scholarly journals Transcriptomics-Based Approach Identifies Spinosad-Associated Targets in the Colorado Potato Beetle, Leptinotarsa decemlineata

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 820
Author(s):  
Pierre Bastarache ◽  
Gabriel Wajnberg ◽  
Pascal Dumas ◽  
Simi Chacko ◽  
Jacynthe Lacroix ◽  
...  

The Colorado potato beetle Leptinotarsa decemlineata is an insect pest that threatens potato crops globally. The primary method to control its damage on potato plants is the use of insecticides, including imidacloprid, chlorantraniliprole and spinosad. However, insecticide resistance has been frequently observed in Colorado potato beetles. The molecular targets and the basis of resistance to imidacloprid and chlorantraniliprole have both been previously quantified. This work was undertaken with the overarching goal of better characterizing the molecular changes associated with spinosad exposure in this insect pest. Next-generation sequencing was conducted to identify transcripts that were differentially expressed between Colorado potato beetles exposed to spinosad versus control insects. Results showed several transcripts that exhibit different expression levels between the two conditions, including ones coding for venom carboxylesterase-6, chitinase 10, juvenile hormone esterase and multidrug resistance-associated protein 4. In addition, several microRNAs, such as miR-12-3p and miR-750-3p, were also modulated in the investigated conditions. Overall, this work reveals a molecular footprint underlying spinosad response in Colorado potato beetles and provides novel leads that could be targeted as part of RNAi-based approaches to control this insect pest.

Insects ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1030
Author(s):  
Vladimír Půža ◽  
Jiří Nermuť ◽  
Jana Konopická ◽  
Oxana Skoková Habuštová

Colorado potato beetle Leptinotarsa decemlineata is among the most destructive pests of potatoes quickly developing resistance to traditional insecticides. In the present study, we tested the effect of various species and strains of entomopathogenic nematodes on CPB adults, and subsequently, the most effective nematodes were applied alone and in combination with entomopathogenic fungus B. bassiana in pots with potato plants and in the field and their effect on the number of emerging adults was evaluated. In the experimental infections, both the nematode invasion and pathogenicity were variable, and, in several strains, the mortality reached 100%. In pot experiments, soil application of nematodes S. carpocapsae 1343 and S. feltiae Jakub and fungus significantly decreased numbers of emerging CPB adults, while, after the application on leaves, only fungal treatment was effective. The field application of fungus B. bassiana significantly decreased the number of emerging CPB adults in comparison to control sites by ca. 30% while the effect of nematodes and the nematodes–fungus combination was not significant. In conclusion, we demonstrate the necessity of thorough bioassays to select the most effective nematode strains. Entomopathogenic nematodes have the potential to effectively decrease the emergence of CPB adults, but further research is needed to improve the effectiveness in the field.


2021 ◽  
Vol 64 (6) ◽  
pp. 2035-2044
Author(s):  
Saad Almady ◽  
Mohamed Khelifi

HighlightsA prototype pneumatic machine used to control the Colorado potato beetle (CPB) had no effect on potato plant growth.Yields in pneumatic treatment plots were comparable to those of control plots treated with a biological insecticide.Pneumatic control of the CPB could be an alternative to reduce reliance on chemical insecticides in potato fields.Abstract. The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the major insect pest of potato plants. Currently, the most effective method for controlling the CPB is to apply chemical insecticides throughout its lifecycle. However, the CPB has the ability to resist most chemical insecticides. Control of this insect pest has therefore become extremely difficult, prompting researchers to explore effective alternatives. The use of pneumatic methods to control the CPB is a promising alternative to chemical means. The objective of this study was to develop an effective pneumatic control method for the CPB to reduce the reliance on chemical insecticides in potato fields. In this context, a prototype pneumatic machine was designed and built. The prototype uses positive air pressure to dislodge CPBs from potato foliage, deposit them on the ground between the rows, and crush them. The effects of three airflow velocities (45, 50, and 55 m s-1) and two tractor travel speeds (5 and 6 km h-1) on CPB control, plant growth, and tuber yield were investigated in potato plots. Overall, the results showed no significant differences in yield between treatments (p = 0.3268), indicating that the yield of potato plants treated with the prototype was comparable to that of plants treated with a biological insecticide (Entrust). In addition, the prototype did not have any negative effects on plant growth. This suggests that the prototype could be safely and efficiently used in potato fields to control the CPB. The success of this innovative control method could greatly contribute to reducing the use of chemical insecticides to control the CPB. Keywords: Airflow velocity, Leptinotarsa decemlineata (Say), Pneumatic control, Potato, Travel speed.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Swati Mishra ◽  
James Dee ◽  
William Moar ◽  
Jodi Dufner-Beattie ◽  
James Baum ◽  
...  

AbstractInsecticidal double-stranded RNAs (dsRNAs) silence expression of vital genes by activating the RNA interference (RNAi) mechanism in insect cells. Despite high commercial interest in insecticidal dsRNA, information on resistance to dsRNA is scarce, particularly for dsRNA products with non-transgenic delivery (ex. foliar/topical application) nearing regulatory review. We report the development of the CEAS 300 population of Colorado potato beetle (Leptinotarsa decemlineata Say) (Coleoptera: Chrysomelidae) with > 11,100-fold resistance to a dsRNA targeting the V-ATPase subunit A gene after nine episodes of selection using non-transgenic delivery by foliar coating. Resistance was associated with lack of target gene down-regulation in CEAS 300 larvae and cross-resistance to another dsRNA target (COPI β; Coatomer subunit beta). In contrast, CEAS 300 larvae showed very low (~ 4-fold) reduced susceptibility to the Cry3Aa insecticidal protein from Bacillus thuringiensis. Resistance to dsRNA in CEAS 300 is transmitted as an autosomal recessive trait and is polygenic. These data represent the first documented case of resistance in an insect pest with high pesticide resistance potential using dsRNA delivered through non-transgenic techniques. Information on the genetics of resistance and availability of dsRNA-resistant L. decemlineata guide the design of resistance management tools and allow research to identify resistance alleles and estimate resistance risks.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 767D-767
Author(s):  
S. Overney ◽  
V.Q. Le ◽  
S. Visal ◽  
S. Yelle

Bioengineering economically important plants with proteinase inhibitors (PIs) is a promising method for the control of insect pests. In the case of the Colorado potato beetle (CPB; Leptinotarsa decemlineata Say), the major insect pest of potato fields, 80% of the digestive proteases are of cysteine type. We showed that 60% of these cysteine proteases are inhibited by oryzacystatins (OCs). The use of these cysteine protease inhibitor genes therefore appears of great interest for the production of Coleoptera-resistant transgenic plants of potato. Complementary studies of biochemical in vitro assays showed an apparent absence of direct interference between OCs and potato proteases. The high regeneration efficiency of the genetically transformed plants with OC gene and the “normal” phenotypical growth of the resulting transgenic potato plants suggested that these foreign genes do not interact with important physiological processes in the potato plants. In vivo assays of PIs against CPB at various developmental stages suggest the significant potential of OCs as an effective way to control CPB populations and crop damage.


2015 ◽  
Vol 24 (4) ◽  
pp. 729-740 ◽  
Author(s):  
Aleksandar Cingel ◽  
Jelena Savić ◽  
Branka Vinterhalter ◽  
Dragan Vinterhalter ◽  
Miroslav Kostić ◽  
...  

2021 ◽  
Vol 37 (4) ◽  
pp. 645-651
Author(s):  
Saad Almady ◽  
Mohamed Khelifi

Highlights A pneumatic prototype machine to control the Colorado potato beetle (CPBs) was successfully designed, built, and tested in a potato field under real conditions. The pneumatic prototype machine is effective in dislodging CPB larvae from potato plants. ABSTRACT . The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is a real threat to potato crops when left uncontrolled. This insect pest is hard to control because it develops resistance to most chemical insecticides. To date, several alternatives including chemical, biological, and physical methods have been used to control CPB populations but have proven to be ineffective on their own. So far, the most reliable method at short and medium scales has been the use of chemicals, i.e., spraying insecticides onto potato plants at regular intervals throughout the life cycle of the CPB. However, the overuse of chemicals due to the resistance developed by the CPB can lead to serious health and environmental problems. The use of a pneumatic method to control the CPB seems to be a viable alternative compared to the use of chemicals. For this purpose, this research focused on engineering a pneumatic control device that could allow farmers to reduce their reliance on chemical insecticides. A pneumatic prototype machine using positive air pressure to dislodge CPBs from potato plant foliage was designed and built at the Department of Soils and Agri-Food Engineering of Université Laval. This prototype was tested in the field using three airflow velocities (31, 35, and 38 m/s) and two travel speeds (5 and 6 km/h). The results indicated that the airflow velocity and travel speed have no significant impact on dislodging the CPB (p = 0.0548 and 0.7033, respectively). However, the interaction between airflow velocities and the development stages of the CPB had a significant effect on dislodging the CPB (p = 0.0194). Overall, the most adequate airflow velocity that resulted in removing most of the CPB larvae from potato leaves was 35 m/s. Obtained results indicate that this pneumatic prototype machine could be efficiently used to control the CPB. However, extensive testing is required to confirm obtained results and investigate the effects of the pneumatic control on both the potato plant growth and the yield compared to other control means. Keywords: Airflow velocity, Colorado potato beetle, Pneumatic control, Potato, Travel speed.


Author(s):  
F. S. Melnichuk ◽  
S. A. Alekseeva ◽  
O. V. Hordiienko

The Colorado potato beetles and aphids are especially harmful pests for potato crops in the conditions of Kyiv region. So, on the 10th day after mass rebirth of the Colorado potato beetle larvae, potato plants on untreated by insecticide plots were completely destroyed by this phytophagus. Preplanting insecticide treatment of potato tubers provided high effectiveness against the Colorado potato beetle prior to the mass rebirth and development of larvae and reduced their density of population and harmfulness. The highest efficacy (93.2-95.2%) against these pests was noted in variants with Prestige, 290 FS, Emesto Quantum 273.5 FS and Celest Top 312.5 FS. Common scab, dry rot and Rhizoctonia solani were prevailed among the diseases of potato tubers. The greatest effectiveness against the common scab was provided by Prestige, 290 FS. Thus, the infestation of potato tubers by common scab in the variant with application of the Prestige, 290 FS was almost twice lower compared to control. Preparation Celest Top 312.5 FS provided a reduction of dry rot in almost 3 times, and Emesto Quantum 273.5 FS leads to reduction of infestation by Rhizoctonia solani in 4 times, respectively. The treatment of tubers is a reliable protection of potato plants against damage by the Colorado potato beetles and lesion diseases, that made it possible to obtain tuber yields at a level of 24.4-27.4 t per ha. However, preplanting treatment of planting material with insecticides is not always able to provide the protection of potato seedlings against damage by Colorado beetles. The mass reproduction of these pests occurs after planting of tubers and emerging of stalks at high air temperatures. Therefore, it is necessary to provide additionally spraying of plants. Typically, the insecticides used in recommended rates have a long period of protective action, which eliminates the need for further treatments on vegetative plants. The anti-resistant effect of this treatment is associated with the use of the neonicotinoids class insecticides (eg, imidacloprid, thiamethoxam, clothianidin), that have different mechanism of action compared to pyrethroids. Under such conditions, it is important to search, investigate and introduce modern, effective insecticides into agricultural production. For this purpose the research on the preparations from separate classes of chemical compounds with various toxic properties was conducted. The most effective against the larvae of Colorado potato beetles were insecticides Confidor, 20% SC, Calypso, 48% SC and Engeo 24.7% SC when spraying potato plantings. Duration of their protection was prolonged for two weeks after the application of insecticides. The maximum technical efficiency was reached as 99.5% (Confidor, 20% SC), 99.2% (Calypso, 48% SC) and 99.3% (Engeo 24.7% SC) on the third day after application. Other insecticides such as Mospilan, 20% SP and Actara, 24% WG (96.2-97.0%) provided somewhat lower the mortality rate of these phytophages. The highest and prolonged effect against aphids was obtained by spraying potato plantings with the preparations Engeo 24.7% SC and Confidor, 20% SC, the efficiency of which reached 98.2% and 93.1%, that decreased the number of aphids in almost 60 times, compared with the control. Spraying potato plantings with insecticides according to the recommended rates of application allows obtaining the yield of tubers at the level of 25,6-28,2 t per ha.    


2017 ◽  
Author(s):  
Victor Izzo ◽  
Yolanda H. Chen ◽  
Sean D. Schoville ◽  
Cong Wang ◽  
David J. Hawthorne

ABSTRACTColorado potato beetle (Leptinotarsa decemlineata Say) is a pest of potato throughout the Northern Hemisphere, but little is known about the beetle’s origins as a pest. To determine the origins of pest populations of CPB, we sampled the beetle from uncultivated Solanum host plants in Mexico, and from pest and non-pest populations in the U.S. We used mtDNA and nuclear loci to examine three hypotheses on the origin of the pest lineages: 1) the pest beetles originated from Mexican populations, 2) the pest beetles descended from hybridization between previously divergent populations, or 3) the pest beetles descended from populations that are native to the Plains states in the United States. We examined patterns of genetic diversity among geographic regions in order to detect invasion-related genetic information. Mitochondrial haplotypes of non-pest populations from Mexico and southern Arizona differed substantially from beetles collected from the southern plains and potato fields in the U. S., indicating that beetles from Mexico and Arizona did not contribute to founding the pest lineages. Similar results were observed for AFLP and microsatellite data. In contrast, non-pest populations from the southern plains of Colorado, Kansas, Nebraska, New Mexico, and Texas were genetically similar to U. S. pest populations, clearly indicating that they contributed to the founding of the pest lineages. Although some pest populations are less genetically diverse (e.g., Washington, Idaho), most of the pest populations do not show a significant reduction in genetic diversity compared to the plains populations in the U. S. In contrast to the colonization patterns typical of exotic pests, our analyses suggests that a large genetically heterogeneous beetle populations expanded onto potato from native Solanum hosts. As an endemic colonization of a novel host plant, this host range expansion may have contributed to the relatively abundant genetic diversity of contemporary populations, perhaps contributing to the rapid evolution of host range and insecticide resistance in this widely successful insect pest.


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