Submitted to: Congreso Nacional de Entomologia Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/25/2007
Publication Date: 7/25/2007
Citation: Lapointe, S.L. 2007. Ecologia Quimica y Expansion Geografica del Gorgojo Polifago Diaprepes abbreviatus (Coleoptera: Curculionidae). Congreso Nacional de Entomologia Proceedings. July 25-27,2007. Interpretive Summary: The invasive and highly polyphagous weevil, Diaprepes abbreviatus, was previously found only in the Caribbean and, since 1964, in the state of Florida. In recent years, it has been discovered in California and Texas where attempts are underway to eradicate the pest. Scientists at the USDA, ARS U.S. Horticultural Research Lab at Ft. Pierce, FL and USDA, APHIS at Raleigh, NC have modeled the ecological niche of this species and produced maps that predict the areas of the southern United States susceptible to invasion by D. abbreviatus. Progress is also being made in the discovery of a chemical attractant based on plant odors and possible insect pheromones. This will provide an important tool for researchers and pest control operators in their efforts to contol this damaging insect pest.
Technical Abstract: The tropical root weevil, Diaprepes abbreviatus (L.), has been a pest of citrus and ornamental plants since its introduction into Lake County, FL in 1964. Since then, it has colonized the Florida peninsula to the south of its point of introduction, but has not expanded its range to the north. A lower threshold for oviposition by D. abbreviatus was estimated as 14.9°C. Archived weather data from Florida was examined to guide a mapping exercise using the lower developmental threshold for larvae (12°C) and the lower threshold for oviposition (15°C) as critical temperatures for mapping the distribution of D. abbreviatus and the potential for establishment of egg parasitoids. Probability maps using the last 10 years of weather data examined the frequency of at least 10, 15, 20, 25, or 30 d per winter when soil temperature was <12°C. The geographic area that experienced between 15 and 20 d per winter with mean daily soil temperature <12°C closely approximated the northern limit of D. abbreviatus in Florida. Homologous maps of Arizona, California, and Texas in the US, and of Central and South America predict the areas where soil temperatures favor establishment of D. abbreviatus and it natural enemies. Progress in the identification of a chemical attractant for D. abbreviatus is described including the discovery of a putative aggregation pheromone.