Recipient Organization
UNIVERSITY OF MISSOURI
(N/A)
COLUMBIA,MO 65211
Performing Department
Plant Sciences
Non Technical Summary
These research studies will provide an understanding of the current status of soybean insects associated with Missouri soybean production. Insects of major interest include several stink bug species, soybean podworm, and other late season insect pests that feed on soybean foliage, pods, and seeds and are difficult to manage with available control methods. Also of concern are three additional soybean insect pests which will soon arrive in Missouri and attack the soybean crop. They include the red banded stink bug, the brown marmorated stink bug, and the bean plataspid. Knowledge gained from the study of current soybean insect pests may help in developing effective management strategies for the invading soybean pests. It is important to document the current distribution and abundance of soybean insects in Missouri's four soybean production regions and within individual soybean fields. This information will be gained through a statewide random survey of 60 producer fields each sampled three times during the growing season for a three year period. Insect samples will be collected by taking 20 sweeps using a 15-inch diameter sweep net. In a second study distribution of soybean insects within a soybean field will be determined through the growing season by collection of monthly sweep net samples at 10 locations within each plot ranging from field border rows to 160 feet into the field interior. Insect abundance will be determined at each of these ten sample locations in soybean planted at 7-, 15, and 30-inch row spacing. Insects that initially infest field edges before moving to field interiors will be the focus of this study. Several stink bug species will be intensively studied. A third soybean insect study will determine insect distribution through the growing season in soybean varieties with four different maturity ratings and three planting dates equivalent to early, mid, and late season. A fourth study will utilize pheromone baited traps and sweep net sampling to determine "first occurrence" and abundance of the red banded and brown marmorated stink bugs, plus the closely related bean plataspid species in Missouri. Pheromone traps and sweeps will be located along major highways and in select border counties. At present, the red banded stink bug is prevalent in Arkansas, the brown marmorated is found in several of Missouri's border states, and the bean plataspid has been found close to Missouri in the adjoining state of Tennessee. Early detection of these invading insect pests of soybean in Missouri should allow producers time to gain the knowledge to better manage these new soybean pests before population grow to economic levels in the state's soybean crop. The more knowledge available about each specific pest allows for development of effective pest control strategies and soybean integrated pest management programs.
Animal Health Component
90%
Research Effort Categories
Basic
(N/A)
Applied
90%
Developmental
10%
Goals / Objectives
1. Complete a statewide survey by regions of insect species richness and abundance currently associated with Missouri soybean production.2. Determine the population dynamics of current stink bug and other soybean insect species associated with soybean plant location within field (edge vs. field interior) and soybean stand widths (7-, 15, and 30-inch row spacing).3. Determine the population dynamics of current stink bug and other soybean insect species associated with soybean variety maturity dates (maturity ratings 4,5,6,7) and planting dates (May, June, July).4. Monitor statewide for the presence and eventual establishment of potential stink bug pest species in soybean including the red banded stink bug, the brown marmorated stink bug, and the bean plataspid.
Project Methods
Objective 1. Determine Soybean Insect Species Richness and Abundance in Missouri's Soybean Production Regions.A statewide survey of soybean insects will be conducted for a three year period. Insects will be sampled three times per growing season in a total of 60 producer fields (15 in each of four regions of the state: NE, SE, NW, SW) by collecting 20 sweeps per field with a 15-inch diameter sweep net. Each field location initially will be randomly selected, insect sample number one collected, and a GPS location marker recorded in order to collect subsequent insect samples two and three from the same field. The insect sweep net collections will be immediately transferred to a 1-gallon plastic bag, placed in a cooler, and then frozen for later laboratory processing. Common soybean insects will be identified to a minimum level of insect family or lower with all stink bugs classified to species. During each visit to a sample site (field) one soybean plant will be randomly selected, harvested with the root, and transferred to a 2.5-gallon plastic bag for freezing and eventual determination of plant height and growth stage. Insect data will be used to develop species population trends by region, year, and overall for select soybean insect species. Data from this 3-year soybean insect survey will be compared to historical data collected from previous soybean insect survey data collected in Missouri (Blickenstaff and Huggans 1962, Baur et al. 2000). Two years of data have been collected for this study with final collections scheduled for 2014. All stink bug species have been identified to species and numbers of each recorded for the 180 insect samples collected in 2012. Identification is approaching completion for the 180 insect samples collected in 2013, with final collections scheduled for the summer of 2014. Once stink bug species data have been processed, identification and numbers of remaining soybean insects will be determined for all years of the study.Objective 2. Determine Seasonal Phenology and Dispersal of Common Stink Bug Species in Soybean from Field Edges into Field Interiors with Three Row Spacing. Stink bugs will be the primary focus of this field study conducted at MU's Bradford Research and Extension Center (Boone County Missouri). Green, brown, and one-spotted stink bug nymphs and adults will be monitored monthly in soybean to determine insect phenology and population expansion from field edges into field interiors. Field edges will be located adjacent to a wooded field borders which often serve as overwintering sites for most stink bug species found in soybean. Additionally, three row spacing of 7-, 15-, and 30-inches will be evaluated to determine whether each stink bug species has a preference for crop canopy cover (Lam and Pedigo 1998) as the populations reproduce and move from field edges toward the field interiors. Insect samples will be collected monthly from all plots at distances of 10 to 160 feet by 15 feet increments from the field edge into the field interior. Numbers of insects will be analyzed and graphic representations of expansion of each stink bug species through the season provided. This is a three year study with strip plots of 20 rows with either 7-, 15- or 30-inch row spacing running 400 feet into the field interior from the wooded field edge. Differences in insect numbers by species, plant canopy cover, and plant growth stages between experimental plots will be determine by analysis of variance (ANOVA)(SAS Institute 2012, release 9.32. If the overall treatment F tests are significant, then treatment means will be further separated for biological interpretation. Differences will be considered statistically significant at the level of P<0.05. All field sampling for this study were completed over a five year period, (extended from 3-years due to drought) and insects are now being identified to species, growth stage determined, and numbers if insects collected by treatment and sample period recorded for statistical analysis. Stink bug species will be the focus of initial identifications with other soybean insects to follow once processing of stink bug samples is completed. A similar study investigating effect of row spacing and crop residue levels on soybean arthropods was conducted in Iowa (Lam and Pedigo 2006). The current study differs in that insect collections were taken from field border to 160 feet into the field interior in three different soybean row spacings in clean till soybean.Objective 3. Phenology and Distribution of Soybean Insects in Soybean Varieties with Differing Maturity Ratings and Planting Dates. This study will primarily focus on the green, Southern green, brown, one-spotted, and red-shouldered stink bugs which will be monitored in four soybean varieties with maturity ratings of 3-6, each planted three times during the growing season in early May, mid-June, and late July. Insects will be monitored monthly by taking 20 sweeps with a 15-inch diameter heavy duty sweep net. Insect sweep samples will immediately be stored in 1 gallon plastic bags which will be placed in coolers and transported to the lab for freezing and later processing. Insects will be identified and numbers of each species recorded for each sample date. Differences in insect numbers by species, soybean variety maturity rating, and planting date will be determined and analyzed using (ANOVA)(SAS Institute 2012, release 9.2). This study is similar to one conducted in Stoneville, Mississippi in 2006 (Gore et al. 2006) in which soybean with maturity ratings of IV and V were planted three times per year for a two year period. This Missouri study is more comprehensive with 4 maturity ratings, three planting dates, and three years of data. The third year of this study will be completed in 2014.Objective 4. Statewide Monitoring for the Presence and Establishment of Invasive Stink Bug Species in Missouri.A statewide series of pheromone traps or sweep net collection sites will be established and monitored monthly during the growing season to determine the absence or presence of three invasive soybean stink bug species including the red banded stink bug, the brown marmorated stink bug, and the bean plataspid. Sampling for these invasive species is dependent on the availability of effective pheromones for attracting these pests to traps. At present, effective pheromone traps are commercially available for the brown marmorated stink bug. Efficient pheromone traps for the red banded stink bug and the bean plataspid are available, but pheromone trap efficiency for these species is variable. Special emphasis will be given to locate traps for the brown marmorated stink bug at interstate rest stops and along major highways as this insect often move about by "hitchhiking" on vehicles and cargo. Collection methods for the red banded stink bug and bean plataspid will include available pheromone traps and backed up by sweep net collection sites in select soybean fields. First reports of such pest are essential if small infestations are found and lend themselves to eradication prior to widespread establishment in the state. This survey project will be initiated in 2014 and serve as an early indicator of the arrival of these stink bug pests in the state of Missouri.