Effects of Dicofol on Survivorship and Oviposition of Colorado Potato Beetle (Coleoptera: Chrysomelidae) and on Field Plant Protection

1988 ◽  
Vol 81 (3) ◽  
pp. 887-891
Author(s):  
Richard K. Jansson ◽  
Gerald M. Ghidiu ◽  
James H. Lashomb
2019 ◽  
Vol 109 (05) ◽  
pp. 695-700
Author(s):  
E. Szilágyi ◽  
C. Hámori ◽  
P. Bíró-Molnár ◽  
L. Kandra ◽  
J. Remenyik ◽  
...  

AbstractColorado potato beetle (Leptinotarsa decemlineata, Say) is the main pest of Solanaceae and its survival is mainly dependent on the carbohydrate digestion. Characterizing the gut enzymes may help us with finding effective inhibitors for plant protection. Activity measurements revealed that gut extracts contain α- and β-glucosidase in addition to α-amylase. For larvae, amylase activity was detected only in gut saturated with nutrients.Leptinotarsa decemlineataα-amylase (LDAmy) had optimum pH of 6.0 and was active under 30–40°C temperature measured on a selective α-amylase substrate, 2-chloro-4-nitrophenyl-4-O-α-D-galactopyranosyl-maltoside. HPLC analysis demonstrated dimer, trimer, and tetramer reducing end amylolytic products from 2-chloro-4-nitrophenyl-maltoheptaoside substrate in similar ratio than that of during porcine pancreatic α-amylase (PPA) catalyzed hydrolysis. The 4,6-O-benzylidene-modified substrate (BzG7PNP) is very stable toward hydrolysis byexo-glycosidases, therefore is very useful to monitor the digestion catalyzed by α-amylases exclusively. Similarly to PPA active site, three glycon and two aglycon binding sites are suggested for LDAmy based on the pattern of early hydrolysis products of BzG7PNP. The observed similarity between LDAmy and PPA raises the possibility of using known inhibitors of mammalian α-amylases to protect the potato plant from attack of Colorado potato beetle.


2017 ◽  
Vol 6 (1) ◽  
pp. 10-14
Author(s):  
Lyudmila Alexandrovna Babkina ◽  
Irina Pavlovna Balabina ◽  
Natalia Ivanovna Trigub ◽  
Sergei Yurevich Mironov ◽  
Christina Vitalievna Merzlyakova

The population of the Colorado potato beetle is characterized by a high degree of polymorphism. This polymorphism provides a considerable adaptive potential and ubiquity of this species. The variability of the central pronotal pattern under the influence of habitat-forming factors (geographical location of the population, variety of fodder plant, group of insecticides) is considered in this paper. Differences in agrobiocenotic conditions determine a direction of microevolution changes and lead to disintegration of the intra-species structure of Leptinotarsa decemlineata . Evaluation of the phenotypic polymorphism in the Colorado potato beetle populations in the Kursk Region was performed by several indicators: ratio of nine main pronotums morphs, average number of variations (), share of the rare forms (h), populations similarity index (r) and identity criteria (I). In various parts of the Kursk Region from 7 to 9 pattern protonum phenoforms were encountered with varying frequency in the populations. The predominance of the 9-phenoform in the beetle populations was identified in the Rylsky, Oktyabrsky, Lgovsky districts. The 3-phenomorf prevailed in populations of Pristensky and Manturovsky districts. The highest level of a phenotypical polymorphism of a protonum was observed in the population in the Lgovsky district, the lowest level was detected in Manturovsky district. The comparative analysis of phenotypic structure of the investigated Colorado beetle populations showed that despite a spatial isolation the insect populations of the Rylsky and Pristensky districts are characterized by the highest similarity in pattern of variability of the central part of a pronotum. The obtained results will enable to improve the system of the plant protection against Colorado potato beetle and control its population.


2018 ◽  
Vol 48 (4) ◽  
pp. 14-19
Author(s):  
T. K. Коvalenko

The work presents the results of comparative field tests on effectiveness of insecticides and bioinsecticides and their tank mixtures for potatoes against the potato ladybird and the Colorado beetle in the South of the Far East. Effectiveness of preplanting and vegetation treatment of potatoes with preparations was observed. The study, conducted in 2012–2014 on the plants of the recognized Yantar potatoes variety, showed high biological efficiency of preparations from the neonicotinoid class of Prestige and Cruiser in the rates of 1.0 l/t and 0.2 l/t by pre-planting treatment of potato tubers. The Prestige and Cruiser provided long-term protective effect against the Colorado potato beetle and the potato ladybird, which eliminated the need for treatment in the growing season of the crop. The use of these insecticides caused productivity increase of potatoes by 7.5 and 8.4 t/ha. For vegetation treatment the preparation Decis Extra showed the highest and the most long-lasting effect. On the 28th day after the treatment, its effectiveness accounted for 84.4–90.3%. Protective effect of bio-insecticide Phytoverm lasted for 14 days. Double treatment of potatoes with this bio-insecticide restrained the number of pests below the threshold number until the end of the growing season. During the research it was found that the joint use of Phytoverm with 3 times lower rates of the insecticides Decis Extra and Konfidor provided a significant reduction in the number of the potato ladybird and the Colorado potato beetle and the preservation of 39.3-41.6% of potato productivity.


2020 ◽  
Vol 71 (9) ◽  
pp. 2670-2677 ◽  
Author(s):  
Wanwan He ◽  
Wenbo Xu ◽  
Letian Xu ◽  
Kaiyun Fu ◽  
Wenchao Guo ◽  
...  

Abstract Transplastomic potato plants expressing double-stranded RNA (dsRNA) targeted against essential genes of the Colorado potato beetle (CPB) can be lethal to larvae by triggering an RNA interference (RNAi) response. High accumulation levels of dsRNAs in plastids are crucial to confer an efficient RNAi response in the insects. However, whether length and sequence of the dsRNA determine the efficacy of RNAi and/or influence the level of dsRNA accumulation in plastids is not known. We compared the RNAi efficacy of different lengths of dsRNA targeted against the CPB β-Actin gene (ACT) by feeding in vitro-synthesized dsRNAs to larvae. We showed that, while the 60 bp dsRNA induced only a relatively low RNAi response in CPB, dsRNAs of 200 bp and longer caused high mortality and similar larval growth retardation. When the dsRNAs were expressed from the plastid (chloroplast) genome of potato plants, we found that their accumulation were negatively correlated with length. The level of dsRNA accumulation was positively associated with the observed mortality, suppression of larval growth, and suppression of target gene expression. Importantly, transplastomic potato plants expressing the 200 bp dsRNA were better protected from CPB than plants expressing the 297 bp dsRNA, the best-performing line in our previous study. Our results suggest that the length of dsRNAs is an important factor that influences their accumulation in plastids and thus determines the strength of the insecticidal RNAi effect. Our findings will aid the design of optimized dsRNA expression constructs for plant protection by plastid-mediated RNAi.


2019 ◽  
Author(s):  
Wanwan He ◽  
Wenbo Xu ◽  
Letian Xu ◽  
Kaiyun Fu ◽  
Wenchao Guo ◽  
...  

AbstractTransplastomic potato plants expressing double-stranded RNA (dsRNA) targeted against essential genes of the Colorado potato beetle (CPB) can be lethal to larvae by triggering an RNA interference (RNAi) response. High accumulation levels of dsRNAs in plastids are crucial to confer an efficient RNAi response in the insects. However, whether length and sequence of the dsRNA determine the efficacy of RNAi and/or influence the level of dsRNA accumulation in plastids is not known. Here we compared the RNAi efficacy of different lengths of dsRNA targeted against the CPB β–Actin gene (ACT) by feeding in vitro-synthesized dsRNAs to larvae. We show that, while the 60 bp dsRNA induced only a relatively low RNAi response in CPB, dsRNAs of 200 bp and longer caused high mortality and similar larval growth retardation. When the dsRNAs were expressed from the plastid (chloroplast) genome of potato plants, we found that their accumulation levels were correlated with length. dsRNA accumulation levels were positively associated with the observed mortality, suppression of larval growth and suppression of target gene expression. Importantly, transplastomic potato plants expressing the 200 bp dsRNA were better protected from CPB than plants expressing the 297 bp dsRNA, the best-performing line in our previous study. Our results suggest that the length of dsRNAs is an important factor that influences their accumulation levels in plastids and thus determines the strength of the insecticidal RNAi effect. Our findings will aid the design of optimized dsRNA expression constructs for plant protection by plastid-mediated RNAi.


2021 ◽  
Vol 117 (3) ◽  
pp. 1
Author(s):  
Primož ŽIGON ◽  
Jaka RAZINGER ◽  
Stanislav TRDAN

<p class="042abstractstekst">Plants respond to pest attack, among other mechanisms, by producing specific proteins with insecticidal properties. Proteins with toxic effects on insects have also been discovered in many other organisms, especially fungi and bacteria. Due to their biological function, insecticidal proteins represent an important potential in the development of more environmentally friendly plant protection methods. Increasing knowledge about the mode of action of insecticidal proteins and the identification of genes encoding their synthesis enable the breeding of transgenic plants resistant to insect pests and the development of new bioinsecticidal agents. The Colorado potato beetle (<em>Leptinotarsa decemlineata</em>) is one of the most important pests of potato, so the study of such control methods is crucial for the development of sustainable integrated pest management strategies of potato. This review highlights the properties of some groups of insecticidal proteins and their modes of action, and summarizes examples of studies of their use for the control of Colorado potato beetle.</p>


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