Colonization and Spatial Distribution of Boll Weevil in Commercial Cotton Fields

Abstract

The departure and arrival of boll weevil in cotton fields have fostered major control decisions against this pest over time. Field colonization and distribution of boll weevil were evaluated using cotton fields from 93.7 to 154 ha each, located in Serra da Petrovina and Campo Verde, both in the Cerrado biome of Mato Grosso State, Brazil, as a function of cotton field bordering vegetation and crop phenology. The monitoring of adult weevils was carried out using traps containing sex and aggregation pheromone. The traps were set up considering the four coordinates of the field, bordering vegetation, and distances from the field margin. Six traps were set in each direction with three representing the field margin (0 m, 60 m, and 120 m from the borderline) and the other three set up equidistant from the center of the field (> 200 m). Traps were evaluated weekly beginning 10 days after plant emergence (DAE) throughout the cotton phenology until harvesting. Boll weevils were caught in the first evaluation 10 DAE, irrespective of the vegetation bordering the cotton field and distance of trap from field margin. The average weevils per trap was relatively low throughout the crop development but increased significantly through the maturation and harvesting periods. Furthermore, the bordering vegetation was not the only determinant factor for boll weevil colonization and distribution throughout the cotton field. Based on these data, boll weevil exhibited early colonization, already occurring beyond the border of the field.

Spatio‐temporal distribution of Anthonomus grandis grandis Boh. in tropical cotton fields

“…Previous research on adult boll weevil in-field distributions used whole-plant sampling 14 and pheromone-based traps both possessing different dimensions for analyzing dispersion compared with the current approach. 8,15,41 Alternatively, application of kriging and other techniques to characterize in-field cotton pest distributions were used to describe spatial distribution of pests such as the pink bollworm, 42 cotton bollworm, 43,44 pentatomid stink bugs [45][46][47][48] and thrips. 49 Our study is the first to describe spatial distribution of the boll weevil with ordinary kriging.…”

“…10,11,13 The spatial distribution of boll weevils has been investigated using mean-variance relationships 4,14 without considering within-field spatial density distribution, or has been based on pheromone-baited trap captures. 15 The most accurate approach is the use of geostatistics because the position of the samples in space is accounted for. 16 Recent work reported that geostatistics is of particular interest for pest management because it allows inferences about the minimum inter-sample distance needed to obtain independent estimations and indicates patterns of distribution and colonization of an organism, all of which are crucial for the development of effective sampling programs.…”

“…Knowing a pest's distribution within a field can help to: (1) develop site‐specific sampling and control efforts; (2) predict pest movement; (3) improve insecticide‐resistance management; (4) conserve biological control agents by precision targeting sprays for the infested areas; and (5) reduce the economic, social and environmental costs associated with pest control 10,11,13 . The spatial distribution of boll weevils has been investigated using mean–variance relationships 4,14 without considering within‐field spatial density distribution, or has been based on pheromone‐baited trap captures 15 . The most accurate approach is the use of geostatistics because the position of the samples in space is accounted for 16 .…”

Field‐evolved resistance to beta‐cyfluthrin in the boll weevil: Detection and characterization

“…This observation supports the hypothesis that resistance selection in the past should be of a low order, considering that boll weevil would be exposed to insecticides only during the cotton season, with most individuals exposed to cotton pesticides likely dying before the next cotton cropping season. However, this hypothesis has been changed recently due to the observed presence of boll weevils in volunteer cotton plants developing in soybean and corn fields 14,51 . This occurrence of volunteer cotton appears to be due to the use of herbicide‐resistant cotton (Roundup Ready cotton), as these plants can survive the herbicide roundup® commonly used in these others 52 .…”

Planting Date of Cotton in the Brazilian Cerrado Drives Boll Weevil (Coleoptera: Curculionidae) Infestation

“…Hence, as soon as cotton plants are available for infestation again, dispersing adults will reinfest the plants from the refuge areas [32] or from surviving individuals in the area [33]. The existence of extensively cultivated areas established in large planting date windows may favor population build-up across the fields [34,35]. Therefore, planting dates can have an impact on pest outbreaks.…”