Plusiinae Species Research Articles

Potential host range of Cotesia vanessae (Hymenoptera: Braconidae), a parasitoid new to North America and a possible biological control agent of noctuid pest species.

The likelihood of parasitoids establishing in new geographic regions depends upon the availability of suitable host species. Identifying these hosts and the degree of their suitability is particularly important when they include species that are economically important as pests. In laboratory studies, we examined the suitability of 47 species of Lepidoptera as potential hosts of a parthenogenetic strain of the gregarious parasitoid Cotesia vanessae (Hymenoptera: Braconidae). Previously known from Eurasia and northern Africa, the first known recovery of C. vanessae in North America was in 2009. C. vanessae completed development in 34 species, of which three were known hosts (Noctuidae) and 31 (30 Noctuidae, 1 Nymphalidae) were not. Many of these noctuid species are economic pests. Parasitoid fitness was generally highest on species of Plusiinae (Noctuidae), measured as either percentage of successful parasitism, developmental time, or number and mass of F1 progeny. Closely related species were generally similar in their suitability as hosts. In some cases, parasitoid eggs or larvae were killed by the immune system of the parasitized host, but the host eventually failed to excrete food waste, did not pupate, and ultimately died. Such cases reached up to 100% mortality depending upon the lepidopteran species. The suitability of many species of noctuid pests as hosts for C. vanessae suggests that this parasitoid will become established widely throughout North America and may help to suppress populations of some pest species.

Temporal Occurrence of Plusiinae on Soybean in the Mississippi River Delta.

The subfamily Plusiinae of the moth family Noctuidae is made up 400 species worldwide. Two species of the subfamily, the soybean looper, Chrysodeixis includens (Walker), and the cabbage looper, Trichoplusia ni (Hübner) (Lepidoptera: Noctuidae), are important defoliating insect pests of various field crops and have been the subject of previous Plusiinae surveys in the Southern U.S. Soybean fields were sampled in the Mississippi Delta from 2010 to 2012 to determine the temporal occurrence of various Plusiinae species on soybean. As in previous surveys, C. includens was the most common Plusiinae species in soybean during the 3-yr survey, especially in late season collections (July-September). Rachiplusia ou (Guenée) (Lepidoptera: Noctuidae) was the predominant species observed in early season collections (May-early July). Populations of R. ou during the first sample dates during 2010 were much higher than those observed during the other years of the survey. Only three collected larvae successfully developed into T. ni adults, one each collected during May, June, and July. Although R. ou was not commonly reported in previous studies on soybean, it occurred in low numbers during June and July during the 3-yr study. The temporal occurrence and species composition followed a predictable pattern in all 3 yr of the study.

The influence of agricultural occupation and climate on the spatial distribution of Plusiinae (Lepidoptera: Noctuidae) on a latitudinal gradient in Brazil

Abstract Studies have reported the presence of certain Plusiinae species in both natural and agricultural landscapes, but their turnover in association with agricultural activities remains unexplored. Aiming to understand how the assemblages of Plusiinae are structured by agricultural occupation and climate, this study used automated light traps sampled moths in 18 sites in Brazil, across a broad latitudinal gradient. Our data has demonstrated that climate variables prevails as the most important variables influencing both the composition of Plusiinae and the abundance of its dominant species Chrysodeixis includens. On the other hand, the lack of significance found for the effect of variables representing agricultural occupation evidences that pest species are present both in agricultural and natural ecosystems, also sharing similar abundances at those locations. In other words, instead of following a gradient of agricultural occupation (e.g. crop sizes around sample sites) the composition of these extremely polyphagous insects is more clearly shaped by the latitudinal gradient, in which temperature and precipitation are better predictors. Thus, in contrary to our expectations, pest species inhabits both natural and agricultural landscapes at similar latitudinal sites, probably due to their wide polyphagy spectrum. These results can be used in management and monitoring programs of pest species in South America, since the local abundance variation and species composition can be more reliable predicted by changes in climate conditions.

Genetic structure of two Plusiinae species suggests recent expansion of Chrysodeixis includens in the American continent

The Plusiinae subfamily has many polyphagous species, many of which occur in South America. Chrysodeixis includens and Rachiplusia nu are two representatives that mainly occurs in soybeans, cotton, common beans, sunflower and alfalfa. A population genetic study of C. includens and R. nu collected in the Southern Cone of America was performed using a partial COI gene sequencing data and compared with specimens from other American countries. Six haplotypes were identified in C. includens populations of Brazil, Argentina, Paraguay and Uruguay, organized within a star‐like haplotype network, with the most common haplotype identified as Chin_MC. R. nu populations are more diverse and stable in comparison to C. includens. Populations from Argentina and Uruguay had the highest haplotype diversity, sharing five haplotypes and putatively indicating haplotype exchange. Demographic change analysis suggested a recent population expansion of C. includens over the American continent. Some C. includens haplotypes were country‐specific, suggesting population expansion in the countries where specimens were collected.

DNA barcoding and Taxonomic account on some selected species of subfamily Plusiinae (Lepidoptera: Noctuidae) from India.

This study represents a detailed taxonomic account of 31 species of Plusiinae (Lepidoptera: Noctuidae) from India. The survey and collection of 39 localities from different regions of India between 2015 and 2018. The tribe Argyrogrammatini Eichlin Cunningham, 1978 with Ctenoplusia Dufey, 1970 was the most species rich genera with seven species, followed by Thysanoplusia Ichinose, 1973 and Chrysodeixis Hubner, 1821 with four and three species respectively. Among 31 species, 15 species are commonly found in Himalayan regions and while other species were distributed from subtropical to tropical region. Five species, T. orichalcea (Fabricius, 1775), Chrysodeixis eriosoma (Doubleday, 1843), C. acuta (Walker, 1858), C. chalcites (Esper, 1789), Trichoplusia ni (Hubner, 1803) are widespread throughout India and reported as serious crop pests. Present study also revealed range expansion of four species viz., Dactyloplusia impulsa (Walker, 1865), Ctenoplusia mutans (Walker, 1865), Ctenoplusia tarassota (Hampson, 1913) and Zonoplusia ochreata (Walker, 1865). Systematic accounts of all 31 species are discussed here with adult images, species diagnostic characters, collection localities, detailed distributions and reported larval host plants. In addition to morphological studies, for the first time, a preliminary barcode library for 25 species of Indian Plusiinae with average intra-specific distance (%), maximum intra-specific distance (%) and distance to nearest neighbor (%) for individual species is provided. Among 25 species, four species barcode data (Ctenoplusia mutans, C. kosemponesis, Plusiopalpa adrasta, Sclerogenia jessica) are novel to world and 18 species barcode sequences were novel to India.

Seasonal cycles of noctuid moths of the subfamily Plusiinae (Lepidoptera, Noctuidae) of the Palaearctic: Diversity and environmental control

Analysis of data on seasonal development of noctuid moths of the subfamily Plusiinae shows that the control of their seasonal cycles is poorly understood. At the same time, the available data demonstrate considerable diversity of the seasonal patterns of Plusiinae species from different regions. The homodynamic type of seasonal development has been found in Trichoplusia ni and Ctenoplusia agnata of the tribe Argyrogrammatini and in Autographa gamma of the Plusiini. The seasonal development of these southern noctuids is accompanied by regular interzonal migrations of flying adults. When spreading northwards, they can produce a different number of annual generations, depending on the local climatic conditions, and establish temporary local populations whose longevity is limited by the available thermal resources. Adults of some species may fly back southwards, but it is more likely that individuals from temporary local populations cannot survive long winters and are destined to die. The heterodynamic type of seasonal cycles allows insects to survive in the regions with pronounced seasonality of climate. This type of seasonal development includes univoltine, multivoltine, and semivoltine seasonal cycles. Univoltine seasonal cycles with obligate diapause are known in Autographa buraetica, A. excelsa, and Syngrapha ain (Plusiini). Diapause provides tolerance to both low temperatures and a prolonged period when food is unavailable. In Syngrapha ottolenguii (Plusiini), the same result is achieved by inclusion of two photoperiodically controlled diapauses (winter larval and summer adult ones) into the life cycle. The semivoltine seasonal cycle has been reported in only one species of Plusiinae, namely Syngrapha devergens. Larvae of this moth overwinter twice before pupation. Multivoltinism is common in the tribe Plusiini. Depending on the latitude, different species of this tribe can produce up to four generations per year and overwinter as middle-instar larvae in the state of facultative diapause. However, the characteristics of diapause vary substantially between the species: diapause can be deep and stable (as in Diachrysia chrysitis, Plusiini) or unstable and thus not ensuring successful overwintering and steady population growth (as in Macdunnoughia confusa, Plusiini). The seasonal adaptations known in Plusiinae include migrations, winter and summer diapauses, photoperiodic control of larval growth rates, and seasonal polyphenism of larval body coloration. In general, seasonal adaptations of Plusiinae are determined by local environmental conditions and only loosely associated with the systematic position of particular taxa. Only the tribe Abrostolini stands apart from other taxa of Plusiinae: moths of this tribe differ not only in morphology but also in peculiarities of their seasonal development, because all the species of this tribe overwinter as pupae and their seasonal cycles are therefore different from those of the rest of Plusiinae.

Night-active Macroheterocera species in traps with synthetic attractants in the Velyka Dobron’ Game Reserve (Ukraine, Transcarpathia)

We allocated some new types of bait traps using different volatile aromatic compounds in the Velyka Dobron’ Game Reserve (Ukraine, Transcarpathian region) where light trap surveys on Macroheterocera were already carried out since 2009. The phenylacetaldehyde-based traps were especially effective for the species of subfamilies Plusiinae and Helio-thinae, while the members of some other subfamilies (Hadeninae, Noctuinae) were more attracted by the isoamyl-alcohol-based traps. The highest attractivity was observed in case of the mixture containing isoamyl-alcohol, acetic acid and red wine. The highest num-ber of species was observed in mid-July, but the peak of individual numbers appeared in early August. Majority of species of this assemblage was formed by bivoltine species connected to herbaceous food plants. The dominant species of this late summer period was Trachea atriplicis (second brood). It was sharply replaced by the monovoltine Allophyes oxyacanthae in September. The bulk of species of this early autumnal period was formed by monovoltine species with woody-shrubby larval food plants. Biogeographical spectrum of the assemblage was dominated by widely distributed Euro-Siberian species combined with significant presence of Mediterranean and Boreo-continental faunal elements. In the ecological spectrum of the assemblage the species connected to forested habitats are well represented but together with the presence of numerous generalist species.

Morphological comparison of proboscis sensilla between Plusiinae and Noctuinae (Lepidoptera: Noctuidae)

In higher Lepidoptera the proboscis and its sensilla vary from species to species in different feeding guilds. However, whether such morphological differences have a phylogenetic significance remains unclear. Here we compared the morphology of proboscis sensilla in 19 representative species of Plusiinae and four of Noctuinae using scanning electron microscopy. In Plusiinae four types of sensilla (sensilla chaetica, sensilla basiconica, sensilla styloconica, and sensilla coeloconica) were present on the proboscis, with cuticular processes only in the proximal region. In Noctuinae three types of sensilla (sensilla chaetica, sensilla basiconica, and sensilla styloconica) were found on the proboscis, with cuticular processes on its whole length. Morphological differences of proboscis sensilla between Plusiinae and Noctuinae mainly involve the shape, number, and length of sensilla styloconica and sensilla chaetica. The sensilla styloconica of Plusiinae are significantly shorter and fewer than those of Noctuinae. The styli of sensilla styloconica are glabrous in Plusiinae and are longitudinally ribbed in Noctuinae. These significant morphological differences are useful in distinguishing the two subfamilies, suggesting that proboscis sensilla may provide useful characters in the systematic and phylogenetic analyses at the subfamily level within Noctuidae.

Redescription of immature stages of the soybean looper (Lepidoptera: Noctuidae: Plusiinae)

AbstractChrysodeixis includens(Walker) is a characteristic Plusiinae (Lepidoptera: Noctuidae) species from the Western Hemisphere. The larva have already been found feeding on several different plant families, including economic value crops such as soybeans. This species coexists and can be confused withRachiplusia nu(Guenée) (Lepidoptera: Noctuidae) in soybean crops. Furthermore, some studies indicate thatC.includensshows tolerance to various insecticides, leading to differentiation among these two species to be most important in relation to control procedures to be undertaken. To contribute to the correct identification ofC.includenswe made detailed redescriptions of all preimaginal stages (egg, larva, and pupa). Immature stages ofC.includenswere reared in laboratory under controlled conditions of 27±2 °C, 70–75% relative humidity, and 14:10 (light/dark) photoperiod. We consider opportune detection of preimaginal stages ofChrysodeixis includenswill help to control this pest species, especially at admissible economical levels.

PLusiinae (Excl. Abrostolini) (Lepidoptera: Noctuidae) of Ethiopia. A faunistical survey with biogeographical comments.

The extensive survey in different regions of Ethiopia between 1987-1990 and 2005-2011 resulted in the recognition of 39 species of Plusiinae. The majority of the species belong to two large genera, Ctenoplusia (15 species) and Thysanoplusia (16 species). A new synonymy is established, Plusiotricha gorilla (Holland, 1894) is proved to represent the female sex of Plusiotricha livida Holland, 1894 (syn. nov.). The present paper does not include the records of the species of the tribe Abrostolini. Eighteen species are recorded for the first time from Ethiopia. Twenty species of the identified taxa are known only from tropical and subtropical Africa, while the areas of ten species extend from Africa to the Arabian Peninsula or even further to the north. Eight species are widespread not only in Africa but also in the Palearctic and Oriental regions. One species-Autographa gamma, a well-known Palearctic pest of different vegetables-is found in the Afrotropical region only in Ethiopia, at medium and high mountain elevations but not in the tropical lowlands.

Molecular Mechanisms Underlying Insect Behaviors: Receptors, Peptides, and Biosynthetic Pathways

Molecular Mechanisms Underlying Insect Behaviors: Receptors, Peptides, and Biosynthetic Pathways

Biosynthetic Pathway for Sex Pheromone Components Produced in a Plusiinae Moth, Plusia festucae

While many Plusiinae species commonly secrete (Z)-7-dodecenyl acetate (Z7-12:OAc) as a key pheromone component, female moths of the rice looper (Plusia festucae) exceptionally utilize (Z)-5-dodecenyl acetate (Z5-12:OAc) to communicate with their partners. GC–MS analysis of methyl esters derived from fatty acids included in the pheromone gland of P. festucae showed a series of esters monounsaturated at the ω7-position, i.e., (Z)-5-dodecenoate, (Z)-7-tetradecenoate, (Z)-9-hexadecenoate (Z9-16:Me), and (Z)-11-octadecenoate (Z11-18:Me). By topical application of D3-labled palmitic acid (16:Acid) and stearic acid (18:Acid) to the pheromone glands, similar amounts of D3-Z5-12:OAc were detected. The glands treated with D13-labeled monoenoic acids (Z9-16:Acid and Z11-18:Acid), which were custom-made by utilizing an acetylene coupling reaction with D13-1-bromohexane, also produced similar amounts of D13-Z5-12:OAc. These results suggested that Z5-12:OAc was biosynthesized by ω7-desaturase with low substrate specificity, which could introduce a double bond at the 9-position of a 16:Acid derivative and the 11-position of an 18:Acid derivative. Additional experiments with the glands pretreated with an inhibitor of chain elongation supported this speculation. Furthermore, a comparative study with another Plusiinae species (Chrysodeixis eriosoma) secreting Z7-12:OAc indicated that the β-oxidation systems of P. festucae and C. eriosoma were different.

Moths trapped in Alaska with feeding attractant lures and the seasonal flight patterns of potential agricultural pests

AbstractTraps baited with two types of chemical feeding attractants yielded 97 species of macrolepidoptera at three areas in Alaska (Fairbanks, Delta Junction, and Palmer). These were 16 geometrid, 1 thyatirid, and 76 noctuid moth species and 4 species of nymphalid butterflies. Potential crop pests trapped included Apamea devastator (Brace) (glassy cutworm), Xestia c-nigrum L. (spotted cutworm), Xestia smithii (Snellen) (Smith's dart), Euxoa ochrogaster (Guenée) (redbacked cutworm), and Discestra trifolii (Hufnagel) (clover cutworm). The clover cutworm was captured early in the season (May into June), while Smith's dart, glassy cutworm, spotted cutworm, and redbacked cutworm were captured in traps in mid to late summer. Many more species and greater numbers of moths were captured in traps baited with acetic acid and 3-methyl-1-butanol than in traps baited with a multicomponent floral lure (phenylacetaldehyde, methyl salicylate, methyl-2-methoxy benzoate, and β-myrcene). However, most of the geometrid moths captured (12 of 16 species) were in floral lure traps, while one species of Hadeninae (Noctuidae) and both species of Plusiinae (Noctuidae) were trapped exclusively in floral lure traps. The one thyatirid, both Catocalinae noctuid species, and most Amphipyrinae, Cuculliinae, Hadeninae, and Noctuinae noctuid species were captured in traps baited with acetic acid and 3-methyl-1-butanol. In addition, large numbers of bumblebees were captured in traps baited with the floral lure, while large numbers of yellowjackets were captured in traps baited with acetic acid and 3-methyl-1-butanol.

The Plusiinae (Lepidoptera: Noctuidae) of Great Smoky Mountains National Park

Seventeen species of Plusiinae have been found in Great Smoky Mountains National Park, in Tennessee and North Carolina, USA. These species are documented with adult images, description, flight period, abundance, elevation range, Park and general distribution, and larval hosts from the literature. Maps illustrate the known distribution of each species within the Park. Sixteen of the 17 species occur above 4,000 feet in elevation. The most diverse locality in the Park has 14 species.

Mating Communication Systems of Four Plusiinae Species Distributed in Japan: Identification of the Sex Pheromones and Field Evaluation

The sex pheromones of four Plusiinae species in the family Noctuidae, Ctenoplusia albostriata (CA), Macdunnoughia purissima (MP), Syngrapha ain (SA), and Diachrysia stenochrysis (DS) were identified by GC-EAD and GC-MS analyses. These were subsequently evaluated by a series of field trials in different ecological habitats. CA females produced (Z)-5-decenyl acetate (I), (Z)-7-dodecenyl acetate (II), and (Z)-7-dodecen-1-ol (III) in a ratio of 2:100:13. While the antennae of CA males responded to all three components, neither I nor III was essential to capture males. The MP females produced II, III, and (Z)-5-dodecenyl acetate (IV) in a ratio of 100:80:20, and this blend captured the most MP males. Compounds II and III were also identified from SA females, and mixtures ranging from 4:1 to 2:3 were equally attractive to males. DS females only produced one active compound, (Z)-7-decenyl acetate (V), and DS is the first Plusiinae species identified as using only the omega3-compound and none of omega5-compounds, such as II and III, which are common components of Plusiinae pheromones. Using previously published chemical and biosynthetic data, together with the finding from this study, we propose a classification of the Plusiinae sex pheromones.

Regulation of Sex Pheromone Biosynthesis in Three Plusiinae Moths:Macdunnoughia confusa,Anadevidia peponis, andChrysodeixis eriosoma

Virgin females of M. confusa, A. peponis, and C. eriosoma secrete (Z)-7-dodecenyl acetate as a common main pheromone component. Their pheromone titers decreased after decapitation, and increased in the decapitated females after injection of a synthetic hormone, pheromone biosynthetic activating neuropeptide (PBAN) of Bombyx mori. In addition, an extract of brain-subesophageal ganglion complexes of each Plusiinae species activated pheromone biosynthesis in decapitated females of not only the corresponding species, but also that of Mamestra brassicae. These results indicate that pheromone biosynthesis of the three Plusiinae species is also controlled by a PBAN-like substance. However, the Plusiinae females exceptionally contained remarkable amounts of the pheromone even 1 day after decapitation. Since it has been reported that pheromones completely disappear at least 1 day after decapitation in females of many other lepdidoptran species including B. mori and M. brassicae, a different mechanism is likely regarding the regulation of the studied Plusiinae pheromone biosynthesis. Furthermore, an incorporation experiment with a labeled pheromone precursor, D9-(Z)-7-dodecenoic acid, showed that moderate biosynthesis still proceeded in the pheromone glands of M. confusa females 1 day after decapitation, providing an evidence why complete disappearance of the pheromone was not observed in the females which otherwise lacked a source of the pheromonotropic neuropeptide.

Identification of Sex Pheromones of Anadevidia peponis and Macdunnoughia confusa and Field Tests of Their Role in Reproductive Isolation of Closely Related Plusiinae Moths

Anadevidia peponis and Macdunnoughia confusa are defoliators of plants in the family Cucurbitaceae and Compositae, respectively, in Japan. GC-MS analyses of crude pheromone gland extracts treated with or without dimethyl disulfide indicated that females of A. peponis produced six monoene acetates and two monoene alcohols and that M. confusa females produced five monoene acetates. These components include (Z)-7-dodecenyl acetate as a major common constituent and three other acetates as minor common constituents. The minor constituents are quite different in blend composition. In addition, with (Z)-7-dodecenyl acetate, an indispensable component for male attraction is (Z)-5-decenyl acetate for A. peponis and (Z)-9-tetradecenyl acetate is essential for M. confusa. Field tests with synthetic lures showed synergistic effects of some other minor components and male attraction of three additional Plusiinae species, Macdunnoughia purissima, Ctenoplusia albostriata, and Chrysodeixis eriosoma, suggesting their reproductive isolation is based in part on pheromonal communication.

Chemical characterization and species specificity of sex pheromones of plusiinae moths in Israel

AbstractThe female sex pheromones of four sympatric Plusiinae species, Autographa gamma, Chrysodeixis chalcites, Cornutiplusia circumflexa, and Trichoplusia ni were investigated in Israel. The research concentrated on the behavioral reproductive isolation regulated by their sex pheromones. The chemical composition of the four sex pheromones was determined by analysis of pheromone gland extracts, and in addition entrained volatiles released from virgin female C. chalcites and T. ni were also analyzed. The pheromones of these latter two species were found to contain several components, among which Z7‐12:Ac was the main one. The pheromone glands of A. gamma and C. circumflexa were found to contain relatively small amounts of material and only Z7–12:Ac and Z7–12:OH could be positively identified. These two pheromone components were present in the two species in roughly inverse rations. Whereas A. gamma utilizes Z7–12:Ac as the main or sole pheromone component, C. circumflexa requires both Z7–12:OH and Z7–12:Ac, with the alcohol being predominant. This is the first reported Plusiinae species using Z7–12:OH as the main pheromone component. Behavioral studies in the wind tunnel and field tests indicate that females of each of the four Plusiinae species utilizes a species‐specific blend of chemicals, consisting of attractive and antagonistic components, to attract conspecific males. Such a complementary strategy provides improved behavioral reproductive isolation among the sympatric species. For example, Z5–12:Ac, which is a specific component of the T. ni sex pheromone, may be redundant as regards the attraction of T. ni males. However, addition of small amounts of this compound to pheromone blends of A. gamma and C. chalcites resulted in complete inhibition of the males' flight behavior and trap catch; thus contributing significantly to the specificity of the T. ni sex pheromone. The relatively high proportion of Z7–12:OH in the sex pheromone of C. circumflexa, essential to the latter, is highly inhinitory to the three other Plusiinae species. The only case of cross‐attraction occurred when T. ni males were attracted to a certain extent to A. gamma lures and females. © 1993 Wiley‐Liss, Inc.

Role of sex pheromone components in behavioral reproductive isolation betweenAutographa gamma (L.) and eitherTrichoplusia ni (H�bner) ORChrysodeixis chalcites (Esp.) (Lepidoptera: Noctuidae: Plusiinae)

The composition of theAutographa gamma sex pheromone was reexamined and only (Z)-7-dodecenyl acetate and (Z)-7-dodecenol were identified by capillary GC, GC-MS, and dimethyl disulfide derivatization and subsequent GC-MS analysis. The fatty acid content of the pheromone glands was also studied, and a series of saturated and unsaturated acids was identified. However, most of the related pheromonal compounds were not detected. The male response to the pheromone components was studied in a flight tunnel and compared with the response to calling females. The best synthetic baits evoked a response similar to that observed to the virgin females, but males spent significantly more time at calling females than at the synthetic baits. The preferred synthetic baits consisted of (Z)-7-dodecenyl acetate alone or of a blend with 5% (Z)-7-dodecenol. Increasing the relative amount of the alcohol caused a gradual reduction in male response, particularly in the last steps of the courtship sequence. The addition of the minor sex pheromone components of the sympatric Plusiinae species,Trichoplusia ni andChrysodeixis chalcites, to theA. gamma pheromone was also investigated in the flight tunnel. Some of these components exhibited a significantly antagonistic effect on theA. gamma male courtship behavior. The most potent antagonists were (Z)-5-dodecenyl acetate and (Z)-9-tetradecenyl acetate. The response ofA. gamma andT. ni males to conspecific and heterospecific females was also compared in the flight tunnel. WhereasA. gamma males were attracted only to their conspecific females, a small percentage ofT. ni males were also attracted toA. gamma females and 11% performed the whole courtship sequence.

Sex pheromone components of female Cornutiplusia circumflexa

Capillary gas chromatography indicated the presence of (Z)-7-dodecenyl alcohol and (Z)-7-dodecenyl acetate in the abdominal tip extracts of female Cornutiplusia circumflexa (L.) (Lepidoptera: Noctuidae: Plusiinae) moths. Gas chromatography combined with mass spectrometry and dimethyl disulfide derivatization confirmed the structure of these two principal pheromone components. In a flight-tunnel bioassay, a 5:1 blend of alcohol and acetate elicited the complete courtship sequence by males. The response was comparable to that evoked by a live virgin female, but males spent significantly longer time at calling females than at the synthetic source. The 5:1 blend was also attractive to male C. circumflexa in the field, as indicated by catches in traps baited with this mixture. (Z)-7-dodecenyl alcohol alone was slightly attractive whereas (Z)-7-dodecenyl acetate alone was completely inactive. C. circumflexa is the first reported Plusiinae species which utilizes (Z)-7-dodecenyl alcohol as the major pheromone component.