Phthorimaea Operculella Research Articles

Reference Genes for Expression Analyses by qRT-PCR in Phthorimaea operculella (Lepidoptera: Gelechiidae).

Simple SummaryQuantitative real-time fluorescent polymerase chain reaction (qRT-PCR) is a momentous tool for calculating the expression levels of targeted genes across various experimental conditions. The selection and evaluation of stable reference genes for qRT-PCR analysis is an essential precondition for reliable expression assessment. Phthorimaea operculella is one of the most serious Lepidopteran pests that attack potatoes around the world. In the present paper, a total of 10 commonly used reference genes, namely ACT, α-TUB, 18S, 28S, GAPDH, EF1α, RPL4, RPL13, RPL27 and SOD, were selected and validated for suitability under three treatments (developmental stages, tissues/organs and temperatures) using five methods (Ct value, geNorm, NormFinder, BestKeeper and RefFinder). These results indicated that EF1α and RPL13 were the best suitable reference genes for diverse backgrounds. The relative transcript levels of the target gene chitin synthase A gene (PoChSA) were abundantly expressed in epidermal cells, and lowly transcribed in the midgut. Our findings will be beneficial for improving the accuracy of qRT-PCR analysis for future functional analysis of the target gene expression in P. operculella.Due to a lack of effective internal references, studies on functional genes in Phthorimaea operculella, a serious Lepidopteran pest attacking potatoes worldwide, have been greatly limited. To select suitable endogenous controls, ten housekeeping genes of actin (ACT), α-tubulin (α-TUB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), elongation factor 1α (EF1α), 18S and 28S ribosomal RNA (18S, 28S), ribosomal protein genes RPL4, RPL13 and RPL27 and superoxide dismutase (SOD) were tested. Their expression levels were determined under three different experimental conditions (developmental stages, tissues/organs and temperatures) using qRT-PCR technology. The stability was evaluated with five methods (Ct value, geNorm, NormFinder, BestKeeper and RefFinder). The results clarified that RPL13, EF1α and RPL27 are ranked as the best reference gene combination for measuring gene expression levels among different developing stages and under various temperatures; EF1α and RPL13 are recommended to normalize the gene expression levels among diverse tissues. EF1α and RPL13 are the best reference genes in all the experimental conditions. To validate the utility of the selected reference pair, EF1α and RPL13, we estimated the tissue-biased expression level of chitin synthase A gene (PoChSA). As expected, PoChSA was abundantly expressed in ectodermally derived epidermal cells, and lowly transcribed in the midgut. These findings will lay the foundation for future research on the molecular physiology and biochemistry of P. operculella.

Phthorimaea operculella granulovirus

This datasheet on Phthorimaea operculella granulovirus covers Identity, Hosts/Species Affected, Further Information.

Entomopathogenic fungus, Metarhizium anisopliae, anchored onto MCM-41 silica nanomaterial: A novel and effective insecticide against potato tuber moth in stored potatoes

Summary Phthorimaea operculella (PTM) is an economically significant invasive potato insect pest in tropical and sub-tropical regions. Due to many problems concerning chemical insecticides, biocontrol agents such as entomopathogenic fungi have attracted researchers’ interest regarding their application as a part of integrated potato tuber moth management strategies in several countries. Hence, in the present study, we examined the lethal effects of entomopathogenic fungus, Metarhizium anisopliae (used as pure culture (PEF) or formulated with MCM-41 silica nanomaterial (MCM-41@fungus)) on eggs and neonate larvae of PTM. The MCM-41was completely characterized by Fourier transform infrared (FT-IR), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDS), X-ray diffraction (XRD), and Thermogravimetric analysis (TGA) techniques. The morphology of MCM-41@fungus was evaluated by scanning electron microscope (SEM). The morphology of the mesoporous structure was exhibited to be homogeneous, regular, and spherical. LC50 values of PEF and MCM-41@fungus were estimated to be 1.7×107 and 2×105 conidia/ml for eggs and 1.8×106 and 1.5×104 conidia/ml for neonate larvae, respectively. Hence, bioassays demonstrated that MCM-41@fungus was more toxic than the pure culture at egg and neonate larval stages of the pest. The results exhibited that pure M. anisopliae and its nano-formulation could play key roles as biopesticides in management programmes of P. operculella.

Efficacy of Biopesticides in Management of Potato Tuber Moth, Phthorimaea Operculella (Zeller), in Potato Under Storage

Efficacy of Biopesticides in Management of Potato Tuber Moth, Phthorimaea Operculella (Zeller), in Potato Under Storage

A Study On Efficacy Of Different Pesticides Against Potato Tuber Moth (Phthorimaea Operculella) In Storage Seed Potato

Mass rearing of potato tuber moths was conducted in a biocontrol laboratory to seek out appropriate management for the pest. The larvicidal efficacy of insecticides was studied by using four insecticides Bojho, Emamectine benzoate, Spinosad, Neem. The study discovered the effectiveness of all the insecticides, however the three pesticides had higher efficacy compare to Neem. The overall result indicates the highest mortality rate in treatments Bojho (100%), Emamectine benzoate (100%), and Spinosad (100%) whereas the lowest mortality rate in treatment Neem (94%). The infestation was conjointly high in Neem compare to the other three pesticides. To examine the efficacy of pesticides against PTM the applied treatments Bojho, Emamectine benzoate, and Spinosad was found to be the best insecticide among the trials in bringing down the PTM population as Neem showed to be less effective out of the total four pesticides applied. All the pesticides were effective in reducing insect population under laboratory conditions; however, their effectiveness was directly proportional to concentration and exposure periods. The study has demonstrated the possibility of using novel compounds in the IPM program.

Potato Moth-In Uzbekistan

More than 10 types of the basic pests have been revealed in the territory of various soil-climatic zones of the Republic. Among them are adventive kinds –the Colorado potato beetle, the whitefly and the potato moth. Biological features of those types and seasonal dynamics of their development are established; the general tactic of protective methods are developed with application of progressive means and receptions. Precautionary receptions of potato tubers’ protection against potato moth are established and recommended.

Entomopatojen nematod Heterorhabditis bacteriophora'nın (Rhabditida: Heterorhabditidae) kontrollü koşullar altında patates güvesi (Phthorimaea operculella (Zeller)) (Lepidoptera: Gelechiidae) üzerinde etkinliğinin belirlenmesi

The potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is an important pest of potato that causes yield losses in potato producing countries all over the world. Many management methods are available for reducing this pest populations. Chemical control methods are at the top of these. However, Entomopathogenic nematode (EPNs), can be used as a potential alternative to chemical insecticides to control potato tuber moth larvae as an eco-friendly management method. We aimed in this study to examine the efficacy of Turkish isolates of Heterorhabditis bacteriophora (TOK-20) against the last instar larvae (fourth stage) of the potato tuber moth under laboratory conditions. Experiments were conducted in 150 milliliter plastic cups with sterile soil mixture. Four nematode concentrations (0, 250, 500 and 1000 IJs) were applied directly to the soil. Potato tuber moth was susceptible to different concentrations of the H. bacteriophora (TOK-20) isolate. All doses were more effective than the control (water). The most effective was the 1000 IJs concentratio, providing a high mortality rate of the last instar larvae of potato tuber moth. No statistically significant difference was observed among temperatures. These results indicated that this H. bacteriophora (TOK-20) isolate is very efficient and could be used against potato tuber moth in biological control programs.

Efficacy of some chemical insecticides and plant extracts combined with Bacillus thuringiensis against Phthorimaea operculella

Abstract Phthorimaea operculella (Zeller, 1873) is one of the most damaging pests of potatoes in the world. Since the chemical pesticides play a key role in managing of potato tuber moth (PTM), the present study was conducted to assess the efficacy of Proteus®, Takumi®, Avaunt®, Dorsban®, Decis®, Consult® and Vertimec® against neonate larval penetration and one-day-old eggs of P. operculella. But adverse effects of chemical insecticides, actuated researchers to seek secure tools such as medicinal plants and biopesticides like Bacillus thuringiensis Berliner, 1715 for pest managements. Hence, we also examined toxicity of savory, ziziphora and cumin methanolic extracts against the pest under laboratory conditions. We also surveyed the synergistic/antagonistic interactions between the most effective insecticide and methanolic extract with Bt against PTM. Our results showed that both Vertimec® and savory synergized the performance of Bt against neonate larval penetration of P. operculella. Probit analysis of insecticides and methanolic extracts demonstrated that Vertimec® and Takumi® had high toxicities to the neonate larval penetration of PTM which exhibited LC50 values equivalent to 7.09 ppm and 0.008 g L−1, respectively. Savory was the most effective extract against larval penetration and hatching rate of the pest (LC50 = 440.36 and 635.93 ppm, respectively). Oviposition preference demonstrated that Vertimec® and Decis® exhibited inhibitory ovipositional effects against P. operculella.

Optimization and field evaluation of sex-pheromone of potato tuber moth, Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae).

The potato tuber moth, Phthorimaea operculella is a key pest of potato and tobacco in China. We compared the sex pheromone titers released by P. operculella female, and the electroantennogram (EAG) responses of male antennae to pheromone compounds under laboratory conditions. Then, the optimal sex pheromone ratio was screened in the field. The P. operculella sex pheromone feeding on potato or tobacco was extracted by solvent-extraction method. Main sex pheromone compounds including E4, Z7-13: AC (PTM1) and E4, Z7, Z10-13: AC (PTM2) were found in gland. The titer and relative ratio of P. operculella sex pheromone compounds secreted by female adult moths differ between host populations, while the relative EAG responses trend of P. operculella males to the pheromone components were the same when directly stimulated. In field trials, PTM1:PTM2=8:1-4:1 and PTM1:PTM2=1:4-1:7 was the most attractive ratio to P. operculella males in tobacco and potato fields, respectively. During 2019-2020, after 8 weeks of mass trapping for each year, the sex pheromone could reduce the population of P. operculella in the potato and tobacco fields. In this study, fixed property and quantity analyzing methods were adopted to compare sex pheromones from feeding on potato versus tobacco. EAG tests then were carried out on P. operculella males. Finally, we optimized the ratio of two sex pheromone compounds in potato and examined how this influenced field trapping. By further improving the parameters of sex pheromone application in the field, we demonstrate that deployment of sex pheromones can provide effective control of P. operculella. © 2021 Society of Chemical Industry.

Invasive insect potato tuber moth Phthorimaea operculella: stages of distribution in Russia and prognosis

This work summarizes all known data on the distributive history of Phthorimaea operculella in Europe, Asia and Russia with special reference to the current process of invasion to different regions of Russia and prognosis on its future spread through Russian territories. The invasion of the pest started in Russia in 1980. During last ten years from 2010 to 2020, Phthorimaea operculella occupied 5 new Regions of Russia. The threat of naturalization of the pest is high because the potato tuber moth has a high reproductive potential and cases of multiple introductions to various territories of Russia as well as registrations of the pest in places of vegetable storage are known. The modern map of the distribution of Phthorimaea operculella in Russia and selected foreign countries is composed.

Comparative studies on biology of <i>Chelonus blackburni</i> (Cameron) (<i>Hymenoptera:Braconidae</i>) on <i>Phthorimaea operculella</i> (Zeller) and <i>Corcyra cephalonica</i> (Stainton) under laboratory conditions

<em>Chelonus blackburni</em> (Cameron) that parasitizes eggs of potato tuber moth is widely distributed and occurs commonly in potato fields throughout the country. Studies on its biology and ovipositional performance were carried out on both hosts i.e. <em>Phthorimaea operculella</em> and <em>Corcyra cephalonica</em> in laboratory conditions. Average number of eggs laid per female was found to be 210.9 ± 16.62 on <em>P. operculella</em> and 118.4 ± 7.49 on <em>C. cephalonica</em>. Incubation period of the parasitoid on <em>P. operculella</em> was 24.5 ± 1.62 hours on an average, while on <em>C. cephalonica</em>, it was found as 25.2 ± 1.33 hours. Total larval duration was 14.5 days and 19.2 days on <em>P. operculella</em> and <em>C. cephalonica</em>, respectively. Pupal period was 10.6 ± 0.70 days on <em>P. operculella</em>, whereas it was slightly higher on <em>C. cephalonica</em> (13 ± 0.57 days). The average life span was observed to be 6.8 days on <em>P. operculella</em> and 7.7 days on <em>C. cephalonica</em>.

Review: Manfaat Feromon Sek Pada Ordo Lepidoptera Untuk Pengendalian Hama Lepidoptera

Lepidoptera is one of the orders of the phylum Arthropoda Insecta class consist of butterflies that are active during the day and moths at night. Both of them belong to the order Lepidoptera and have an important role in the ecosystem. Beneficial role for plants as pollinating insects and disadvantaged role as pests of cultivated plants. An example is the fall armyworm Spodoptera sp attacking rice plants, Pteroma sp attacks sengon plants, and Helicoverpa armigera attacks red chili plants. One of the efforts to control pests is the use of sex pheromones. Several types of sex pheromones were identified, for example the sex pheromone of the cabbage leaf caterpillar Pluttela xylostella was )-11-hexadecenal, (Z)-11-hexadecenol, and (Z)-11-hexadecenyl acetate with ratio 8:18:100 and 10:1:90. Potato tuber borer (Phthorimaea operculella Zell.) sex pheromones is (E,Z)- 4,7-13 Ac (trans-4, cis-7-tridecadienyl acetate) and (E,Z,Z)-4,7,10-13 Ac (trans-4, cis-7, cis-10-tridecatrienyl acetate) with ratio 1 : 2,5. Using pheromones sex on agricultural land can significantly suppress Lepidoptera pest populations.

Potato plant variety affects the performance and oviposition preference of Phthorimaea operculella Zeller (Lepidoptera: Gelechiidae).

Damage by the potato tuber moth Phthorimaea operculella is one of the major constraints to commercial production of potato in many areas of the world. To promote effective pest management practices for P. operculella based on host plant, larval and adult performance of P. operculella fed on Lishu 6, Hezuo 88, Yunshu 304, and Qingshu 9 potato varieties was compared by examining their survival rate, larval feeding, pupal weight, and oviposition preference. Compared with larvae fed on the other three potato plants, those fed on Lishu 6 exhibited the highest survival rate, with almost 61.67% developing to the adult stage. Females also preferred to lay their eggs on Lishu 6 over Hezuo 88, Yunshu 304 and Qingshu 9; and the weight of P. operculella pupa on Lishu 6 plant (0.0085 g) was significantly heavier than that of on others, especially on Qingshu 9 (0.0062 g). Moreover, first instar larvae fed on Lishu 6 showed host preference to Qingshu 9. This study demonstrated that Lishu 6 is susceptible to P. operculella, and Qingshu 9 is not relatively susceptible to P. operculella, which suggested that the P. operculella feeding responses to dominant potato varieties in China is different. This variation can be applied for the potato breeding and pest management practice. © 2021 Society of Chemical Industry.

Epidemiology of potato late blight disease and other major postharvest biotic stressesin Malawi

The epidemiology of Potato Foliar Late Blight (PFLB) disease (Phytophthora infestans) was quantified in major potato production areas of Malawi. Seed multiplication fields, tests clones and local farmers’ fields were sampled basing on Area Under Disease Progress Curve (AUDPC). The determined severity values were transformed into AUDPC coefficients characterizing rate of disease spreading across the crop. Results indicate minimum and maximum AUDPC values of 0 and 1050 respectively, with an average value of 233.57. The results show significant statistical differences in PLB disease across seed multiplication fields, test clones and local farmers’ fields. AUDPC values differed significantly (p < 0.001) among potato growing districts, as well as sources of seed (aeroponics, sandponics, and vendors). Post-harvest survey targeting potato tubers showed that tubers that were sampled from Mzimba district had the highest likelihood of being infected with Potato Tuber Late Blight (PTLB), followed by potatoes that were sampled from Lilongwe (coefficients, b= 1.89, t = 6.11, p-value<0.001) while the potatoes tubers that were sampled from Ntcheu did not vary in the severity with those that were sampled in Dedza. Susceptibility to potato PTLB among potato varieties were varied, with Rosita likelihood to PTLB disease, while there were no other significant differences to PTLB in the rest varieties (b=1.12, t=4.23, p-value<0.001). An extended study on bacterial wilt (PBW) revealed that disease was influenced by the district where the tubers were sampled (x2= 9.26, p-value < 0.001) while the type of variety sampled did not have any significant difference on PBW (x2= 3.59, p-value = 0.268). The presence of potato tuber moth which varied among the sampled districts, was not influenced by variety sampled. The paper has documented and quantified increasing epidemic spread of late blight disease and the consequent effect on sustainable potato production and clean seed systems in Malawi.

Integrated Management of Phthorimaea operculella (Zeller) Infesting Solanum tuberosum L. in Storage in MT Elgon Region, Kenya

The production of potato, a second major staple food crop in Kenya is being constrained by an insect pest potato tuber moth (PTM), Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae). The present study investigated two Integrated Pest Management techniques which would reduce (PTM) population in potato storage, four potato cultivars and two botanical quantities were used in storage in Mt Elgon region of Western Kenya. The insecticidal efficacy of Lantana camara L. and Azandiracta indica A. Jusss (Sapindales: Meliaceae) and in storage at Kapsokwony and Chemoremo villages were investigated in the present study years. In each of the studied site the experiment was laid down in randomized block Design (RBD) in a split plot arrangement at room temperature of 27 ± 2. Four cultivars (Tigoni, Sherekea, Mayan gold and Asante) were the first factor and treatments (L. camara and A. indica leaves powder and control) as the second factor, each of which was repeated three. The room was partitioned at the center into two (3m x3m) using a PVC sheet to separate two portions for the two botanical and to prevented insect migration. We set up 4 caring bags per cultivar per botanical. We placed 2 kg PTM-free tubers per each cultivar in one caring bag hence 4 caring bags/split/ cultivar and 16 caring bags / block, therefore the total number of caring bags was (4 x 4)= 16 bags per cultivar hence (16 x 4) = 64 caring bags/ botanical. The splits had four 2kg caring bags hence (2x4) = 8 kg per split and (8x16) = 32kg/cultivar hence N =128kg. The caring bags were covered with a layer of the botanicals at a rate 100g, 150g, 200g, and untreated control respectively. Twenty (10♀ + 10♂) newly emerged moths were introduced inside the storage. We assessed for week one number of tubers infested and tunnels of PTM larvae, at week two for number of tubers infested and tunneling length. Week three number of tubers infested, tunneling length in tubers and number of second generation larva. Analysis was done by comparison of the means and there mean differences using R software. Results indicated use of 200g/ 2kg of the botanicals significantly reduced number of PTM larvae. Lantana camara was the most effective insecticide followed by Azadrachta indica compared to the controlled tubers. Thus the use of 200g of L. camara and Tigoni cultivar may be promising components of IPM strategies for reducing P. operculella population in potato fields and storage.

Recovery of phenotypically normal transgenic potato plants is facilitated by regenerating multiple lines from transformation events: field validation using a cry9Aa2 gene conferring insect resistance

ABSTRACT A modified cry9Aa2 gene under the transcriptional control of the CaMV 35S promoter was transferred to four potato cultivars (‘Iwa’, ‘Karaka’, ‘Pacific’ and ‘Red Rascal’) using Agrobacterium-mediated gene transfer. Field plots were established for 170 independently regenerated transgenic lines derived from 113 transformation events. Phenotypic changes such as stunted plants, reduced vigour and/or leaf puckering, were observed in 29% of these lines. Foliage from the remaining 117 lines inhibited larval growth of potato tuber moth (Phthorimaea operculella Zeller) compared with non-transgenic controls. A high correlation was observed between greenhouse- and field-grown foliage for insect resistance using a detached leaf bioassay. Independently regenerated lines recovered from the same transformation event exhibited similar insect resistance. However, these lines derived from the same transformed cell differed markedly in phenotypic appearance and tuber yield. The first shoot regenerated from each transformation event was equivalent to the non-transgenic control for yield traits in only eight transformation events. A further 19 transformation events exhibited agronomic performance equivalent to the non-transgenic control when the second or subsequent regenerated shoots were evaluated. In clonal crops, multiple shoots from each transformation event should be independently assessed to ensure recovery of high-performing transgenic lines.

Parámetros reproductivos de Tecia solanivora (Povolný, 1973) (Lepidoptera: Gelechiidae) en genotipos de papa (Solanum tuberosum L.)

The Guatemalan potato moth Tecia solanivora is the main pest of potato crop in Colombia. In 2003, Agrosavia began the identification and selection of potato genotypes from the Central Colombian Collection (CCC) for T. solanivora resistance. In 2013 reciprocal diallelic crosses were carried out between commercial varieties and the Guatemalan moth resistant native genotypes. The objective of this study was to determine the effect of potato hybrids obtained from crosses, on T. solanivora demographic parameters under laboratory conditions. Five genotypes and two commercial varieties were evaluated in a non-choice trial, through the development of a life table with two consecutive cohorts. Genotypes 4-69, 23-31 and Perla Negra (PN) were found to cause the highest larval mortality (90, 98 and 98%); 23-31 and PN did not allow adults development. In genotypes 4-69 and 23-31, the net reproductive rate (Ro) (3.92 and 4.38) and the intrinsic rate of natural growth (rm) (0.030 and 0.035) decreased, and the initial population doubling time (TD) increased significantly (18,14 and 19,35). These results suggest that three of the evaluated genotypes could have attributes of resistance to T. solanivora due to the antibiosis mechanism by affecting its biology. This study contributes to the search for materials with resistance to the Guatemalan moth, a line of research for potato breeding in Colombia. Additional Keywords: Guatemalan potato moth, life table, antibiosis, antixenosis, pest resistance.

Development of a Quarantine Postharvest Treatment against Guatemalan Potato Moth (Tecia solanivora Povolny)

Tecia solanivora is a quarantine organism regarded as one of the insect pests causing major economic losses during potato cultivation and storage in Central America. The potatoes trade between countries, the interest in introducing new potato varieties, the great adaptability of the insect to different agro-ecological conditions, and the globalization world are serious risks in other potato growing countries. This pest was first recorded in Europe in the Canary Islands, Spain, in 1999, later in Galicia (2015) and then in Asturias (2016). Unfortunately, there are no effective chemical treatments for field control, and their integrated management has variable efficacy. Therefore, the implementation of a postharvest treatment to eradicate the insect, at any stage, during storage and marketing of potato becomes essential to achieve a product free of the insect that prevents its dissemination while maintaining the quality during its commercialization. This article presents the development of a new postharvest treatment of potatoes to eliminate all developmental stages of the Guatemalan moth by the application of a control atmosphere enriched in carbon dioxide. Infested potatoes were exposed to different control atmospheres combination (10, 20, 30, 40, or 50% CO2, 20% O2, and rest of N2). These treatments were applied for 4, 7, and 10 days at 18 ± 2 °C. The 10 days duration treatment (30 ± 2% CO2, 20 ± 2% O2 and 50 ± 2% N2) killed the insect in the semi and commercial trials performed without affecting potatoes quality and postharvest life, giving the possibility of its consideration as a quarantine postharvest treatment against T. solanivora.

Ways to Regulation of the Quantity of Potato Moths and Algorithms for Diagnosing its Development

Consideration of issues of the quantity of potato moths according to the data of pheromone traps, which make it possible to simplify the monitoring system for the development of the pest and make optimal decisions in their extermination. We have considered the regulation of the number of potato moths according to the data of pheromone traps. These data make it possible to simplify the monitoring system for the development of the pest and make optimal decisions in their extermination. The idea of the proposed algorithms is to form a set of preferred features and make diagnostic decisions based on comparing these features.

Optimization of the sex pheromone-based method for trapping field populations of Phthorimaea operculella (Zeller) in South China

Despite the identification of the potato tuber moth Phthorimaea operculella (Zeller) sex pheromone, no effective application based on this pheromone has yet been developed and evaluated. This study investigated the effect of pheromone lures, trap densities, heights of trap deployment, and pheromone doses in Yunnan, China, for the purpose of increasing the control efficiency of P. operculella and improving the application of pheromone technology in the field. The results showed that lures made of corn oil and red PVC pipes attracted the highest number of moths (11.73±1.90 per trap per day). Sex pheromone loading of 100 µg was optimal for trapping moths, but higher doses of pheromone inhibited attraction. The density of traps did not affect capture rates; therefore, the optimum trap density was 30–40 traps ha–1. The optimum height of trap deployment was not above the height of the plant canopy. This study provides technical details necessary for the monitoring and control of potato tuber moth using sex pheromones.