scholarly journals A Promising Predator-In-First Strategy to Control Western Corn Rootworm Population in Maize Fields

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1984
Author(s):  
Antoine Pasquier ◽  
Lucie S. Monticelli ◽  
Adeline Moreau ◽  
Benjamin Kaltenbach ◽  
Candice Chabot ◽  
...  

Western Corn Rootworm is a pest of maize that mostly damages roots. Many alternative strategies have been explored to control this species, with little or non-lasting success, and it remains a threat to maize production worldwide. Gaeolaelaps aculeifer, a soil-dwelling predatory mite that inhabits the first few centimeters of the soil, showed high predatory potential against WCR larvae in the laboratory. In this study, we explored the efficiency of G. aculeifer against WCR in more realistic contexts. First, we infested maize plants isolated in pots in a greenhouse with WCR, and tested the impact of different densities of mites on plant protection. Using standard indicators of WCR population presence and impact, we confirmed that G. aculeifer has the potential to control WCR at densities starting from 100 mites/plant. Then, considering that the release of a large amount of biocontrol agents at WCR emergence might be too costly and constraining for large-scale implementation, we tested the efficiency of a predator-in-first strategy in a maize field infested by WCR. The goal was to introduce fewer G. aculeifer combined with Aleuroglyphus ovatus eggs as an alternative food source in order to let the mite population grow in the field and reach sufficient density at the critical stage for protection. This strategy gave comparable results to pesticide on all indicators examined in our field trial, highlighting the potential to sustainably manage this pest.

2005 ◽  
Vol 53 (1) ◽  
pp. 71-79 ◽  
Author(s):  
E. Széll ◽  
I. Zsellér ◽  
G. Ripka ◽  
J. Kiss ◽  
G. Princzinger

Western corn rootworm (WCR) first appeared in Europe near Belgrade airport in 1992. The first adult of this species was found near Mórahalom, in the southern part of Hungary, on 30th June 1995. Small-plot trials were started in Szeged (Cereal Research Non-Profit Co.) and large-scale trials in Mezohegyes (Ménesbirtok Ltd.) in 1996 to elaborate strategies to control this insect pest. To make the work more efficient, eight experts working at different institutions formed a team. At the same time, monitoring was begun on when and where the insect appeared and in what numbers. The experiments were adapted to the life cycle of the species. WCR has one generation per year, laying eggs that overwinter. Larvae begin to hatch in late May to mid-June. Adults emerge by mid-July and survive till early October. They lay eggs in abundance from mid-July to late August.  Trials were conducted to control WCR both with and without chemicals. For adult control pesticides were sprayed from an aircraft or using a field sprayer. Larval control involved seed treatment with insecticide or the use of soil insecticide at planting or at cultivation.


2013 ◽  
Vol 50 (3) ◽  
pp. 205-214 ◽  
Author(s):  
A. Čerevková ◽  
Ľ. Cagáň

Abstract Western corn rootworm, Diabrotica virgifera virgifera, is a pest that needs to be controlled with chemicals in the maize monoculture. The aim of this study was to examine the influence of insecticides on nematode communities in a maize field. Four soil treatments were used in this experiment: variant 1 — a granular application with tefluthrin (199.5 g a.i./ha); variant 2 — a granular application with clothianidin (110 g a.i./ha); variant 3 — a seed treatment with clothianidin (1.25 μg a.i/seed); and control — a maize field without insecticides. During the investigated period, a total of 19 117 soil nematode individuals were captured and 9 orders, 33 genera and 37 species were identified. Acrobeloides nanus, Cephalobus persegnis, Eucephalobus striatus and Basiria gracilis were the dominant species, accounting for 48 % of the total number of individuals. The mean abundance and species diversity index were significantly lower for variant 2. Bacterial feeders were the dominant trophic group for all 4 variants. The numbers of nematodes in particular trophic groups (i.e., bacterial feeders, fungal feeders and omnivores) were significantly different between variant 2 and the control. The Σ Maturity index, Maturity index and Plant parasitic index did not show significant differences among the variants. The higher values of the Enrichment and Structure indices were observed in the first month of the investigation in all 4 variants. A cluster analysis showed that nematode species population densities were strongly affected by the date of soil sample collection and by the variants used in the experiment.


Weed Science ◽  
2012 ◽  
Vol 60 (2) ◽  
pp. 193-198 ◽  
Author(s):  
P. Marquardt ◽  
C. Krupke ◽  
W. G. Johnson

Glyphosate-resistant (GR) volunteer corn has emerged as a problematic weed in corn:soybean rotational systems, partly because of the rapid increase in adoption of corn hybrids that contain traits for both glyphosate and insect resistance. Volunteer GR corn can decrease soybean yields. The objectives of this study were to quantify the impact of volunteer corn on soybean growth and yield and determine how volunteer corn densities affect western corn rootworm (WCR) emergence. Volunteer corn seed was hand-planted at targeted densities of 0.5, 2, 4, 8, 12, and 16 seeds m−2at soybean planting and 21 d after planting to evaluate both early- and late-emerging cohorts. WCR emergence was assessed with the use of field emergence traps placed over individual corn plants in the 0.5- and 16-plants-m−2plots in 2008 and 2009. In 2010, WCR emergence traps were also placed over individual and clumped volunteer corn plants at densities of two and eight plants m−2. Soybean yield reductions ranged from 10 to 41% where early-emerging volunteer corn densities ranged from 0.5 to 16 plants m−2. No soybean yield loss occurred with the late-emerging cohort of volunteer corn. Twice as many adult WCRs emerged from a single volunteer corn plant growing at densities of 8 and 16 plants m−2, compared with plots containing 0.5 and 2 plants m−2. These results demonstrate that controlling volunteer corn will not only prevent soybean yield loss, but also may reduce the risk of WCR larval survival after exposure to Bt (Bacillus thuringiensisBerliner derived) corn.


1995 ◽  
Vol 75 (4) ◽  
pp. 851-856 ◽  
Author(s):  
Rafik A. Assabgui ◽  
J. Thor Arnason ◽  
Robert I. Hamilton

Recently identified resistance factors in two inbreds of maize (Zea mays L.) were investigated in relation to their concentrations over the course of maize root development. The purpose of this study was to determine the time of peak expression in relation to field resistance to larvae of the western corn rootworm (Diabrotica virgifera virgifera LeConte). Bi-weekly variation in root hydroxamic acid content, as determined by high-pressure liquid chromatography, was compared with field resistance of 4- to 16-wk-old maize plants. The phytochemical analysis showed that the major hydroxamic acids in corn roots were 2,4-dihydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one (DIMBOA), and its main degradation product was 6-methoxy-benzoxazoline (MBOA). The highest concentrations of DIMBOA equivalents, 2-hydroxy-7-methoxy-1,4(2H)-benzoxazin-3-one (HMBOA) and total hydroxamic acids were found in 6-wk-old root extracts for the inbred with low susceptibility, and 10-wk-old root extracts for the inbred with high susceptibility. In field trials, the inbred with low susceptibility suffered maximal root damage 8 wk post-infestation, followed by a rapid and pronounced recovery. Damage to the root system of the inbred with high susceptibility rose rapidly throughout the growing season, reaching a maximum 12 wk post-infestation, followed by minimal recovery. Plant morphological factors were unaffected and are insensitive as measurements of plant damage. Based on the observations of this study, it would appear that the concentration of hydroxamic acids in the root systems of maize plants plays a role in resistance to western corn rootworm larvae under field conditions. Key words: 2,4-dehydroxy-7-methoxy-1,4-benzoxazin-3-one, Diabrotica virgifera virgifera, western corn rootworm, antibiosis, hydroxamic acids, biochemical resistance


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Salamida Daudi ◽  
Livingstone Luboobi ◽  
Moatlhodi Kgosimore ◽  
Dmitry Kuznetsov

In this paper, we propose and analyze a stage-structured mathematical model for modelling the control of the impact of Fall Armyworm infestations on maize production. Preliminary analysis of the model in the vegetative and reproductive stages revealed that the two systems had a unique and positively bounded solution for all time t ≥ 0 . Numerical analysis of the model in both stages under two different cases was also considered: Case 1: different number of the adult moths in the field assumed at t = 0 and Case 2: the existence of exogenous factors that lead to the immigration of adult moths in the field at time t > 0 . The results indicate that the destruction of maize biomass which is accompanied by a decrease in maize plants to an average of 160 and 142 in the vegetative and reproductive stages, respectively, was observed to be higher in Case 2 than in Case 1 due to subsequent increase in egg production and density of the caterpillars in first few (10) days after immigration. This severe effect on maize plants caused by the unprecedented number of the pests influenced the extension of the model in both stages to include controls such as pesticides and harvesting. The results further show that the pest was significantly suppressed, resulting in an increase in maize plants to an average of 467 and 443 in vegetative and reproductive stages, respectively.


2019 ◽  
Vol 68 (1-2) ◽  
pp. 28-33
Author(s):  
Branka Popović ◽  
Snežana Tanasković ◽  
Sonja Gvozdenac

Summary From the economic perspective, the western corn rootworm (WCR), Diabrotica virgifera sp. virgifera (Col., Chrysomelidae), poses the gravest threat to the field maize production in Serbia. The purpose of this study is to examine the impact of WCR larvae on the morphology of maize characters during a low-level artificial egg infestation. A field experiment involving the Serbian cultivar ‘NS-640’ was carried out in Bečej, Vojvodina Serbia, in 2016. In the experimental field, a total of 96 maize plants were selected, marked and arranged in 48 pairs. Each pair consisted of an infested plant (WCR eggs injected in the root zone) and an uninfested plant (distillate water injected in the root zone). The number of leaves, height and stem diameter of the plants observed were recorded. Root damage and root weight were measured and evaluated at the end of the trail. For the purpose of statistical analysis, the non-parametric Kruskal-Wallis one-way analysis of variance and a correlation matrix were used. The statistical analysis performed indicate a highly significant difference in the number of leaves and plant height between the infested and uninfested maize plants examined in July (the third field observation). During the last field inspection, significant differences were recorded only between the stem diameters of the infested and uninfested maize plants. A negative correlation was found to exist between the root damage and root weight of the plant pairs. There were positive correlations between the stem diameter, plant height and number of leaves of the infested plants, whereas positive correlations were found between the root damage and plant height of the uninfested plants.


Author(s):  
M. Tóth ◽  
É. Csonka ◽  
I. Szarukán ◽  
G. Vörös ◽  
L. Furlan ◽  
...  

In the course of research aimed at the development of non-sticky, easy-to-use alternative trap designs for the capture of selected beetle pests, a newly designed "hat" trap, codenamed CSALOMON® KLP+, was compared with conventional trap designs. In the case of the western corn rootworm (WCR) Diabrotica v. virgifera (Coleoptera, Chrysomelidae) the new KLP+ traps baited with pheromonal or floral baits were equally sensitive as the former PAL or PALs sticky "cloak" designs, but the KLP+ traps catch capacity and selectivity was much higher. When baited with the floral WCR bait, the KLP+ trap proved to be more sensitive in capturing female \VCR, than the former sticky PALs trap design. In capturing cabbage flea beetles (Phyllotreta spp., Coleoptera, Chrysomelidae), the new KLP+ trap design baited with allyl isothiocyanate performed better than the previously used VARL+ funnel traps in all respects studied. In conclusion, the new KLP+ trap design, baited with the respective attractants, appears to be advantageous to use for the trapping of both WCR and cabbage flea beetles, and can be recommended for use as a trapping tool in plant protection practice in the detection and monitoring of these pest Coleoptera.


2010 ◽  
Author(s):  
◽  
Kristen A. Leach

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Drought and western corn rootworm (WCR), Diabrotica virgifera virgifera, can have substantial impacts on the potential yield of maize, Zea may L. Maize lines were selected to survey the level of diversity available for primary root elongation maintenance under water stress and three WCR-related traits: WCR damage, root size, and root regrowth. Data analysis suggests that lines belonging to the Tropical/Semi-tropical population structure group are a significant source of alleles which would improve resistance/tolerance to these stressors. Further analysis of the WCR trait data found significant correlations with agronomically important traits related to plant maturity, confirming the impact of maize phenology on WCR damage. This indicates that phase change or changes in biochemical pathways as the plant matures may serve as additional criteria to effectively select germplasm that is resistant/tolerant to WCR feeding. In an effort to identify maize genes responsible for defense against WCR herbivory, a transcriptome analysis discovered that the presence of an endosymbiont, Wolbachia, down-regulated the expression of defense genes. Gene expression time courses suggest WCR elicits a response to herbivory by WCR+wb which was confirmed by a more extensive analysis of the microarray data. Maize defense genes were found to be down-regulated in agreement with the previous study. Transcriptional down-regulation may be the result of transposable element interference or post-transcriptional regulation by small RNAs, i.e. siRNAs or miRNAs. Three classes of miRNA were identified based on their response to WCR+wb, WCR-wb, and control treatments in the CRW3 germplasm; WCR-specific response, Wolbachia-specific response, and generalized defense response. Models based on the miRNA expression patterns along with information from the literature about their targets and downstream effects enabled us to predict phenotypes based on miRNA mediated-changes in gene expression. Results of the GO term enrichment analysis together with miRNA expression analysis support miRNA-mediated post-translational modification as one mechanism underlying the Wolbachia-associated changes in maize gene expression.


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