Attraction of moth species of Tortricidae,Gelechiidae, Geometridae,Drepanidae, Pyralidae,and Gracillariidae families to field traps baited with conjugated dienes

Field surveys of a series of conjugated diunsaturated straight-chain primary alcohols, acetates, and aldehydes (dienes), including the 3,5-dode-cadienyl, 8,10-dodecadienyl, 3,5-tetradecadienyl, 8,10-tetradecadienyl, 9,11-tetradecadienyl, and 10,12-tetradecadienyl primary alcohols, acetates, and most aldehydes, and the related monounsaturated straight-chain primary alcohols, acetates, and aldehydes (monoenes), including the 3-dodecadienyl alcohol and acetates, attracted the following species from the title families. Diene attractants have been demonstrated for at least onePhyllonorycter sp.,Chionodes lugubrella (Fabr.),Leptostales ferruminaria (Zell.),Drepana bilineata (Pack.),Pyrausta fodinalis (Led.),Notocelia purpurissatana Heinr.,Phaneta alterana Heinr. Monoene attractants were demonstrated forHedya separatana (Kft.),Cydia fletcherana (Kft.),Barbara mappana Free.,Ancylis burgessiana (Zell.),Ancylis nubeculana Clem.,Evippe prunifoliella Cham.,Phlyctaenia coronata tertialis (Gn.), aChionodes sp., a Gelechiidae sp., and an unidentifiedPhyllonorycter sp. Replicated field experiments showed attraction-inhibition relationships for most species. Electroantennagram data are presented forLeptostales ferruminaria andDrepana bilineata.     

Influence ofAmaranthus hybridus L. allelochemics on oviposition behavior ofSpodoptera exigua andS. eridania (Lepidoptera: Noctuidae)

Common pigweed,Amaranthus hybridus L., is a favorite host of the beet army worm (BAW),Spodoptera exigua L. Chemicals extracted from homogenized pigweed with distilled water, ethanol, or dichloromethane and sprayed back on pigweed deterred oviposition by the BAW. Similarly, water extracts of frass from conspecific larvae or southern armyworm (SAW) larvae,S. eridania (Cramer), fed pigweed leaves and sprayed back on pigweed plants also deterred BAW oviposition, thus confirming that deterrence was due to plant allelochemics rather than specific compounds associated with the metabolic or excretory products of the larvae. Confirmation of the presence of oviposition-deterring chemicals in pigweed was used to explain a previously observed seasonal displacement of BAW by SAW on pigweed in the field.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Determining pheromone content of hairpencils from individual virgin males ofPseudaletia unipuncta (Haw.) (Lepidoptera: Noctuidae)

Levels of benzaldehyde recovered from virginPseudaletia unipuncta (Haw.) males were not influenced by (1) the time hairpencils remained in the solvent (1-72 hr), (2) anesthetization or agitation of males prior to excision of hairpencils, or (3) the time (photophase or scotophase) that hairpencils were excised. Thus the interindividual variability observed is not a methodological artifact. Most males had similar concentrations in both hairpencils, although in some cases only one hairpencil contained pheromone. In one case, a male with partially extruded hairpencils had no benzaldehyde at all. Neither pupal weight nor hairpencil length proved to be reliable indicators of pheromone content.Contribution No. 373, Département de biologie, Université Laval.     

Floral volatiles ofTanacetum vulgare L. attractive toLobesia botrana den. et schiff. females

The European grapevine moth (EGVM),Lobesia botrana, is a major pest of grapes in Europe. Females are attracted to a nonhost plant: tansy (Tanacetum vulgare L.), which is a common weed in Slovakian vineyards. A steam distillate extract of tansy flowers was analyzed by means of a GC-EAG technique to screen constituents detected by the olfactory receptors of EGVM females. From more than 200 GC peaks, nine peaks corresponding to monoterpenoids released an EAG response in more than 70% of the females (N=15):p-cymene,d-limonene,-thujene,-thujone,-thujone, thujyl alcohol, terpinene-4-ol, (Z)-verbenol, and piperitone. The steam distillate of tansy as well as a synthetic blend of identified compounds released consistent attraction in a field cage. The use of nonhost plants and host plant odors in integrated pest management is discussed.     

Behavioral and electrophysiological activity of (Z,E)-7,9,11-dodecatrienyl formate,a mimic of the major sex pheromone component of carob moth,Ectomyelois ceratoniae

The behavioral and electrophysiological activity of a mimic [(Z,E)7,9,11-dodecatrienyl formate] of the major sex pheromone component [(Z,E) 9,11,13-tetradecatrienal] of carob moth was assessed. Wind-tunnel bioassays demonstrated that the formate was as effective as natural gland extracts, and significantly more effective than the trienal alone or than the trienal blended with two minor pheromone components, in evoking source contact. Dispensers containing the formate were as effective as trienal-containing blend lures in attracting males when placed at the same dosage in traps in date gardens. Single-cell recordings showed that at least two olfactory neurons, differentiated by spike amplitude, are located in the long trichoid hairs on male carob moth antennae. Dose-response relationships indicated that puffs from cartridges loaded with at least 0.1 g of the formate or of the trienal were necessary to elicit spiking by either the small or the large-spiking cell within a sensillum. Cross-adaptation studies demonstrated that both compounds stimulated the same large-spiking cell. The frequencies of spikes evoked from the large cell when stimulated by emissions from 0.1-g, 1-g, or 10-g cartridges of either the formate or the trienal were not significantly different, suggesting that the formate is an effective mimic of the trienal at the antennal receptor cell level.     

Intraspecific variation and interspecific differences in sex pheromones of sibling species inCtenopseustis obliquana complex

The specific status ofCtenopseustis obliquana pheromone-types I, II, and III has been more fully examined. Females of types I and III produce a mixture of (Z)-8- and (Z)-5-tetradecenyl acetates (Z8-14:Ac, Z5-14: Ac). The previously reported different ratios of these two components in females of the two types (type I=8020, III=9010) have been reinvestigated. The median ratios of each type differed significantly, although there was some overlap in the ranges of these ratios. A field cage trial showed that males of type III are attracted to females of type I, so the observed differences may be ascribed to intraspecific variation. In contrast to females of types I or III, females of type II produce Z5-14Ac but no Z8-14Ac. The electroantennogram (EAG) profile of antennae of type II males shows a maximum response to Z5-14Ac, while the EAG profiles of types I and III show a strong response to Z8-14Ac. In wind tunnel tests using mixtures of these two compounds, type II males prefer blends consisting of all or mostly Z5-14: Ac, while type I males showed a preference to a mix of 70% Z8-14Ac plus 30% Z5-14Ac. We found that type I males are attracted to type I females when offered a choice between type I and type II females in a field cage test and that type II males similarly prefer type II females. Males of types I and II have specialist cells for Z8-14Ac and Z5-14Ac but differ with respect to relative densities of these cells and to further cell types responsive to other alkenyl acetates. Type IIC. obliquana is considered therefore a sibling species of types I and III. In addition, the amount of Z5-14Ac produced by type II females varied geographically. Females from the North Island produced significantly less (median=1.2 ng) Z5-14Ac than females from the South Island (median=2.2 ng). Type II populations in the North Island morphologically resembled sympatric type I, rather than type II from the South Island and are designated as type II (North Island). Type II (North Island) populations have so far been found only at Rukuhia (near Hamilton) and from Kerikeri. In contrast, type II populations are sympatric with type III populations over much of the South Island. In a field cage trial, males of types II and II (North Island) were attracted to females of both II and II (North Island). We tentatively ascribe the differences between type II and type II (North Island) to intraspecific variation.     

Identification of a minor component of the sex pheromone ofLeucoptera malifoliella (Lepidoptera,lyonetiidae)

A new minor component in the female volatile extract ofLeucoptera malifoliella (Costa) (Lepidoptera, Lyonetiidae) has been identified as 5,9-dimethyloctadecane (2). The amount detected of the minor compound2 ranged from 4 to 8% in comparison with the major component 5,9-dimethylheptadecane (1). Neither compound has been found in the male volatile extract. The identification has been based on its spectroscopic properties and Chromatographic behavior in comparison with an authentic synthetic sample. The synthesis has been carried out through a short route from 2,6-dimethylcyclohexanone (3). In field tests, compound2 appears to act as a Synergist of the major component1 when mixed with the latter in a 1000.1– 5 ratio.     

Multivariate analysis of the correlation between noctuidae subfamilies and the chemical structure of their sex pheromones or male attractants

Female-emitted pheromones and sex attractants of Noctuidae were investigated using a specific computer procedure to analyze data collected from the literature. Correspondence analysis was used to survey the structure-activity relationships of sex pheromones in seven subfamilies. Structural, stereochemical, and functional features of active molecules were related to taxonomy. This multidimensional analysis revealed that the prevalent chemical frame of noctuid moth pheromones was a monounsaturated acetate withZ stereochemistry and a double bond on the fifth carbon closest to the nonfunctional branch of the molecule. Possible phylogenetic relationships within Noctuidae and between Noctuidae and other families are discussed in light of the sex pheromone biochemistry. Female sex pheromones appeared to be an additional character to be considered in the classification of noctuid moths.     

Different feeding and gustatory responses to ecdysone and 20-hydroxyecdysone by larvae of the silkworm,Bombyx mori

The feeding and gustatory responses to ecdysone and 20-hydroxyecdysone were investigated in the silkworm,Bombyx mori. 20-Hydroxyecdysone reduced feeding response strongly in fourth- and fifth-instar larvae, whereas ecdysone had no effect on feeding response. 20-Hydroxyecdysone stimulated the R receptor, the receptor to feeding deterrents, to a great degree. By contrast, ecdysone was much less effective for stimulating the R receptor. These results indicate that ecdysone and 20-hydroxyecdysone have different effects on feeding response due to different interactions with mouthpart chemoreceptors.     

Evidence for (E,Z)-8,10-dodecadienyl acetate as the major component of the sex pheromone of the eastern pine seedworm,Cydia toreuta (Lepidoptera: Tortricidae)

The sex pheromone ofCydia toreuta (Grote), the eastern pine seedworm, was investigated using electroantennogram (AG) measurements, gas chromatography (combined GC-FID-EAD) measurements, and field tests. (E,Z)-8,10-dodecadienyl acetate (E,Z8,10-12:Ac) and (E,E)-8,10-dodecadienyl actetate (E,E8,10-12: Ac) produced both the highest EAG and EAD responses. Only a single antennal stimulatory peak was observed when female abdominal tip extracts were analyzed by GC-FID-EAD, which corresponded exactly with that of authenticE,Z8,10-12: Ac. Field tests confirmedE,Z8,10-12: Ac as the major pheromone component. TheE,Z isomer by itself caught equivalent numbers of male moths as did caged females. The addition of theE,E isomer to theE,Z form increased trap catch, although not significantly (P = 0.05). The addition of (Z,Z)-8,10-dodecadienyl acetate to theE,Z isomer significantly (P=0.05) reduced trap catch, while the addition of (Z,E)-8,10-dodecadienyl acetate to theE,Z form also decreased trap catch, but not significantly (P=0.05).