Using the solid injection technique with gas chromatography and mass spectrometry to identify cuticular hydrocarbons in several thrips insect species

Covaci, Anca-Dafina

Abstract

Thrips are a group of insects included in the order Thysanoptera. So far, over 6000 species have been described, among which over 100 are known as crop pests There is a plethora of studies on various species of thrips, yet the CHC composition is known in less than 10 species. By considering the fact that quite a high number of the thrips species are major pests and that some of the detected hydrocarbons are known to act as pheromones, the interest in investigating their chemistry is both for chemotaxonomy reasons and discovering sustainable measures for their control.
In this research study, the CHC content was described in five species of thrips using a new extraction technique based on solid injection. Principal Component Analysis was used to compare the CHC profile across the five species of thrips and the results showed that each species of thrips is characterized by the presence of a different class of hydrocarbons. Therefore, this indicates that the CHC profile can be used as a tool in thrips identification.
The efficiency of the solid injection method was tested on a cultured thrips species, western flower thrips, Frankliniella occidentalis. A proof-of-concept experiment was conducted and the CHC dataset obtained through whole-body analysis was compared with the one obtained through hexane extraction which is currently the most commonly used extraction method. Unpaired t - test was used for the statistical comparison of the two techniques and it showed no difference between the two hydrocarbon patterns, proving the efficiency of the solid injection method. Additionally, alkenes monoenes have been detected for the first time in western flower thrips with the aid of the solid injection method, through direct analysis of the whole body, but not through solvent extraction.
Moreover, in this work, it is reported for the first time, the CHC content in three species of thrips (Franklinella borinquen, Frankliniella schultzei and Hydatothrips adlofifriderici). Also, based on the data processing and the overall findings, it can be confirmed that with the aid of solid injection method specific CHC patterns can be detected and associated with a particular species of thrips, highlighting their role in thrips chemotaxonomy.

Citation

Covaci, A. (2023). Using the solid injection technique with gas chromatography and mass spectrometry to identify cuticular hydrocarbons in several thrips insect species. (Thesis). Keele University

• Thesis Type: Thesis
• Deposit Date: Oct 12, 2023
• Publicly Available Date: Oct 12, 2023
• Award Date: 2023-10