invasive Species and Global Climate Change. CABI Publishing, Wallingford, UK. ISBN: 978-1780641645. http://www.cabi.org/bookshop/book/9781780641645

Trophic interactions in the yellow starthistle PBDM system.

Asian citrus psyllid and citrus greening disease

December 2, 2013 Leave a comment

The invasive Asian citrus psyllid Diaphorina citri Kuwayama vectors the bacterial pathogen ‘Candidatus Liberibacter asiaticus’ that is the putative causal agent of citrus greening disease (Huanglongbing disease) in citrus in many areas of the world. The capacity to predict the potential geographic distribution, phenology and relative abundance of the pest and disease is pivotal to developing sound policy for their management. A weather-driven physiologically based demographic model (PBDM) system is developed that summarizes the available data in the literature, and used to assess prospectively the geographic distribution and relative abundance of citrus, the psyllid, its parasitoid (Tamarixia radiata Waterston), and citrus greening disease in North America and the Mediterranean Basin. The potential for natural and biological control of citrus psyllid is examined prospectively.

Gutierrez A.P., Ponti L., 2013. Prospective analysis of the geographic distribution and relative abundance of Asian citrus psyllid (Hemiptera: Liviidae) and citrus greening disease in North America and the Mediterranean Basin. Florida Entomologist, 96:1375-1391. http://dx.doi.org/10.1653/024.096.0417

Deconstructing the control of the spotted alfalfa aphid

May 14, 2013 Leave a comment

Control of insect pests and other taxa may be due to many factors that are difficult to separate and quantify as was the case for the control of the spotted alfalfa aphid (SAA, Therioaphis maculata Monell) in California and elsewhere. Introduced parasitoids, host plant resistance, pathogens and native predators led to its successful control, but the relative contribution of each factor remained largely unknown. The relative contribution of each control factor was estimated using a weather-driven physiologically-based demographic system model consisting of alfalfa, SAA (a), its three exotic parasitoids [Trioxys complanatus (Quilis) (b), Praon palitans Muesebeck (c), and Aphelinus semiflavus Howard (d)], a native coccinellid beetle [Hippodamia convergens (Guérin-Menéville)], a fungal pathogen [Erynia neoaphidis Remaudière & Hennebert (Zygomycetes: Entomophthorales) (g)], and host plant resistance (HPR) (h). Alone, each factor failed to control SAA, as did combinations of the parasitoids and coccinellid predation (f). Control was predicted across all ecological zones only when all mortality factors were included (i).

Gutierrez A.P., Ponti L., 2013. Deconstructing the control of the spotted alfalfa aphid Therioaphis maculata. Agricultural and Forest Entomology, 15: 272-284.
http://dx.doi.org/10.1111/afe.12015