Volatiles juvenile

Females of the desert spider Agenelopsis aperta emit a volatile pheromone that attracts conspecihc males (Riechert and Singer, 1995). This pheromone was identified as 8-methyl-2-nonanone (1 Fig. 4.1), a previously unknown arthropod semio-chemical. It was found by headspace analysis and abdominal washings of females 2 weeks after their hnal molt, when they become sexually receptive it was absent in females of other age classes. The pheromone attracted males in a three-choice arena system at doses as low as 500 ng (Papke et al., 2001). Another female-specific ketone, 6-methyl-3-heptanone (2), was not attractive. Very low doses of 1 (10-9 mg/ml applied to a hlter paper placed in empty juvenile female webs) also induced courtship behavior in males (Papke et al., 2001). The normal behavioral sequence was followed, except for phases which required input from the female. The ED50 value (mean effective dose) of 1 was 5.5x 10-4 mg/ml hexane. In contrast, ketone 2 only induced a response in some males at unnaturally high concentrations... 

Jeffrey pine beetle, Dendroctonus jeffreyi Hopkins, which had been previously treated with juvenile hormone III (JH III, 2.2 pg/beetle in acetone) and then placed in an aeration tube for 25 to 30 h. Ips paraconfusus and I. pini were each injected with 0.2 pCi of sodium [1-14C]acetate prior to placement in cut pine logs and volatile collection, while D. jeffreyi were each injected with 3.8 (male) and 3.7 (female) pCi of sodium [1-14C]acetate 6.4 (male) and 10.7 (female) h after JH application. (G) The role of the mevalonate pathway in frontalin biosynthesis is supported by the incorporation of radiolabel from [2-14C]mevalonolactone into frontalin by male D. jeffreyi (2.2 pg JH 11 l/beetle in acetone, 10 h incubation and volatile collection, 1.1 pCi of [2 14C] mevalonolactone injected, 20 h volatile collection). Figures adapted from Seybold et al. (1995b) and Barkawi (2002). 

Juvenile It is generally believed that the Earth s atmosphere was formed by degassing of volatiles from the interior. Volatiles that have remained in the Earth s interior, have never been part of the atmosphere, and are observed to be entering the atmosphere for the first time are designated as juvenile. Atmospheric is an antonym to juvenile. 

Novotny, Jemiolo, Harvey, Wiesler Marchlewska-Koj (1986) compared the volatile profiles of urine from normal and adrenalectomized female mice and noted that several urinary constituents were adrenal-mediated. A synthetic mixture of these components, diluted to appropriate concentrations in water, was found as effective as the natural urinary stimulus in delaying puberty of juvenile females. In the following studies (Jemiolo Novotny, 1993 and 1994), it was established that one of these urinary metabolites, 2,5-di-methylpyrazine, had a strong effect on both puberty and overall reproductive fitness of females. 

Seedlings of Eucalyptus accumulate essential oil rich in pinenes, while adult plants produce 1,8-cineole (eucalyptol) as main component. Similarly, seedlings of Cinnamomum camphora synthesize safrole as major volatile compound of the leaves, but later, different other compounds start to accumulate in abundance corresponding to the different intraspeci c chemotype (Tetenyi, 1975). Juvenile parts of Thuja occidentalis show a multiple difference in the quantitative composition of the volatiles compared with that of the mature shoots. The accumulation rate of sabinene (25.37%) and a-pinene (26.29%) are especially high compared to the leaves of the adult plant (0.76% and 3.54%, respectively) (Gnilka et al., 2010). Interestingly, the adaptive role or other function of these changes is still not adequately declared and is worth of further research. 

Zeft A, Costanzo D, Alkhouri N, et al. Metabolomic analysis of breath volatile organic compounds reveals unique breathprints in children with juvenile idiopathic arthritis. Arthritis Rheumatol. 2014 66 S159. 

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