Field Trapping of Tomato Moth, Tuta absoluta with Pheromone Traps

Field evaluations demonstrate that the addition of the minor pheromone component (3E,8Z)-tetradecadien-1-yl acetate to the major component (3E,8Z,11Z)-tetradecatrien-1-yl acetate does not significantly increase the trap catches of Tuta absoluta males in the field. The triene acetate itself is highly attractive, catching about 869 ± 255 males per trap in three consecutive nights. The addition of two isomers of the minor component (3E,8Z)-tetradecadien-1-yl acetate, (3E,11Z)-tetradecadienyl-yl acetate and (8Z,11Z)-tetradecadien-1-yl acetate, to the major component (3E,8Z,11Z)-tetradecatrien-1-yl acetate also did not significantly alter the number of the males caught in the traps.     

Sex pheromone of tobacco stem borer,Scrobipalpa heliopa (Lower) (Lepidoptera: Gelechiidae)

The major volatile component in the extract of the female sex pheromone gland ofScrobipalpa heliopa was shown to be (E)-3-tridecen-1-ol acetate (V). The identification was based on mass spectral analyses, comparison of retention times with those of synthetic compounds on polar, nonpolar, and liquid crystal gas chromatographic columns and microchemical studies. The latter included hydrolysis and reacetylation, and mass spectral studies of the derivatives formed by epoxidation and methoxymercuration-demercuration. Analysis of gland extracts by gas chromatography linked to electroantennography showed this component to be the only one with significant biological activity, similar to that of the synthetic compound. (E)-3-Tridecenyl acetate (V) attracted male moths to traps in the field while addition of theZ isomer (III) reduced the numbers of moths caught.     

Sex pheromone scent marking by females ofPectinophora gossypiella (Lepidoptera: Gelechiidae)

Females of the pink bollworm moth,Pectinophora gossypiella (Saunders), scent marked the substrate to which they were clinging with the extended pheromone gland during nocturnal pheromonereleasing periods. Scent marks were deposited on both natural (cotton leaf) and atypical (glass) substrates. In both situations, the scent marks elicited attraction responses from conspecific males.     

Heritable variation in pheromone response of the pink bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Heritability of variation in male pheromone response by pink bollworm moths,Pectinophora gossypiella (Saunders), was examined using a still-air, wing-fanning bioassay. Heritability (±SE) of overall responsiveness, as measured by the mean duration of wing fanning to the blend of pheromone components produced by females [4456 ratio of (Z, E)- to (Z, Z)-7,11-hexadecadienyl acetate], was 0.385 ± 0.095. Heritabilities of wingfanning duration to blends with 25 and 65%Z, E isomer were 0.377 ± 0.113 and –0.145 ± 0.103, respectively. These findings indicate an asymmetry in the genetic component of variation in response to pheromone blends with high and low proportions of theZ, E isomer. An index of response specificity for individual males was developed based on the response to an off-blend (either 25 or 65%Z, E isomer) relative to the response to the 44%Z, E blend. Heritabilities of response specificity were 0.117 ± 0.059 and –0.043 ± 0.067 for the 25 and 65%Z, E blends, respectively.     

Isolation and identification of sex pheromone ofSymmetrischema tangolias (Gyen) (Lepidoptera: Gelechiidae)

The sex pheromone of the South American potato tuber mothSymmetrischema tangolias (syn.:Symmetrischema plaesiosema) was identified as a 2:1 mixture of (E,Z)-3,7-tetradecadien-1-ol acetate and (E)-3-tetradecen-1-ol acetate by means of dual-column GC, EAG, GC-EAD, GC-MS, NMR, and wind-tunnel bioassays. (Z)-5-Tetradecen-1-ol acetate and (Z)-7-tetradecen-1-ol acetate were also identified in the pheromone gland extract. MaleS. tangolias were able to detect these acetates (EAG), but their addition to the two-component sex pheromone did not improve attractiveness. Field trials in Cajamarca and Cusco, Peru, showed that traps baited with the synthetic sex pheromone were able to catch large numbers of maleS. tangolias.     

Variability in pheromone composition and periodicity of pheromone titer in potato tuberworm moth,Phthorimaea operculella (Lepidoptera: Gelechiidae)

The ratios and quantities of the pheromone components, (E,Z)-4,7-tridecadien-1-yl acetate (diene) and (E,Z,Z)-4,7.10-tridecatrien-1-yl acetate (triene), in the glands of individual female potato tuberworm moths (Phthorimaea operculella) originating from the United States (California) and Japan (Nagoya) were analyzed by gas chromatography. Quantities of glandextracted pheromone components of Nagoya females fluctuated in a periodic fashion during the photoperiod. Maximal titers coincided with the onset of scotophase (and calling), then gradually declined to minimal levels soon after lights-on. The average daily pheromone quantities decreased significantly as females aged. Both populations exhibited considerable variation in the ratio of the two components. The proportions of triene in the blend ranged from 27% to 88% (triene –X = 56 ± 13% SD; CV = 23%) for California females and from 16% to 71% (42 ± 13%; CV = 31%) for Nagoya females. Nagoya females also stored significantly higher amounts of pheromone in their glands (8.6 ± 3.9 ng) than did California females (2.7 ± 1.4). The differences between the populations, while substantial, would probably not be sufficient to impart a barrier to panmixis, given the wide range of component ratios favored by the males.     

Effect of temperature on biosynthesis of sex pheromone components in potato tuberworm moth,Phthorimaea operculella (Lepidoptera: Gelechiidae)

Rearing temperature modified the sex pheromone component ratio in the potato tuberworm moth,Phthorimaea operculella. This phenomenon seemed to be induced with ambient temperature by differences in timing and speed of biosynthesis between two pheromone components. (E,Z,Z)-4,7,10-Tridecatrienyl acetate (triene) was mainly synthesized during the pupal period, while most of (E,Z)-4,7-tridecadienyl acetate (diene) was synthesized during a short period just after emergence. Therefore, the ratio of triene in a newly emerging adult was relatively high at all temperatures although the amount of triene was relatively low at 35°C. On the other hand, the synthetic rate of accumulation of diene was clearly modified by ambient temperature. Biosynthesis of diene at 15°C was very low in the first two days and high in the third day. Consequently, a titer of the diene component at 15°C became approximately equivalent to that at 25°C one day later.     

Effect of rearing temperature on pheromone component ratio in potato tuberworm moth,Phthorimaea operculella, (Lepidoptera: Gelechiidae)

The ratio of two components in the sex pheromone of the potato tuberworm moth,Phthorimaea operculella, was influenced by the rearing temperature. The percentage of the (E,Z,Z)-4,7,10-tridecatrienyl acetate dropped as the rearing temperature was raised. The total amount of the pheromone did not change parallel with the change of ratio. The critical period sensitive to temperature seemed to be the pupal stage. Temperature in the larval stage may also influence the ratio slightly. The biological significance of the phenomenon was also discussed.     

Wing fanning as a measure of pheromone response in the male pink bollworm,Pectinophora gossypiella (Lepidoptera: Gelechiidae)

A still-air, wing fanning bioassay measured male pheromone response in the pink bollworm moth,Pectinophora gossypiella (Saunders). As pheromone concentration was increased, the duration of wing fanning increased while its latency decreased. Response duration was longest for the natural pheromone blend [44:56 (Z,E)- and (Z,Z)-7,11-hexadecadienyl acetates], although responses to 38% and 50%Z,E blends were not significantly briefer. Preexposure to pheromone had no effect on wing fanning in males retested after 24 hr. Wing fanning was highly correlated with upwind flight and other responses observed in a wind tunnel. Wing fanning duration provides a continuous measure of pheromone response and allows a large number of males to be tested in a short time; these two characteristics of the wingfanning assay are helpful for genetic analyses of male response.     

Identification of sex pheromone of tomato pinworm,Keiferia lycopersicella (Wals.)

A sex pheromone produced by femaleKeiferia lycopersicella (Walsingham) was isolated and identified as (E)-4-tridecenyl acetate, based on chemical analyses, electroantennogram assays, and field trapping in California and Florida. Males were captured equally well in traps baited with (E)-4-tridecenyl acetate alone or a variety of (Z)- and (E)-4-tridecenyl acetate blends, although theZ isomer was not detected in extracts of female glands.Lepidoptera: Gelechiidae.     

Sex pheromone of lucerne leafroller,Merophyas divulsana (Walker) (Lepidoptera: Tortricidae): Evidence for two distinct populations

When specimens of the lucerne leafroller,Merophyas divulsana, were sampled from an area with a history of crop damage, they were found to have (E)-11-tetradecenyl acetate, hexadecyl acetate, and tetradecyl acetate as principal components of the pheromone gland. A synthetic mixture of these compounds proved to be a successful lure in delta traps. On the other hand, apparently identical moths collected in areas with no history of crop damage were found to have (Z)-11-tetradecenyl acetate as the major component of the sex pheromone gland. The distribution of the two moths provides the basis for a plausible explanation of the regional pest activity reported forM. divulsana.     

Role of pheromone components in evoking behavioral responses from male potato tuberworm moth,Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)

Responses of the male potato tuberworm moth,Phthorimaea operculella (Zeller), to two sex pheromone components and female crude extract were studied. Both in a wind tunnel and the field, males were better able to locate a source consisting of a 11 mixture of (E,Z)-4,7-tridecadien-1-yl acetate and (E,Z,Z)-4,7,10-tridecatrien-1-yl acetate than a source consisting of the triene alone. The addition of the diene increased the time spent in the vicinity of the pheromone source, time spent on the source itself, and also increased the average number of visits to the source per individual when compared to the triene alone. The triene elicited high levels of locomotor activity and may play a major role in eliciting earlier (long-range) steps in the behavioral sequence of sexually activated moths. The diene appeared to influence later (short-range) behavior. The behavioral responses of males to a 11 mixture of the diene and triene were similar to those elicited by female crude extract.From a thesis submitted by M. Toth to the Australian National University in fulfillment of the requirements for the degree of Master of Science.These studies were supported by an Australian Department of Education award under the AEAP award scheme.     

Sex pheromone ofStenoma cecropia Meyrick (Lepidoptera: Elachistidae)

(Z,E)-9,11-tetradecadienal (Z9,E11–14: Ald; 11%), (Z,E)-9,11,13-tetradecatrienal (Z9,E11, 13–14: Ald; 67%), (Z,E)-9,11-tetradecadienyl acetate (Z9,E11–14: Ac, 5.5%), and (Z,E)-9,11,13-tetradecatrienyl acetate (Z9,E11,13–14: Ac; 16.5%) were identified in the extracts of female pheromone glands ofStenoma cecropia (Lepidoptera: Elachistidae). From electroantennograms and single sensillum recordings, receptors toZ9,E11,13–14:Ald andZ9,E11–14: Ald were found on male antenna. Behavioral data were obtained from olfactometric tests in the laboratory and field trapping experiments in Colombia. It appeared that a blend ofZ9,E11,13–14:Ald (83%) andZ9,E11–14:Ald (17%) was attractive to males. These aldehydes are assumed to be components of the sex pheromone ofS. cecropia, whereas the acetates found in gland extracts might be precursors of the pheromone.     

Sex pheromone of the tomato looper,Plusia chalcites (ESP)

Z-7-Dodecenyl acetate (A) andZ-9-tetradecenyl acetate (B), in a 51 ratio, have been identified as sex pheromone components of femalePlusia chalcites. In addition, small amounts of dodecyl acetate, tetradecyl acetate, hexadecyl acetate, andZ-9-dodecenyl acetate have been found in the abdominal tip extracts. This is the first known Plusiinae species which utilizes a two-component primary sex pheromone system. The most effective lure found in field experiments was a mixture of 1 mg A and 0.2 mg B absorbed on rubber septa.Lepidoptera: Noctuidae.Contribution from the Agricultural Research Organization (ARO) No. 325-E, 1980 series.     

Sex pheromone of cranberry fruitworm,Acrobasis vaccinii riley (Lepidoptera: Pyralidae)

The following compounds and (approximate ratios) were identified in sex pheromone gland extracts of femaleAcrobasis vaccinii Riley by comparison of gas chromatography-mass spectrometric traces with those of synthetic standards: (E,Z)-, (Z,E)-, (Z,Z), and (E,E)-8, 10-pentadecadien-l-ol acetates (100:1:2:12), a dodecen-l-ol acetate (8), (Z)-8-, (Z)-9-, and (E)-9-pentadecen-l-ol acetates (3:23:4), two heptadecen-l-ol acetates (4:4), tetradecyl, pentadecyl, hexadecyl, and heptadecyl acetates (3:15:10:8), dodecan-l-ol (6), tetradecan-l-ol (5), and hexadecan-l-ol (23). The amount of (E,Z)-8, 10-pentadecadien-l-ol acetate (E8,Z10–15:Ac) in the extract was about 0.5 ng/female. Electroantennographic analysis of gas chromatographic fractions of female sex pheromone gland extract showed that the fraction containingE8,Z10–15:Ac elicited the greatest response. Alone,E8,Z10–15:Ac failed to elicit upwind flight of males in flight-tunnel tests, and traps baited with it did not catch males in field experiments. WhenE8,Z10–15:Ac was combined with (E)-9-pentadecen-l-ol acetate (100:4), male upwind flight response in flight-tunnel tests was equivalent to those obtained with extract of female sex pheromone glands (synthetic, 62%; natural, 51%), but the percent of males flying upwind that contacted the source was lower (synthetic, 47%; natural, 88%). The lower percent of source contact elicited by the synthetic pheromone could be a result of the difference in isomer ratios of 8,10–15:Ac in the natural and synthetic pheromone or could indicate that the synthetic pheromone is incomplete. Traps baited with the 100:4 combination caught large numbers of males in field experiments.     

Sex pheromone of the avocado pest,Amorbia cuneana (Walsingham) (Lepidoptera: Tortricidae)

The major volatile components in the extract of the female sex pheromone gland ofAmorbia cuneana consisted of (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates. The identification was based on electroantennogram bioassay of gas Chromatographic effluent from sex pheromone gland extract, relative retention times on polar and nonpolar gas chromatographic columns, chemical degradation (ozonolysis, saponification), mass spectrometry, chemical synthetic methods, and field tests. Based on mass spectrometry and retention times by capillary gas chromatography, traces of (E)-10-tetradecen-1-ol acetate and 1-tetradecanol acetate were also present in the extract. Traps baited with a combination of synthetic (E,E)- and (E,Z)-10,12-tetradecadien-1-ol acetates caught more males than did traps baited with females.This paper reports the results of research only. Mention of a commercial product in this paper does not constitute a recommendation by the U.S. Department of Agriculture.     

Release kinetics of liquid flowable formulations of gossyplure,sex pheromone of the pink bollworm mothPectinophora gossypiella saunders (Lepidoptera: Gelechiidae)

The kinetics of the release of gossyplure, measured in the laboratory at 34.5 ± 0.5 °C, from two liquid flowable formulations are presented and discussed. The data indicate that liquid flowable formulations, defined as those formulations where the active ingredient (in this case gossyplure) is attached to a particulate material, which in turn is suspended in a liquid medium, probably can be successfully used to disseminate pheromones and other behavior-modifying chemicals, although much work remains to be done in the development of these and other liquid flowable formulations.     

Sex pheromone of tomato fruit borer, Neoleucinodes elegantalis

Five candidate pheromone components were identified by analyzing pheromone gland extracts by gas chromatography (GC), coupled GC-electroantennographic detection (EAD), and coupled GC-mass spectrometry (MS): (E)-11-hexadecenol(E11–16 : OH), (Z)-11-hexadecenol (Z11–16 : OH),(E)-11-hexadecenal, (E)-11-hexadecenyl acetate, and (Z)-3,(Z)-6,(Z)-9-tricosatriene (Z3,Z6,Z9–23 : Hy). In electroantennogram (EAG) recordings, synthetic E11–16 : OH elicited stronger antennal responses at low doses than other candidate pheromone components. Field tests demonstrated that synthetic E11–16 : OH as a trap bait was effective in attracting males, whereas addition of Z11–16 : OH inhibited the males' response. Z3,Z6,Z9–23 : Hy strongly enhanced attractiveness of E11–16 : OH, but was not attractive by itself. A pheromone blend with synergistic behavioral activity of an alcohol (E11–16 : OH) and hydrocarbon (Z3,Z6,Z9–23 : Hy) component is most unusual in the Lepidoptera. The synthetic two-component pheromone is approximately 60 times more attractive than the female-produced blend and might facilitate the control of this pest.     

Sex pheromone of the armyworm,Pseudaletia unipuncta (Haworth) (Lepidoptera: Noctuidae)

(Z)-11-Hexadecen-1-ol acetate (Z11–16Ac) free of theE isomer (<1%), hexadecan-1-ol acetate (16 Ac), and a hexadecen-1-ol [the (Z)-11 isomer based on the retention time on a Carbowax capillary column] were identified in extracts of the sex pheromone glands of adult virgin female armyworms,Pseudaletia unipuncta. Also, gas Chromatographic retention times on polar and nonpolar columns indicated the possible presence of (Z)-9-hexadecen-1-ol acetate (Z9–16Ac). The ratioZ11–16Ac/16Ac/Z11–16OH/Z9–16Ac was 10.150.130.02. Infield testsZ11–16 Ac was attractive alone, and the addition ofZ9–16Ac,Zll–16 OH, or 16 Ac singly or in combination in ratios found in the gland did not increase trap capture.Mention of a proprietary product does not constitute an endorsement of this product by the USDA.     

Sex pheromone components from asian corn borer,Ostrinia furnacalis (Hubner) (Lepidoptera: Pyralidae) in Taiwan

The female sex pheromone of the Asian com borer,Ostrinia furnacalis, widespread in Taiwan, was confirmed as (Z)-12-tetradecenyl acetate and its geometric isomer (E)-12-tetradecenyl acetate in a ratio of ca. 31 by gas chromatography and gas chromatography-mass spectrometry in selected ion monitoring mode. Males were attracted by the mixture of these two synthetic components in the field, but the attractiveness was less than by virgin females. The presence of minor components in the sex pheromone was therefore suggested.