Fertility Life Table, Thermal Requirements, and Ecological Zoning of Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae) in Brazil

Simple Summary The boll weevil is a key pest of cotton in Central and South America. Its thermal requirements, development time, oviposition, survival, adult longevity, and sex ratio were determined under laboratory conditions, and the data were used to construct a fertility life table. Based on the results and a GIS (Geographic Information System), the R-0 was estimated for different Brazilian regions and represented on a map. This information can be useful for developing strategies to manage the pest in cotton crops. The boll weevil, Anthonomus grandis grandis Boh., is the most important cotton pest in Central and South America. The biological characteristics and thermal requirements of boll weevils reared on an artificial diet were assessed at seven constant temperatures (18, 20, 22, 25, 28, 30, and 32 & PLUSMN; 1 & DEG;C) under laboratory conditions. These data were used to determine the ecological zoning for the pest in Brazil. The development time; oviposition period; the number of eggs produced; survival of eggs, larvae, and pupae; adult longevity; and sex ratio were recorded, and additional life table parameters were calculated. The total development duration ranged from 16.1 (32 & DEG;C) to 46.2 (18 & DEG;C) days. Temperature significantly affected the number of eggs laid per female (fecundity), with the highest number of eggs observed at 25 & DEG;C (251 & PLUSMN; 15.8). The parameters from the fertility life table indicated the greatest population growth at 25 & DEG;C and 28 & DEG;C. The net reproductive rate (R-0) at these temperatures was 22.25 times higher than at 18 & DEG;C. Based on R-0 and temperature, an ecological zoning of the pest was developed for Brazil. Brazilian regions with mean temperatures above 20 & DEG;C and below 30 & DEG;C are most favorable for the population growth of the boll weevil. The most suitable crop areas were found to be the north, midwest, and part of the northeast region, although the weevil can occur throughout Brazil if the host plants are available.