Specificity of laboratory trail following by the argentine ant,Iridomyrmex humilis (Mayr), to (Z)-9-hexadecenal,analogs, and gaster extract

In laboratory trail-following bioassays of Argentine ant workers,Iridomyrmex humilis (Mayr), the geometric isomer, (E)-9-hexadecenal, of the trail pheromone component (Z)-9-hexadecenal elicited insignificant trail following as did the potentially more stable formate analogs, (Z)-7-tetradecenyl formate, (E)-7-tetradecenyl formate, and tetradecyl formate. Further, in direct choice tests, workers showed no preference for gaster extract trails (0.002 ant equiv/cm) over trails of (Z)-9-hexadecenal (0.2 ng/cm). Moreover, a 10-fold increase in synthetic trail concentration to 2.0 ng/cm caused (Z)-9-hexadecenal trails to be significantly preferred over gaster extract trails by trail-following ants.     

Characterization of aggregation factors and associated compounds from the argentine ant,Iridomyrmex humilis

(Z)-9-Hexadecenal (I), 13-(1-methylpropyl)tridecanolide (II), and (Z)-10-nonadecene-2-one (IV) have been characterized from a lipid fraction of the total extract ofI. humilis. Glycerides of normal fatty acids constitute the bulk of the lipid fraction. Compound I, a general aggregation factor ofI. humilis, is a constituent of the ventral gland secretion. Actinidine has been characterized from the pyrazine-containing fraction of the total extract.     

Disruption of foraging by argentine ants,Iridomyrmex humilis (mayr) (hymenoptera: Formicidae), in citrus trees through the use of semiochemicals and related chemicals

Foraging in trees by the Argentine ant,Iridomyrmex humilis (Mayr), was disrupted by a variety of synthetic chemicals, with the most effective chemical being farnesol. Testing of substrates for presentation of the disruptant chemicals gave some success with rubber or Tygon tubing, although best results were obtained through incorporation of the material into Stikem, which was then banded around tree trunks. Amounts of farnesol used for effective, long residual ant control were between 0.8 and 2 g per tree.     

Isolation of the trail recruitment pheromone ofSolenopsis invicta

TheSolenopsis invicta trail pheromone is synthesized by the Dufour's gland and is released through the sting apparatus. The recruitment subcategory of theS. invicta trail pheromone was shown to be composed of a mixture of the orientation pheromone, (Z,E)--farnesene and an unidentified homosesquiterpene consisting of three rings and one double bond (C-1). C-1 is present in worker Dufour's glands at only 75 pg per worker equivalent. This is the first report that demonstrates that different exocrine products from the same gland control different subcategories of behavior related to mass recruitment.     

Sex pheromone chemistry of the female tobacco budworm moth,Heliothis virescens

(Z)-11 -Hexadecenal (77–91%), (Z)-7-hexadecenal (0.1–2%), (Z)-9-hexadecenal (0.3–2%), hexadecanal (3–19%), (Z)-11-hexadecen-1-ol (1–5%), tetradecanal (1–3%), and (Z)-9-tetradecenal (1–3%) were identified from the heptane washes of the ovipositor of femaleHeliothis virescens (F.) females. In field bioassays, a 152-g mixture of these seven compounds deployed in an insect trap exceeded the attractiveness of 4 virgin femaleH. virescens for males and was 5–6 times more attractive than a mixture of (Z)-1 1-hexadecenal and (Z)-9-tetradecenal (virelure) that was previously reported as the sex pheromone of the species. Four of the seven compounds produced byH. virescens females are also produced byH. zea (Boddie). Specificity of pheromonal signals among the two species is ostensibly dependent upon one or more of the three additional compounds [tetradecanal, (Z)-9-tetradecenal, and (Z)-1 1-hexadecen-1-ol] produced by femaleH. virescens.     

Intrapopulational changes in sex pheromone composition during scotophase in oriental tobacco budworm,Helicoverpa assulta (Guenée) (Lepidoptera: Noctuidae)

Solvent extracts of individual pheromone glands were prepared from femaleHelicoverpa assulta (Guenée) at 2-hr intervals throughout the scotophase. The amounts of female sex pheromone components, (Z)-9-hexadecenal, (Z)-11-hexadecenal, (Z)-9-hexadecenyl acetate, and (Z)-11-hexadecenyl acetate, in the extracts were determined by gas chromatographic analysis. Although females called from early scotophase (2 hr) until late scotophase (6 hr) the quantity of extracted pheromone remained high at 8 hr, the end of the scotophase. More than 70% of the pheromone gland extracts contained sex pheromone components regardless of whether the donor females had been called or resting. Pheromone components were absent from gland extracts prepared at the onset of the scotophase. The quantity of (Z)-9-hexadecenal and (Z)-11-hexadecenal increased rapidly to reach a maximum of approximately 260 and 30 ng/female, respectively, that was maintained for up to 8 hr, the duration of the scotophase. The quantity of (Z)-9-hexadecenyl acetate and (Z)-11-hexadecenyl acetate increased continuously during the scotophase to peak at 600 and 30 ng/female, respectively, 8 hr into the scotophase. At the end of scotophase the quantity of all pheromone components decreased significantly.     

Diel rhythms of calling behavior and pheromone production of oriental tobacco budworm moth,Helicoverpa assulta (Lepidoptera: Noctuidae)

Both calling behavior and titer of (Z)-9-hexadecenal (Z9-16: Al), the major sex pheromone component ofHelicoverpa assulta, in pheromone glands showed distinct diel periodicity, and these two were synchronous. Calling was most actively performed and the pheromone titer reached a maximum from 2 to 6 h after lights-off. During photophase, no calling was shown and only a relatively small amount of Z9-16:A1 was detected. However, there was a time lag of a few days between peak calling activity and maximum pheromone titer. The pheromone titer was maximal from age 1 day to age 5 days and thereafter decreased while calling was most actively performed after age 3 days. Titers of three minor components, hexadecenal, (Z)-11-hexadecenal, and (Z)-9-hexadecenyl acetate, showed similar daily fluctuation patterns to that of Z9-16:Al, but relative to the titer of Z9-16:Al, the titer of the two aldehyde components remained relatively constant whereas that ofZ9-16:Ac increased in the late scotophase.     

Sex pheromone chemistry of female corn earworm moth,Heliothis zea

Glass open-tubular capillary Chromatographic and combined glass open-tubular capillary chromatographic-mass spectrometric analyses of ovipositor washes of femaleHeliothis zea, chemical characterization, chemical synthesis, and laboratory and field bioassays showed that the ovipositor wash of the species is made up of 90–95% (Z)-11-hexadecenal, 1–2% (Z)-9-hexadecenal, 0.4–2% (Z)-7-hexadecenal, and 2–7% hexadecanal. Stimuli containing a binary mixture of (Z)-11-hexadecenal and (Z)-9-hexadecenal or the binary mixture in combination with any of the other aldehydes identified from the females elicited intense attraction and close-range precopulatory reactions fromH. zea males.Mention of a commercial or proprietary product in this paper does not constitute a recommendation or an endorsement of that product by the U.S. Department of Agriculture.     

Female sex pheromone of oriental tobacco budworm,Helicoverpa assulta (Guenee) (Lepidoptera: Noctuidae): Identification and field testing

Analysis of ovipositor washings from virgin femaleHelicoverpa assulta (Guenée) (Lepidoptere: Noctuidae) from Korea by gas chromatography (GC) linked to electroantennography and GC linked to mass spectrometry resulted in the identification of nine compounds, hexadecanal, (Z)-9-hexadecenal, (Z)-11-hexadecenal, hexadecyl acetate, (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, hexadecan-l-ol, (Z)-9-hexadecen-l-ol, and (Z)-11-hexadecen-1-ol. However, ovipositor washings from females from Thailand contained mainly the 16-carbon aldehydes with very small amounts of (Z)-9-hexadecenyl acetate. Field tests conducted in Korea, China, and Thailand indicated that a binary blend of (Z)-9-hexadecenal and (Z)-11-hexadecenal was sufficient for attraction, although the most attractive ratio of compounds varied with location. In Korea a 201 blend of compounds was the most attractive, while in Thailand a 7.51 blend was most attractive. In China both blends of hexadecenal isomers were equally attractive. Addition of the hexadecenyl acetates to the 201 blend of hexadecenals in the ratio of 13.3 increased the trap catch of maleH. assulta compared to lures containing the aldehydes alone in Korea but reduced trap catch in China. Addition of the hexadecenyl acetates to the 7.51 blend of hexadecenals had no significant effect on trap catch in Thailand or China compared to the aldehydes alone. The addition of the 16-carbon alcohols to the aldehydes had a significantly inhibitory effect in all three countries, suggesting they are not pheromone components. Taken together these results indicate thatH. assulta is polymorphic with at least two populations responding to different sex pheromones.     

Identification of sex pheromone components from pheromone gland volatiles of the tomato looper,Plusia chalcites (Esp.)

The sex pheromone glands ofPlusia chalcites release, dodecyl acetate, (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, 11-dodecenyl acetate, (Z)-8-tridecenyl acetate, and (Z)-9-tetradecenyl acetate. A combination of capillary GC, GC-MS, and dimethyl disulfide derivatization enabled a rigorous identification of all these compounds, some of which were previously found in gland extracts. Bioassays in a flight tunnel showed that a ternary blend of (Z)-7-dodecenyl acetate, (Z)-9-dodecenyl acetate, and (Z)-9-tetradecenyl acetate elicited directed flights from 85 to 100% of the males tested and elicited copulation attempts, at the end of the flights, from 44 to 74% of the males tested. This blend was equal in activity to the natural gland extract. Addition of the other acetates had only a slight influence on the activity of this mixture. Substitution of either (Z)-9-dodecenyl acetate or (Z)-9-tetradecenyl acetate in this blend by 11-dodecenyl acetate gave two ternary mixtures which also elicited high levels of courtship activity, almost as high as that of the original blend. Addition of (Z)-7-dodecenyl alcohol inhibited almost totally the flight activity of males.Lepidoptera: Noctuidae.Contribution from the Agricultural Research Organization (ARO) No. 1701-E, 1986 series.     

Behavioral responses of male turnip moths,Agrotis segetum,to sex pheromone in a flight tunnel and in the field

The response of individual male turnip mothsAgrotis segetum was observed in a sustained flight tunnel to a mixture of decyl acetate, (Z)-5-decenyl acetate, (Z)-7-dodecenyl acetate, and (Z)-9-tetradecenyl acetate in proportions similar to those found in gland extracts from virgin females (0.6: 1:5:2.5). Lures containing 3–30 g (Z)-5-decenyl acetate proved to be maximally attractive, with approximately 60% of the males completing all behavioral steps from activation to copulation efforts. A 300-g dosage caused significant arrestment of upwind flight. Peak response to synthetics, however, was significantly lower than to female glands. Omitting decyl acetate from the blend did not affect the activity, while omission of any of the three monounsaturated acetates caused a dramatic decrease in response. In the field maximum trap catches were achieved with 1- to 30-g lures. The subtractive assay carried out in the field confirmed the neutrality of decyl acetate and the importance of the three monoenes. Adding 1% of (Z)-8-dodecenyl acetate (earlier reported as an inhibitor) to the four-component mixture decreased the trap catch to about 50%, and increasing the amount of (Z)-8-dodecenyl acetate to 27% decreased the activity further to about 10%. (Z)-8-Dodecenyl acetate also decreased the number of successful flights in the flight tunnel.Schiff., Lepidoptera: Noctuidae.This study was made within the Swedish project Odour Signals for Control of Pest Insects.     

Identification of the sex attractant pheromone of the southwestern corn borerDiatraea grandiosella Dyar

We report the identification of the southwestern corn borer,Diatraea grandiosella Dyar (Lepidoptera: Pyralidae), female sex attractant pheromone as a mixture of (Z)-9-hexadecenal, (Z)-11-hexadecenal, and (Z)-13-octadecenal in the ratio 21.570.67.9. Initially, six 16- and 18-carbon aldehydes includingn-hexadecanal, (Z)-9-octadecenal, (Z)-11-octadecenal, and the three above were isolated from female gland rinses and evaluated as potential pheromone components by GLC-MS and laboratory bioassays. By laboratory flight chamber and field tests, the stated mixture of (Z)-9-hexadecenal, (Z)-11-hexadecenal, and (Z)-13-octadecenal was shown to be as effective as the female for male attraction. Electrophysiological studies confirmed the requirement for these three compounds, but not forn-hexadecanal, (Z)-9-octadecenal, and (Z)-11-octadecenal.Lepidoptera: Pyralidae.Mention of a commercial or proprietary product in this paper does not constitute endorsement of this product by USDA.     

Sex pheromone of the chokecherry leafroller moth,Sparganothis directana

(E)-9,11-Dodecadienyl acetate and (Z)-9,11-dodecadienyl acetate in conjunction with (E)-11-tetradecenyl acetate and (Z)-11-tetradecenyl acetate were found to comprise the sex pheromone ofSparganothis directana, based on chemical analysis, electroantennogram tests, and field trapping. (E)-9-Dodecenyl acetate and (Z)-9-dodecenyl acetate were also found in gland extracts but did not influence trap catches. The relative amounts of these compounds in the gland were 3521928 106, in the order named. Only (E)-9,1 1-dodecadienyl acetate, (E)-11-tetradecenyl acetate, and (Z)-11-tetradecenyl acetate were required for attraction of males to traps, dispensed in the relative amounts 501238, respectively.Lepidoptera: Tortricidae.Supported by National Science Foundation grant PCM 78-13241.     

Sex pheromone components of corn stalk borerSesamia nonagriodes (Lef.) isolation,identification, and field tests

Z-11-Hexadecenyl acetate (Z11–16OAc), dodecyl acetate (12OAc),Z-11-hexadecenal (Z11–16Aid), andZ-11-hexadecenol (Z11– 16OH), were found in pheromone gland extracts of femaleSesamia nonagriodes (Lef.) [Lepidoptera: Noctuidae]. These four components were also present in airborne volatiles collected from calling virgin females in a 651889 ratio. Hexadecyl acetate (16OAc) was also detected but found to be inactive. The identification was based on multicolumn GC analysis, mass spectrometry, and field activity.Z11–16OAc is the major sex pheromone component; the addition of the secondary components individually decreased male captures. The blend of the four synthetic components in 691588 ratio was highly attractive to males; 200 g per trap was the most effective concentration in field tests.Lepidoptera: Noctuidae     

Identification and field testing of additional components of female sex pheromone of African armyworm,Spodoptera exempta (Lepidoptera: Noctuidae)

Ovipositor washings from virgin femaleSpodoptera exempta (Walker) (Lepidoptera: Noctuidae) were analyzed by high-resolution gas chromatography (GC) linked to a male electroantennogram (EAG). GC retention times of the two major EAG responses observed were consistent with their assignment as (Z)-9-tetradecenyl acetate and (Z,E)-9,12-tetradecadienyl acetate, as previously identified. However, three other EAG responses were also noted that had GC retention times consistent with (Z)-9-tetradecenal, (Z)-9-tetradecen-1-o 1, and (Z)-11-hexadecenyl acetate. The components were present in the ratio of 10051.53.54, respectively. Further analysis of the ovipositor washings by GC linked to a mass spectrometer (GC-MS) confirmed these findings and indicated the presence of a sixth component consistent with (Z)-11-tetradecenyl acetate present at 2 % of the major component. In field tests carried out in Kenya, (Z)-11-hexadecenyl acetate was the only newly identified component to enhance the catch of the original two-component mixture when presented in their natural ratio. The addition of (Z)-9-tetradecen-1-ol reduced catch, while (Z)-9-tetradecenal and (Z)-11-tetradecenyl acetate had no apparent effect.     

Sex pheromone of blackheaded fireworm,Rhopobota naevana (Lepidoptera: Tortricidae), a pest of cranberry

Splitless capillary gas chromatography indicated the presence of (Z)- and (E)-11-tetradecenyl acetate and (Z)-11-tetradecenyl alcohol in the washes of female abdominal tips of the blackheaded fireworm,Rhopobota naevana (Hubner). Gas chromatography combined with mass spectroscopy confirmed the presence of tetradecenyl acetate in extracts of female tips. The low levels observed in these extracts (< 1 ng/female equivalent), prevented further chemical and spectroscopic identification. These materials were found to be stimulatory at low levels in electroantennogram studies. A combination of 9 g of (Z)-11-tetradecenyl acetate and 3 g of (Z)-11-tetradecenyl alcohol on rubber septa in wing traps provided an effective attractant. (Z)-9-Dodecenyl acetate, a previously reported attractant, did not significantly increase field trapping catches when added to the binary mixture, but was found to enhance trap catches when added to each of the primary components.     

Identification of volatile sex pheromone components released by the southern armyworm,Spodoptera eridania (Cramer)

Analysis of sex pheromone gland extracts and volatile pheromone components collected from the calling female southern armyworm,Spodoptera eridania (Cramer), by high-resolution capillary gas chromatography and mass spectroscopy indicated that a number of 14-carbon mono- and diunsaturated acetates and a monounsaturated 16-carbon acetate were produced. Gland extracts also indicated the presence of (Z)-9-tetradecen-1-ol. However, this compound was not found in collections of volatiles. Field trapping studies indicated that the volatile blend composed of (Z)-9-tetradecen-1-ol acetate (60%), (Z)-9-(E)-12-tetradecadien-1-ol acetate (17%), (Z)-9-(Z)-12-tetradecadien-1-ol acetate (15%), (Z)-9-(E)-11-tetradecadien-1-ol acetate (5%), and (Z)-11-hexadecen-1-ol acetate (3 %) was an effective trap bait for males of this species. The addition of (Z)-9-tetradecen-1-ol to the acetate blends tested resulted in the capture of beet armyworm,S. exigua (Hubner), males which provides further evidence that the alcohol is a pheromone component of this species.     

9,11-Dodecadienyl alcohols,acetates, or aldehydes as synthetic chemical sex attractants for four Lepidoptera:Cosmopterix gemmiferella (Clemens),Dichrorampha simulana (Clemens),Tortricidia testacea (Packard), and anAncylis sp.

Four lepidoptera were lured to field traps containing various combinations of 9,11-dodecadienes with alcohol, acetate, or aldehyde functional groups. All species required two chemical components for best attraction.Cosmopterix gemmiferella was most responsive to a combination of (9Z)-9,11-dodecadienyl acetate and (9E)-9,11-dodecadienyl acetate in 21 ratio;Dichrorampha simulana to (9E)-9,11-dodecadienyl acetate and (9E)-9,11-dodecadien-1-ol in 101 ratio;Tortricidia testacea to (9Z)-9,11-dodecadienal and (9E)-9,11-dodecadienal in 101 ratio; andAncylis sp. to (9Z)-9,11-dodecadienyl acetate and (9Z)-9,11-dodecadien-1-ol in 101 ratio.     

Sex pheromone of the face fly,Musca autumnalis De Geer (Diptera: Muscidae)

Components of a sex pheromone that cause male face flies to strike at females were found to be the straight-chain monoalkenes (Z)-14-nonacosene, (Z)-13-nonacosene, and (Z)-13-heptacosene. Although these compounds were found in the extracts of both sexes, extracts from sexually mature males contained a much higher proportion of nonacosane and heptacosane, which attenuated the activity of the active monoalkenes. The monoalkenes were readily synthesized by a Wittig reaction modified by the use of hexamethylphosphoric triamide as a cosolvent with tetrahydrofuran to produce a product containing 94–96% (Z) isomer.     

Identification of sex pheromone components of darksided cutworm,Euxoa messoria,and modification of sex attractant blend for adult males

Eleven pheromone-like compounds were identified in excised abdomen tip extracts of calling adult females of darksided cutworm,Euxoa messoria (Harris). The essential pheromone components were (Z)-7- and (Z)-11-hexadecenyl acetates in a ratio of 140, which agreed with an attractant blend developed empirically by field testing the attractancies of synthetic blends. The pheromone component, (Z)-11-hexadecenol, improved the attraction of darksided cutworm males whereas the components (Z)-9-tetradecenyl acetate and (Z)-7-dodecenyl acetate inhibited their attraction. The other pheromone-like compounds identified in the female extracts had no obvious effect on the attraction of darksided cutworm males. Three compounds that functioned as parapheromones when substituted for (Z)-7-hexadecenyl acetate in the two-component blend were (Z)-7-pentadecenyl, (Z)-7-tetradecenyl, and (Z)-7-tridecenyl acetates. (Z)-11-hexadecenal was not detected in the female extracts, but it had a synergistic effect on the attraction of darksided cutworm moths and inhibited the attraction of male moths of a nontarget species,Helotropha reniformis (Grote). As a trap bait for monitoring purposes, we recommend a four-component blend of (Z)-7-hexadecenyl acetate, (Z)-11-hexadecenyl acetate, (Z)-11-hexadecenol, and (Z)-11-hexadecenal at 12.5, 500, 1, and 10 g/red rubber septum dispenser containing 5 g of antioxidant 2,6-tert-butyl-4-methyl phenol. This blend is effective under field conditions for at least six weeks.