Francis P. F. Reay-Jones

Reduction of Soybean Yield Components by Megacopta cribraria (Hemiptera: Plataspidae)

ABSTRACT Since its discovery in the United States, the invasive plataspid Megacopta cribraria (F.) (Hemiptera: Plataspidae) has infested soybean [Glycine max (L.) Merrill] fields in often alarming numbers in parts of the southeastern United States. Although a known feeder on soybean, reports of its pest status in its native Asian range are conflicting, and little information exists documenting its impact on soybean yields. Our objective was to examine the relationship between M. cribraria density and soybean yield loss. M. cribraria adults and nymphs were confined to small soybean plots by using walk-in field cages from late vegetative stage to harvest in 2011 and 2012. Adults (0, 5, or 25 per plant) were added at late vegetative stages, and their progeny were allowed to complete a full generation within the caged plots. Densities reached as high as 182.5 ± 23.1 (SEM) nymphs and adults per plant, and soybean yield was reduced by as much as 59.6% at the highest density treatment. The yield components seeds per pod and individual seed weight were reduced as M. cribraria densities increased, but pods per plant and protein and oil content were not affected. Preliminary economic injury level curves for a range of grain prices and management costs were calculated based on 2012 yield loss data combined with population monitoring. M. cribraria is capable of causing severe reductions in soybean yields at densities that are relevant within its invasive U.S. range.

Spatial and Temporal Patterns of Stink Bugs (Hemiptera: Pentatomidae) in Wheat

ABSTRACT A 2-yr study was conducted in South Carolina wheat fields to describe spatial and temporal dynamics of stink bugs sampled with sweep nets. In 2008, the main phytophagous species were Euschistus servus (Say) (35.8, 36.7%), Oebalus pugnax (F.) (35.0, 6.0%), Nezara viridula L., (15.2, 46.3%), and Thyanta custator (F.) (14.0, 10.5%) for adults and nymphs, respectively. In 2009, the main phytophagous species were O. pugnax (39.8, 37.8%), E. servus (38.4, 30.0%), N. viridula (14.6, 29.5%), and T. custator (6.8, 2.8%). &khgr;2 goodness-of-fit tests indicated that all species (both adults and nymphs) had observed distributions that did not match the Poisson distribution. Indices of dispersion (ID) across sampling dates were significantly >1 for all species and life stages, also suggesting a nonrandom distribution. Slopes of Taylors power law were significantly greater (P < 0.05) than a value of 1 for only adult O. pugnax and nymph T. custator. Coefficients &bgr; of patchiness regressions were significantly >1 in all cases except for E. servus adults and T. custator nymphs. The inverted distance weighted interpolation method showed considerable levels of spatial variability in densities within fields. Sampling along the edge of fields showed a significant distance from field border effect (P < 0.05) on all adults in both years except for N. viridula. High densities in wheat adjacent to a susceptible crop such as corn suggests that localized control methods in wheat may be effective in mitigation of stink bugs and damage in corn.

Predicting economic losses from the continued spread of the Mexican rice borer (Lepidoptera: Crambidae).

Abstract The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive species that originated from Mexico, and it is threatening to cause major economic losses to sugarcane, Saccharum spp., and rice, Oryza sativa L., industries in Louisiana. The insect is expected to reach sugarcane and rice production areas in Louisiana by 2008, and infest all of Louisiana sugarcane and rice industries by 2035. When all sugarcane in Louisiana becomes infested, annual yield losses of

Spatial dynamics of stink bugs (Hemiptera: Pentatomidae) and associated boll injury in southeastern cotton fields.

220 million would be expected for a cultivar of comparable susceptibility to LCP 85-384 (assuming this cultivar is planted on 100% of the production area). This also assumes the use of the current practice of rainfed production and one application of insecticide, which is presently used by farmers in Louisiana. Irrigation with 30 cm of water is predicted to reduce estimated losses by 29%, whereas four applications of a biorational insecticide such as tebufenozide are expected to reduce the loss in revenue by 53%. The use of the resistant ‘HoCP 85-845′ would reduce the projected loss in revenue by 24%. Combining all three management tactics on sugarcane, anticipated net loss in revenue would decrease by 66%. The rice industry in Louisiana is projected to suffer from a loss in revenue of

Effects of Adjacent Habitat on Populations of Stink Bugs (Heteroptera: Pentatomidae) in Cotton as Part of a Variable Agricultural Landscape in South Carolina

45 million when the entire state is infested. A 77% reduction in loss in revenue is expected with one application of lambda-cyhalothrin. A quarantine on east Texas sugarcane is estimated to save the Louisiana industry between

Frankliniella fusca resistance to neonicotinoid insecticides: an emerging challenge for cotton pest management in the eastern United States

1.1 billion and

Within-Field Spatial Distribution of Megacopta cribraria (Hemiptera: Plataspidae) in Soybean (Fabales: Fabaceae)

3.2 billion (depending on management) during the time needed for the insect to fully invade the state’s sugarcane and rice producing area by natural migration rather than by accidental introduction. The rapid deployment of appropriate management tactics will have a key role in reducing the anticipated economic impact of E. loftini once it becomes a pest in Louisiana sugarcane and rice.

Sampling Stink Bugs (Hemiptera: Pentatomidae) for Population Estimation and Pest Management in Southeastern Cotton Production

ABSTRACT Grid sampling (one sample per 0.40 ha) in 12 cotton (Gossypium hirsutum L.) fields for stink bugs and boll injury caused by stink bug feeding was conducted in 2007 and 2008 in South Carolina and Georgia. The main species collected using the beat cloth method were the green stink bug, Acrosternum hilare (Say) (69%); brown stink bug, Euschistus servus (Say) (18%); and the southern green stink bug, Nezara viridula (L.) (14%), respectively. The inverted distance weighted interpolation method and Spatial Analysis by Distance IndicEs analyses showed spatial variability in both boll injury and stink bug densities. Four of five fields with field-average boll injury exceeding 15% had a combination of either soybean or peanut adjacent to the cotton field of interest. The Spatial Analysis by Distance IndicEs index of dispersion for stink bug densities and boll injury averaged over the season indicated significant aggregation at the 5% error rate in only one and four analyses (combinations of fields, species, and life stages) of a total of 54 in 2007 and 2008, respectively. By sampling date, overall indices of dispersion for boll injury data indicated significant aggregation in four of the 63 date-field combinations at the 5% error rate. Across years, overall indices of spatial association between boll injury and stink bug densities were significant in 17 of 69 analyses, with positive associations detected in seven of 12 fields; these data suggest that spatial distribution of stink bugs in cotton fields does not always coincide with boll injury.

Inhibition of Helicoverpa zea (Lepidoptera: Noctuidae) Growth by Transgenic Corn Expressing Bt Toxins and Development of Resistance to Cry1Ab

ABSTRACT The distribution of phytophagous stink bugs and associated boll injury in margins of cotton fields bordering various agronomic crops and woodlands were studied in 2007 and 2008. Two commercial cotton fields, ranging in size from 7.8 to 12.1 ha in Barnwell and Lee Counties, SC, were sampled weekly each year along predetermined transects at 0, 5, 10, and 25 m from the outside margin into the cotton field. Stink bugs were sampled using a ground cloth (0.91 by 0.91 m), and quarter-sized bolls (≈2.5 cm in diameter) were collected and examined for internal damage. Density (bugs/row-m) of total stink bugs (adults plus nymphs) was greatest in cotton adjacent to peanut. Boll injury was significantly greater in cotton adjacent to soybean and peanut than in cotton next to other habitats, including corn, cotton, and woodlands, during midseason. Density of nymphs was greatest in cotton adjacent to peanut during mid and late season. Densities of total stink bugs and adults were greatest in cotton immediately adjacent (0 m) to all bordering crops and decreased as distance from the margin increased. Boll injury was greatest in cotton immediately adjacent (0 m) to the bordering crop in mid and late season. Because densities of stink bugs and boll injury vary spatially and temporally along field margins of cotton and can vary significantly based on the adjacent crop, such factors should be considered when developing integrated pest management strategies in cotton.

Spatial analysis of the cereal leaf beetle (Coleoptera: Chrysomelidae) in wheat.

BACKGROUND Over the past two decades, neonicotinoid seed treatments have become the primary method to manage tobacco thrips, Frankliniella fusca Hinds, on seedling cotton. Because this insect is highly polyphagous and the window of insecticide exposure is short, neonicotinoid resistance was expected to pose a minimal risk. However, reports of higher than expected F. fusca seedling damage in seed-treated cotton fields throughout the Mid-South and Southeast US production regions suggested neonicotinoid resistance had developed. To document this change, F. fusca populations from 86 different locations in the eastern United States were assayed in 2014 and 2015 for imidacloprid and thiamethoxam resistance to determine the extent of the issue in the region. RESULTS Approximately 57 and 65% of the F. fusca populations surveyed had reduced imidacloprid and thiamethoxam sensitivity respectively. Survivorship in diagnostic bioassays was significantly different at both the state and regional scales. Multiple-dose bioassays conducted on 37 of the populations documented up to 55- and 39-fold resistance ratios for imidacloprid and thiamethoxam respectively. CONCLUSION Estimates of neonicotinoid resistance indicate an emerging issue for management of F. fusca in the eastern United States. Significant variation in survivorship within states and regions indicated that finer-scale surveys were needed to determine factors (genetic, insecticide use) driving resistance evolution.