Comparative analysis of volatile organic compounds from flowers attractive to honey bees and bumblebees

Dekebo, Aman,Kim, Min-Jung,Son, Minwoong,Jung, Chuleui The Ecological Society of Korea 2022 Journal of Ecology and Environment Vol.46 No.1

Background: Pollinators help plants to reproduce and support economically valuable food for humans and entire ecosystems. However, declines of pollinators along with population growth and increasing agricultural activities hamper this mutual interaction. Nectar and pollen are the major reward for pollinators and flower morphology and volatiles mediate the specialized plant-pollinator interactions. Limited information is available on the volatile profiles attractive to honey bees and bumblebees. In this study we analyzed the volatile organic compounds of the flowers of 9 different plant species that are predominantly visited by honey bees and bumblebees. The chemical compositions of the volatiles were determined using a head space gas chromatography-mass spectrometry (GC-MS) method, designed to understand the plant-pollinator chemical interaction. Results: Results showed the monoterpene 1,3,6-octatriene, 3,7-dimethyl-, (E) (E-𝞫-ocimene) was the dominating compound in most flowers analyzed, e.g., in proportion of 60.3% in Lonicera japonica, 48.8% in Diospyros lotus, 38.4% Amorpha fruticosa and 23.7% in Robinia pseudoacacia. Ailanthus altissima exhibited other monoterpenes such as 3,7-dimethyl-1,6-octadien-3-ol (𝞫-linalool) (39.1%) and (5E)-3,5-dimethylocta-1,5,7-trien-3-ol (hotrienol) (32.1%) as predominant compounds. Nitrogen containing volatile organic compounds (VOCs) were occurring principally in Corydalis speciosa; 1H-pyrrole, 2,3-dimethyl- (50.0%) and pyrimidine, 2-methyl- (40.2%), and in Diospyros kaki; 1-triazene, 3,3-dimethyl-1-phenyl (40.5%). Ligustrum obtusifolium flower scent contains isopropoxycarbamic acid, ethyl ester (21.1%) and n-octane (13.4%) as major compounds. In Castanea crenata the preeminent compound is 1-phenylethanone (acetophenone) (46.7%). Conclusions: Olfactory cues are important for pollinators to locate their floral resources. Based on our results we conclude monoterpenes might be used as major chemical mediators attractive to both honey bees and bumblebees to their host flowers. However, the mode of action of these chemicals and possible synergistic effects for olfaction need further investigation.

Olfactory responses of Aethina tumida murray (Coleoptera: Nitidulidae) to some major volatile compounds from hive materials and workers of Apis mellifera

Dekebo Aman,정철의 한국응용곤충학회 2020 Journal of Asia-Pacific Entomology Vol.23 No.2

The small hive beetle (Aethina tumida Murray) is an invasive pest affecting honey bee colonies. The beetles are known to be attracted to volatiles from hive products and honey bees like Apis mellifera L. Previously we reported the presence of five major compounds from the volatile extracts of hive materials; ethyl linolenate and ethyl palmitate from pollen dough, oleamide and tetracosane in fermenting honey, and oleamide and 5-methyl-2-phenyl-1H-indole from A. mellifera worker bees. This study tested the attractiveness of the aforementioned five volatile organic compounds to small hive beetles (SHB) by Y-tube olfactometric bioassay. Ethyl linolenate was highly attractive to both male and female adults of SHB. Ethyl palmitate was attractive to SHB only at higher concentration (0.01–01 mg/ml). Interestingly, tetracosane, 5-methyl-2-phenyl-1H-indole and oleamide were repellent for SHB of both sexes, but ethyl linolenate and ethyl palmitate as components of honey bee brood pheromone attracted SHB. The results highlight that SHB differentially utilizes volatile chemicals from hive materials and honey bees as cues to locate honey bee hives.

Volatiles Analysis of Honey by Gas Chromatography-Mass Spectrometry (GC-MS)

Aman Dekebo,Soon-Youl Kwon,Dae-Ho Kim,Chuleui Jung 한국양봉학회 2018 韓國養蜂學會誌 Vol.33 No.2

Olfactometry responses of small hive beetle (Aethina tumida) to hive materials

Aman Dekebo,Chuleui Jung 한국농약과학회 2018 한국농약과학회 학술발표대회 논문집 Vol.2018 No.10

Chemical interaction of tomato and potato tuber moth mediated by leaf volatiles

Aman Dekebo,Chuleui Jung,Sunil Aryal 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.10

The potato tuber moth (PTM) is an oligophagous pest on solanaceous crops. We tested adult olfactory behavior and larval development on 5 cultivated tomato varieties leaves including Moneymaker, Campari, Ailsa craig, LA3475 and E6203, and one wild species, S. pimpinellifolium. Bioassay on PTM larvae showed highest developmental performances in Ailsa craig, and lowest in LA3475. Tomato leaf hydro-distilled oils of Moneymaker, Campari, Ailsa craig, S. pimpinellifolium and E6203 showed strong attractiveness and LA3475 exhibited repulsiveness for mated adult PTM of both sexes in two-armed bioassay. The hydro-distilled oils of all tomato leaves contain the fatty acid n-hexadecanoic acid as a major compound. We conformed presence of n-hexandecanoic acid (palmitic acid) in the leaves by GC-MS. LA3475 consists of (1-hexyltetraecyl) cyclohexane (10.5%) as the second major compound which was absent in all other tomato varieties. A standard sample palmitic acid was tested against the pest at 0.1, 1 and 10 mg/ml did not show any significant olfactometer effect. On other hand, phytol showed a weak attractiveness (60.7-63.6%) and (57.6-60.5%) for male and female PTM, respectively at 0.1, 1 and 10 mg/ml. Additionally, SEM of these tomato varieties leaves showed they have trichomes with distinct shapes. We are working on HPLC, and GC-MS analysis of specific chemicals in trichomes of these tomato varieties leaves.

Opportunities and Constraints of Beekeeping Practices in Ethiopia

Aman Dekebo,Daniel Bisrat,Chuleui Jung 한국양봉학회 2019 韓國養蜂學會誌 Vol.34 No.2

Olfactory responses of adult Potato Tuber Moth, Phthorimaea operculella (Zeller) measured by attraction relative to the tomato leaf volatiles

Aman Dekebo,Sunil Aryal,정철의 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

The potato tuber moth (PTM) is an oligophagous herbivore and a severe pest of solanaceous crops in many countries of the world. Previously, we reported host expansion and damage potential of PTM on tomato, a congeneric crop of potato. Here we tested adult olfactory behaviour of PTM to leaves of five different cultivated tomato varieties including Moneymaker, Campari, Ailsa craig, LA3475 and E6203, and one wild species, Solanum pimpinellifolium. Tomato leaf hydro-distilled oils of Moneymaker, Campari, Ailsa craig, S. pimpinellifolium and E6203 showed strong attractiveness and LA3475 exhibited repulsiveness for adult PTM of both sexes in two-armed bioassays. Volatiles of Moneymaker, Campari, Ailsa Craig, S. pimpinellifolium and E6203 showed attractiveness for mated adult PTM of both sexes (> 70%). The extracted oil of all tomato leaves contains monoterpenes, sesquiterpenes, diterpenes and C 6 alcohols as well as other components. Phytol is one of the common and major compounds in all tomato varieties. Phytol showed weak attractiveness: 60.8–63.6% and 57.6–60.6% for male and female PTM, respectively when tested at concentrations of 0.1–10 mg/mL. Therefore, the attractiveness of tomato leaf volatiles might be due to synergistic effects of plant volatile mixtures. Identification PTM attractant volatile in tomato leaf is important in its control in environmentally friendly manner.

Suitability of tomato leaves for larval development of Potato Tuber Moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)

Aman Dekebo,Sunil Aryal,정철의 한국곤충학회 2019 Entomological Research Vol.49 No.6

The potato tuber moth (PTM) is an important pest of the potato plant and its tuber. With the expansion of its geographic range, the PTM could be potential threat to the tomato (Solanum lycopersicum L.), a congeneric species of the potato. To assess that risk, we tested larval feeding and development of PTM on leaves of five cultivated tomato varieties namely Moneymaker, Campari, Ailsa Craig, LA3475, E6203 and one wild tomato variety S. pimpinellifolium. PTM larvae accepted all tested plant leaves and developed into adults. Larval development was fastest on the Ailsa Craig variety. Pupae developed fastest on the Moneymaker variety and slowest on LA3475. Host acceptance and survival were highest on Ailsa Craig and lowest on LA3475. The significantly highest male proportion occurred on LA3475 variety. The study showed that PTM could be a potential threat to tomato cultivation which is rapidly increasing in temperate regions owing to climate change.

Olfactometry of adult potato tuber moth, Phthorimaea operculella (Zeller) to tomato leaves volatiles and its larval development on tomato leaves

Aman Dekebo,Sunil Aryal,Chuleui Jung 한국응용곤충학회 2018 한국응용곤충학회 학술대회논문집 Vol.2018 No.04

The potato tuber moth (PTM) is an oligophagous insect pest on solanaceous crops. Potato tuber is regarded as the main host of PTM but it can also feed, develop and reproduce on other solanaceous crops such as tomato. We tested adult olfactory behavior and larval development on 5 cultivated tomato varieties namely Money maker, Campari, Ailsa craig, LA 3475 (M82) and E-6203, and one wild species, S. pimpinellifolium. Tomato leaf hydro-distilled oils of Money maker, Campari, Ailsa craig, S. pimpinellifolium and E-6203 leaves showed strong attractiveness for mated adult PTM of both sexes (> 70%) in two-armed bioassay. LA 3475 (M82) oil showed repulsive response (83.7% for males and 87.3% for females). GC-MS analysis of the hydro-distilled oils of all tomato leaves contain the fatty acid n-hexadecanoic acid (Palmitic acid) as a major compound with relative percentage as S. pimpinelifollium (32.1%) > E-6203 (26.5%) > money maker (26.1%) > LA-3475 (16.3%) > Campari (15.0%) > Ailsa craig (10.4%). LA 3475 consists of (1-hexyltetraecyl)cyclohexane (10.5%) as the second major compound which was absent in all other tomato varieties. In no choice test, PTM larvae showed highest developmental performances such as number of mines, headcapsule size, pupal weight and survival in Ailsa craig, and lowest in LA 3475. In choice test, similar results were observed. This study indicates the leaf volatile of n-hexadecanoic acid might be responsible for PTM attractiveness and (1-hexyltetraecyl)cyclohexane for repulsiveness. And varieties of tomato leaves could support suitable nutritional contents to PTM, posing pest potential in the future where higher exposure is expected.

Attractive response of fermented pollen dough to adults and wandering larvae of Aethina tumida

Aman Dekebo,Chuleui Jung 한국응용곤충학회 2021 한국응용곤충학회 학술대회논문집 Vol.2021 No.04