alpha-farnesene and linalool

The study of insect semiochemicals, especially pheromones, is of fundamental importance for the development of strategies for controlling agricultural pests. In this study, volatile compounds involved in the communication between males and females of the fruit fly, Anastrepha obliqua (Diptera: Tephritidae), for mating purposes were characterized to develop attractant formulations for females of this species. Extracts containing volatile compounds released by males of A. obliqua were obtained by the dynamic headspace technique and analyzed by gas chromatography coupled with an electroantennographic detector (GC-EAD) and gas chromatography coupled with mass spectrometry (GC-MS). Twenty-one volatile compounds were identified in the aeration extracts of males. Five of them caused EAD responses from the antennae of females: 1-heptanol, linalool, (Z)-3-nonen-1-ol, (E,Z)-3,6-nonadien-1-ol, and (Z,E)-α-farnesene. Six synthetic mixtures of these compounds, including the five-component blend and all possible four-component blends, were formulated in a biopolymer and used in behavioral bioassays conducted in the laboratory arena with conspecific virgin females. One blend of 1-heptanol, linalool, (Z)-3-nonen-1-ol, and (Z,E)-α-farnesene attracted more females than the collection of volatiles from virgin males used as control. The other mixtures were as attractive to A. obliqua females as the control treatment. This study indicates potential for use of these compounds in monitoring and control strategies for this pest.

Topics: Acyclic Monoterpenes; Animals; Arthropod Antennae; Female; Gas Chromatography-Mass Spectrometry; Heptanol; Male; Sesquiterpenes; Sex Attractants; Tephritidae

The lesser mealworm, Alphitobius diaperinus Panzer 1797 (Coleoptera: Tenebrionidae), is a cosmopolitan insect pest affecting poultry production. Due to its cryptic behavior, insecticide control is usually not efficient. Thus, sustainable and effective methods would have an enormous and positive impact in poultry production. The aim of this study was to confirm the identity of the male-produced aggregation pheromone for a Brazilian population of A. diaperinus and to evaluate its biological activity in behavioral assays. Six male-specific compounds were identified: (R)-limonene (1), (E)-ocimene (2), 2-nonanone (3), (S)-linalool (4), (R)-daucene (5), all described before in an American population, and a sixth component, (E,E)-α-farnesene (6), which is apparently exclusive to a Brazilian population. Y-Tube bioassays confirmed the presence of a male-produced aggregation pheromone and showed that all components need to be present in a similar ratio and concentration as emitted by male A. diaperinus to produce a positive chemotactic response.

Topics: Acyclic Monoterpenes; Alkenes; Animals; Behavior, Animal; Brazil; Bridged Bicyclo Compounds; Chemotaxis; Chromatography, Gas; Cyclohexenes; Female; Gas Chromatography-Mass Spectrometry; Ketones; Limonene; Male; Monoterpenes; Olfactometry; Pheromones; Sesquiterpenes; Tenebrio; Terpenes; Volatile Organic Compounds

This paper reports on the compounds identified in the leaf and flower essential oils obtained by hydrodistillation of Plumeria alba L. (Apocynaceae) grown in Nigeria. The chemical analysis of the essential oils was achieved by means of gas chromatography (GC) and gas chromatography coupled with mass spectrometry (GC-MS). Linalool (13.2%), n-nonanal (9.6%), phenyl acetaldehyde (8.5%), neryl acetone (5.3%) and n-decanal (5.1%) were the main constituents of the leaf oil. On the other hand, the flower oil comprised mainly of limonene (9.1%), linalool (7.9%), α-cedrene (8.0%), caryophyllene oxide (7.9%) and (E, E)-α-farnesene (6.6%). This is the first report on the essential oil constituents of P. alba.

Topics: Acyclic Monoterpenes; Apocynaceae; Cyclohexenes; Flowers; Gas Chromatography-Mass Spectrometry; Limonene; Monoterpenes; Nigeria; Oils, Volatile; Plant Leaves; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes

Phenylacetonitrile, (E)-β-ocimene, linalool, (E)-4,8-dimethyl-1,3,7-nonatriene and (E,E)-α-farnesene were identified as Japanese beetle, Popillia japonica, feeding-induced volatiles from the leaves of the giant knotweed, Fallopia sachalinensis, but not by mechanical damage. Volatile emission was also induced by treatment with a cellular signaling molecule, methyl jasmonate. These results suggest that volatiles will be synthesized de novo by a biotic elicitor from P. japonica oral secretion.

Topics: Acetates; Acetonitriles; Acyclic Monoterpenes; Alkenes; Animals; Chromatography, Gas; Coleoptera; Cyclopentanes; Feeding Behavior; Insecticides; Mass Spectrometry; Monoterpenes; Oxylipins; Plant Immunity; Plant Leaves; Polygonum; Sesquiterpenes; Terpenes; Volatilization

Parasitoids employ different types of host-related volatile signals for foraging and host-location. Host-related volatile signals can be plant-based, originate from the herbivore host or produced from an interaction between herbivores and their plant host. In order to investigate potential sex- and species-related differences in the antennal response of parasitoids to different host-related volatiles, we compared the electroantennogram (EAG) responses of both sexes of the specialist parasitoid, Microplitis croceipes (Cresson), and the generalist, Cotesia marginiventris (Cresson), to varying doses of selected plant-based host-related volatiles: two green leaf volatiles (cis-3-hexenol and hexanal) and three inducible compounds (cis-3-hexenyl acetate, linalool, and (E,E)-alpha-farnesene). Mating had no significant effect on EAG response. Females of both species showed significantly greater EAG responses than conspecific males to green leaf volatiles, which are released immediately after initiation of herbivore feeding damage. In contrast, males showed greater responses than conspecific females to inducible compounds released much later after initial damage. Cotesia marginiventris females and males showed greater EAG responses than counterpart M. croceipes to the tested compounds at various doses, suggesting that the generalist parasitoid shows greater antennal sensitivity than the specialist to the tested host-plant volatiles. These results are discussed in relation to the possible roles of green leaf volatiles and inducible compounds in the ecology of female and male parasitoids.

Topics: Acetates; Acyclic Monoterpenes; Animals; Electric Conductivity; Female; Hexanols; Male; Monoterpenes; Plant Leaves; Sesquiterpenes; Sex Factors; Sexual Behavior, Animal; Species Specificity; Wasps