Spatial Associations of Key Lepidopteran Pests With Defoliation, NDVI, and Plant Height in Soybean

2021 ◽  
Author(s):  
Anthony Daniel Greene ◽  
Francis P F Reay-Jones ◽  
Kendall R Kirk ◽  
Brandon K Peoples ◽  
Jeremy K Greene
Keyword(s):  
South Carolina ◽  
Plant Height ◽  
Vegetation Index ◽  
Management Practices ◽  
Insect Pests ◽  
Limiting Factors ◽  
Anticarsia Gemmatalis ◽  
Soybean Plant ◽  
Velvetbean Caterpillar ◽  
Lepidopteran Pests

Abstract In soybean, Glycine max (L.) Merrill, production, losses to, and control costs for insect pests can be significant limiting factors. Although the heterogeneity of pests has typically been ignored in traditional field management practices, technological advancements have allowed for site-specific pest management systems to be developed for the precise control of pests within a field. In this study, we chose to determine how the in-field distributions of the larvae of three major lepidopteran pests [velvetbean caterpillar Anticarsia gemmatalis (Hübner) (Lepidoptera: Erebidae), soybean looper Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae), and green cloverworm Hypena scabra (Lepidoptera: Erebidae) (Fabricius)] were spatially associated with defoliation, Normalized Difference Vegetation Index (NDVI), and plant height in soybean. Spatial analysis by distance indices (SADIE) of data from two South Carolina soybean fields in 2017 and 2018 revealed a limited number of spatial aggregations for insect datasets. However, 14% and 6% of paired plant–insect datasets were significantly associated or dissociated, respectively. NDVI was found to be more associated with pest distributions than soybean plant heights and defoliation estimates, and the majority of all plant–insect associations and dissociations occurred in the first 4 wk of sampling (late July–early August). If changes are to be implemented regarding how a pest is managed, critical factors explaining the spatial distribution of pests must be identified. Results from this study advocate for the relationship between early-season distributions of pests and important plant variables such as NDVI to be further investigated to better determine the strength of the correlations across years and sites.

Influence of Irrigation and Maturity Group on the Seasonal Abundance of Soybean Arthropods

1998 ◽  
Vol 33 (4) ◽  
pp. 378-392 ◽  
Author(s):  
R. M. McPherson ◽  
R. C. Layton ◽  
W. J. McLaurin ◽  
W. A. Mills
Keyword(s):  
Insect Pests ◽  
Field Tests ◽  
Seasonal Abundance ◽  
Anticarsia Gemmatalis ◽  
Soybean Plant ◽  
Stink Bugs ◽  
Population Densities ◽  
Maturity Group ◽  
Group V ◽  
Arthropod Predators

The effects of irrigation and soybean maturity group (Group V ‘Forrest’ variety vs Group VII ‘Braxton’ variety) on the seasonal abundance of arthropod pest and beneficial population densities were examined in large-plot field tests at the Attapulgus Research Center in Attapulgus, GA, in 1987 through 1990. In general, soybean plant growth was more abundant, yields were higher, and canopy closure indices were lower in irrigated than in non-irrigated plots for both varieties. Irrigation and the resultant increased soybean vegetation supported a greater overall seasonal abundance of all five of the insect pests monitored: stink bugs, primarily Nezara viridula (L.), velvetbean caterpillars, Anticarsia gemmatalis Hübner, soybean loopers, Pseudoplusia includens (Walker), threecornered alfalfa hoppers, Spississtilus festinus (Say), and green cloverworms, Plathypena scabra (F.). No overall varietal effects were noted for N. viridula; however, each year, population densities were higher in the early-maturing ‘Forrest’ up to julian day 250 then densities were higher in the later-maturing ‘Braxton’ for the remainder of the grown season. Mean estimates of the seasonal abundance of A. gemmatalis and P. scabra populations were similar between the two varieties; however, P. includens and S. festinus were more abundant on Forrest than on Braxton. Total arthropod predators, including Nabis spp., Geocoris spp., and spiders, also were more abundant on irrigated soybeans, while overall varietal means were similar. Yearly analyses revealed significant irrigation and variety effects for most of the species sampled.

scholarly journals Mode of Action and Specificity of Bacillus thuringiensis Toxins in the Control of Caterpillars and Stink Bugs in Soybean Culture

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Rogério Schünemann ◽  
Neiva Knaak ◽  
Lidia Mariana Fiuza
Keyword(s):  
Bacillus Thuringiensis ◽  
Mode Of Action ◽  
Insect Pests ◽  
Insect Pest ◽  
Anticarsia Gemmatalis ◽  
Stink Bug ◽  
Stink Bugs ◽  
Velvetbean Caterpillar ◽  
Promising Tool ◽  
Major Pest

The bacterium Bacillus thuringiensis (Bt) produces delta-endotoxins that possess toxic properties and can be used as biopesticides, as well as a source of genes for the construction of transgenic plants resistant to insects. In Brazil, the introduction of Bt soybean with insecticidal properties to the velvetbean caterpillar, the main insect pest of soybean, has been seen a promising tool in the management of these agroecosystems. However, the increase in stink bug populations in this culture, in various regions of the country, which are not susceptible to the existing genetically modified plants, requires application of chemicals that damage the environment. Little is known about the actual toxicity of Bt to Hemiptera, since these insects present sucking mouthparts, which hamper toxicity assays with artificial diets containing toxins of this bacterium. In recent studies of cytotoxicity with the gut of different hemipterans, susceptibility in the mechanism of action of delta-endotoxins has been demonstrated, which can generate promising subsidies for the control of these insect pests in soybean. This paper aims to review the studies related to the selection, application and mode of action of Bt in the biological control of the major pest of soybean, Anticarsia gemmatalis, and an analysis of advances in research on the use of Bt for control hemipterans.

Assessing Lepidopteran Abundance and Crop Injury in Soybean Lines Exhibiting a Synthetic Bacillus thuringiensis cry1 A Gene

2009 ◽  
Vol 44 (2) ◽  
pp. 120-131 ◽  
Author(s):  
Robert M. McPherson ◽  
Ted C. MacRae
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Trials ◽  
Anticarsia Gemmatalis ◽  
Population Densities ◽  
Velvetbean Caterpillar ◽  
Larval Population ◽  
Lepidopteran Pests ◽  
Crop Injury ◽  
Transgenic Lines ◽  
Soybean Looper

Transgenic lines of soybean, Glycine max (L.) Merrill, expressing a synthetic cry 1A gene from Bacillus thuringiensis Berliner (Bt), were evaluated in replicated field trials in 1999–2002 for suppression of lepidopteran pests and the resultant crop injury. Velvetbean caterpillar, Anticarsia gemmatalis Hübner, soybean looper, Pseudoplusia includens (Walker), and green cloverworm, Hypena scabra (F.), population densities were essentially absent throughout the growing season in each year of the study in each of the Bt lines evaluated compared with moderate (5–10 larvae per row-m) to heavy (15–20 larvae per row-m) populations in the isogenic and parental lines serving as soybean controls. Significant A. gemmatalis larval population reductions were observed in the Bt entries compared with the nonBt entries in each year of this study. The P. includens larval densities were significantly lower in Bt entries in the 3 yrs of this study when population densities were abundant, whereas H. scabra were lower in the Bt lines in the 2 yrs of this study when this species was present. Cumulative defoliation in nonBt soybean entries exceeded 95% in some years compared with 0.0–1.6% in the transgenic lines containing Bt. Yields of the transgenic soybean lines were equal to or higher than the non Bt lines examined in each year of this study. It appears that these Bt transgenic soybeans provide superior season-long control of the common lepidopteran pests on soybeans in the southern U.S., resulting in reduced defoliation levels and potentially higher yields compared with equivalent cultivars that lack the Bt trait.

Cropping Preferences of Common Lepidopteran Pests in a Cotton/Soybean Cropping System

2007 ◽  
Vol 42 (1) ◽  
pp. 105-118 ◽  
Author(s):  
C. Scott Bundy ◽  
R. M. McPherson
Keyword(s):  
Helicoverpa Zea ◽  
Cropping System ◽  
Anticarsia Gemmatalis ◽  
Large Field ◽  
Bt Cotton ◽  
Trap Crop ◽  
Velvetbean Caterpillar ◽  
Group V ◽  
Growing Seasons ◽  
Lepidopteran Pests

Two soybean varieties (an early-maturing Group V and a later-maturing Group VII) and two cotton varieties (a conventional and a transgenic Bacillus thuringiensis Berliner [Bt]) were grown in adjacent replicated large field plots at two locations for 3 growing seasons. The abundance of commonly-observed lepidopteran pests within these two crops was observed weekly throughout each growing season. The green cloverworm, Hypena scabra (F.); soybean looper, Pseudoplusia includens (Walker), and; velvetbean caterpillar, Anticarsia gemmatalis Hübner, preferred soybeans over cotton at all six test sites. The bollworm complex, Helicoverpa zea (Boddie) and Heliothis virescens (F.), preferred soybeans at one site, cotton at two sites, and no crop preference at three sites. There was no difference in the seasonal mean abundance of the pests between the two soybean maturity groups. A few varietal differences were noted on soybeans on specific sampling dates; however, they occurred when insect numbers were low. Population densities approached economic injury levels on both the early and later-maturing soybean varieties. In cotton, the bollworm complex was significantly more abundant in conventional cotton than in Bt cotton. Although soybean loopers are a pest of both crops, soybeans are preferred when they are planted adjacent to cotton. Given this behavioral response, soybeans might serve as a trap crop to attract soybean loopers into a small planting of soybeans and out of the major planting of cotton.

scholarly journals Bacillus thuringiensis chimeric proteins Cry1A.2 and Cry1B.2 to control soybean lepidopteran pests: New domain combinations enhance insecticidal spectrum of activity and novel receptor contributions

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0249150
Author(s):  
Danqi Chen ◽  
William J. Moar ◽  
Agoston Jerga ◽  
Anilkumar Gowda ◽  
Jason S. Milligan ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insect Pests ◽  
Anticarsia Gemmatalis ◽  
Cross Resistance ◽  
Moderate Activity ◽  
Velvetbean Caterpillar ◽  
Spodoptera Eridania ◽  
Protein Resistance ◽  
Bt Protein ◽  
Common Domain

Two new chimeric Bacillus thuringiensis (Bt) proteins, Cry1A.2 and Cry1B.2, were constructed using specific domains, which provide insecticidal activity against key lepidopteran soybean pests while minimizing receptor overlaps between themselves, current, and soon to be commercialized plant incorporated protectants (PIP’s) in soybean. Results from insect diet bioassays demonstrate that the recombinant Cry1A.2 and Cry1B.2 are toxic to soybean looper (SBL) Chrysodeixis includens Walker, velvetbean caterpillar (VBC) Anticarsia gemmatalis Hubner, southern armyworm (SAW) Spodoptera eridania, and black armyworm (BLAW) Spodoptera cosmioides with LC50 values < 3,448 ng/cm2. Cry1B.2 is of moderate activity with significant mortality and stunting at > 3,448 ng/cm2, while Cry1A.2 lacks toxicity against old-world bollworm (OWB) Helicoverpa armigera. Results from disabled insecticidal protein (DIP) bioassays suggest that receptor utilization of Cry1A.2 and Cry1B.2 proteins are distinct from each other and from current, and yet to be commercially available, Bt proteins in soy such as Cry1Ac, Cry1A.105, Cry1F.842, Cry2Ab2 and Vip3A. However, as Cry1A.2 contains a domain common to at least one commercial soybean Bt protein, resistance to this common domain in a current commercial soybean Bt protein could possibly confer at least partial cross resistance to Cry1A2. Therefore, Cry1A.2 and Cry1B.2 should provide two new tools for controlling many of the major soybean insect pests described above.

A Guide to Planting Wildflower Enhancements in Florida

EDIS ◽  
2017 ◽  
Vol 2017 (5) ◽  
Author(s):  
Mary C. Bammer ◽  
Josh Campbell ◽  
Chase B. Kimmel ◽  
James D.. Ellis ◽  
Jaret C. Daniels
Keyword(s):  
Management Practices ◽  
Insect Pests ◽  
Native Plant ◽  
Agricultural Producers ◽  
Native Plant Species ◽  
Control Techniques ◽  
Wild Bee ◽  
Pollinator Species ◽  
Nesting Sites ◽  
The Right

The establishment of native wildflower plantings in Florida can benefit agricultural producers as well as native pollinators and other beneficial insects (predators and parasitoids). The plantings do this by:  providing forage and nesting sites for bees, butterflies, and other pollinators, increasing wild bee numbers possibly across the farm, and increasing natural enemies of insect pests (that also depend on forage and nesting sites). This document discusses choosing the right mix of native plant species to benefit many pollinator species, as well as proper site selection, planting practices, and weed control techniques. Wildflower plots should be practical to manage, maximize benefits to wildlife, and fit into the overall management practices of the property. 

scholarly journals Survey on maize post-harvest losses and its management practices in the western hills of Nepal

2015 ◽  
Vol 1 (1) ◽  
pp. 98-105 ◽  
Author(s):  
Ghanashyam Bhandari ◽  
Bhuddhi Bahadur Achhami ◽  
Tika Bahadur Karki ◽  
Balram Bhandari ◽  
Gopal Bhandari
Keyword(s):  
Management Practices ◽  
Insect Pests ◽  
Storage Conditions ◽  
Maize Weevil ◽  
Farming Communities ◽  
Storage Losses ◽  
Angoumois Grain Moth ◽  
Development Committee ◽  
Village Development Committee ◽  
Open Floor

A survey was conducted in order to assess the losses of maize under farmers’ storage conditions in the Western hills of Nepal in 2014. The survey area included Thanapati Village Development Committee (VDC) of Gulmi, Aalamdebi VDC of Syangja, Khasauli VDC of Palpa and Baglung municipality-12, Baglung district. Primary information was collected through semi-structured questionnaires among the heterogenous groups of the farming communities. Survey revealed that about 61% respondents reported the storage pest as the major pests and about 12% respondents reported that field pests as the major pests in the western hills. Maize weevil (Sitophylus zeamais Mostsch.) and Angoumois grain moth (Sitotroga cerealella Oliv.) were found to be major storage insect pests in surveyed areas. Majority of respondents (39%) presumed on 10-20% losses during storage. Among the other biotic factors, farmers ranked insect (42%), weeds (32%) and diseases (17%) respectively. Maize storage methods had distinct among the surveyed areas compared with Baglung district to other surveyed areas. In Baglung, about (73%) farmers had stored maize in the form of grain whereas in Palpa, Gulmi and Syangja, about (77%) farmers had practice of storing maize with husk for 5-7 months. Approximately, 40% respondents were using open floor in upper stair “Aanti”as a major maize storage place in Palpa, Gulmi and Syangja whereas almost (79%) of respondents were using sacks to store shelled grains in Baglung. Hence, there is ample opportunity to reduce the storage losses of maize depending upon the existing situation.Journal of Maize Research and Development (2015) 1(1):98-105DOI: http://dx.doi.org/10.5281/zenodo.34288

scholarly journals Marker Development for Differentiation of Fusarium oxysporum f. sp. Niveum Race 3 from Races 1 and 2

2021 ◽  
Vol 22 (2) ◽  
pp. 822
Author(s):  
Owen Hudson ◽  
Sumyya Waliullah ◽  
James C. Fulton ◽  
Pingsheng Ji ◽  
Nicholas S. Dufault ◽  
...  
Keyword(s):  
South Carolina ◽  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Conventional Polymerase Chain Reaction ◽  
Detection Methods ◽  
Limiting Factors ◽  
Pcr Marker ◽  
Primer Sets ◽  
Race Differentiation ◽  
Race 2

Fusarium wilt of watermelon, caused by Fusarium oxysporum f. sp. niveum (FON), is pathogenic only to watermelon and has become one of the main limiting factors in watermelon production internationally. Detection methods for this pathogen are limited, with few published molecular assays available to differentiate FON from other formae speciales of F. oxysporum. FON has four known races that vary in virulence but are difficult and costly to differentiate using traditional inoculation methods and only race 2 can be differentiated molecularly. In this study, genomic and chromosomal comparisons facilitated the development of a conventional polymerase chain reaction (PCR) assay that could differentiate race 3 from races 1 and 2, and by using two other published PCR markers in unison with the new marker, the three races could be differentiated. The new PCR marker, FNR3-F/FNR3-R, amplified a 511 bp region on the “pathogenicity chromosome” of the FON genome that is absent in race 3. FNR3-F/FNR3-R detected genomic DNA down to 2.0 pg/µL. This marker, along with two previously published FON markers, was successfully applied to test over 160 pathogenic FON isolates from Florida, Georgia, and South Carolina. Together, these three FON primer sets worked well for differentiating races 1, 2, and 3 of FON. For each marker, a greater proportion (60 to 90%) of molecular results agreed with the traditional bioassay method of race differentiation compared to those that did not. The new PCR marker should be useful to differentiate FON races and improve Fusarium wilt research.

Soybean Sensitivity to Florpyrauxifen-benzyl during Reproductive Growth and the Impact on Subsequent Progeny

2017 ◽  
Vol 32 (2) ◽  
pp. 135-140 ◽  
Author(s):  
M. Ryan Miller ◽  
Jason K. Norsworthy
Keyword(s):  
Plant Height ◽  
Field Studies ◽  
Yield Reduction ◽  
Growth Stages ◽  
Soybean Plant ◽  
Reproductive Growth ◽  
Similar Reduction ◽  
Structural Class ◽  
Soybean Plants ◽  
The Impact

AbstractTo address recent concerns related to auxin herbicide drift onto soybean, a study was developed to understand the susceptibility of the reproductive stage of soybean to a new auxin herbicide compared with dicamba. Florpyrauxifen-benzyl is under development as the second herbicide in a new structural class of synthetic auxins, the arylpicolinates. Field studies were conducted to (1) evaluate and compare reproductive soybean injury and yield following applications of florpyrauxifen-benzyl or dicamba across various concentrations and reproductive growth stages and (2) determine whether low-rate applications of florpyrauxifen-benzyl or dicamba to soybean in reproductive stages would have similar effect on the progeny of the affected plants. Soybean were treated with 0, 1/20, or 1/160, of the 1X rate of florpyrauxifen-benzyl (30 g ai ha−1) or dicamba (560 g ae ha−1) at R1, R2, R3, R4, or R5 growth stage. Soybean plant height and yield was reduced from 1/20X dicamba across all reproductive stages. High drift rates (1/20X) of florpyrauxifen-benzyl also reduced soybean plant height >25% and yield across R1 to R4 stages. Germination, stand, plant height, and yield of the offspring of soybean plants treated with dicamba and florpyrauxifen-benzyl were significantly affected. Dicamba applied at a rate of 1/20X at R4 and R5 resulted in 20% and 35% yield reduction for the offspring, respectively. A similar reduction occurred from florpyrauxifen-benzyl applied at R4 and R5 at the 1/20X rate, resulting in 15% to 24% yield reduction for the offspring, respectively. Based on these findings, it is suggested that growers use caution when applying these herbicides in the vicinity of reproductive soybean.

Sign in / Sign up

Export Citation Format

Share Document