Ailton Pinheiro Lôbo¹, Evaldo Ferreira Vilela¹, Geraldo Papa², Fernando Celoto²

In most cotton-growing of the world the pink bollworm is a key pest. The pheromone use for mating disruption this pest has been used with success in several parts of the world, mainly for the use of high rate formulations. In Brazil, however, use of this control technique doesn't still exist, mainly of low rate formulations, needing studies that prove your efficiency and characterization of the conditions that it favors. Like this, this study aimed at to evaluate the technique of mating disruption of P. gossypiella with the use of themicroencapsulated sexual pheromone of (7Z, 11Z)-7,11_hexadecadienyl acetate and (7Z, 11E)-7,11_hexadecadienyl acetate. For so much, in Campus Experimental of UNESP, in Selvíria-MS, an experiment was installed where the treatments consisted of three areas, distanced one of the other in 300 m, being the first of 8 hectare, where the pheromone was applied , the second of 2 hectare, it was also come the conventional chemical control of insecticide and the third from 2 hectare that served as control. For your evaluation, it was monitored the treatments with pheromone traps and it was determined your losses. The results showed that the treatment with pheromone suppressed the capture in 80% and it provided increment of 64% in the productivity, in relation to control. In relation to the conventional treatment for insecticide, the pheromone promoted an increase of 23% in the productivity.

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^1/ Universidade Federal de Viçosa, Departamento de Biologia Animal, UFV

36571-000, Viçosa, MG. aplobo@alunos.ufv.br

^2/ Departamento de Biologia, UNESP- Campus de Ilha Solteira.

ALEXSANDRO. A. DA SILVA¹; GULAB. N. JHAM¹ AND ATHULA. B. ATTYGALLE²

Some constituents of moth pheromones are straight-chain unsaturated alcohols bearing 12-20 carbon atoms. Mono-unsaturated alcohols in pheromone mixtures are often identified by comparing their gas chromatographic retention times (R_t) obtained on several stationary phases of different polarities with those of authentic standards. Moreover, polyunsaturated pheromones can be identified by a random reduction to monoenes followed by the GC-MS analysis of the DMDS derivatives of the products (Attygalle et al., 1996). Since only a few laboratories have access to authentic samples of all the isomers of monounsaturated alcohols, and literature information on retention time and mass spectrometric data are rather incomplete, a compilation of an extensive information base containing such data would be invaluable to researchers interested in pheromone characterization. Hence, we have determined mass spectral fragmentation patterns and the retention times of 76 isomers of Z and E monoene alcohols (19 dodecenyl, 23 tetradecenyl, 22 hexadecenyl, and 12 octadecenyl alcohols) on three stationary phases of different polarity [DB1 (non-polar), Carbowax (polar) and DB 23 (highly polar)] coated on fused-silica capillary columns. Analytical data were obtained using a GC/MS (Shimadzu QP5000) system. Each standard (5 ng) was injected five times and data obtained (retention times, and relative abundances of mass spectral peaks) were statistically analyzed. A computation of averages and standard deviations showed excellent reproducibility under repetitive conditions. In general, best gas chromatographic separations were obtained on the DB 23 column. Although peaks for molecular ions were absent in all the spectra, a low-intensity peak (about 3%) at m/z (M^+. - H₂O) allowed the mass determination. In most cases, specific intensity differences in many peak clusters in mass spectra together with the R_t values allow unambiguous determination of double bond position and configuration of these acetates.

Attygalle, A. B.; Jham, G. N.; Svatos, A.; Frighetto, T.; Meinwald, J.; Vilela, E. Ferrara, F. A. (3E,8Z,11Z)-3E,8Z-11Z -Tetradecatrienyl acetate. A major component of sex pheromone of tomato pest Scrobipalpuloides absoluta. Bioorganic and Medicinal Chemistry, 4,305-314, 1996.

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¹UNIVERSIDADE FEDERAL DE VIÇOSA, DEP. DE QUÍMICA, L.P.P.N., VIÇOSA, MG, BRAZIL

²DEPARTMENT OF CHEMISTRY & CHEMICAL BIOLOGY, CORNELL UNIVERSITY, ITHACA, NY, USA

Analía Salvatore¹, Susana Borkosky², Alicia Bardón² and Eduardo Willink¹

Ceratitis capitata (Weidemann) is known as the "Mediterranean fruit fly". This insect attacks a wide variety of hosts in subtropical and temperate regions of Argentina, causing serious economical damages and preventing fruit exports. It has been reported that C. capitata can not develop in lemons while still on the tree. Resistance was attributed to flavedo thickness, high concentration of oxygenated terpenoids and the absolute amount of oil, though, no systematic research has been performed to prove these hypotheses. It is important to point out that resistance declines significantly after harvest.

In our search for natural pest bioregulators, we chose lemon as a good "C. capitata resistant model" and carried out the following experiments and analytical procedures. We extracted the peel with solvents of different polarities and tested the extracts for toxicity on C. capitata larvae. The ether and methanol extracts resulted to be the most toxic. At first, we analysed the chemical composition of the ether extract after harvest, weekly, during a two-month period by GC-MS. We also evaluated, weekly, the toxicity of the ether extract employing a specific bioassay we designed. Our results showed that the concentrations of some constituents of the extract are noticeably reduced after harvest. These modifications could account for the found variation of resistance. Addition of those compounds whose concentration had been lowered after harvest, produced a recovery of toxicity to the original levels. Synergetic and antifeedant effects of some constituents were also evaluated.

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¹ Estación Experimental Agroindustrial Obispo Colombres, Avda. William Cross 3150, Las Talitas 4101, Tucumán, Argentina. saneeaoc@tucbbs.com.ar

² Cátedra de Química Orgánica III, Facultad de Bioquímica, Química y Farmacia, Universidad Nacional de Tucumán, Ayacucho 471, Tucumán 4000, Argentina. alisan@unt.edu.ar

Rosemary A. Roque, Adson L. Sant'Ana & Álvaro E. Eiras.

Grass infusions of Panicum maximum have been used with success to enhance oviposition of the yellow fever mosquito Aedes aegypti. This work aimed to evaluate the different ages of grass infusions of P. maximum and a range of concentrations as oviposition attractant and/or stimulant. In the first experiment, we evaluated the different ages of fermentation of grass and hay infusions (0, 1, 3, 5, 7, 10, 15, 20 and 30 days). The results showed that ovitraps baited with grass infusion of 15 and 20 days old collected the highest number of eggs whereas the hay infusion ranged from 7 up to 30 days old. In the second experiment we evaluated a range of concentrations (0, 0.33, 1, 3.3, 10, 33 and 100%) of grass and hay infusions. The results showed that hay infusions showed to be more effective when low concentrations were tested (0.33 and 3.3% of concentration collected 23.9 and 37.2% of eggs, respectively). However, ovitrap baited with grass infusion showed to be efficient also at high concentration (concentrations of 1% and 33% collected the highest percentages of eggs, 20.2 and 41,6%, respectively). Therefore, identification of the volatiles released from grass infusions that attract gravid female mosquitoes Ae. aegypti to ovitrap will be carried out in order to use specific synthetic chemicals to eliminate the need to create infusions.

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Laboratório de Culicídeos, Depto de Parasitologia, Universidade Federal de Minas Gerais, Brazil alvaro@icb.ufmg.br.

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¹Laboratório de Culicídeos, Depto de Parasitologia, Universidade Federal de Minas Gerais, Brazil alvaro@icb.ufmg.br, ² Depto Química, Universidade Federal do Paraná

Álvaro E. Eiras, Eduardo S. Ivo & Adson L. Sant'Ana

There are many reports that larval rearing water attracted gravid Aedes mosquitoes in laboratory. However, there is no evidence that larval rearing water increases the efficacy of oviposition trap (ovitrap) in the field. Grass infusions also increase the effectiveness of the ovitraps in the field and laboratory. Therefore, we studied for the first time, the effect of larval rearing water in ovitrap the field alone and in combination with grass infusion. In laboratory, larval rearing water showed to be effective when presented at concentration of 3 larvae/ml, whereas in the field at 8 larvae/ml. In the field, larval rearing water increased the number of eggs caught in ovitraps only at higher concentration (8 larvae/ml). A synergistic effect was observed when both stimuli were presented in combination.

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Depto de Parasitologia, Universidade Federal de Minas Gerais, Brazil alvaro@icb.ufmg.br

Ann M. Fraser, Wendy L. Mechaber & John G. Hildebrand

Female Manduca sexta moths (Lepidoptera: Sphingidae) exhibit upwind orientation and egg laying-related behavior when exposed to volatiles released by their hostplants. We collected headspace volatiles from four hostplants (Solanaceae: Lycopersicon esculentum, Capiscum annuum, Datura wrightii; Martyniaceae: Proboscidea parviflora) and used coupled gas chromatography-electroantennographic detection (GC-EAD) to determine what components stimulated olfactory receptors in the antennae of female moths. Antennae consistently responded to 14 to 28 GC peaks, depending on the plant species sampled. Comparisons of GC-EAD traces revealed nine response-evoking peaks of similar retention time among the four hostplant species. The non-host, cabbage (Cruciferae: Brassica oleraceae), also elicited antennal responses at these retention times. Additional GC-EAD recordings using plant-reared wild moths revealed that neither larval diet (artificial diet vs. hostplant), nor moth origin (laboratory culture vs. wild population) had a strong influence on antennal responses to plant headspace volatiles. Response-evoking GC peaks were identified by gas chromatography-mass spectrometry (GC-MS) and verified with synthetic standards where possible. Electrophysiologically-active components included aliphatic, aromatic and terpenoid compounds. The relative proportions of these components were quantified and used to prepare a series of synthetic hostplant volatile blends for behavioral testing in a wind tunnel.

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ARL Division of Neurobiology & Center for Insect Science, 611 Gould-Simpson Bldg, University of Arizona, Tucson, AZ 85721-0077, USA. afraser@neurobio.arizona.edu

Aurélia Reckziegel¹, Wittko Francke¹, Christiana Klingenberg ², and Wolf Engels

Queens, workers, males and soldiers of the leaf-cutting ant, Atta laevigata, have been dissected into head, thorax and abdomen, wich were extracted with pentane and subjected to analysis by gaschromatography-mass spectrometry (GC-MS). Among the volatiles, 3,5-dimethylnonan-1-ol (1) was exclusively found in head extracts of virgin queens, while 4-methylheptan-3-ol (2) and 4-methylheptan-3-one (3) also occured in samples of males and workers. Here we report on the separation of stereoisomers of compounds (1), (2) and (3) by chiral gaschromatography and the determination of their composition in samples of Atta laevigata. Stereoisomers of (1) could be separated by using a 25m x 0.25mm x 0.25mm column, coated with heptakis-[6-O-tert-butyldimethylsilyl-2,3-di- O-methyl]-b-cyclodextrin. Extracts from heads of virgin Atta laevigata queens showed a 10:50:30:10-ratio of (3R,5R)-(1a):(3R,5S)-(1b):(3S,5S) -(1c):(3S,5R)-(1d). Separations of stereoisomers of (2) and (3) were achieved by using a 25m x 0.25mm x 0.25mm column, coated with heptakis-[6-O-methyl-2,3-di-O-pentyl]-g-cyclodextrin. While both naturally occuring (2) and (3) exclusively showed (4S)-configuration, the alcohol (2) consisted of a ~4:1 mixture of the (3S,4S)- and (3R,4S)-diastereomers. (4S)-(3) is an alarm pheromone of many leaf-cutting ant species. (3S,4S)-(2) is an aggregation pheromone of Scolytus bark beetles, while (3R,4S)-(2) is a trail pheromone in the ant, Leptogenys diminuta. The biological function of (1) is yet unknown. Whether it plays a role in the communication system of queens of Atta laevigata is presently under investigation.

1) Reckziegel A., Braga, A.L., Menezes, P.H., Stefani, H.A., „Alkynyl Sulfides and Selenides from Alkynyl Bromides and Diorganoyl Chalcogenides Promoted by Copper(I) Iodide",Tetrahedron Lett., 34, 393, 1993.

2) Reckziegel A., Braga, A.L., Silveira, C.C., Menezes, P.H., „Convenient Preparation of Alkynyl Selenides, Sulfides and Tellurides from Terminal Alkynes and Phenylchalcogenyl Halides in the Presence of Copper(I) Iodide", Tetrahedron Lett., 34, 804, 1993.

3) Reckziegel A., Braga, A.L., Silveira C.C., Comasseto J.V.,"Vicinal difunctionalization of Alkynyl Selenides with Lithium Butylcyano Cuprate and Electrophiles", Synth. Commun., 1165, 1994.

4) Subchev M., Harizanov A., Francke, W., Franke S., Plass E., Reckziegel A., Schröder F., Pickett J.A., Wadhams L.J., Woodcock C.M., „The Sex pheromone of the female vine bud moth, Theresimima ampellophaga, Bayle-barelle (Lepidoptera: Zygaenidae), comprises (2R)-Butyl (7Z)-tetradecenoate„, J. Chem. Ecol., 24: 1141, 1998.

5) Coracini M.D.A., Reckziegel A., Bengtsson, Löfqvist J., Eira A. E., Vilela E.F., Wittzgall P., „Sex pheromone of the Brazilian apple leafroller, Bonagota cranaodes (Lepidoptera: Tortricidae): effect of geometric isomers on male attraction to (E,Z)-3,5-dodecadienyl acetate, IOBC wprs Bulletin, 22: 43, 1999.

6) Subchev M., Toshova T., Stanimirova, Stan G.H., Francke W., Reckziegel A., Ferreira, J.T.B.=⁼, Priesner, E., „1-Methylethyl octanoate, a New Lepidopteran Sex Pheromon from Bagworm, Megalophanes viciella (Denis & Schiffermüller) (Lepidoptera: Psychidae)„, J. Chem Ecol., 26:487,2000.

7) Zarbin P.H., Reckziegel A., Plass E., Borges M., Francke W., „Synthesis and biological activity of methyl 2,6,10-trimethyldodecanoate and methyl 2,6,10-trimethyltridecanoate: Sexual pheromones of the stink-bugs Euschistus heros and Piezodorus guildinii", J. Chem. Ecol., in progress.

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¹Inst. of Organic Chemistry - Univ. Hamburg, ²Inst. of Biology, Univ. Tübingen

A.Wada¹, Y. Isobe², R. Yamaoka³ & M. Ozaki³

The symbiosis is known in Japan between the ant, Camponotus japonicus and the larvae of lycaenid butterfly, Niphanda fusca. The ants take care of the larvae in their nest. On the other hand, the larvae offer the ants the secretion including a significant amount of glycine (76% of the total amino acid) besides glucose (75% of the total sugar) (Nomura et al., 1992).

Focusing on glycine in the secretion, we investigated the feeding threshold of the ants to glucose in the absence or the presence of glycine. The feeding thrshold of glucose was obviously decreased in a glycine concentration dependent manner.

We let the ants choose between plane glucose and glucose plus glycine. As the result, they preferably drank glucose plus glycine, even if the concentration of glycine was too low to induce their feeding behavior by itself.

We also found in some chemosensilla on the labial pulps of the ant that glycine synergistically enhanced the electrophysiological response to glucose.

These results suggested that glycine makes the secretion of the larvae attractive for the ants. This might be one of the motivations by which the ants assiduously feed to the larvae to get their secretion flavored by glycine.

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¹Venture Laboratory, Kyoto Institute of Technology, Kyoto, 606-8585 Japan;

²Dept. of Biology, Faculty of Science, Nara Women's University, Nara, 630-8506 Japan; ³Lab. of Chemical Ecology, Kyoto Institute of Technology, Kyoto, 606-8585 Japan, mamiko@ipc.kit.ac.jp

Erika Banchio, Graciela R. Valladares & Julio Zygadlo

Secondary plant metabolites or allelochemicals can be produced or accumulated as a response to insect feeding. Chemical changes induced by herbivores could be particularly important for aromatic or medicinal plants, specially if the specific compounds giving economic value to the plant are affected.

The present paper analyses chemical changes induced by Aphis gossypii Glover (Homoptera: Aphididae) feeding on Myntosthachis mollis (Kunth.) Griseb., a Lamiaceae native to Central Argentina with medicinal and aromatic uses in the region. We have dealt with monoterpenoids, since the most important compounds of M. mollis belong to this group, and given previous records of increased terpenoid production following herbivory in other plants. Ten samples of damaged and undamaged leaves, were collected from cultivated M. mollis plants. After hydrodistillation of the plant material, the volatile fraction was collected in hexane. Analyses were accomplished with a gas-chromatograph and a mass selective detector. Although 33 different compounds were recorded in the essential oils of M. mollis, two monoterpenes accounted for 70-90% of their volume: pulegone and menthone. Damaged leaves showed a remarkable increase in total monoterpene production (p<0.001. Wilcoxon Test) , which was 2.6 times higher than the value observed in undamaged leaves. Both pulegone (p=0.001) and in a lesser degree mentone (p=0.056) increased in damagted leaves.

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Centro de Investigaciones Entomológicas de Córdoba y Cátedra de Química Orgánica. FCEFyN. UNC. Av. V. Sarsfield 299. 5000 Córdoba - Argentina. banchioe@com.uncor.edu.

Bárbara Moreno-Murillo¹, María Luisa Salmerón², Víctor Fajardo² and Margoth Suárez M.¹

In our search for new natural bioactive compounds from native species, we have analyzed several extracts of plants of the genus Nicandra, Solanum, Jaborosa and Salpichroa belonging to the Solanaceae family. Salpichroa is a tropical genus with 22 species (1), some of them widely used as curative agents (2). Leaves and fruits of the vines Salpichroa diffusa Miers and S. tristis Miers, growing in highlands of Colombia were analyzed. Bioassay guided fractionation of these extracts yielded two compounds as major constituents that were characterized by their chemical and spectroscopic properties. The structures of the compounds were assigned by ¹H and ¹³CNMR, DEPT, HMQC and HMBC spectra, and those of their acylated derivatives. Compound 1, is present in leaves and stems of both species. From fresh leaves compound 2, an aromatic glycoside was the most abundant constituent and it shows moderate cytotoxicity in Brine Shrimp Test (LD₅₀ = 44 ppm). Also it presents notable antifeedant effects to Spodoptera sunia larvae analysis. Colciencias, DIB Universidad Nacional de Colombia and Universidad de Magallanes supported this work.

1- Hunziker, AT. 1979 South American Solanaceae: a synoptic survey IN: Biology and Taxonomy of Solanaceae , Hawkes lester & Skelding Eds. 49-86.

2- García- Barriga H. 1975 Flora Medicinal de Colombia Vol. III, 115.

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¹Departamento de Química-Facultad de Ciencias, Universidad Nacional de Colombia, Apdo. aéreo 27586, Santafé de Bogotá, DC 1, Colombia. bmorenom@ciencias.ciencias.unal.edu.co

²Facultad de Ciencias, Universidad de Magallanes, casilla 113-D, Punta Arenas. Chile.

Beatriz Grosso Fleury, Bernardo Antonio Perez da Gama e Renato Crespo Pereira

The search for antifouling agents among marine natural products is a novel proposal, not only in Brazil, but also abroad. Part of the great interest in this subject is due to the urgent need to substitute highly toxic agents (e.g., TBT) used nowadays in biocides, and to use products properly degradable under environmental conditions. As part of this continuing study, we recently performed experiments to evaluate the effect of natural concentrations of crude extracts of the macroalgae Dictyota mertensii, Laurencia sp. and the octocoral Renilla muelleri, upon the biofouling communities. Contrary to what was expected, our results from weekly monitoring of fouling in experimental plates, revealed that D. mertensii extract had a significant stimulating effect on the fouling by algal tufts, relative to the control and other treatments; the other extracts showed no effect upon fouling.

CNPq, IEAPM

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Departamento de Biologia Marinha, UFF, Niterói (RJ), Brasil _ C.P. 100644

Bird cherry-oat aphid, Rhopalosiphum padi (L.) belongs to aphid species that change host plants during their life cycle. The aphid alternates between primary host (Prunus padus L.) and secondary hosts (cereals). Phenology of this phenomenon has been extensively studied, nevertheless its mechanism is less known. The present paper reports on effect of phenolic compounds occurring in the bird cherry tissues on R. padi feeding behaviour.

Bird cherry-oat aphid migrates from primary host onto cereals in the middle of May. At that time, an increase in content of the phenolic compounds within the bird cherry leaves was noted. EPG (electrical penetration graphs) recordings showed that winged migrants of the aphid were not ingested any phloem sap from the primary host-plant. Most of the punctures were terminated in the peripheral tissues or ingestion of xylem sap was observed. Importance of changes in content of the phenolics in the primary host tissues and in the bird cherry-oat aphid feeding behaviour for its host-plant alternation is discussed.

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¹Department of Biochemistry, University of Podlasie, B. Prusa 12, PL-08110 Siedlce, Poland, leszczb@ap.siedlce.pl

²Department of Entomology, Agricultural University, Wageningen,

The Netherlands

Leszczynski Bogumil, Urbanska Anna, Jozwiak Beata

Bird cherry (Prunus padus L.) contains cyanogenic glycosides that generate highly toxic hydrogen cyanide. Thus it is important for all herbivores feeding on such cyanogenic plants to adapt towards these xenobiotics. Bird cherry-oat aphid (Rhopalosiphum padi L.) spends most of the spring feeding on P. padus leaves, however there is no information on its adaptation to the toxic HCN. The present paper reports on presence and activity of the aphid b-cyanoalanine synthase (E.C. 4.4.1.9) involved in detoxication of the cyanide.

The highest concentration of the cyanogenic glycosides and cyanide was found in the youngest leaves of the bird cherry. Later on, a constant decrease in level of the cyanogenesis in the primary host tissues was observed. Therefore, the first generations of the bird cherry-oat aphid, including fundatrix hatched from winter eggs, were mostly exposed to the toxic cyanide. The carried out experiments showed the highest activity of the b-cyanoalanine synthase in tissues of the early aphid generations. Importance of the induction of the enzyme activity in the aphids mostly exposed to the dietary cyanide is discussed.

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Department of Biochemistry, University of Podlasie, B. Prusa 12,

PL-08110 Siedlce, Poland, leszczb@ap.siedlce.pl

Urbanska Anna, Leszczynski Bogumil, Matok Henryk, Lukasik Iwona

Wide range of xenobiotics such as phenolics, hydroxamic acids or indole alkaloids play an important role in plant protection towards aphids. However, herbivores possess enzymes counteracting such plant metabolites. These enzymes were conveniently classified into: primary phase oxidoreductases and hydrolases and secondary phase transferases responsible for conjugations with endogenous sugars, amino acids, sulfate and phosphate. The present paper is focused on activity of glutathione transferase, UDP-glucosyl transferase, sulfotransferase and phosphotransferase in the grain aphid, Sitobion avenae (Fabr.) and bird cherry _ oat aphid, Rhopalosiphum padi (L.).

Activity of the all transferases has been detected in the both aphid species and much higher activity has been noted in larvae than within adult tissues. Moderately resistant cereal cultivars with relatively high content of the allelochemicals in flag leaf tissues exerted an inhibitory effect on activity of the UDP-glucosyl transferases. However, such cereal cultivars induced activity of the aphid glutathione transferase, sulfotransferase and phosphotransferase. The UDPglucosyl transferase had broad substrate specificity towards the plant phenolics naturally occurring within the cereal tissues. Importance of the conjugation reactions as defensive mechanisms of the aphid species towards the cereal xenobiotics is specified.

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Department of Biochemistry, University of Podlasie, B. Prusa 12,

PL-08 110 Siedlce, Poland, E-mail leszczb@ap.siedlce.pl

Urbanska Anna, Leszczynski Bogumil, Matok Henryk, Lukasik Iwona

Phenolic compounds are principal xenobiotics in plant resistance to aphids. They are highly toxic and consequently of that reduce aphids' growth, development and reproduction. However, aphids developed defensive mechanisms and thereby they are able to survive on cultivars with relatively high concentration of these xenobiotics. It is well known, that insects defensive metabolism towards plant phenolics consists mostly of oxidative reactions. The present paper concerns rapid oxidation of plant phenolics, in the grain aphid, Sitobion avenae (Fabr.) and bird cherry-oat aphid, Rhopalosiphum padi (L.) tissues, catalysed by the aphids' polyphenol oxidase and peroxidase.

Activity of the both oxidoreductases in the aphid tissues was mostly found within the alimentary tract and in the salivary secretions. The aphid enzymes were highly specific to the cereal phenolics. However, their activity in the aphid tissues, was not always corresponded to quantity of the phenolics in the cereal tissues exploited by the aphids. Activity of the studied enzymes within the bird cherry-oat aphid that alternates between woody and herbaceous plants differed depends on actually exploited host-plant. The obtained results point out that the studied oxidoreductases are involved in the aphid biochemical adaptation towards the plant phenolics.

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Department of Biochemistry, University of Podlasie, B. Prusa 12,

PL-08110 Siedlce, Poland, Email leszczb@ap.siedlce.pl

Carmen Pires¹, Edison Sujii¹, Miguel Borges¹, Francisco Schmidt¹ & Paulo Zarbin²

Previous studies showed that field traps baited with a synthetic racemic mixture of methyl 2,6,10-trimethyltridecanoate, a sex pheromone compound of the stink bug Euschistus heros (Borges et. al 1998a, J. Appl. Entomol.122:335-338), have caught different species of the soybean stink bug complex (Borges et. al 1998b, Physiol. Entomol. 23, 202-207). Additionally, it was found that the pheromone compounds methyl 2,6,10-trimethyldodecanoate and methyl 2,6,10-trimethyltridecanoate, are shared between two species of soybean stink bug, E. heros and Piezodorus guildinii (Borges et. al 1999, J. Chem. Ecol 25, 629-634). Based on these results we tested different compounds of sex pheromone of E. heros for monitoring the different species from the soybean stink bug complex. Field evaluation showed that the addition of the minor pheromone component methyl 2,6,10-trimethyldodecanoate and the major component 2,4 decadienoate to the methyl 2,6,10-trimethyltridecanoate does not change the species of stink bugs caught in the traps. Also, we found a similar number of individuals caught in field traps baited with methyl 2,6,10-trimethyltridecanoate alone and baited with a mixture of 2,4 decadienoate + methyl 2,6,10-trimethyldodecanoate + methyl 2,6,10-trimethyltridecanoate (55:3:42). Rubber septum impregnated with 1 ml of pheromone blend diluted in 140 ml of n-hexane remained active for more than 12 days in soybean field. Using a blend of the three pheromone compounds, we tested the efficiency of different trap designs in capturing and retaining the insects at field conditions.The most efficient model was the one modified from the "mesh perforated trap" model (Borges et. al 1998b), where one funnel was inserted inside the trap just below the insect entrance holes to avoid the escape of individuals. The traps caught more individuals when the insect entrance holes were located between 30-40 cm from the base of the plants than when they were located at the top of plant height or at 20 cm from the base of the plants. Preliminary field test showed that traps without pheromone lures also caught insects. We hypothesize that the brilliance of the traps might affect the trapping of the stink bugs. If it is true, we can associate the effect of the pheromone lure with the effect of the trap material and improve the effectiveness of the traps. Further studies are underway to test this hypothesis and to develop a method based on pheromone traps for monitoring of stink bugs.

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¹ Embrapa Recursos Genéticos e Biotecnologia, Cx. Postal 02372, Brasília, DF, 70.849-970, Brasil.

² Universidade Federal do Paraná, Depto. de Química, Curitiba, PR, 81.530-990, Brasil.

Carsten T. Müller¹, Manfred Beckmann¹ and Jörg D. Hardege²

Female specimen of the ragworm, Nereis succinea, employ cysteinyl-glutathione (CSSG) as mate recognition and gamete release pheromone during reproduction. The isolation of the pheromone also revealed that the concentration of CSSG in seawater, which had been exposed to female worms, appeared to be significantly higher than in coelomic fluid. The findings proposed that the females produce the pheromone in course of the reproductive behaviour rather than prior to it during e.g. metamorphosis.

This hypothesis was further investigated in a series of experiments, which tried to establish the rate of excretion and the concentration of CSSG in the coelomic fluid of mature female specimen. The rate of excretion was determined with the behavioural bioassay using the known threshold concentration of the behavioural response of male specimens. The concentrations of CSSG and those of the likely precursor reduced glutathione (GSH) and oxidised glutathione (GSSG) in coelomic fluid were determined by HPLC and LC-MS.

The experiments showed that female worms excrete 16.0 to 74,5µg/h CSSG over a period of at least two hours whilst the concentration of CSSG in the coelomic fluid varied between 10.7 and 14.7µM (1.4 to 1.9µg/female) within 24h. The amount of CSSG in the coelomic fluid is to low to account for excretion only providing further evidence that CSSG is produced during reproduction. This evidence is supported by the concentration profile of GSH, the likely precursor of CSSG. The concentration of GSH increased from 379 to 701µM after 12 hours and declined sharply from 701 to 180µM after a subsequent period of 12 hours. It appears that GSH is mobilised or synthesised and consumed in order to maintain a steady concentration of continuously excreted CSSG.

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1 Cardiff School of Biosciences, Cardiff University, Park Place, PO Box 915, Cardiff CF10 3TL, UK

2 School of Biological Sciences, University of Hull, Hull, HU6 7RX, UK

Christine Errard ¹, Cyril Astruc ^{1, 2} & Christian Malosse ³

Tetramorium bicarinatum (Myrmicinae) is an ant species frequently found in tropical and subtropical areas, particularly in Africa, in Southeast Asia (Japan) and in South America (Brazil). The species is polygynous, reproduces by budding and has sterile workers. Since the nests are widely distributed in a given area, the problem arise of territory defense against conspecifics. Because not all ants defend territories, we assessed defensive behavior of T. bicarinatum workers by intraspecific and interspecific aggression tests. A detailed behavioral study of the interactions between workers from several different colonies of T. bicarinatum (Japan and Brazil societies) showed that workers do not discriminate against conspecific non nestmate individuals while they strongly aggress allospecifics (Myrmica rubra, Myrmicinae). These results suggest that each colony of this ant species possess a nearly colonial odor. Cuticular hydrocarbon chemical studies of these species were made using gas chromatography coupled with mass spectrometry. Results showed that the different colonies of T. bicarinatum possess a common chemical profile mainly composed of straight-chain alkanes and alkenes while M. rubra possess more methyl branched alkanes. We suggest that methyl alkane cues have a determining role in colonial recognition and that these results could explain the underlaying basis of the T. bicarinatum lack of intraspecific aggression.

Index terms: Social Insects, Formicinae, intraspecific aggression, cuticular hydrocarbon profile, Tetramorium

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¹ Institut de Recherche sur la Biologie de l'Insecte, (UPRES.A CNRS 6035), Faculté des Sciences et Techniques, Parc de Grandmont, F-37200 Tours, France

² Laboratoire d'éthologie Expérimentale et Comparée, (CNRS 2214), Université Paris Nord, F-93420 Villetaneuse, France

³ Unité de Phytopharmacie et Médiateurs chimiques, I.N.R.A. de Versailles, F-78026 Versailles, France