Gymnandrosoma aurantianum (Lepidoptera: Tortricidae): Calling Rhythm and Effect of Age on Female Sex Pheromone Titer and Male Antennal Responses.

The macadamia nut borer, Gymnandrosoma aurantianum Lima (Lepidoptera: Tortricidae), is the main pest of Macadamia integrifolia Maiden & Betche (Proteales: Proteaceae) in Central America. Despite its importance, there is little information on its reproductive behavior. We studied the calling behavior and effect of age on female sex pheromone production and male antennal response to the pheromone. Calling behavior of G. aurantianum females occurred at the onset of scotophase, between 17:00 and 20:00 h. The mean time spent calling was 64 min. It was observed that 30% of the 50 females exhibited a calling posture characterized by extrusion of the pheromone gland from the tip of the abdomen and they spread their wings slightly. Female age had no influence on the sex pheromone production, while male antennal response increased with age and pheromone dosage. The information obtained in this work contributes to understanding the sexual behavior of G. aurantianum and thus to the creation of strategies to control this important pest in macadamia.

Attraction of the two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), to healthy and damaged strawberry plants mediated by volatile cues.

Tetranychus urticae Koch (Acari: Tetranychidae), the two-spotted spider mite, is a pest that limits strawberry production in Mexico. Little is known about the interactions that occur between T. urticae and healthy strawberry plants or strawberry plants infested by conspecific spider mites. Therefore, in this study we evaluated the attraction of T. urticae to healthy strawberry plants mediated by volatile organic compounds (VOCs), and to plants damaged by conspecifics mediated by herbivore-induce plant volatiles (HIPVs). First, we conducted dual-choice tests using a Y-tube olfactometer with plants and extracts obtained through dynamic aeration. The volatile composition of the extracts was identified using gas chromatography-mass spectrometry (GC-MS). Once the compounds were identified, we also conducted dual-choice tests with selected synthetic compounds. Tetranychus urticae exhibited greater attraction to both healthy and damaged plants compared to the control (clean air). However, when healthy and damaged plants were offered simultaneously, there was no significant preference observed. Bioassays with extracts obtained by dynamic aeration yielded similar results. The identified compounds were terpenes and aromatic hydrocarbons. We found qualitative and quantitative changes between the VOCs emitted by the healthy plant and the HIPVs from mite-damaged plants. The individual compounds α-pinene (10 ng), pseudocumene (10 ng), and limonene (1 ng) and 10 ng of the blend made of α-pinene + pseudocumene + mesitylene + limonene (5:34:57:4) attracted more T. urticae than the control. However, the binary blend of pseudocumene + limonene (91:9) was more attractive than the other binary or three-compound blends evaluated. These results may contribute to developing strategies for the management of this pest.

Dog hair volatiles attract Rhipicephalus sanguineus sensu lato (Acari: Ixodidae) females.

Rhipicephalus sanguineus sensu lato (s.l.) (Latreille) feeds on domestic dogs worldwide. This tick species uses dog volatiles during host-seeking behavior. In this study, we identified volatile compounds from dog hairs involved in the host location of R. sanguineus s.l. The R. sanguineus s.l. females, but not males, were attracted to hair samples and Super Q extracts from Schnauzer dogs in Y-tube olfactometer bioassays. A total of 54 compounds from dog hair extracts were identified by gas chromatography coupled to mass spectrometry, including hydrocarbons, aldehydes, alcohols, ketones, and carboxylic acids. Screening the identified compounds by the single sensillum recording technique showed that isovaleric acid, hexanal, heptanal, and sucaltone (6-methyl-5-hepten-2-one) significantly stimulated the olfactory receptor neurons of the basiconic, chaeticum, and trichodeum sensilla of female ticks. When synthetic compounds were evaluated alone, or in binary, tertiary, or quaternary mixtures, female ticks were only attracted to isovaleric acid and 1 tertiary mixture (hexanal, heptanal, and isovaleric acid). We conclude that isovaleric acid functions as an attractant for R. sanguineus s.l. These findings contribute to the understanding of the chemical ecology of ticks during host location.

Olfactory Responses of Anastrepha obliqua (Diptera: Tephritidae) to Mango Fruits as Influenced by Cultivar and Ripeness Stages.

Anastrepha obliqua Macquart (Diptera: Tephritidae) is a polyphagous species with hog plums (Spondias spp.) (Sapindales: Anacardiaceae) and mangoes (Mangifera indica L.) (Sapindales: Anacardiaceae) as primary host fruits. In this study, the olfactory preference of A. obliqua for three stages of ripeness of two mango cultivars ('Coche' and 'Ataulfo') was investigated. The female flies were more attracted to ripe 'Coche' fruits compared to those ripe 'Ataulfo'. Further, they were more attracted to the 'Coche' half-ripe and ripe fruits than to the unripe ones, but they did not discriminate among the stages of ripeness of 'Ataulfo' fruits. The male flies did not show preference for any specific mango cultivars or ripeness stage tested. Four compounds from ripe 'Coche' mangoes, and two from ripe 'Ataulfo' fruits were identified using coupled gas chromatography-electroantennographic (GC-EAD) recording and gas chromatography-mass spectrometry (GC-MS) analysis. 'Coche' mango volatiles eliciting responses from the female antennae were ethyl butyrate, ethyl hexanoate, ethyl heptanoate, and ethyl octanoate. The two 'Ataulfo' mango volatiles were identified as 3-carene and ethyl octanoate. These compounds were absent in unripe mangoes of both cultivars. Synthetic blends of these compounds were attractive to females as mango extracts in field cage tests. Our results suggest that the olfactory preference of A. obliqua for attractive hosts is based on the presence or absence of the compounds associated with fruit maturity.

Volatiles as Attractants of Mahogany Shoot Borer, Hypsipyla grandella Zeller (Lepidoptera: Pyralidae).

The mahogany shoot borer, Hypsipyla grandella Zeller (Lepidoptera: Pyralidae), is one of the most economically important pests in all American tropical forests because it prevents the establishment of monoculture plantations of the family Meliaceae, such as Spanish cedar, Cedrela odorata L. Various studies have focussed on the bioecological aspects and the chemical and silvicultural control of this pest. However, relatively little is known about the biological interactions between this insect and its host plant. In this study, the shoot borer's behavior and attraction response to cedar host plants was evaluated in field cages. We also identified the volatiles emitted by healthy C. odorata plants that were attractive to H. grandella adults. The attraction to headspace volatiles from cedar plants and a synthetic blend were evaluated in a Y-glass tube olfactometer. We observed that virgin and mated females exhibited low activity at night, frequent movement of the antennae, sporadic flight activity, and short (< 10 s) and long (> 30 s) wing-fanning. Virgin females assumed a calling position, whereas mated females exhibited three periods of oviposition. The results showed that all evaluated categories - virgin females, virgin males, and mated females - were attracted to cedar plants. We identified the following volatile compounds: α-pinene, (E)-ß-ocimene, 2-ethyl-1-hexanol, limonene, nonanal, (E)-4,8-dimethyl-1,3,7-nonatriene, α-copaene, ß-caryophyllene, and germacrene D. A synthetic blend significantly attracted virgin male and mated female shoot borers. Our results suggested that C. odorata volatiles compounds are responsible for the attraction of H. grandella.

Effect of Aging on Three Lures Used for Monitoring Ceratitis capitata (Diptera: Tephritidae): Release Rate, Volatile Composition, and Fly Recaptures.

Prevention and control programs for Ceratitis capitata require a large supply of lures and traps for use in established trapping networks and mass-trapping suppression measures. The main lures currently used are: Trimedure (TML), three-component Biolure (BL), and Ceratrap (CT). The aim of this study was to determine the release rates of these lures, the chemical composition of their volatiles, and how these parameters change with exposure time. Tests were conducted under field conditions at three different elevations (25, 500, and 1,300 masl) during the dry and rainy seasons in Chiapas, Mexico. We found that for TML and BL, the release rate was similar in both seasons and at all three elevations. In the case of CT, the release rate was greater during the dry season and at the lowest elevation during the rainy season. With the caveat of using solid-phase microextraction technique for identification of lure compounds in this study, we found that the volatile compounds of TML were maintained throughout the rainy season, however, in the dry season, some compounds could not be detected. The volatile compounds emitted by BL were trimethylamine, ammonium acetate, and acetamide. Among volatile compounds of CT, acetic acid was the most abundant in the rainy season, while minor compounds were only detected during the first five weeks. Recapture rates were affected by elevation in the three lures tested and there was a significant interaction between elevation in exposure time for TML and BL.

Attractiveness and Sexual Competitiveness of Anastrepha obliqua Males (Diptera: Tephritidae) Fed on a Diet Enriched With Providencia rettgeri.

The West Indian fruit fly, Anastrepha obliqua (Macquart), is the second most important tephritid fruit fly in Mexico, infesting mango, hog plum and guava fruits. To control this pest, the Mexican government has implemented the use of the sterile insect technique (SIT), which involves the mass production, sterilization and release of flies. However, the A. obliqua laboratory males used in SIT are selected to a lesser extent by the wild females during competitiveness tests. The objective of this study was to compare the effects of males fed on fruit fly food enriched with Providencia rettgeri to those in males fed on food alone, assessing male mating competitiveness, capture of females using traps baited with males fed with the enriched diet and sex pheromone components. The results indicated that males fed with the diet enriched with P. rettgeri had increased mating competitiveness and captured more females in the field cage tests. However, no difference was observed in the proportion of volatile sex pheromone components identified during the calling of A. obliqua males. The results suggest the value of incorporating bacteria into the mass rearing technique of A. obliqua adults in order to improve the sexual competitiveness of males from the laboratory compared to wild males.

The Succession of Flies of Forensic Importance Is Influenced by Volatiles Organic Compounds Emitted During the First Hours of Decomposition of Chicken Remains.

After death, a series of primary reactions occur that produce volatile organic compounds (VOCs) that are released into the environment. In this study, we investigated if the succession of flies of forensic importance in the first hours after death is mediated by VOCs in order to better understanding of the ecology of necrophagous insects. In total, 685 adult insects (Diptera and Hymenoptera) were collected by traps baited with chicken remains at different decomposition times (0, 6, 12, 24, 36, or 48 h). Of the total of insects caught, individuals from six families of Diptera can be cataloged of forensic importance. The most abundant dipteran family was Piophilidae with 213 individuals, followed by Calliphoridae with 178 specimens. Of the total flies caught, 90% were females and the rest were males. Most of the caught females were categorized as gravid, which visited more often the decaying tissues compared to nongravid females. The abundance of the flies increased in the remains with a longer time of decomposition. Six VOCs emitted in different relative quantities were identified according to the decomposition time of the remains. An apparent association was observed between the emission of ρ-cresol with Lucilia eximia (Wiedemann), between the emission of phenol, dimethyl disulfide, and dimethyl trisulfide with Chrysomya rufifacies (Macquart), and between the emissions of indole with Cochliomyia macellaria (Fabricius).

The Aggregation Pheromone of Metamasius spinolae (Coleoptera: Dryophthoridae) Revisited: Less is More.

The weevil Metamasius spinolae (Gyllenhal) is the most important insect pest of cultivated prickly pear in Mexico. A previous work reported that the pheromone of this weevil species was composed by three components. In this study, we reinvestigated the aggregation pheromone of M. spinolae using gas chromatography-electroantennography and gas chromatography-mass spectrometry to locate and identify new potential pheromonal compounds. The behavioral activity of identified compounds was evaluated in laboratory and field trials. Metamasius spinolae males released four compounds: 2-methyl-4-heptanone, 6-methyl-2-hepten-4-one, 2-methyl-4-octanone, and 2-hydroxy-2-methyl-4-heptanone. In the laboratory assays, depending on the concentration, the compounds were attractive, neutral, or repellent to M. spinolae. Field evaluation showed that traps baited with 2-hydroxy-2-methyl-4-heptanone singly or in most of the binary or tertiary blends where this compound was present captured a higher number of M. spinolae compared to live males and the other compounds identified. In conclusion, our results indicate that 2-hydroxy-2-methyl-4-heptanone is the main component of the aggregation pheromone of M. spinolae. We suggest that this compound should be used for developing a monitoring or a mass-trapping system for M. spinolae.

Rat volatiles as an attractant source for the Asian tiger mosquito, Aedes albopictus.

Aedes albopictus is a vector of dengue, chikungunya, and dirofilariasis. Volatile compounds are crucial for mosquitoes to locate their hosts. This knowledge has allowed the identification of attractants derived from human odours for highly anthropophilic mosquito species. In this study, we used rats as a experimental model to identify potential attractants for host-seeking Ae. albopictus females. Porapak Q extracts from immature female rats were more attractive to Ae. albopictus females than those from mature and pregnant females, and males. Phenol, 4-methylphenol, 4-ethylphenol, and indole were identified compounds in male, immature, mature, and pregnant female extracts. There were quantitative differences in these compounds among the extracts that likely explain the discrepancy in their attractiveness. Ae. albopictus females were not attracted to the single compounds when was compared with the four-component blend. However, the binary blend of 4-methylphenol + 4-ethylphenol and the tertiary blend of 4-methylphenol + 4-ethylphenol + indole were as attractive as the four-component blend. In the field trials, BGS traps baited with the tertiary or quaternary blends caught more Ae. albopictus females and males than BGS traps without lures. This is the first laboratory and field study to identify compounds that mediate the attraction of Ae. albopictus to one of its hosts.

The Colonization of Necrophagous Larvae Accelerates the Decomposition of Chicken Carcass and the Emission of Volatile Attractants for Blowflies (Diptera: Calliphoridae).

The decomposition of a living being involves a series of changes produced by a number of interacting abiotic and biotic factors. In this study, we analyzed the effect of the colonization of blowflies on the decomposition of chicken carcasses and on the emission of sulfur compounds. The loss of the mass of carcasses and the release rate of sulfur compounds were compared for 30 d in chicken carcasses with and without blowflies in field conditions. The tissue degradation was slower in the carcasses without insects compared to those colonized by blowflies. The decomposition stages of fresh, bloated, active decay, and advanced decay were observed in the carcasses without flies; while the decomposition stages of fresh, active decay, advanced decay, and dry remains were identified in carcasses with flies. Two sulfur compounds, dimethyl disulfide and dimethyl trisulfide, were present during the entire decomposition process. The emission of these compounds is not directly associated with the presence of the blowflies' immature stages during the whole decomposition process. However, in cadavers with insects, the highest emission of both compounds occurred in day 2, while in cadavers without insects, the peak of emission was observed in day 4. In addition, the presence of the larval stages I and II of Lucilia eximia (Wiedemann, 1819) (Diptera: Calliphoridae), Chrysomya rufifacies (Macquart, 1842) (Diptera: Calliphoridae), Chrysomya megacephala (Fabricius, 1794) (Diptera: Calliphoridae), and Cochliomyia macellaria Fabricius, 1775 (Diptera: Calliphoridae) matched with the peak of emission of both compounds.

Herbivore-Induced Volatiles from Maize Plants Attract Chelonus insularis, an Egg-Larval Parasitoid of the Fall Armyworm.

Chelonus insularis (Hymenoptera: Braconidae) is an egg-larval endoparasitoid that attacks several lepidopteran species, including the fall armyworm (FAW), Spodoptera frugiperda, as one of its main hosts. In this study, we identified the volatiles emitted by maize plants undamaged and damaged by S. frugiperda larvae that were attractive to virgin C. insularis females. In a Y-glass tube olfactometer, parasitoid females were more attracted to activated charcoal extracts than Porapak Q maize extracts. Chemical analysis of activated charcoal extracts from maize plants damaged by S. frugiperda larvae by gas chromatography coupled with electroantennography (GC-EAD) showed that the antennae of virgin female wasps consistently responded to three compounds, identified by gas chromatography-mass spectrometry (GC-MS) as α-pinene, α-longipinene and α-copaene. These compounds are constitutively released by maize plants but induction via herbivory affects their emissions. α-Longipinene and α-copaene were more abundant in damaged maize plants than in healthy ones, whereas α-pinene was produced in higher amounts in healthy maize plants than in damaged ones. Female parasitoids were not attracted to EAD-active compounds when evaluated singly; however, they were attracted to the binary blend α-pinene + α-copaene, which was the most attractive blend, even more attractive than the tertiary blend (α-pinene + α-longipinene + α-copaene) and the damaged maize plant extracts. We conclude that C. insularis is attracted to a blend of herbivore-induced volatiles emitted by maize plants.

Photo-assisted electrochemical degradation of polychlorinated biphenyls with boron-doped diamond electrodes.

The capacity of the photo electro-Fenton (PEF) process to degrade a mixture of seven polychlorinated biphenyl (PCB) congeners was studied. Boron-doped diamond (BDD) sheets were used as anode and cathode in the experimental electrolytic cell that contained Na2SO4 0.05 M at pH 3 as supporting electrolyte for the electro generation of H2O2 at the cathode. The effects of UV light intensity (254 and 365 nm), current density (8, 16 and 24 mA cm-2) and ferrous ion dosage (0.1, 0.2 and 0.3 mM) on PCB (C0 = 50 µg L-1) degradation were evaluated. The highest level of PCB degradation (97%) was achieved with 16 mA cm-2 of current density, 0.1 mM of ferrous ion and UV light at 365 nm as irradiation source after 6 h of reaction. PCB28, PCB52 and PCB101 were not detected after 0.5, 1.5 and 3 h of reaction, respectively. The degradation of PCB138, PCB153, PCB180 and PCB209 was also high (>95%). The PEF system outperformed other oxidation processes (electro-Fenton, anodic oxidation, Fenton, photo-Fenton and UV photolysis) in terms of reaction rate and degradation efficiency. These results demonstrate for the first time the degradation of PCB209, the most highly chlorinated PCB congener, by an advanced electrochemical oxidation process.

A Home-Made Trap Baited With Sex Pheromone for Monitoring Spodoptera frugiperda Males (Lepidoptera: Noctuidae) in Corn crops in Mexico.

Fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), populations are monitored with a variety of commercial sex pheromone-baited traps. However, a number of trap-related variables may affect the number of FAW males captured. In this study, we tested the effect of trap design, trap size, and trap color for monitoring FAW males in corn crops in Mexico. We found that plastic jug trap (a home-made trap), captured significantly more FAW males than a commercial trap (Scentry Heliothis) and water bottle trap (another home-made trap). We also found that size of plastic jug traps (3.78, 10, or 20 liters) did not affect the captures of FAW males. Our results indicated that plastic yellow jug traps captured significantly more males than blue and black traps. Plastic jug white, red, and green traps captured a similar number of FAW males than plastic jug yellow, blue, and black traps. Plastic jug blue, white, and yellow traps captured more nontarget insects compared to black traps. The number of nontarget insects captured by green and red traps was similar and not significantly different to that caught by blue, white, yellow, and black traps. Traps captured more individuals from Diptera than Coleoptera and Hymenoptera. Overall, the results suggest that yellow plastic jug may be used for monitoring FAW males in corn and sorghum crops in Mexico.

Effect of Temperature on the Release Rate of Trimedlure Under Laboratory and Field Cage Conditions.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann), is an exotic pest of economic importance in several parts of the world. Systems for monitoring this pest employ mainly trimedlure (TML), a parapheromone specifically for males. Understanding the performance of these attractants under different conditions should contribute to better design trapping networks, better field data interpretation, and a more efficient use of the products. In this study, the release rate of TML was determined at 15, 25, and 35 °C, through plug weight loss over 80 d in a bioclimatic chamber. The attraction of TML of different ages was determined in field cage tests located in a mango orchard. Our results showed a direct relationship between TML release rate and temperature. Attraction was dependent on release rate. We found that TML storage for >4 yr at 27 °C affected the quantity of the active ingredient available for release. The results are discussed in terms of the effects of these conditions on the efficiency of trapping networks used for the detection of this pest and quality assurance for detection programs.

Calling Behavior, Copulation Time, and Reproductive Compatibility of Corn-Strain Fall Armyworm (Lepidoptera: Noctuidae) From Populations in Mexico.

The calling behavior, mating time, and the reproductive compatibility of virgin adults of fall armyworms, Spodoptera frugiperda (J. E. Smith), were studied in this work. Larvae were collected on maize (Zea mays L.) from six states located on the Pacific coast (Chiapas, Michoacán, and Sinaloa), on the Gulf of Mexico (Veracruz and Yucatan), and in central Mexico (Morelos). Before the experiments, insects were reared under laboratory conditions for one generation. We recorded the age at which females called for the first time, the onset time of calling, the duration of calling, the onset time of copulation, and the duration of copulation. The calling rhythms of the six populations were dissimilar. Females from all populations began to call in the second or third scotophase. The time for onset of calling and the duration of calling were significantly different among the S. frugiperda populations studied. Spodoptera frugiperda pairs from Sinaloa, Veracruz, Yucatan, and Morelos started to copulate earlier than the pairs from Chiapas and Michoacán. Pairs from Veracruz and Yucatan copulated longer than those from Michoacán, Morelos, Chiapas, and Sinaloa. Our crossing experiment using females and males from the six populations showed that individuals from different populations could copulate and produce fertile offspring. Thus, although the S. frugiperda populations showed variability in the timing of reproduction, the populations were not reproductively incompatible, which indicated that geographic distance has not led to reproductive isolation in corn-strain populations of S. frugiperda in Mexico.

The Stingless Bee Melipona solani Deposits a Signature Mixture and Methyl Oleate to Mark Valuable Food Sources.

Stingless bees foraging for food improve recruitment by depositing chemical cues on valuable food sites or pheromone marks on vegetation. Using gas chromatography/mass spectrometry and bioassays, we showed that Melipona solani foragers leave a mixture composed mostly of long chain hydrocarbons from their abdominal cuticle plus methyl oleate from the labial gland as a scent mark on rich food sites. The composition of hydrocarbons was highly variable among individuals and varied in proportions, depending on the body part. A wide ratio of compounds present in different body parts of the bees elicited electroantennogram responses from foragers and these responses were dose dependent. Generally, in bioassays, these bees prefer to visit previously visited feeders and feeders marked with extracts from any body part of conspecifics. The mean number of visits to a feeder was enhanced when synthetic methyl oleate was added. We propose that this could be a case of multi-source odor marking, in which hydrocarbons, found in large abundance, act as a signature mixture with attraction enhanced through deposition of methyl oleate, which may indicate a rich food source.

Mass trapping is as effective as ground bait sprays for the control of Anastrepha (Diptera: Tephritidae) fruit flies in mango orchards.

BACKGROUND: Anastrepha fruit flies are considered one of the main phytosanitary problems for the fresh fruit industry in the USA, Caribbean islands and Latin America. Since 1994, the Mexican government has implemented the National Fruit Fly Program using an area-wide integrated pest management approach. In this paper, we evaluate the effectiveness of mass trapping and compare it with ground GF-120 spraying against Anastrepha obliqua and Anastrepha ludens populations in mango cv. Ataulfo orchards. RESULTS: Multilure® traps baited with Ceratrap® or Biolure® captured significantly more fruit flies than Captor 300 in field cage tests. Mass trapping and ground GF-120 spray significantly suppressed fruit fly populations compared with untreated plots. In Multilure traps placed in untreated plots, we captured significantly more fruit flies than in treated plots with mass trapping or GF-120 sprays. Plots treated with either mass trapping or GF-120 sprays reduced the percentage of infested fruit significantly compared with untreated plots. There was no difference between mass trapping and GF-120 ground bait spraying. CONCLUSION: Our results demonstrate that mass trapping was as effective as GF-120 ground spraying for the control of fruit flies in mango cv. Ataulfo orchards. The suppression effect of mass trapping was similar to GF-120 ground bait spraying. © 2017 Society of Chemical Industry.

Herbivore Damage and Prior Egg Deposition on Host Plants Influence the Oviposition of the Generalist Moth Trichoplusia ni (Lepidoptera: Noctuidae).

Female insects have the difficult task of locating host plants that maximize the survival and success of their offspring. In this study, the oviposition preferences of the cabbage looper moth, Trichoplusia ni (Hübner), for soybean plants, Glycine max (L.), under various treatments-undamaged, mechanically damaged, damaged by T. ni or Spodoptera frugiperda (Smith) larvae or by Bemisia tabaci (Gennadius) adults, egg-free plants, and plants previously oviposited by conspecific or heterospecific females (S. frugiperda)-were investigated using two-choice tests. Additionally, the volatile compounds emitted by the plants under the different treatments were identified by gas chromatography-mass spectrometry. Our results showed that females showed no preferences for undamaged or mechanically damaged plants. However, they oviposited more often on undamaged plants than on those previously damaged by T. ni, S. frugiperda, or B. tabaci. In contrast, females preferred to oviposit on plants previously oviposited by conspecific and heterospecific females than on egg-free plants. Plants damaged by conspecific or heterospecific larvae emitted methyl salicylate, indole, and octyl butyrate, compounds not released by undamaged or mechanically damaged plants. Whitefly damage induced the release of higher quantities of Z(3)-hexenyl acetate, (R)-(+)-limonene, and (E)-ß-ocimene compared to plants damaged by larvae and suppressed the emission of linalool. Egg deposition by conspecific and heterospecific moths induced the emission of (R)-(+)-limonene, octyl butyrate, and geranyl acetone but suppressed the release of linalool. This study showed that a generalist moth species can discriminate between plants of different quality, and suggests that females use volatile compounds as cues during this process.

Presence of Putative Male-Produced Sex Pheromone in Lutzomyia cruciata (Diptera: Psychodidae), Vector of Leishmania mexicana.

Lutzomyia cruciata (Coquillet) is a vector of cutaneous leishmaniasis in Mexico and Central America. However, several aspects of its ecology and behavior are unknown, including whether a male pheromone partially mediates the sexual behavior of this sand fly. In this study, we evaluated the behavioral response of females to male abdominal extracts in a Y-tube olfactometer. The volatile compounds from male abdominal extracts were identified by gas chromatography-mass spectrometry and compared with those of female abdominal extracts. Finally, the disseminating structures of the putative sex pheromone were examined by scanning electron microscopy in the male abdomen. Females were more attracted to male abdominal extract than to the hexane control, suggesting the presence of male-produced sex pheromone. The male abdominal extracts were characterized by the presence of 12 sesquiterpene compounds. The major component, an unknown sesquiterpene with an abundance of 60%, had a mass spectrum with molecular ion of m/z 262. In contrast, the abdominal female extracts contained saturated fatty acids. Finally, we detected the presence of small "papules" with a mammiform morphology distributed on the abdominal surface of tergites IV-VII of male Lu. cruciata These structures are not present in females. We conclude that Lu. cruciata males likely produce a pheromone involved in attracting or courting females.