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Two different laboratory bioassays were developed to quantitatively determine the repellent activity of semiochemicals, such as famesol and methyl eugenol, against the Argentine ant. lridomymzex humilis (Mayr). One assay, based on the ability of ants to cross barriers of beeswax containing different concentrations of test chemicals, was not designed to discriminate between olfactory or gustatory modes of detection. The other was based on the ability of an ant to detect airborne chemicals and, therefore, measured only the olfactory response of ants to the chemicals. Both assays permitted construction nof dosage-response curves and determination of a Bl50, the concentration that provided 50% behavioral inhibition.

Lemon trees banded with experimental formulations of farnesol and other natural ant repellents were examined for efficacy of disruption of the foraging of the Argentine ant, Linepithema humile (Mayr), at varying periods of time after application. Excellent disruption of foraging was achieved by the use of a band constructed from a single strand of cotton twine permeated with 40 mg each of farnesol and Stickem per centimeter of twine. An “ant tape,” consisting of twine similarly permeated with farnesol and Stickem and covered with a strip of waxed paper, was under some conditions superior in duration of disruption of ant foraging to the noncovered, treated twine. Efforts to produce an effective barrier from farnesol mixed with Stickem and beeswax and formulated into a paste, which was then applied around tree trunks, have not been successful. The better formulations of farnesol tested have given between 2 and 3 mo of complete ant exclusion from banded trees. Other tested repellent compounds have not been as active or provided as long a duration of effectiveness as farnesol.

Multiple treatments of mevinphos, methomyl, and permethrin were applied to head lettuce ( Latuca sativa L.) under commercial field conditions, and harvest residues compared with those of single treatments made at identical periods before harvest. Single treatments resulted in harvest residue levels below current legal tolerances for these materials on head lettuce. Two consecutive treatments of all insecticides 8 d apart resulted in similarly low harvest residues. However, at shorter treatment intervals of 4 and 2 d, the same materials showed extensive residue accumulation. This trend was greatest at successive treatment intervals of 2 d, where mevinphos increased by 79%, methomyl by 161%, and permethrin by 242%. The importance of this residue loading phenomenon is discussed in light of management of insecticide residues on lettuce in commercial production.

Fifteen compounds used for suppression of lepidopteran pests of citrus were applied in a commercial manner to lemon trees. Amounts of dislodgable residues, together with mortality of Aphytis melinus DeBach confined on treated foliage, were monitored for 36 days following treatment. Most materials caused high mortalities on the 1st day following treatment. Several materials had little effect on A. melinus after 7 days post-treatment. These included a formulation of Bacillus thuringiensis Berliner endotoxin, a formulation of B. thuringiensis exotoxin, cryolite, methomyl, mevinphos, naled, parathion, and trichlorfon. Carbosulfan, chlorpyrifos, esfenvalerate, fluvalinate, methomyl, and two formulations of carbaryl caused mortality for up to 30 days post-application. Mortality in the thiodicarb treatment was above 60% for the 36 days of the study. Mortality was correlated with amounts of dislodgable residue for each material tested.

A variety of chemicals that are identical or similar to known ant alarm pheromone components or ant-defensive allomones produced by organisms other than ants were evaluated for effectiveness in disrupting the foraging activities of Formica aerata (Francoeur). The chemicals were applied as bands around the trunks of plum trees or around wooden stakes holding ant feeding stations at their tops. Some of the chemicals were highly effective in excluding ants from the trees or feeding stations. Long-duration (up to 53 d) disruption of foraging was obtained with farnesol when incorporated in Stickem as a slow-release substrate

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.

Fourteen compounds used for suppression of lepidopteran pests of citrus were applied in a commercial manner to citrus trees. Amounts of dislodegable residues, together with mortality and fertility of Euseius stipulatus Athias-Henriot confined on treated foliage, were monitored for up to 100 days post-treatment. Several materials had little effect on E. stipulatus after seven days post-treatment. These included cryolite, trichlorfon, naled, parathion, chlorpyrifos, mevinphos, and a formulation of Bacillus thuringiensis endotoxin. Carbosulfan, thiodicarb, methomyl and two formulations of carbaryl caused mortality for up to 30 days. Fluvalinate and esfenvalerate caused the greatest mortalities for up to 60 days post-treatment. Mortality was correlated with amounts of dislodegable residue for each material tested. There was little effect on fertility by any compound. Zusammenfassung Zur Toxizitat von Pestizidruckstanden auf Euseius stipulatus Athias-Henriot (Acarina, Phytoseiidae) im Zitrusanbau Es wurden 14 Praparate, die im Zitrusanbau zur Bekampfung von Schadlepidopteren eingesetzt werden, in praxisublicherweise auf Zitronenbaume ausgebracht. Bis zu 100 Tagen nach der Behandlung wurden die Ruckstande sowie die Mortalitat und Fertilitat von Euseius stipulatus auf den behandelten Blattern untersucht. Einige Praparate hatten sieben Tage nach der Behandlung einen geringen Effekt auf E. stipulatus. Dazu gehorten Cryolit, Trichlorfon, Parathion, Chlorpyrifos, Mevinphos und eine Bacillus thuringiensis-Endotoxin-Formulierung. Carbosulfan, Thiodicarb, Methomyl und zwei Carbaryl-Formulierungen fuhrten bis zu 30 Tagen nach der Behandlung zu einer erhohten Mortalitat von E. stipulatus. Fluvalinat und Esfenvalrat wiesen die hochsten Mortalitatsraten noch bis zu 60 Tagen nach der Behandlung auf. Die Mortalitat korrelierte bei allen Praparaten mit den Ruckstandsmengen. Allgemein konnte nur ein geringer Effekt auf die Fertilitat festgestellt werden.

Synergism with metabolic inhibitors showed that resistance to fluvalinate was polyfactorial in a strain of citrus thrips, Scirtothrips citri (Moulton). Mixed-function oxidases were responsible for a major portion of the resistance (synergism as much as 61-fold at LC90), followed by est erases (synergism as much as 14-fold at Le90) Glutathione S-transferases may or may not be involved in fluvalinate resistance. Lack of total fluvalinate synergism with combinations of metabolic inhibitors, as well as limited synergism of DDT with piperonyl butoxide + dichlorophenyl ethanol, suggests a knock-down resistance ( kdr ) component. Sesame oil synergized fluvalinate up to 48-fold at LC90, suggesting the possible use of this product in the field. Resistance to dimethoate that was apparent in the parental TB84 strain before selection with fluvalinate may be due to enhanced activity of mixed-function oxidases.

Pesticide use was simulated to determine the amount and location of pesticide residues within lettuce heads at harvest and to determine whether wrapper leaf removal reduced head residues. Excessive application of insecticides adversely affected head weight and total yield, independent of the direct effects of pests. Highest residues resulted from excessively high field use and minimum preharvest intervals. Wrapper leaf removal resulted in a low or residue-free head across all materials studied.

Male Trichoplusia ni were tested individually in a sustained-flight tunnel to different amounts and ratios of the two sex pheromone components, ( Z )-7-dodecenyl acetate ( Z 7-12:Ac) and dodecyl acetate (12:Ac). The primary component, Z7-12:Ac, was responsible for activation and initiation of upwind oriented flight. The secondary component, 12:Ac, elicited no behavioral response when presented alone. When 12:Ac was combined with Z7-l2:Ac in the natural blend, 93:7 Z7-l2:Ac and 12:Ac, at the optimum dosage tested, the number of upwind flights to the source, the duration of close range flight, contact and attempted copulations with the source were significantly higher than in response to Z7-l2:Ac alone. Males exhibited individual variation in duration of various phases of the response, but no significant dosage effects were observed with respect to initiation of activation or duration of wing fanning and upwind flight in moths that flew to within 25 cm of the source.

Males of Trichoplusia ni (Hubner), the cabbage looper moth, were maintained at two constant temperature regimes, 25° and 15°C, as well as at an alternating 25° day:15° night regime. The males held at constant 15° required at least 9 days following emergence from the pupa to acquire maximal responsiveness to the synthetic female sex pheromone, cis -7-dodecenyl acetate, whereas those held at constant 25° or at 25:15° were maximally responsive by 3–5 days following emergence. Within a 10-hr scotophase, males held at 25°, 25:15°, and 15° achieved maximal pheromone responsiveness by the 7th, 3rd, and 1st hours, respectively, after the onset of darkness. This advancing of the diel expression of responsiveness with reducing temperatures is similar to that seen earlier for the time of release of pheromone by T. ni females. Males conditioned at the more natural, fluctuating (25:15°) temperatures tended to be 3 to 6-times more responsive to pheromone than those maintained at the constant (25° or 15°) temperatures.

Soldier defensive secretions were analyzed by GC/MS in eight spatially separated groups of Amitermes wheeleri collected in Arizona and California. Eleven sesquiterpenoids, four of known structure, were isolated. Quantitative and qualitative differences among the groups of termites were extensive; composition of the defensive secretions among colonies varied from one to six components. Intraspecific differences between pairs of sympatric colonies at six sites were much less pronounced. The variability found in A. wheeleri suggests that soldier defensive secretions in the genus Amiterines are not reliable markers for interspecific systematic comparisons.

Impacts of field-weathered residues of nine acaricides (amitraz, avermectin + oil, chlorobenzilate + oil, cyhexatin, dicofol, fenbutatin-oxide, oil, oxythioquinox, and propargite) on survival of selected beneficial arthropods of citrus ( Aphytis melinus DeBach, Cryptolaemus montrouzieri Mulsant, and Euseius stipulatus Athias-Henriot) were evaluated in two field trials. Concurrent with bioassays, foliar residue analyses were performed and were correlated with mortality. With the exception of moderate (causing amitraz > oxythioquinox > cyhexatin > chlorobenzilate + oil > propargite (least persistently toxic).

In choice feeding tests, Argentine ant, Iridomyrmex humilis (Mayr), workers preferred 25% honey water or sucrose water over granulated brown sugar or other solid foods with high protein content such as tuna meal. In the field in competition with the preferred natural food, honeydew, workers fed consistently on sucrose water and honey water over a period of 15 days and exhibited a significant preference for sucrose water. Various emulsifiers and ethanol used to suspend toxicants in the sucrose water did not by themselves significantly deter feeding. Workers readily fed upon, and were killed by, the sucrose water bait containing 10 or 100 ppm Avermectin.

The rate and periodicity of the emission of the sex pheromone [(Z)-11-hexadecenal] from the pheromone glands of individual female artichoke plume moths, Platyptilia carduidactyla, were quantified. The mean rate of volatilization of (Z)-11-hexadecenal from the glands of the moths peaked at 1.52 ± 0.41 (SE) ng/min during the scotophase, and was at low levels during the entire photophase. This periodicity in emission rate paralleled the behavioral periodicity of calling by females, indicating a close coordination of the biochemical and behavioral aspects of pheromone release. The highest recorded emission rate from a female P. carduidactyla was 5.1 ng/min. No other pheromone-like compounds were detected in these pheromone collections.

Dodecyl acetate was identified as a second component of the sex pheromone ofTrichoplusia ni (Hubner). Dodecyl acetate comprised 9.6% by weight of the total pheromone [(Z)-7-dodecenyl acetate plus dodecyl acetate] extracted from glands and 7.3% by weight of the total pheromone evaporated from the surfaces of glands. Dodecyl acetate appears to function as a short-range pheromone component. Evaporation at female release rates of a 10∶90 mixture of dodecyl acetate and (Z)-7-dodecenyl acetate in the field caused a significantly greater percentage of males to land on the pheromone source, increased significantly the time they spent on the source, but decreased significantly the time they spent searching for the source when within 50 cm, as compared to (Z)-7-dodecenyl acetate alone.

Electroantennogram responses of male and femalePseudaletia unipuncta to the two major components of the presumed pheromone associated with the male anterior abdominal scent brushes vary with age. There is a postemergence period of maturation of responsiveness, followed by senescence. The age of maximum responsiveness differs according to the sex and to the compound tested.

The behavior of males of the pink bollworm, Pectinophora gossypiella (Saunders), flying within an aerial trail of female sex pheromone was influenced by the concentration of pheromone, the spatial position and intensity of the illuminating light source, and visual cues from nearby objects. When exposed to pheromone, most moths held at light intensities ranging from 10 to

Gel filtration with Sephadex G-25 or Bio-Gel P-2 of homogenates of the sexes of the zooparasitic nematode Nippostrongylus brasiliensis revealed two fractions with pheromonal activity. One active fraction with a suggested molecular weight over 500 was found in aqueous extracts of both helminth sexes and was attractive to both sexes by in vitro bioassay. A second region of pheromone activity was found in only female Nippostrongylus and was attractive to only male helminths. A molecular weight under 400 is proposed for this region. Additionally, a third region that represented ionic weights was present in both sexes, but attracted only female worms. These results indicated that helminth to helminth attraction is present at both species and sexual levels of recognition.

Both males and females ofRhabditis pellio release pheromones that attract the opposite sex prior to copulation. A quantitative bioassay for the female-produced pheromone was designed, based on male movement toward a pheromone source placed at one end of a 10-mm strip of bacterial material maintained on nutrient agar in a petri plate. Females produced pheromone from the age at which they attained the adult stage (∼3 days following hatching from the egg) and maintained a relatively constant production level until at least the ninth day of life. Similarly, males became responsive to the female pheromone by the third day and remained responsive through the ninth day, although the time required for the males to migrate toward a female pheromone source increased with increasing age. No daily rhythm of pheromone responsiveness by males or pheromone production by females was observed when the nematodes were conditioned to a 12∶12 h light-dark cycle.

Partial purification of a pheromone of the zooparasitic nematodeNippostrongylus brasiliensis was achieved. The polypeptide pheromone is degraded by Pronase while increased recovery is obtained after treatment with the protease inhibitors phenylmethylsulfonyl fluoride orl-1-tosylamide-2-phenylethyl chloromethyl ketone. The pheromone has a net negative charge, based on retention on DEAE cellulose and an approximate isoelectric point of 7.3. A combination of double treatments with phenylmethylsulfonyl fluoride and gel filtration enables storage up to nine days which yields biological activity similar to fresh, untreated chromatographic fractions.

[Demean and aldoxycarb were applied to mature lemon trees by drip irrigation. Chemical analyses of leaf tissue of three different ages show that both materials were rapidly trans located into the leaves. Aldoxycarb residues initially were much higher than demean residues. Analyses for 120 d post treatment showed that demean residues were more persistent in the leaf tissues than aldoxycarb residues. Leaves from neither treatment caused any appreciable mortality to two phytophagous species, citrus drips ( Scirtothrips cirri (Mouton)), and citrus red mite ( Panonychus cirri Gregor), nor to the arenaceous mite, Eugenius tularemia Condone, over the course of the study.

The short-range precopulatory behavior of males of Pectinophora gossypiella was examined by direct observation and sequential photography. A pheromone-stimulated male takes flight and moves upwind toward a pheromone-releasing female. He usually lands several centimeters from her and then walks toward her while fluttering his wings and extending his hairpencils. The female typically withdraws her pheromone gland when the male first contacts her. The male makes a copulatory attempt and, if coupling occurs, he moves to an “end-to-end” position. Males oriented toward a synthetic pheromone source even in the absence of visual stimuli from a female, and their forward locomotion was usually arrested when they arrived at the source. Copulatory attempts were then sometimes directed toward the source. In the presence of pheromone, three-dimensional female models were much more effective than the pheromone source alone in eliciting copulatory attempts. Downwind models showed decreasing abilities to elicit male precopulatory responses with increasing distances from the source. However, increasing the amount of pheromone at the source resulted in an increase in the percentage of responses occurring at the furthest downwind models. The various components of precopulatory behavior observed for P. gossypiella are compared and contrasted with the published records of similar behaviors in other nocturnal moth species.

In the Argentine ant, optimum trail following to gaster extracts was displayed to 0.1 and 1.0 equivalents/50 cm of circular trail. Trail following to airborne components was demonstrated when ants exhibited normal trail following behaviour while walking 3 or 6 mm below a 0.1 ant equivalent trail. However, at 8 or 12 mm separation, following ceased, indicating that the height of the active space was ca. 6–8 mm. The average horizontal distance from the centre of the trail at which ants exhibited following behaviour increased with concentration to 3–4 mm beyond the applied trail boundaries, indicating both an ability to follow airborne chemicals, and possibly a non-tolerance of excessively high concentration. Activity of 0.1 ant equivalent trails on filter paper declined to about half the original level by four hours; after eight hours, responses were significantly different from, but almost as low as, solvent controls.

Single, responding males of Nippostrongylus brasiliensis exhibited a dose-dependent movement toward a pheromone source that was derived from incubation or homogenization of female helminths in Tyrode's solution. Increases in female homogenate beyond an optimum concentration resulted in reduced male movement toward the pheromone source. Crowding of male N. brasiliensis prior to their exposure to female pheromone gradients diminished the males' response. However, crowding of females had no effect on response to the pheromone. The locomotory responses of males exposed to various mixed male and female pheromone sources reaffirmed earlier suggestions of a pheromone feedback system in which males influence the pheromone released from females.

A high-efficiency collection device for sex pheromones volatized from forcibly extruded female glands is described. Filtered nitrogen gas is the carrier and glass wool the adsorbent. Small quantities of distilled carbon disulfide are used to rinse the glass wool. Recovery efficiency of synthetic compounds was usually 90-100%, and a mean of 2.4 ± 0.65 SD ng/min of (Z)-7-dodecenyl acetate was recovered in emissions from individualTrichoplusia ni (Hubner) glands.

Hexalure was continuously evaporated into the air of cotton fields throughout the growing season. The consequent disruption of premating pheromonal communication between males and females of the pink bollworm resulted in a reduction in larval boll infestations comparable to that provided by commercial insecticide applications.

The release rate of the pheromone component Z-7-dodecenyl acetate was determined for individual female Trichoplusia ni by using small glass tubes filled with Porapak Q to extract pheromone from air in the immediate vicinity of the everted gland. The change in release rate as a function of time was determined by taking sequential 5 min. samples from individual 4-day-old females through each pheromone release period over an entire night. The release rate was found to decline exponentially from a mean of 22 ng per min. initially to 12 ng per min. at the end of 20 min., the average length of a pheromone release period. Pheromone collections were also made from females of different ages, using a single tube of Porapak per female to collect pheromone for an entire night. The nightly mean release rate increased significantly with age, although the time spent releasing pheromone per night decreased significantly with age (to 6 days old).

The alarm pheromone of southern California populations of the ant Forelius foetidus (Buckley) was identified as 2-heptanone. This compound (2.9µg per worker) occurs in an admixture with cis, trans-iridodial and a minor unidentified iridodial isomer, which together constitute a defensive secretion emitted posteriorly from the gaster. Secretory components were isolated and quantified from extracts by gas chromatography and structurally elucidated by 1H and 13C nuclear magnetic resonance analyses. Videorecordings of agonistic encounters with foreign ants revealed a stereotypical defense behavior of F. foetidus workers culminating in aerial transfer of their secretion onto the heterospecific worker. The defensive spray was repellent but not toxic to either Solenopsis maniosa or Crematogaster califomica Chemical and behavioral comparisons between F. foetidus and F. (=Iridomyrmex) pminosus indicate a high degree of similarity between these sympatric ants and support the generic reclassification of the latter species.

Individual male cabbage looper moths, Trichoplusia ni , were tested in a sustained-flight tunnel to the sex pheromone, a 93:7 blend of (Z)-7-dodecenyl acetate and dodecyl acetate. Two experimental procedures were used to investigate the interaction of the two components in the upwind flight response of males. In the first test, chemical components were selectively removed from the moths' flight path at two distances from the source, corresponding to areas of the tunnel in which the blend was or was not active in increasing the number of upwind flights. In the second test, males were offered a choice between plumes, in their normal flight path, which contained different components. Results of both tests showed that males were unresponsive to dodecyl acetate alone at all phases of the flight response, responses to the blend were dependent on the two components being mixed in the same plume, and response to the blend altered the males subsequent flight response to Z7–12:Ac alone.

Field and greenhouse experiments were done to determine the extent of methyl parathion degradation to p -nitrophenol on and in leaves of cotton and head lettuce and the biological response of lettuce seedlings to these chemicals. The amount of p -nitrophenol on and in cotton leaves 5 d after a single application of methyl parathion reached a maximum of 2.12 ppm. The results were less conclusive on lettuce, presumably because of a single overhead irrigation early in the experiment and intermittent rainfall that occurred throughout the remainder of the experiment. In the same experiment, however, dry weights of whole lettuce plants treated three times with either methyl parathion or p -nitrophenol were reduced significantly 50.9 and 32.1%, respectively, compared with untreated controls. In contrast, the solvent with emulsifier that were used to formulate methyl parathion reduced dry weight

Ether extracts of the terminal abdominal segments of females of Trichoplusia ni (Hubner) (Lepidoptera: Noctuidae) were assayed for sex pheromone activity by gas-liquid chromatography and by bioassay. No pheromone was found in female pupae. Immediately following the moths' emergence from the pupa approximately 0.01 µg of sex pheromone per female moth was detected. The amount increased to approximately 0.2 µg on the first night following emergence, and stabilized at approximately 1 µg on the second through sixth nights. No correlation was found between the quantity of sex pheromone per female and the time of day at which they had been collected and extracted. The sex pheromone level remained high among females that had mated; this fact is consistent with observations that T. ni females characteristically mate more than once. The quantity of sex pheromone in mature females was positively correlated with their initial weights. No evidence was found indicating the presence of a sex pheromone or pheromone-potentiator in any area of the female body except the terminal abdominal segments. The T. ni sex pheromone volatilizes rapidly from filter paper, having a half-life retention time of approximately 8 minutes. The sex pheromone released by individual living T. ni females stimulated more males than did filter papers impregnated with extract equivalent to 1 female. However, no reduction has been detected in the amount of sex pheromone remaining in females that have been releasing the pheromone for up to 30 minutes.

A flight tunnel was designed in such a manner that males of Trichoplusia ni (Hubner), stimulated to orient toward the source of a current of air containing female sex pheromone, moved in a direction opposite from that of males stimulated to orient toward an incandescent light. When low-intensity light and pheromone odor were present in the tunnel at the same time, male orientation toward the pheromone source was completely abolished, and most of the males congregated adjacent to the light source.

Quantitative determinations of the response thresholds of male moths exposed to ether extracts of female abdomen tips provided evidence for the behaviorally similar nature of female sex pheromones between Trichoplusia ni (Hubner) and Autographa californica (Speyer) and between Heliothis sea (Boddie) and H. virescens (F.). Males of A. californica attempted to mate with females of T. ni , without successful coupling occurring. Certain males of H. zea that succeeded in coupling with females of H. virescens could neither transfer spermatophores nor separate from the females. No successful interspecific transfer of a spermatophore occurred among any of the species, indicating the existence of morphological or physiological reproductive isolating mechanisms other than the female sex pheromone.

Various environmental factors were evaluated for their influence on numbers of males of the cabbage looper, Trichoplusia ni (HA¼bner) (Lepidoptera: Noctuidae), captured in traps baited with living females or with T. ni synthetic sex pheromone, cis -7-dodecenyl acetate. More males were captured in traps at an elevation of 2 in above the soil surface in a broccoli planting than in those at higher (3- or 4-m) or lower (0-, 0.3-, or 1-m) elevations. Captures in traps placed on trunks of citrus or eucalyptus trees tended to remain steady or increase through an elevation of 4 m. Captures in traps situated up to 3200 m from the nearest planting of a cole crop were about as high as captures at the plantings. Seasonal highs and lows of numbers of males captured during 2 years occurred around September and January, respectively. However, a large variation in seasonal trends occurred during the 2 years. No correlations could be obtained relating daily variations in captures with daily (or nightly) variations in temperature and relative humidity. Periods of full moonlight did not influence numbers of males captured. The time of the median capture occurred around midnight in July and occurred progressively earlier through August and September to around 8 PM in October.

Synthetic sex pheromone of the cabbage looper, Trichoplusia ni (Hubner), was released at various constant rates from several trap designs. An open, horizontal, cylindrical trap (A), 11 em 10, was used as the standard for comparison. A circular trap (B) consisted of a 60cm-radius circular roof supported 4 em above a circular base. A double cone trap (C) consisted of an upright cylinder having a metal base and wire screen lid plus 2 screen cones through which attracted male moths flew. Males were ensnared in Stickem® in traps A and B and were captured alive in trap C. Optimal pheromone release rates varied among the traps, being about 0.3 μg per minute from trap A and about 1kg per minute from traps Band C. Rates about 3 times higher or lower than the optimum for each trap generally resulted in reduced captures. When evaluated at their optimal release rates, traps Band C captured 4 and 26 times, respectively, more males than trap A.

Three indicators of reproductive maturity—sperm storage, sex pheromone responsiveness, and mating—were examined for males of the following 8 species of the family Noctuidae: subfamily Plusiinae; Trichoplusia ni (Hubner), Autographa californica (Speyer), Pseudoplusia includens (Walker), and Rachiplusia ou (Guenee) ; subfamily Amphipyrinae; Prodenia ornithogalli Guenee and Spodoptera exigua (Hubner) ; subfamily Heliothinae; Heliothis zea (Boddie) and H. virescens (F.). On an average, for the 8 species, movement of sperm bundles from the testes into the ductus ejaculatorius duplex occurred about 1.3 days before the systems for pheromone responsiveness or mating had matured. The 2 last-mentioned systems matured about the same time. In 5 of the species, more than ⅔ of the males contained sperm in the ductus ejaculatorius duplex at the time of emergence from the pupa.

About half of the sexually mature virgin females of Trichoplusia ni Hubner observed in the laboratory released sex pheromone on any given night. Those releasing pheromone typically did so for about 40 minutes per night in 2 or more separate periods. A gas-liquid chromatographic and a bioassay method were developed, allowing measurement of pheromone emanating from single females. The mean pheromone release rate for females was about 7×l0−3 µg/minute. The minimum male threshold of response to pheromone, determined by laboratory bioassay, was found to be at about 8 molecules/mm3 of air. These data are used to estimate potential female to male communication distances in the field.

The rate of evaporation of lauryl acetate, the saturated analogue of the sex pheromone of Trichoplusia ni (Hubner), from various substrates as a function of temperature was determined. Filter paper showed the largest temperaturc dependence, whereas a nonadsorptive surface such as glass or stainless steel had a relatively low temperature dependence. Using a pheromone-baited trap, the number of male moths caught went through a maximum as a function of the rate of evaporation of pheromone.

The following 3 aspects of female sex pheromone production and release were quantitatively studied, using a laboratory colony of Trichoplusia ni (Hubner) : the amount of pheromone contained on and in the whole gland, the amount contained on the gland surface only, and the amount evaporated into the air from the gland surface after the gland was everted (exposed to the air). The whole-gland content and the evaporation rate were strongly influenced by female age and by unexplained population variation over several weeks and months. Time of day had no pronounced effect on wholegland content or evaporation rate. In an air stream moving 10 cm per second, mean evaporation rate was 7 nanograms per minute during the first 10 minutes following gland eversion. This evaporation rate rapidly depleted the amount of pheromone initially found on the gland surface (about 48 nanograms), and a considerably reduced rate occurred during the second 10 minutes of gland eversion. Evaporation took place more rapidly in an air stream moving 100, as opposed to 10, cm per second.

Males of the alfalfa looper, Autographa californica (Speyer); tohacco budworm, Heliothis virescens (F.) ; beet armyworm, Spodoptera exigua (Hubner); and cabbage looper, Trichoplusia ni (Hubner) exhibited a cyclic rhythm of responsiveness to the sex pheromones extracted from females of their respective species. When the males were synchronized to a 12:12-hour light :dark cycle, maximum pheromone-responsiveness occurred during the hours of darkness. The response rhythms were maintained for at least 36 hours under conditions of continuous darkness. In T. ni , a reversal in the 12:12-hour light:dark cycle was followed by a complete reentrainment of the male responsiveness rhythm to the new cycle within 24 hours. A 24-hour rhythm of responsiveness could be synchronized in T. ni males by light:dark cycles as abnormal as 20:4 or 4:20. However, the time of maximum responsiveness did not appear to be related in a constant manner to the time of initiation of light or darkness.

The nightly time of mating among adults of Trichoplusia ni (Hubner), the cabbage looper moth, appears to be regulated by an endogenous circadian rhythm of females pheromone release. The results of variable photoperiod experiments indicate that this rhythm may be reentrained at the initiation of the light period each day. The mean time of sex pheromone release is advanced at cool temperatures, occurring earlier in the dark period than it does at moderate or warm temperatures. Warm day :cool night conditions result in a time-of-pheromone-release curve which approximates a time-of-mating curve obtained from caged moths held under field conditions.

Experiments were conducted with Trichoplusia ni (Hubner), the cabbage looper, to evaluate the male inhibition technique for behavioral control. The technique is based on the permeation of the atmosphere with synthetic female sex pheromone. Assuming male adaptation to the omnipresent pheromone, and the fact that the additional increment of pheromone contributed by females in nature may be imperceptible to the males, the males would theoretically be incapable of orienting to and inseminating the females. The lower threshold for male behavioral responses to the cabbage looper female sex pheromone was established in the laboratory at about 2×10-14 g/liter of air (about 60 molecules/mm3). In the laboratory, male responsiveness to a high concentration of sex pheromone (2×10-9 g/liter) was completely inhibited when they had been conditioned for 25 minutes in air containing lower pheromone concentrations. A much higher concentration (5×10-5 g/liter) was required to prevent males from orienting to and mating with females in the confines of a 2 liter container. In the field, a concentration of roughly 1×10-10 g/liter was sufficient to completely prevent orientation of males to pheromone-emitting females. For large area cabbage looper mating control by sex pheromones, it was calculated that less than 0.5 g/hectare (0.2 g/acre) must be expended per night.

General extraction and purification steps for sex pheromones of noctuid moths are outlined as derived from the specific case of Trichoplusia ni (Hubner). These include an ether extraction, a falling-film distillation, preparative thin-layer chromatography, and preparative gas-liquid chromatography. Operating parameters are given for these procedures. Collecting only abdomen tips gave a 4-fold purification over extracting whole moths. In the case of T. ni the distillation was carried out at 100°C (0.5 mm) and 140° (0.1 mm) and resulted in a 10-fold purification. Thin-layer chromatography of the pheromones of T. ni , Autographa californica (Speyer), and Heliothis virescens (F.) all resulted in R t 's of 0.30 to 0.50 on silica gel, using benzene as the developing solvent. The retention time for the pheromone of T. ni was determined for 4 different gas-liquid chromatography columns. The time of biological activity was correlated with the electrical response of a hydrogen flame detector. Criteria for the purity of a gas chromatogram are given. A procedure for quantitative analysis for the pheromone of T. ni is given. This analysis made use of an internal standard. Apparatus and procedures are given for the collection of sub-milligram amounts from a gas chromatograph.

The gland that produces the female sex pheromone of Trichoplusia ni (Hubner) is an eversible sac of glandular epithelium situated dorsally in the intersegmental membrane between the eighth and ninth abdominal segments. Histological studies indicate that the pheronione is continuously secreted by females 1–7 days old. Dissection and chemical assay confirmed that the organ described produces the pheromone.

Hexalurc, cis -7-hexadecenyl acetate, a compound which is attractive to males of Pectinophora gossypiella (Saunders) but not believed to be the primary sex pheromone of P. gossypiella females, was continuously released into the air from arrays of uniformly spaced evaporators in cotton fields. When a sufficient quantity of hexalure was released, males were almost completely prevented from locating females releasing their pheromone from traps located in the centers of the arrays. Disruption of pheromone communication was most efficient when hexalure was evaporated at the plane formed by the top of the plant canopy. An attempt was made to influence mating in the resident pink bollworm population of a 7.3-hectare cotton field by permeating the atmosphere over the field with hexalure during a 4-week period. The occurrence of multiple mating by females in the treated field was reduced relative to that occurring in a control field; however, the percent of females that mated at least once was not reduced.