Z-ll-Hexadecenal

Com earworm moth, Helicoverpa zea, females emit a blend of hexade-canal and (Z)-7-, (Z)-9-, and (Z)-ll-hexadecenal (16) that is a highly... 

FIGURE 2 Relative proportions of three identified components of M. comigera spider volatiles (47). The variation in the ratios suggests that spiders change the moth-attracting blends they produce. Z11-16 AL, (Z)-ll-hexadecenal Z9-14-.AC, (Z)-9-tetradecenyl acetate Z9-14 AL, (Z)-9-tetradecenal. 

Fig. 4.7. Volatiles identified from the bolas spider Mastophora cornigera and Mastophora hutchinsoni (15-19) and the pheromone components of Tetano-lita myenesalis (20, 21). 15, (Z)-9-Tetradecenal 16, (Z)-9-tetradecenyl acetate 17, (Z)-ll-hexadecenal 18, (Z)-ll-hexadecenyl acetate 19, (9Z,12F)-9,12-tetradecadienyl acetate 20, (3Z,6Z,9Z)-3,6,9-henicosatriene 21, (3Z,9Z)-(6S, 1R) ...

Quero C. and Baker T. C. (1999) Antagonistic effect of (Z)-ll-hexadecen-l-ol on the pheromone-mediated flight of Helicoverpa zea (Boddie) (Lepidoptera Noctuidae). J. Insect Behav. 12, 701-710. 

The sex attractant of the eastern spruce budworm, Choristoneura fumiferana, is (E)-ll-tetradecenal (73). A probable precursor, (E)-ll-tetradecen-l-ol, is produced in the sex attractant gland (74), but this compound, which inhibits the male response to the aldehyde, does not appear to be released by the calling female. The (Z)-isomer of tetradecenal has been identified as one of the sex pheromones of the tobacco budworm, Heliothis virescens it is accompanied by (Z)-ll-hexadecenal (75, 76)7 Similarly, the female of the striped rice borer secretes two alkenals--(Z)-ll-hexadecenal and (Z)-13-octadecenal as its sex pheromone blend (77). 

In an earlier investigation of the H. virescens sex pheromone we identified two compounds, (Z)-ll-hexadecenal and (Z)-9-tetradecenal in a ratio of 16 1, respectively, from ether washes of calling female bodies ( 1). These compounds were also identified as H. virescens sex pheromones by Roelofs ejt al. (9) However, field evaluation of crude extracts and synthesized pheromone led us to speculate that other pheromone components might be present. Subsequently Klun et al. (10) identified seven components in the ovipositor rinses of H. virescens females by capillary GC. Our analysis of H. virescens ovipositor washes by methods similar to Klun s gave results consistent with his data. The seven components and the relative amounts found were tetradecanal (14 A1) (1.61, (Zl-9-tetradecenal (Z9-14 A1) (21, hexadecanal (16 A11 (9.51, (Zl-7-hexadecenal (Z7-16 A1 (11, (Zl-9-hexadecenal (Z9-16 A1 (1.31, (Z)-ll-hexadecenal (Z11-16 AU (81.41, and (Z)-ll-hexadecenol (Z11-16.-OH) (3.21. 

The analyses of the H. subflexa ovipositor extracts (171 revealed eight major components coinciding in retention times on SP-2340 and p-chloro cholesteryl cinnamate capillary columns (Figure 9) with 16 A1, Z9-16 A1, Z11-16 A1, (Z -7-hexadecen-l-ol acetate, (Z7-16 Ac), (Z)-9-hexadecen-l-ol acetate (Z9-16 Ac), (Z)-ll-hexadecen-l-ol acetate, (Zll-16 Ac), Z9-16 OH, and Z11-16 0H. Several other peaks were also variably present but, when present, each composed less than 1% of the total mixture. Mass spectral data confirmed the identity of the major components. 

The blend of pheromone components identified from H. subflexa female gland extracts has two components in common with H. virescens, Z9-16 A1 and Z11-16 A1 and three not found in H. virescens, (Z)-7-hexadecen-l-ol acetate (Z7-16 Ac), ( >-9-hexa-decen-l-ol acetate (Z9-16 Ac) and (Z)-ll-hexadecen-l-ol acetate (Zll-16 Ac). Field studies (Table III) indicate that at the very least, the two aldehydes plus Zll-16 Ac are of importance to the capture of male H. subflexa. Hence, the absence of these three acetate components from the H. virescens pheromone ( 10), and different ratios of Z9-16 A1 to Z11-16 A1 probably account for the semiochemical isolation between H. subflexa males and H. virescens females. However, the release of pheromone components by female H. virescens such as 14 A1 and Z9-14 A1 may be disorienting to male H. subflexa and cannot be discarded as a possible mechanism for reproductive isolation. 

The pheromone of the rice stem borer, Chilo suppressalis, is a mixture of two aldehydes, (Z)-ll-hexadecenal and (Z)-13-octa-decenal. Field-cage trials carried out in the Philippines at the International Rice Research Institute showed that the fully stabilised microencapsulated formulations of these aldehydes persisted for over 30 days and virtually eliminated the laying of fertile eggs during this period (6). 

A number of insect species, including corn earworm, Heliothis zea (Boddie), and tobacco budworm, Heliothis virescens (F.), contain and C,g aldehydes (C al and C al) in their pheromone blends (22, 23). The release rate of a C. al would be expected to be higher than that of a Cj al because of the molecular weight difference. A mixture containing 10% n-tetradecanal (CjA°al) in Z)-ll-hexadecenal [(J0-Il-Cj al] was formulated in four laminates, each made from a different type of polymeric membrane as the top and bottom layers vinyl, Mylar -coated vinyl, acrylic, and rigid vinyl film. (The saturated C,.°ol was used as a model because of availability.) The total alaehyde content was approximately 2.3 mg per cnr of laminate 0.7% (of the pheromone weight) of 2,6-di-tert-butyl-4-methylphenol (BHT) was added as an antioxidant. Table II gives the thickness of the polymers. 

Release of Tetradecanal (C ) and (Z)-ll-Hexadecenal (Cj ) from Laminate Dispensers... 

In another experiment, a mixture of C °al (5%), (Z)-ll-Cjg al (90%) and (Z)-ll-Cj ol [( Z)-ll-hexadecen-l-ol] (5%) was Incorporated Into 3 other types of laminate dispensers at approximately 1.6 mg/cm BHT was again added as an antioxidant. The alcohol was Included since It Is a component of the pheromone of the tobacco budworm. The laminates were cut into 4 x 20 mm dispensers and again were aged In 2 locations at room temperature In a laboratory In Maryland and outdoors In Arizona (October-December). At selected Intervals, sample dispensers from each location were extracted and GC analyses performed for all 3 components as well as for acid formed through oxidation. Again, no acid was detected In any of the formulations. The tj values for the laboratory and field aged dispensers are given In Table III. 

Trace components in a set of compounds produced by a female often are essential for the expression of biological activity of a sex pheromone and the pickleworm pheromone exemplifies this quality. Figure 2 shows that component 4 constituted only 0.1% of the total mixture of compounds produced by the pickleworm female. Bioassays showed, however, that if this compound was deleted from the set of compounds produced by the female, males were behaviorally unresponsive to the mixture despite the fact that all other components of the pheromone complement were present. Similarly, when component 2 [(Z)-ll-hexadecenal], also a trace component (ca., 3%), was deleted from the set of pickleworm compounds, the tendency of males to fly upwind to the stimulus was reduced by 70% relative to the response elicited by the complete set of compounds. 

Steck, W., E.W. Underhill, and M.D. Chisholm Attraction and Inhibition in Moth Species Responding to Sex-Attractant Lures Containing Z-ll-Hexadecen-l-yl-acetate. J. Chem. Ecol. 3, 603-612 (1977). 

The sex attractant produced by the female clover cutworm, Scoto-gramma trifolii, is a mixture of (Z)-ll-hexadecenyl acetate and (Z)-ll-hexadecenol 288). A mixture of these two compounds containing about 10% Zll-16 OH has proved to be most attractive 289, 290) while 20—25% Z11-16 OH decreases the catch of males appreciably 290). Adult males of the glassy cutworm, Crymodes devastator, are attracted by traps baited with equal parts of (Z)-ll-hexadecenyl acetate, (Z)-ll-hexadecenal and (Z)-7-dodecenyl acetate 291). No other species were trapped by this mixture. The addition of small quantities of either (Z)-11-hexadecenol or (Z)-9-tetradecenyl acetate completely inhibited attrac-tancy in the field. As a result of field tests, Underhill et al. 292) have recently found that alkenals may be as important in lepidopteran sex attractants as the acetates and alcohols. 

The sex pheromone components of the diamondback moth, Plutella xylostella, a pest of cruciferous crops, has been identified as (Z)-ll-hexadecenal and (Z)-l 1-hexadecenyl acetate (293). More recent data show that (Z)-ll-hexadecenol is a synergist of these two compounds in field trapping experiments 294). 

Z)-ll-Hexadecenal has been isolated from the female moth, Heliothis armigera, and is a potent olfactory stimulant for males in laboratory and field tests (657). The olfactometer response of laboratory-reared males of H. virescens to its pheromones, (Z)-ll-hexadecenal and (Z)-9-tetra-decenal and the inhibitor (Z)-9-tetradecen-l-ol formate has been studied 658). 

Struble, D. L., and G. E. Swailes A sex attractant for the clover cutworm, Scotogramma trifolii (Rottenberg), a mixture of Z-ll-hexadecen-l-ol acetate and Z-ll-hexadecen-l-ol. Environ. Entomol. 4,632—636 (1975). 

Steck, W., E. W. Underhill, B. K. Bailey, and M. D. Chisholm A sex attractant for male moths of the glassy cutworm Crymodes devastator (Brace) a mixture of Z-ll-hexadecen-l-yl acetate, Z-ll-hexadecenal and Z-7-dodecen-l-yl acetate. Environ. Entomol. 6, 270—273 (1977). 

Tamaki, Y., K. Kawasaki, H. Yamada, T. Koshihara, N. Osaki, T. Ando, S. Yoshida, and H. Kakinohana (Z)-ll-Hexadecenal and (Z)-ll-hexadecenyl acetate sex-pheromone components of the diamond back moth (Lepidoptera Plu-tellidae). Appl. Ent. Zool. 12,208—210 (1977). 

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