scholarly journals TLC-Based Bioassay to Isolate Kairomones from Tea Tree Essential Oil That Attract Male Mediterranean Fruit Flies, Ceratitis capitata (Wiedemann)

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 683
Author(s):  
Nurhayat Tabanca ◽  
Jerome Niogret ◽  
Paul E. Kendra ◽  
Nancy D. Epsky

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) poses a major threat to fruit and vegetable production in the United States and throughout the world. New attractants and detection methods could improve control strategies for this invasive pest. In this study, we developed a method that combined thin-layer chromatography (TLC) of tea tree essential oil (TTO) (Melaleuca alternifolia) with short-range bioassays to isolate attractive kairomones for male C. capitata. After development, the TLC chromatogram indicated that TTO separated into five major spots, designated as zones 1 to 5. When the TLC plate was exposed to flies, zones 1 and 3 were strongly attractive to male C. capitata. To confirm activity, the developed TLC plate was cut into five zones which were then tested in short-range bioassays. Again, flies were observed to aggregate around zones 1 and 3, which corresponded with Rf values of 0.93 and 0.59. In addition, zones 1 to 5 were separated using preparative-TLC, and olfactory responses to volatile emissions from the five fractions were quantified by electroantennography (EAG). Highest amplitude EAG responses were recorded with fractions 1 and 3, further supporting the bioactivity of these samples. In conclusion, a TLC-based bioassay system can provide an effective, rapid screening protocol for initial isolation of insect kairomones from complex mixtures such as essential oils or plant extracts. Further analysis of TTO fractions 1 and 3 is needed to identify the specific constituents attractive to male C. capitata.

2021 ◽  
Vol 16 (2) ◽  
pp. 1934578X2199019 ◽  
Author(s):  
Iris Stappen ◽  
Juergen Wanner ◽  
Nurhayat Tabanca ◽  
Ulrich R. Bernier ◽  
Paul E. Kendra

Blue tansy essential oil (BTEO) ( Tanacetum annuum L.) was analyzed by GC-MS and GC-FID using two different capillary column stationary phases. Sabinene (14.0%), camphor (13.6%), myrcene (8.0%), β-pinene (7.7%), and chamazulene (6.9%) were the main components using an SE52 column (non-polar). On a polar CW20M phase column, sabinene (15.1%), camphor (14.4%), α-phellandrene (7.9%), β-pinene (7.7%), and myrcene (6.9%) were the most abundant compounds. To assess the oil for potential applications in integrated pest management strategies, behavioral bioassays were conducted to test for repellency against yellow fever mosquito Aedes aegypti, and for attractant activity for Mediterranean fruit fly Ceratitis capitata. Results showed that BTEO was not effective in repelling Ae. aegypti (minimum effective dosage [MED]: 0.625 ± 0.109 mg/cm2 compared with the standard insect repellent DEET (N,N-diethyl-3-methylbenzamide). In assays with male C. capitata, BTEO displayed mild attraction compared with two positive controls (essential oils from tea tree Melaleuca alternifolia and African ginger bush Tetradenia riparia). Additional studies are needed to identify the specific attractant chemicals in BTEO and to determine if they confer a synergistic effect when combined with other known attractants for C. capitata. To the best of our knowledge, this study represents the first investigation of BTEO for repellency against the mosquito vector Ae. aegypti and for attractancy to C. capitata, a major agricultural pest worldwide.


2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095395
Author(s):  
Eugene K. Blythe ◽  
Nurhayat Tabanca ◽  
Betul Demirci ◽  
Paul E. Kendra

The Mediterranean fruit fly or medfly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), is one of the most economically important invasive pests worldwide, with over 300 known hosts. Essential oils have great promise for application in integrated pest management, where they function as natural repellents, attractants, and toxicants with a reduced impact on the environment. In this study, we evaluated essential oil from aerial parts of the African ginger bush, Tetradenia riparia (Hochst.) Codd (Lamiaceae), as a potential new attractant for male C. capitata. Tetradenia riparia essential oil (TREO) was analyzed by gas chromatography (GC)-flame ionization detection and GC-mass spectrometry (GC-MS). The primary compounds identified were fenchone (15%), δ-cadinene (11%), 14-hydroxy-β-caryophyllene (8%), and tau-cadinol (7%). In short-range laboratory bioassays with sterile male medflies, TREO exhibited attractancy comparable to that observed with a positive control, essential oil from tea tree ( Melaleuca alternifolia (Maiden and Betche) Cheel.). This study provides the first report of C. capitata behavioral response to TREO. Further research is needed, particularly with the 2 enantiomers of fenchone, to determine the chemical constituents responsible for the attraction of C. capitata.


2006 ◽  
Vol 96 (6) ◽  
pp. 616-621 ◽  
Author(s):  
N. W. Schaad ◽  
J. Abrams ◽  
L. V. Madden ◽  
R. D. Frederick ◽  
D. G. Luster ◽  
...  

Natural, accidental, and deliberate introductions of nonindigenous crop pathogens have become increasingly recognized as threats to the U.S. economy. Given the large number of pathogens that could be introduced, development of rapid detection methods and control strategies for every potential agent would be extremely difficult and costly. Thus, to ensure the most effective direction of resources a list of high-threat pathogens is needed. We address development of a pathogen threat assessment model based on the analytic hierarchy process (AHP) that can be applied world-wide, using the United States as an illustrative example. Previously, the AHP has been shown to work well for strategic planning and risk assessment. Using the collective knowledge of subject matter expert panels incorporated into commercial decision-making software, 17 biological and economic criteria were determined and given weights for assessing the threat of accidental or deliberately introduced pathogens. The rating model can be applied by experts on particular crops to develop threat lists, especially those of high priority, based on the current knowledge of individual diseases.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 518d-518
Author(s):  
W. Letchamo ◽  
V.S. Krutilina

Echinace from the Asteracea family has been among the top 10 marketed herbs in North America and Europe. So far, only a limited amount of Echinace originate from commercial cultivation. Echinacea purpurea has been commercially cultivated in the United States since the mid 1970s, in Russia since 1935, while in Europe since the 1960s. However, there has been no published information in the English language on methods of cultivation, expected yields, limiting factors, nutrient requirements, and the optimum plant development stage to obtain maximum yield and concentration of the biologically active substances for pharmaceutical and cosmetic processing. The objective of this investigation was, therefore, to study the general distribution of major nutrients and biologically active substances and the relationship between the two groups, and the pattern of the accumulation of cichoric acid, echnacoside, isobutylamides (tetraenes) and essential oil in commercially cultivated Echinacea purpurea. There was a significant variation in the content of essential oil, cichoric acid, and isobutylamides (tetraenes) in different organs and stages of the plant development. Similarly, the difference in the distribution of N, P, K, Ca, Mg, and Fe in different organs and developmental stages is demonstrated. The correlation between the content of the active substances and nutrients is demonstrated, while recommendations for an optimum harvesting stage and date are made.


2021 ◽  
pp. 104063872110214
Author(s):  
Deepanker Tewari ◽  
David Steward ◽  
Melinda Fasnacht ◽  
Julia Livengood

Chronic wasting disease (CWD) is a prion-mediated, transmissible disease of cervids, including deer ( Odocoileus spp.), which is characterized by spongiform encephalopathy and death of the prion-infected animals. Official surveillance in the United States using immunohistochemistry (IHC) and ELISA entails the laborious collection of lymphoid and/or brainstem tissue after death. New, highly sensitive prion detection methods, such as real-time quaking-induced conversion (RT-QuIC), have shown promise in detecting abnormal prions from both antemortem and postmortem specimens. We compared RT-QuIC with ELISA and IHC for CWD detection utilizing deer retropharyngeal lymph node (RLN) tissues in a diagnostic laboratory setting. The RLNs were collected postmortem from hunter-harvested animals. RT-QuIC showed 100% sensitivity and specificity for 50 deer RLN (35 positive by both IHC and ELISA, 15 negative) included in our study. All deer were also genotyped for PRNP polymorphism. Most deer were homozygous at codons 95, 96, 116, and 226 (QQ/GG/AA/QQ genotype, with frequency 0.86), which are the codons implicated in disease susceptibility. Heterozygosity was noticed in Pennsylvania deer, albeit at a very low frequency, for codons 95GS (0.06) and 96QH (0.08), but deer with these genotypes were still found to be CWD prion-infected.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 801-807
Author(s):  
Nathaniel A Young ◽  
Ryan L Lambert ◽  
Angela M Buch ◽  
Christen L Dahl ◽  
Jackson D Harris ◽  
...  

ABSTRACT Introduction Per- and polyfluoroalkyl substances (PFAS) are a class of synthetic compounds used industrially for a wide variety of applications. These PFAS compounds are very stable and persist in the environment. The PFAS contamination is a growing health issue as these compounds have been reported to impact human health and have been detected in both domestic and global water sources. Contaminated water found on military bases poses a potentially serious health concern for active duty military, their families, and the surrounding communities. Previous detection methods for PFAS in contaminated water samples require expensive and time-consuming testing protocols that limit the ability to detect this important global pollutant. The main objective of this work was to develop a novel detection system that utilizes a biological reporter and engineered bacteria as a way to rapidly and efficiently detect PFAS contamination. Materials and Methods The United States Air Force Academy International Genetically Engineered Machine team is genetically engineering Rhodococcus jostii strain RHA1 to contain novel DNA sequences composed of a propane 2-monooxygenase alpha (prmA) promoter and monomeric red fluorescent protein (mRFP). The prmA promoter is activated in the presence of PFAS and transcribes the mRFP reporter. Results The recombinant R. jostii containing the prmA promoter and mRFP reporter respond to exposure of PFAS by activating gene expression of the mRFP. At 100 µM of perfluorooctanoic acid, the mRFP expression was increased 3-fold (qRT-PCR). Rhodococcus jostii without exposure to PFAS compounds had no mRFP expression. Conclusions This novel detection system represents a synthetic biology approach to more efficiently detect PFAS in contaminated samples. With further refinement and modifications, a similar system could be readily deployed in the field around the world to detect this critical pollutant.


Insects ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Ya-Wen Chang ◽  
Yu-Cheng Wang ◽  
Xiao-Xiang Zhang ◽  
Junaid Iqbal ◽  
Yu-Zhou Du

The leafminer fly, Liriomyza trifolii, is an invasive pest of vegetable and horticultural crops in China. In this study, a microinjection method based on dsRNA was developed for RNA interference (RNAi) in L. trifolii using genes encoding vacuolar-ATPase (V-ATPase). Expression analysis indicated that V-ATPase B and V-ATPase D were more highly expressed in L. trifolii adults than in larvae or pupae. Microinjection experiments with dsV-ATPase B and dsV-ATPase D were conducted to evaluate the efficacy of RNAi in L. trifolii adults. Expression analysis indicated that microinjection with 100 ng dsV-ATPase B or dsV-ATPase led to a significant reduction in V-ATPase transcripts as compared to that of the dsGFP control (dsRNA specific to green fluorescent protein). Furthermore, lower dsRNA concentrations were also effective in reducing the expression of target genes when delivered by microinjection. Mortality was significantly higher in dsV-ATPase B- and dsV-ATPase D-treated insects than in controls injected with dsGFP. The successful deployment of RNAi in L. trifolii will facilitate functional analyses of vital genes in this economically-important pest and may ultimately result in new control strategies.


Author(s):  
James T. Vogt ◽  
David R. Coyle ◽  
David Jenkins ◽  
Chris Barnes ◽  
Christopher Crowe ◽  
...  

Abstract Callery pear (Pyrus calleryana Decne.) is rapidly spreading in the United States, gaining attention in the last two decades as a serious invasive pest. Recommended control methods include foliar, basal bark, cut stump, and hack-and-squirt application of herbicides, but there are few published studies with replicated data on efficacy. Four readily available herbicidal active ingredients and a combination of two active ingredients were tested for control efficacy against P. calleryana in old-field areas and loblolly pine (Pinus taeda L.) understory. Basal bark applications (triclopyr, triclopyr + aminopyralid), foliar applications (glyphosate, imazapyr), and a soil application (hexazinone) effectively killed P. calleryana with the exception of hexazinone at one site, where rainfall may not have been optimal. Foliar application of glyphosate provided the most consistent control. Our results demonstrate efficacy of registered herbicide formulations for P. calleryana control in two geographic locations and two habitat types. The need for development of integrated pest management programs for P. calleryana is discussed.


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