Effects of Burial and Soil Condition on Postharvest Mortality of Boll Weevils (Coleoptera: Curculionidae) in Fallen Cotton Fruit

Greenberg, S. M.; Showler, Allan T.; Sappington, Thomas W.; Bradford, J. M.

doi:10.1603/0022-0493-97.2.409

Cited by 4 publications

(2 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We modeled survival through each of these two time periods as a binomial process similar to germination and seedling survival in plants. We set overwintering mortality at 20%, although this may be low based on the few published estimates of overwintering mortality for other weevil species (e.g., Greenberg et al 2004, ). In the two‐trophic‐level scenario (plant and biocontrol agent), we set weevil larval mortality equal to mortality attributable to causes other than parasitism (coast 41%; Central Valley 4%).…”

Section: Methodsmentioning

confidence: 99%

Variable effects of a generalist parasitoid on a biocontrol seed predator and its target weed

Swope

Satterthwaite

2012

Ecological Applications

View full text Add to dashboard Cite

Biological control (the importation of enemies from an invader's native range) is often considered our best chance of controlling the most widespread invaders. Ideally, the agent reduces invader abundance to some acceptably low level, and the two coexist at low density with the agent providing continuous control over the long-term. But the outcome may be complicated when the agent is attacked by native predators and parasites. We used a spatially explicit, discrete-time, individual-based, coupled plant-seed predator-parasitoid model to estimate the impact of the biocontrol agent Eustenopus villosus (a seed predator) on the invasive, annual weed Centaurea solstitialis, both with and without the generalist parasitoid Pyemotes tritici. We estimated the agent's ability to reduce plant density, spread rate, and population growth rate over 50 years. We used long-term demographic data from two sites in central California, USA, to parameterize the model and assess how populations in different climatic zones might respond differently to the agent and the parasitoid. We found that the biocontrol agent reduced plant density (relative to predictions for an uncontrolled invasion), but its impact on the invader's spread rate was modest and inconsistent. The agent had no long-term impact on population growth rate (lambda). Parasitism caused a trophic cascade, the strength of which varied between sites. At our coastal site, the parasitoid entirely eliminated the impact of the agent on the plant. At our Central Valley site, even when parasitized, the agent significantly reduced plant density and spread rate over several decades (although to a lesser degree than when it was not parasitized), but not invader lambda. Surprisingly, we also found that the length of time the invader was allowed to spread across the landscape prior to introducing the agent (5, 25, or 50 years) had little influence over its ability to control the weed in the long-term. This is encouraging news for land managers attempting to control invasive plants that have already established widespread, high-density populations. Unfortunately, our results also show that attack by the native generalist parasitoid had a larger influence over how effectively the agent reduced invader performance.

show abstract

Section: Methodsmentioning

confidence: 99%

Variable effects of a generalist parasitoid on a biocontrol seed predator and its target weed

Swope

Satterthwaite

2012

Ecological Applications

View full text Add to dashboard Cite

show abstract

“…Without using pheromonebaited traps that can attract them from undetermined distances, our study indicates that boll weevils do not move quickly (e.g., within days) after harvest operations in large numbers much beyond 30 m from cotton Þeld edges. Elimination of the cotton crop causes boll weevils to search for secondary (noncotton) food sources (Guerra 1986, Jones andCoppedge 1999), but substantial numbers of boll weevils remain in the Þeld even after cotton is defoliated, harvested, and shredded (Cowan et al 1963, Showler 2003, presumably because of the cotton plant material, including bolls, left on or under the soil surface (Cowan et al 1963, Rummel and Summy 1997, Greenberg et al 2004).…”

Section: Discussionmentioning

confidence: 99%

Short-Range Dispersal and Overwintering Habitats of Boll Weevils (Coleoptera: Curculionidae) During and After Harvest in the Subtropics

Showler¹

2006

Journal of Economic Entomology

View full text Add to dashboard Cite

Field experiments in the subtropical Lower Rio Grande Valley of Texas were conducted to determine the extent of adult boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), dispersal from cotton, Gossypium hirsutum L., fields during harvest operations and the noncotton-growing ("overwinter") period between 1 September and 1 February. Using unbaited large capacity boll weevil traps placed at intervals extending outward from commercial field edges, boll weevils did not move in substantial numbers during harvest much beyond 30 m, primarily in the direction of prevailing winds. From traps placed in fallow cotton; citrus; lake edge; pasture; treeline; sorghum, Sorghum bicolor (L.) Moench, and sugarcane, Saccharum spp., habitats during the overwinter period, the most boll weevils were collected in the fallow cotton fields and adjacent treelines during the fall. However, the greatest abundances of boll weevils were found in citrus orchards in the spring, before newly planted cotton fields began to square. One of the three lake edges also harbored substantial populations in the spring. Egg development in females was not detected between November and April, but in cotton fields most females were gravid between May and August when cotton fruiting bodies were available. Mated females, as determined by discoloration of the spermatheca, made up 80-100% of the female population during November and December but declined to approximately 50% in February. The lower incidence of mating indicates a reduction in physical activity, regardless of overwinter habitat, until percentages increased in March and April after cotton fields had been planted and squares were forming.

show abstract

Relationships of Abscised Cotton Fruit to Boll Weevil (Coleoptera: Curculionidae) Feeding, Oviposition, and Development

Showler

2008

View full text Add to dashboard Cite

Abscised cotton, Gossypium hirsutum L., fruit in field plots planted at different times were examined to assess adult boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), use of squares and bolls during 2002 and 2003 in the Lower Rio Grande Valley of Texas. Although boll abscission is not necessarily related to infestation, generally more bolls abscised than squares and abundances of fallen bolls were not related to the planting date treatments. During 2003, fallen squares were most abundant in the late-planted treatment. Although large squares (5.5-8-mm-diameter) on the plant are preferred for boll weevil oviposition, diameter of abscised squares is not a reliable measurement because of shrinkage resulting from desiccation and larval feeding. Fallen feeding-punctured squares and bolls were most abundant in late plantings but differences between fallen feeding-punctured squares versus fallen feeding-punctured bolls were found in only one treatment in 2003. During the same year, fallen oviposition-punctured squares were more numerous in the late-planted treatment than in the earlier treatments. Treatment effects were not found on numbers of oviposition-punctured bolls, but fallen oviposition-punctured squares were more common than bolls in the late-planted treatment compared with earlier treatments each year. Dead weevil eggs, larvae, and pupae inside fallen fruit were few and planting date treatment effects were not detected. Living third instars and pupae were more abundant in fallen squares of the late-planted treatment than in the earlier treatments and bolls of all three treatments. This study shows that fallen squares in late-planted cotton contribute more to adult boll weevil populations than bolls, or squares of earlier plantings.

show abstract

Effects of Burial and Soil Condition on Postharvest Mortality of Boll Weevils (Coleoptera: Curculionidae) in Fallen Cotton Fruit

Cited by 4 publications

References 15 publications

Variable effects of a generalist parasitoid on a biocontrol seed predator and its target weed

Variable effects of a generalist parasitoid on a biocontrol seed predator and its target weed

Short-Range Dispersal and Overwintering Habitats of Boll Weevils (Coleoptera: Curculionidae) During and After Harvest in the Subtropics

Relationships of Abscised Cotton Fruit to Boll Weevil (Coleoptera: Curculionidae) Feeding, Oviposition, and Development

Contact Info

Product

Resources

About