Characterization of cuticular chitin-binding proteins of Leptinotarsa decemlineata (Say) and post-ecdysial transcript levels at different developmental stages

2010 ◽  
pp. no-no ◽  
Author(s):  
J. Zhang ◽  
Y. Pelletier
Author(s):  
Jiří Skuhrovec ◽  
Ondřej Douda ◽  
Miloslav Zouhar ◽  
Marie Maňasová ◽  
Matěj Božik ◽  
...  

Abstract The Colorado potato beetle ranks as one of the most important potato pests, mainly due to its high feeding rate during all developmental stages, particularly third and fourth larval instar, and high fecundity. The effect of essential oil (EO) from anise (Pimpinella anisum L. [Apiales: Apiaceae]) prepared as conventional and encapsulated (EN) formulations on the mortality and antifeedant responses of young larvae of Colorado potato beetles was studied to evaluate the insecticidal and antifeedant effects of five concentrations of this EO and to assess the persistence of both formulations on potato plants. The EN formulation had a significantly higher residual amount compared with that of the conventionally formulated EO. Significantly different values of LC50 and LC90 (ppm) were established for the EO (LC50 = 1,700 and LC90 = 9500) and EN (LC50 = 3,100 and LC90 = 14,300) formulations. The effects of both P. anisum formulations (EO and EN) applied topically to Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) larvae were distinctly different from those observed with the contact treatment. At the highest concentration of 20,000 ppm, the mortality of the second instars of the L. decemlineata larvae did not exceed 25%. On the other hand, both tested formulations of P. anisum were highly effective when administered orally. The encapsulated EO formulation achieved a distinctly higher biological activity. Our results confirm that the EO from P. anisum, especially the encapsulated formulation, has high insecticidal properties that may lead to the development of new organic products for the control of Colorado potato beetles.


2020 ◽  
Vol 113 (3) ◽  
pp. 1445-1454
Author(s):  
K F Wiebe ◽  
O O Elebute ◽  
C M R LeMoine ◽  
B J Cassone

Abstract The Colorado potato beetle (Leptinotarsa decemlineata (Say)) is an important pest of the cultivated potato (Solanum tuberosum (L.) [Solanales: Solanaceae]). With its broad resistance toward commonly used insecticides, it is clear that more sophisticated control strategies are needed. Due to their importance in insect development, microRNAs (miRNAs) represent a potential tool to employ in insect control strategies. However, most studies conducted in this area have focused on model species with well-annotated genomes. In this study, next-generation sequencing was used to catalogue the miRNAs produced by L. decemlineata across all eight stages of its development, from eggs to adults. For most stages, the length of miRNAs peaked between 21 and 22 nt, though it was considerably longer for the egg stage (26 nt). Global profiling of miRNAs revealed three distinct developmental clusters: 1) egg stage; 2) early stage (first, second, and third instar); and 3) late stage (fourth instar, prepupae, pupae, and adult). We identified 86 conserved miRNAs and 33 bonafide novel miRNAs, including stage-specific miRNAs and those not previously identified in L. decemlineata. Most of the conserved miRNAs were found in multiple developmental stages, whereas the novel miRNAs were often stage specific with the bulk identified in the egg stage. The identified miRNAs have a myriad of putative functions, including growth, reproduction, and insecticide resistance. We discuss the putative roles of some of the most notable miRNAs in the regulation of L. decemlineata development, as well as the potential applications of this research in Colorado potato beetle management.


Author(s):  
Jelica Lazarević ◽  
Igor Kostić ◽  
Slobodan Milanović ◽  
Darka Šešlija Jovanović ◽  
Slobodan Krnjajić ◽  
...  

Abstract The Colorado potato beetle, Leptinotarsa decemlineata (Say), is one of the most destructive pest species to have developed resistance to most chemical insecticides. We determined the composition and evaluated the potential of Tanacetum parthenium L. and Tanacetum vulgare L. (Asteraceae family) essential oil (EO) application as an alternative eco-friendly control strategy against L. decemlineata. We assessed the antifeedant activity for L. decemlineata larvae and adults by estimating the damage to potato leaves treated with three concentrations of EOs dissolved in ethanol (0.125, 0.25 and 0.5%). Results showed that T. parthenium EO was more effective against larvae, and T. vulgare was more effective against adults. In an olfactometer assay, the time required to choose an untreated leaf disc did not depend on the Tanacetum species, or life stage examined. However, the concentration of EO exhibited a significant effect on the behaviour of both developmental stages. At higher EO concentrations, both third instar larvae and adults require less time to choose an untreated leaf disc. Additionally, T. parthenium EO provoked more rapid movement away from the treated leaf disc than T. vulgare, especially at the highest concentration. Successful modification of L. decemlineata behaviour by the two Tanacetum oils suggests that they possess the potential for use in potato protection.


2021 ◽  
Vol 13 (11) ◽  
pp. 6167
Author(s):  
Darija Lemic ◽  
Matej Orešković ◽  
Katarina M. Mikac ◽  
Marijan Marijan ◽  
Slaven Jurić ◽  
...  

Alternatives and replacements for synthetic chemical-based plant protectants are required. In this study biopolymeric microspheres containing arthropod-derived apitoxin are explored as a possible novel environmentally friendly formulation for plant protection. Here we document the optimization process for microencapsulation of apitoxin into a stable formulation, for ready use in agricultural applications. Efficacy trials were carried out on three different beetle species at various developmental stages (Leptinotarsa decemlineata (Say, 1824.), Tenebrio molitor (Linnaeus, 1758.), Sitophilus granarius (Linnaeus, 1758.)). The encapsulated apitoxin has a steady initial and long residual effect, due to the slow release of apitoxin which is one of its main advantages over other conventional control methods. Microspheres loaded with apitoxin have a detrimental effect on insects, of which it is significantly better gastric compared to contact action (due to pH). The results showed that the highest and fastest mortality was obtained when the highest concentrations (0.6%) were applied, chosen to be economically acceptable. These important findings contribute to knowledge on the application and development of encapsulated apitoxin formulations, and their effectiveness, as an alternative eco-friendly control method in agricultural production.


2011 ◽  
Vol 51 (3) ◽  
pp. 225-233 ◽  
Author(s):  
Safaei Mahdi ◽  
Jafarnia Sasan ◽  
Khosroshahi Sara

Contact Toxicities of Oxygenated Monoterpenes to Different Populations of Colorado Potato Beetle,Leptinotarsa DecemlineataSay (Coleoptera: Chrysomelidae)In the present study, 12 pure oxygenated monoterpenes at 2 different doses were tested for their toxicity against second and third instar larvae and adults of three different populations of Colorado potato beetle (Leptinotarsa decemlineataSay). Some of tested compounds were found to be toxic to larvae and adults, but the degree of toxicity was variable. The mortality range was 20-100%. In general, fenchone, linalool, citronella and menthone showed a strong toxicity against the tested developmental stages; camphor, carvone and linalyl acetate showed moderate toxicity against larvae and adults of Colorado potato beetle and some compounds like fenchol, isomenthol, menthol, nerol and neryl acetate showed the least or no toxicity against the tested developmental stages ofL. decemlineata.Another important result was that although the tested populations of Colorado potato beetle showed some resistance to Endosulfan (50% WP), there was no resistance to tested oxygenated monoterpenes. The present results indicate that some of these compounds can be used as potential control agents against both larvae and adults of Colorado potato beetle.


2020 ◽  
Vol 66 (4) ◽  
pp. 274-287
Author(s):  
Yao Peng ◽  
Lifang Wang ◽  
Yan Gao ◽  
Liang Ye ◽  
Huihui Xu ◽  
...  

Fungal chitinases play essential roles in chitin degradation, cell wall remodeling, chitin recycling, nutrition acquisition, autolysis, and virulence. In this study, 18 genes of the glycoside hydrolase 18 (GH18) family were identified in the Isaria cicadae genome. Seventeen of the genes belonged to chitinases and one was an endo-β-N-acetylglucosaminidase (ENGase). According to phylogenetic analysis, the 17 chitinases were designated as subgroups A (7 chitinases), B (7), and C (3). The exon–intron organizations of these genes were analyzed. The conserved regions DxxDxDxE and S/AxGG and the domains CBM1, CBM18, and CBM50 were detected in I. cicadae chitinases and ENGase. The results of analysis of expression patterns showed that genes ICchiA1, ICchiA6, ICchiB1, and ICchiB4 had high transcript levels in the different growth conditions or developmental stages. Subgroup A chitinase genes had higher transcript levels than the genes of all other chitinases. Subgroup B chitinase genes (except ICchiB7) presented higher transcript levels in chitin medium compared with other conditions. ICchiC2 and ICchiC3 were mainly transcribed in autolysis medium and in blastospores, respectively. Moreover, ICchiB1 presented higher transcript levels than genes of other chitinases. This work provides an overview of the GH18 chitinases and ENGase in I. cicadae and provides a context for the chitinolytic potential, functions, and biological controls of these enzymes of entomopathogenic fungi.


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