Field evaluation of chemical attractants against the flyFannia femoralis (Diptera: Muscidae)

Four chemical compounds previously shown to be attractants toHippelates eye gnats and houseflies were evaluated againstFannia femoralis (Stein). Two of the compounds, trimethylamine hydrochloride andn-butyric acid, were determined to be the principal attractants against this fly. A composition containing trimethylamine hydrochloride (yielding trimethylamine in presence of water),n-butyric acid, and an anchovy meal inert carrier proved highly attractive. To evaluate the practical use of the synthetic fly attractant (SFA) formulation, a large-scale trial over an entire poultry ranch was implemented using SFA formulation and a sugar toxicant (as a killing agent) in specially designed traps. Within 2 weeks after initiation of SFA-toxicant treatments, significant reduction inF. femoralis population from the pretreatment level occurred. This high level of reduction prevailed during the remainder of the treatment period.     

Synergism between chemical attractants and visual cues influencing oviposition of the mosquito,Culex quinquefasciatus (Diptera: Culicidae)

Physical factors, such as the color of the oviposition substrate, have seldom been compared with chemical cues in their ability to elicit oviposition behavior in mosquitoes. The role of dyed oviposition waters in attracting ovipositingCulex quinquefasciatus was examined in laboratory experiments. Oviposition waters dyed with ink were found to be significantly attractive to ovipositingCx. quinquefasciatus when compared to distilled water controls. Experiments demonstrated that the mosquitoes were responding to the increased optical density of the dyed oviposition water rather than volatile components of the dye. Ink was also considered in combination with chemical oviposition cues. No comparative data exist on the effect of physical and chemical factors presented together on the oviposition behavior ofCx. quinquefasciatus. Waters dyed with ink acted synergistically with a five-component chemical attractant mixture (3-methylindole, indole, 4-methylphenol, 4-ethylphenol, and phenol) in inducing oviposition in a 2×2 factorial experiment.     

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.     

Search for potent attractants of onion flies

Of various chopped vegetables tested,Allium spp. high in propyl-containing alkyl sulfides (e.g.,cepa group) caught the most onion flies in trapping tests in the field. Fly catches to chopped onion increased with bait quantity. Attractancy of chopped onion changed dramatically during aging in the field; catch increased over the first few days, peaked at ca. fivefold over fresh material by 3–5 days, and then declined sharply. This age-dependent increase in attraction was not seen for garlic (known to have antimicrobial properties) nor with chopped onion mixed with chopped garlic. These data suggested that attraction of onion flies to onions was strongly influenced by microbial activity associated with decomposing onions. The bacteriumKlebsiella pneumoniae was identified as a major colonizer of onions maximally attractive to onion flies. This increased attraction is not due to the previously reported microbially produced volatiles ethyl acetate and tetramethyl pyrazine.Diptera: Anthomyiidae.Paper No. 11047 of the Michigan State University Agricultural Experiment Station.     

Mating stimulant pheromone and cuticular lipid constituents ofFannia pusio (Wiedemann) (Diptera: Muscidae)

Chromatograms of the cuticular lipids washed from newly emerged male and femaleFannia pusio were nearly identical. By the time the flies were 1 day old, the chromatographic profiles for the sexes were different. Mature females contained more C₃₁- and C₃₃-hydrocarbons than the males. The double bonds of the female monoolefins were mostly at the eleventh and thirteenth carbons, but those of the males were predominantly at the ninth carbon. Most active in stimulating copulation by males were the unbranched monoolefins with 31 and 33 carbons from the females. When they were synthesized and tested, the most active compound was (Z)-11-hentriacontene.A portion of a dissertation intended for submission by the first author to the Graduate School of the University of Maryland in partial fulfillment of the requirements for the Ph.D. degree.Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the U.S. Department of Agriculture or the University of Maryland.     

Mating stimulant pheromone and cuticular lipid constituents ofFannia femoralis (Stein) (Diptera: Muscidae)

The cuticular lipids of male and femaleFannia femoralis were similar for recently emerged insects but soon began to develop chromatographic patterns characteristic of each sex. Mature females contained more C₃₁ and C₃₃ monoolefin in the cuticular lipid than males. Also, the double bonds in the monoolefins of the female lipid were situated predominantly at the eleventh and thirteenth carbons, while most of those from the males were centrally located in the molecule or at the ninth carbon.The female C₃₁ monoolefin stimulated copulation by the males, but more mating activity occurred when the saturated hydrocarbons present in the female cuticular lipids were added. The synthetic monoolefin most active as a mating stimulant pheromone was (Z)-11-hentriacontene, but the addition of female alkanes or of syntheticn-alkanes to (Z)-11-hentriacontene increased the activity of the synthetic pheromone.A portion of a dissertation intended for submission by the first author to the Graduate School of the University of Maryland in partial fulfillment of the requirements for the Ph.D. degree.Mention of a proprietary or commercial product in this paper does not constitute an endorsement of this product by the U.S. Department of Agriculture or the University of Maryland.     

Yeast and corn hydrolysates and other nutritious materials as attractants for onion and seed flies

The attractancy of enzymatic yeast hydrolysate, a corn hydrolysate, brewers' yeast, honey, ammonia,n-dipropyl disulfide, and several combinations of these treatments was tested in an onion field containing onion flies,Hylemya antiqua (Meigen) and seedcorn flies,H. platura (Meigen). Enzymatic yeast hydrolysate (concentrated powder) proved to be highly attractive to both fly species; females were more responsive than males. Brewers' yeast and corn hydrolysate were intermediately attractive, while all other treatments were only slightly or not at all attractive. Although no steps were taken to prolong release of volatiles, some of the nutritious materials remained highly attractive even after 11 days. The yeast products may, at certain times, be even more attractive than specific host volatiles. However, their activity was not constant over time and may be influenced by the stage of reproductive development of female flies.Diptera: AnthomyiidaePaper No. 9511 of the Michigan State University Agricultural Experiment Station.     

Field evaluation of synthetic compounds mediating oviposition inCulex mosquitoes (Diptera: Culicidae)

3-Methylindole (skatole), a compound shown to be an oviposition attractant/stimulant forCulex quinquefasciatus in laboratory tests, was evaluated against natural populations of mosquitoes in the field. In experiments using paired black plastic tubs that contained water treated with an attractant solution containing a mixture of 3-methylindole, 4-methylphenol, 4-ethylphenol, phenol, and indole or that contained only tap water, the attractantbaited traps received significantly moreCx. quinquefasciatus egg rafts than did the untreated tap water. Gravid female traps that were baited with attractant solution collected significantly moreCx. quinquefasciatus females than did traps containing only tap water. There was no significant difference in number ofCx. quinquefasciatus collected in the traps baited with the attractant solution compared to the traps that contained water with 3-methylindole alone, indicating that 3-methylindole was solely responsible for the attraction. In replicated experiments conducted in experimental ponds, ponds that were treated with 3-methylindole received significantly moreCx. quinquefasciatus, Cx. tarsalis, andCx. stigmatosoma egg rafts than did untreated ponds. Experimental ponds treated with 3-methylindole at two levels (0.12 and 0.6 mg/liter) were equally attractive to ovipositingCx. quinquefasciatus. This is the first record of 3-methylindole showing attractancy/stimulation to ovipositingCx. stigmatosoma andCx. tarsalis under field or laboratory conditions.     

Evaluation of organic infusions and synthetic compounds mediating oviposition inAedes albopictus andAedes aegypti (Diptera: Culicidae)

Oviposition responses of gravidAedes albopictus andAe. aegypti were evaluated to natural organic infusions (hay infusion, larval rearing water, and field-collected larval water) as well as compounds isolated from hay infusion (3-methylindole, 4-methylphenol, 4-ethylphenol, indole, and phenol) known to elicit oviposition inCulex mosquitoes. In laboratory bioassays, significant oviposition responses were obtained fromAe. albopictus, but not fromAe. aegypti, to dilutions of hay infusion and field water. Oviposition responses of both species were moderate to the synthetic compounds tested in the laboratory (0.01–100 µg/liter). Only 3-methylindole (0.1 µg/liter) and 4-ethylphenol (1.0 µg/liter) elicited significantly more oviposition byAe. albopictus than did well water. Of the synthetic compounds tested withAe. aegypti, only phenol (1.0 µg/liter) and 4-ethylphenol (0.1 µg/liter) elicited significantly more oviposition than did well water. Significant repellency or oviposition deterrence for both species occurred in response to at least one high concentration of most of the compounds tested. In field cage evaluations, oviposition responses byAe. albopictus were strongest to larval water and field water, moderate to hay infusion and 3-methylindole (100 µg/liter), and low to well water. A mixture of five synthetic compounds mimicking hay infusion was no more effective than 3-methylindole alone. ForAe. aegypti, oviposition responses were greatest to larval water and least to 3-methylindole. In an olfactometer, gravid females of both species oriented more to field water than to well water and onlyAe. albopictus oriented more to larval water or hay infusion than well water. In general, gravidAe. albopictus responded more strongly to oviposition stimuli than didAe. aegypti.     

On insect attractants from pitcher plants of the genusHeliamphora (sarraceniaceae)

Examination ofHeliamphora heterodoxa andH. tatei from the Guayana Highlands of Venezuela reveals that the enol diacetal monoterpene, sarracenin, is the major volatile compound present in the spoon-shaped structures of leaves of the pitchers. In addition, erucamide, phenol, cinerone, phenylacetaldehyde, and a series of methyl esters also occur in extracts of the spoon-shaped appendages of pitchers at the time during which they attract insects.     

Influence of cage design on precision of tube-trap bioassay for attractants of the onion fly,Delia antiqua

Responses of onion flies,Delia antiqua, to known attractants were measured in the laboratory with a novel tube-trap bioassay. The relative numbers of flies caught in tube traps baited with enzymatic yeast hydrolysate, brewer's yeast, andn-dipropyl disulfide were similar to those obtained previously with cone traps in the field. Changing the shape of the bioassay cage from a cuboid to a cylinder decreased the experimental error obtained from analysis of variance, as did rotating the floor of the circular cage. This bioassay should be useful in evaluating attractants for other insects that orient along the substrate.Diptera: Anthomyiidae.Paper No. 11327 of the Michigan State University Agricultural Experiment Station. Received for publication June 8, 1984.     

Composition of Chemical Attractants Affects Trap Catches of the Australian Sheep Blowfly, Lucilia cuprina, and Other Blowflies

Numbers of Lucilia cuprina (Australian sheep blowfly), Chrysomya spp., and Calliphora spp. blowflies caught on sticky traps baited with various synthetic attractants or a standard liver/sodium sulfide attractant in western Queensland were recorded. Numbers of each genus collected were influenced by the composition of the chemical attractants. Attractant mixtures based on 2-mercaptoethanol, indole, butanoic/pentanoic acid, and a sodium sulfide solution gave 5- to 20-fold higher L. cuprina catches than the liver standard. These blends attracted similar numbers of Chrysomya spp. (0.85-2.7x) and fewer Calliphora spp. (0.02-0.2x) compared to the liver standard. These synthetic attractants were more effective and selective for L. cuprina than the standard liver/sodium sulfide attractant, and they can be packaged in controlled-release dispensers to generate constant, prolonged release of the attractant.     

Age-related response of male melon fliesDacus cucurbitae (Diptera: Tephritidae) to cue-lure

Laboratory-reared and wild adults of the melon fly,Dacus cucurbitae Coquillett, were tested for response to cue-lure at various ages. Virgin laboratory (4, 6, 8, 10, 12, and 14 days old) and wild (10, 12, 14, 16, 18, 20, and 22 days old) flies were released into outdoor field cages and trapped from 0800 until 1600 hr. Response of males to cue-lure increased with age and corresponded with sexual maturity for each strain. Females of both strains were relatively nonresponsive to cue-lure. Failure to eradicate in past male annihilation programs againstD. cucurbitae may be explained in part by the fact that only older males, which may have already mated with gravid females, respond to cue-lure.     

Relationship of sexual maturation rate to response of oriental fruit fly strains (Diptera: Tephritidae) to methyl eugenol

Laboratory-reared and wild, fruit-reared adults of the Oriental fruit fly,Dacus dorsalis Hendel, were tested for response to methyl eugenol at various ages. Virgin laboratory (2, 4, 6, 8, and 10 days old) and wild (7, 11, 15, 19, and 23 days old) flies were released into an outdoor field cage and trapped over a two-day period. Response of males increased with age as ca. 32% and 22% of laboratory and wild males responded at 2 and 7 days of age, respectively, while ca. 93% of both strains responded at 10 and 23 days of age, respectively. These correspond approximately to the ages at which they reach sexual maturity. Female response did not increase with age and fluctuated between 15% and 29% for the laboratory strain and 10% and 45% for the wild strain. The age-related response profiles, when integrated with sexual maturation curves, indicate that one of the major reasons the male-annihilation technique is effective is because methyl eugenol is able to attract 40–50% of male flies prior to the onset of sexual maturation.     

Residual activity of oviposition-deterring pheromone inRhagoletis pomonella (Diptera: Tephritidae) and female response to infested fruit

Under dry conditions, oviposition-deterring pheromone (ODP) of the apple maggot fly (Rhagoletis pomonella Walsh) on host fruit proved deterrent to ovipositing females for at least three weeks, with a half-life of ca. 11 days. There was no difference in decline of residual activity under lab vs. field conditions or between fly-deposited ODP vs. an application of a water extract of ODP. A decline in pheromone activity resulted from exposure to both natural and simulated rainfall. For natural rainfall, greatest losses (50– 61%) in activity resulted from high-intensity rains, with substantially less activity lost (13–35%) following light or moderate intensity rains.R. pomonella females discriminated against fruit without ODP but with conspecific larvae. Discrimination against infested fruit was manifested within fewer days following infestation of small fruit (9 mm diam.) as compared to larger fruit (15 mm diam.).     

Trimedlure enantiomers: Differences in attraction for mediterranean fruit fly,Ceratitis capitata (Wied.) (Diptera: Tephritidae)

The most biologically active enantiomer of trimedlure, a synthetic lure attractive to male Mediterranean fruit flies, is the 1S,2S,4R enantiomer of isomer C, the fert-butyl ester of ris-4-chloro-trans-2-methylcyclohexanecarboxylic acid. We also determined that the 1R,2R,5S enantiomer of isomer A is significantly more attractive than its optical antipode. Essential differences in the current synthetic work that are critical to possible commercialization of this preparation are detailed herein.Deceased.     

(Z,Z)-5,27-Tritriacontadiene: Major sex pheromone ofDrosophila pallidosa (Diptera; Drosophilidae)

A crude cuticular extract from both sexes of 3660 fruit flies (Drosophila pallidosa) was subjected to SiO₂ and AgNO₃/SiO₂ column chromatography, accompanied by bioassay for the sex pheromone activity. After three chromatographic steps, the active fraction was obtained. The main component of the active fraction was determined to be (Z,Z)-5,27-tritriacontadiene [(Z,Z)-5,27-C_33:2, on the basis of gas-liquid chromatographic analysis, chemical derivatization and gas chromatography-mass spectrometry. Synthetic (Z,Z)-5,27-C_33:2 at 5 female equivalents (FE) elicited a clear courtship response with a high courtship index amongD. pallidosa males. Therefore it was concluded that (Z,Z)-5,27-C_33:2 was a major sex pheromone component in this species.     

Wind tunnel studies of sex pheromone-mediated behavior of the Hessian fly (Diptera: Cecidomyiidae)

In a wind-tunnel, male Hessian flies flying toward a source of the female-produced sex pheromone exhibited flight maneuvers very similar to those described for male moths. Upwind flight, consisting of zigzagging and straight flight upwind, was initiated within seconds after flies were placed in the odor plume. This upwind flight was sometimes interrupted by casting, which consisted of wide excursions in the horizontal plane ranging 10–35 cm across the central zone of the tunnel. Comparison of the flight maneuvers of males exposed to ten female equivalents of a hexane extract of female ovipositors and males exposed to 20 ng of (2S)-(E)10-tridecen-2-yl acetate (SE10-13:OAc), which has been identified as a component of the Hessian fly sex pheromone, indicated that the sex pheromone probably contains additional components. However, SE10-13: OAc elicited upwind flight and source location by a significant number of males, even at dosages as low as 2 ng on filter paper. At the highest dosage of SE10-13:OAc tested (200 ng on filter paper), there was a significant decrease in net flight velocity and a slight, but not significant, reduction in the number of males contacting the odor source. The addition of increasing amounts of the R enantiomer to the S enantiomer resulted in increased inhibition of upwind flight and source contact by males.     

House fly oviposition inhibition by larvae ofHermetia illucens,the black soldier fly

Wild populations of house flies were inhibited from ovipositing into poultry manure containing larvae of the black soldier fly,Hermetia illucens (L.). A laboratory strain of house fly responded differently, readily ovipositing into manure with lower densities of soldier fly larvae, but avoiding the higher densities tested. The amount of timeH. illucens larvae occupy the manure prior to an oviposition test influences ovipositional responses of house flies. Manure conditioned byH. illucens larvae for 4–5 days did not significantly inhibit house fly oviposition. We suggest that some type of interspecific chemical communication (allomone) is present.Diptera: Stratiomyidae.Portion of an MS thesis by S.W.B.Research partially supported by State and Hatch funds.     

Sex-specific activity of (R)-(−)- and (S)- (+)-1,7-dioxaspiro[5.5]undecane,the major pheromone ofDacus oleae

1,7-Dioxaspiro[5.5]undecane (olean), the major component of the female sex attractant pheromone blend of the olive fruit flyDacus oleae (Gmelin) was shown to be released as a racemate. The response of males and females to pure (R)-(–) and (S)-(+)-enantiomers was tested under laboratory and field conditions. Males in laboratory and field tests responded only to (R)-(–)-olean, which functions as a sex attractant. Females responded only to (S)-(+)-olean in laboratory tests but not in the field. There are indications that the latter enantiomer fuctions as a short-range arrestant throughout the day and as an aphrodisiac in the process of mating.Diptera: Tephritidae.