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.

Insect Pests and Yield Potential of Vegetable Soybean (Edamame) Produced in Georgia

2008 ◽  
Vol 43 (2) ◽  
pp. 225-240 ◽  
Author(s):  
R. M. McPherson ◽  
W. C. Johnson ◽  
E. G. Fonsah ◽  
P. M. Roberts
Keyword(s):  
Insect Pests ◽  
Insect Pest ◽  
Organic Production ◽  
Yield Potential ◽  
Stink Bug ◽  
Stink Bugs ◽  
Vegetable Soybean ◽  
Green Seed ◽  
Seed Damage ◽  
Seed Yields

A series of replicated field experiments was conducted with vegetable soybean (edamame), Glycine max (L.) Merrill, to assess the impacts of cultivars, planting dates, and insecticidal controls on insect pest abundance, crop damage and yield potential. The velvetbean caterpillar, Anticarsia gemmatalis Hübner, was the most common lepidopteran defoliator in this study, causing heavy defoliation in some years when left untreated. Other lepidopterans observed included the soybean looper, Pseudoplusia includens (Walker), and the green cloverworm, Hypena scabra (F.). Stink bugs, primarily the southern green stink bug, Nezara viridula (L.), also caused seed damage in some cultivars when left untreated. Stink bug damage exceeded expectations on edamame seeds when exposed to moderate stink bug densities (≤3 bugs per 25 sweeps). Other arthropods that were commonly observed included threecornered alfalfa hoppers, Spissistilus festinus (Say), grasshoppers, Melanoplus spp., and the potato leafhopper, Empoasca fabae (Harris). Arthropod infestations on edamame were similar to reported pest problems on conventional soybeans being produced for oil and meal. Midseason applications of the insecticides diflubenzuron plus l-cyhalothrin reduced insect pest populations, percentage of arthropod-induced defoliation and percentage of seeds damaged by stink bugs, but had little effect on edamame yields. Most defoliation and seed damage occurred during R5 development when seeds were approaching full size, thus only minimal yield reductions were noted. However, seed quality of the untreated vegetable soybeans would be unacceptable for the consumer. Total fresh green yields ranged from 2343–11,895 kg ha−1, depending on year, cultivar and planting date, whereas fresh green seed yields ranged from 1208–6,119 kg ha−1. Early-maturing edamame cultivars planted in April had fewer insect pests and less damage than the cultivars planted later. Avoidance of insect pests is an important production consideration for insect management, especially critical in an organic production system. The fresh green seed yields produced during this study demonstrate that this emerging alternative crop has the potential for economic success in the southern region, assuming that the arthropod pests are effectively managed to maintain acceptable edamame quality and yield.

scholarly journals Two new Brazilian isolates of Bacillus thuringiensis toxic to Anticarsia gemmatalis (Lepidoptera: Noctuidae)

2012 ◽  
Vol 72 (2) ◽  
pp. 363-369 ◽  
Author(s):  
LM. Fiuza ◽  
R. Schünemann ◽  
LMN. Pinto ◽  
MHB. Zanettini
Keyword(s):  
Bacillus Thuringiensis ◽  
Field Tests ◽  
Protein Crystals ◽  
Anticarsia Gemmatalis ◽  
Cry Genes ◽  
Velvetbean Caterpillar ◽  
Protein Fragments ◽  
Transmission Electron ◽  
Major Pest ◽  
Lepidoptera Noctuidae

Bacillus thuringiensis is a bacterium used for biopesticides production and pest-resistant plants due to the synthesis of protein crystals by cry genes, which are effective in controlling several insect orders such as Lepidoptera. This work aimed at the evaluation and characterisation of two new B. thuringiensis isolates active against A. gemmatalis (Hübner 1818) larvae, which is the soybean major pest. The results showed that Bt117-4 isolate amplified fragments corresponding to cry2 and cry9 genes, and synthesised protein fragments equivalent to 130, 90 and 45 kDa. The Bt3146-4 isolate amplified DNA fragments corresponding to cry9 gene and synthesised protein fragments of 70, 58 and 38 kDa. Transmission electron microscopy revealed the presence of protein crystals in both isolates. CL50 with Cry purified proteins from Bt117-4 and Bt3146-4, corresponded to 0.195 and 0.191 µg larvae-1, respectively. The two B. thuringiensis isolates selected in this study were effective to control velvetbean caterpillar at laboratory conditions. Field tests should be carried on to develop new biopesticides formulation as well for cry genes resource for Anticarsia gemmatalis resistant transgenic plants.

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.

The Effect of Alternative Southern Green Stink Bug (Heteroptera: Pentatomidae) Insecticide Controls on Soybean Pest Management, Quality and Yield

1995 ◽  
Vol 30 (2) ◽  
pp. 216-236 ◽  
Author(s):  
R. M. McPherson ◽  
D. J. Boethel ◽  
J. E. Funderburk ◽  
A. T. Wier
Keyword(s):  
Methyl Parathion ◽  
Field Trials ◽  
Leaf Beetle ◽  
Anticarsia Gemmatalis ◽  
Lower Percentage ◽  
Stink Bug ◽  
Velvetbean Caterpillar ◽  
Pyrethroid Insecticides ◽  
Southern Green Stink Bug ◽  
Residual Control

Seven alternative insecticides to methyl parathion were assessed for stink bug control and yield and quality losses in soybean field trials in Georgia, Louisiana and Florida during 1988 and 1989. Several pyrethroid insecticides including lambda-cyhalothrin, cyfluthrin, tralomethrin and cypermethrin controlled the southern green soybean stink bug, Nezara viridula (L.). These insecticides had greater residual control than methyl parathion, the standard for stink bug control, and acephate, another labeled soybean insecticide. The residual control of the pyrethroids also prevented the buildup of green cloverworm, Plathypena scabra (F.), velvetbean caterpillar, Anticarsia gemmatalis Hübner, and bean leaf beetle, Cerotoma trifurcata (Forster). Permethrin, another pyrethroid insecticide, did not provide adequate stink bug control at the rate tested. Yields and 100-seed weights in the alternative insecticide plots were equal to or exceeded those in the standard treatments. Soybean quality (lower percentage of stink bug damaged kernels) was higher in plots treated with pyrethroids. Several alternative insecticides for controlling stink bugs are available to replace methyl parathion in soybean, should this product become unavailable to producers due to its patent expiration or denial of re-registration.

scholarly journals HAIRY FLEABANE AS A SOURCE OF MAJOR INSECT PESTS OF SOYBEAN

2016 ◽  
Vol 34 (3) ◽  
pp. 403-409 ◽  
Author(s):  
G. DALAZEN ◽  
L.E. CURIOLETTI ◽  
D. CAGLIARI ◽  
R.F. STACKE ◽  
J.V.C. GUEDES
Keyword(s):  
Insect Pests ◽  
Anticarsia Gemmatalis ◽  
Population Fluctuations ◽  
Alternative Host ◽  
Stink Bugs ◽  
Conyza Bonariensis ◽  
Weedy Species ◽  
Winter Crops ◽  
Piezodorus Guildinii ◽  
Hairy Fleabane

ABSTRACT Weeds compete with crops for essential inputs, but they are also important hosts for pests, both during the crop and between crops. Hairy fleabane (Conyza bonariensis) is an important weed growing in both summer and winter crops. The aim of this study was to evaluate the occurrence and population fluctuations of soybean pests using hairy fleabane as an alternative host. Samples of hairy fleabane plants were collected fortnightly over twelve months at two sites (Boa Vista do Incra and São Vicente do Sul) in Rio Grande do Sul state, Brazil. The results showed that hairy fleabane plants provided shelter to important soybean pests, including the pentatomid stink bugs Edessa meditabunda, Piezodorus guildinii, Dichelop sp. and Euschistus heros, especially after soybean maturation, and also served as an alternative food source. This weedy species was also an important alternative host for caterpillars such as Anticarsia gemmatalis, Chrysodeixis includens, Spodoptera spp. and Helicoverpa gelotopoeon.

scholarly journals Specific binding of Bacillus thuringiensis Cry1Ea toxin, and Cry1Ac and Cry1Fa competition analyses in Anticarsia gemmatalis and Chrysodeixis includens

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yolanda Bel ◽  
Marc Zack ◽  
Ken Narva ◽  
Baltasar Escriche
Keyword(s):  
Bacillus Thuringiensis ◽  
Brush Border ◽  
Binding Sites ◽  
Brush Border Membrane ◽  
Specific Binding ◽  
Anticarsia Gemmatalis ◽  
Binding Studies ◽  
Velvetbean Caterpillar ◽  
Competition Binding ◽  
Chrysodeixis Includens

AbstractAnticarsia gemmatalis (velvetbean caterpillar) and Chrysodeixis includens (soybean looper) are two important defoliation pests of soybeans. In the present study, we have investigated the susceptibility and brush border membrane-binding properties of both species to Bacillus thuringiensis Cry1Ea toxin. Bioassays performed in first-instar larvae demonstrated potent activity against both soybean pests in terms of mortality or practical mortality. Competition-binding studies carried out with 125Iodine-labelled Cry1Ea, demonstrated the presence of specific binding sites on the midgut brush border membrane vesicles (BBMV) of both insect species. Heterologous competition-binding experiments indicated that Cry1Ea does not share binding sites with Cry1Ac or Cry1Fa in either soybean pest. This study contributes to the knowledge of Cry1Ea toxicity and midgut binding sites in A. gemmatalis and C. includens and sheds light on the cross-resistance potential of Cry1Ea with other Bt proteins aimed at controlling lepidopteran pests in soybeans.

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.

Interactions in Entomology: Mid-Season Dimilin and Boron Treatment Impact on the Incidence of Arthropod Pests and Yield Enhancement of Soybeans

1999 ◽  
Vol 34 (1) ◽  
pp. 17-30 ◽  
Author(s):  
R. M. McPherson ◽  
G. J. Gascho
Keyword(s):  
Pest Control ◽  
Insect Pests ◽  
Foliar Application ◽  
Field Trials ◽  
Insect Growth Regulator ◽  
Yield Enhancement ◽  
Anticarsia Gemmatalis ◽  
Stink Bugs ◽  
Yield Increase ◽  
Arthropod Pests

Twelve replicated soybean field trials were conducted in 1993–1997 to evaluate the effects of a foliar application of the insect growth regulator Dimilin® (0.07 or 0.035 kg Al/ha) and the plant nutrient boron (0.28 kg nutrient/ha) on the incidence of insect pests and the enhancement of yield and quality. Dimilin (diflurbenzuron) was very effective at all test locations in controlling velvetbean caterpillars, Anticarsia gemmatalis Hübner, for the remainder of the season once the foliar application was made on soybeans in the R2 (full bloom) to R5 (pods filling with seeds) growth stage. Six of the test sites had significant yield increases in the Dimilin plots due to protection from economic crop injury from this pest. Dimilin was not effective in controlling stink bugs, primarily Nezara viridula (L.) and Euschistus servus (Say), and Mexican bean beetles, Epilachna varivestis Mulsant. Scout® (tralomethrin) and MVP® (Bacillus thuringiensis Berliner) did not provide adequate residual pest control when combined with the boron treatment. Yield enhancements from boron (Solubor®, soluble disodium octaborate tetrahydrate) were observed in seven tests, but yields were significantly higher than the no boron treatments in only three experiments. The nutrient applications did not influence the abundance of arthropod pests at any test location. The overall soybean yield enhancement of around 440 kg/ha (6.5 bu/a) above the untreated plots represents a positive net economic return for the total investment of around $55 per ha. Dimilin accounted for most of the yield increase due to effective pest control, but the addition of boron costs very little ($3.00/ha) with a return of about 35 kg/ha across all soil types (higher response in sandy soils). It appears that a dimilin/boron foliar application around R3 stage soybeans (small pods forming) can be a profitable strategy in south Georgia, especially in areas where velvetbean caterpillars are annual economic pests and the fields contain sandy soil with low levels of available boron.

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.

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.

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