Trail Pheromone of the Chinese Pavement ant Tetramorium smithi
Description
General Context The Chinese pavement ant is a species native to China which prove capable of thriving in habitats largely stressed by human activities, such as inside mechanically-irrigated plant nurseries within large cities. More information on it can be found online at https://www.gbif.org/species/1323360 These tramp pavement ants have been recently proposed as a biological control agent against the red imported fire ant (RIFA) after displaying impressive resistance against attempted territory invasion by RIFA in plant nurseries in Guangdong, China. See published manuscript (free of charge): https://doi.org/10.1127/entomologia/3319 One of the main strategies employed by the pavement ants is sustaining intensive workers recruitment while foraging under pressure by RIFA invading and pillaging their territory. Therefore, their pheromone signalling system is worth of scrutinity. The present dataset looks into the chemistry of volatiles from this species, with special emphasis on their trail pheromone. It serves as the repository of raw data for a manuscript currently under review for publication [this will be edited once it gets published]. The present dataset includes main raw chromatograhy analysis files, from an Agilent system. - Gas-chromatography coupled with mass-spectrometry (GC-MS) results of different body parts of the ants, ranging from whole-body down to a few dissected out organs. - GC-MS chromatograms of chemical standards, including a standardized mixture of linear n-alkanes (C7-C40, all at 1 mg/mL) , and also the synthetic analogues: (i) perillene, (ii) 8-heptadecene, (iii) pentadecane, (iv) heptadecane.
Files
Steps to reproduce
- Obtaining the ants. Colonies of the pavement ant Tetramorium smithi were collected from Yinpingle Park, Tianhe District, Guangzhou City, Guangdong Province, China (23.368800°N, 113.199776°E). The ants were separated from soil using the light-avoidance method, later transferred into standard plastic trays (30 × 20 × 10 cm) held under controlled conditions: temperature 26 ± 1℃, relative humidity 70 ± 5%, photoperiod 16L : 8D (Light:Dark, in hours). -Preparing the extracts. Workers ants (n = 10) were anesthetized with carbon dioxide and submerged into 1 mL of hexane under ultrasonic agitation for 1 min, for whole-body organic extraction. The obtained organic extracts were added some anhydrous sodium sulfate to remove residual water for 1 min, and individually filtered through a 0.45 μm organic filter membrane, and finally concentrated under nitrogen flow to 200 μL, which were stored at -20℃. Regarding body parts extractions, individual ant workers (n = 10) had their head, alitrunk (mesossoma), and gaster separated using a metal razor, and each excised body part was extracted in isolation into 1 mL of hexane, as described. Regarding selected exocrine glands, selected ant workers were left for 5 minutes on an ice plate as anesthesia, and had the following glands carefully dissected out under a stereomicroscope: (i) mandibular glands (n = 7), obtained from excised heads split open to release the mandibles and surrounding tissues containing the glands; the mandibular glands were gently isolated using fine tweezers and immersed into 200 μL of hexane. (ii) Dufour's glands (n = 13) and venom glands (n = 8) were obtained from excised gasters from which the digestive system and fat tissue had been removed; the whole venom apparatus connected to the stinger was excised using fine tweezers, from which the translucid Dufour gland and whitish venom gland were separately dissected out, and extracted in 1mL hexane as explained above, but concentrated down to 50 μL to be stored at -20℃. - Chemical analysis. The chemical components of each extracted sample was analyzed individually using a gas chromatography-mass spectrometry (GC-MS) system (Agilent 7890B/5977A). The chromatographic separation was performed using an HP-5ms capillary column (30 m × 0.25 mm × 0.25 μm), with high-purity helium gas as the carrier gas at a flow rate of 1.0 mL/min. The injection port temperature was set at 250℃; injections done in the splitless mode. The mass spectrometry parameters were set as follows: electron impact ion source (EI) at 70 eV, with the ion source temperature at 280℃. The temperature program was as follows: initial temperature of 50℃ held for 2 min, then increased to 250℃ at a rate of 15℃/min and held for 5 min, followed by an increase to 280℃ at a rate of 15℃/min and finally held for 5 min. Each sample was injected three times.
Institutions
- Lanzhou UniversityGansu, Lanzhou
- Universidade Estadual de GoiasGO, Anapolis
- Guangdong Academy of Agricultural SciencesGuangdong, Guangzhou