Recebido em 16/1/09; aceito em 17/3/09; publicado na web em 2/4/09INSECT PHEROMONES: TECHNOLOGY AND CHALLENGES FOR A COMPETITIVE AGRICULTURE IN BRAZIL. Pheromones are chemical compounds used by species to communicate intra and inter specifically. As strategy of integrated pest management (IPM), the use of these compounds allows the monitoring of target insects that results in more reliable interventions and consequently avoiding unnecessary use of pesticides. In certain crops these compounds are used as a control measure, not only monitoring. The Brazilian agriculture has a portfolio of 49 major crops that are attacked by 447 species of insects. Of this total, 103 species have already been the subject of study in the research with pheromones. Currently, in the Brazilian market, 28 pheromone products are indicated for the control of 19 insect pests. However, these products are not used regularly in major crops of the country. This stems from the lack of implementation of IPM of these crops. While the research focused on the main species of agribusiness pests, marked of pheromones products is serving to more marginal crops like apples and peaches at the expense of major crops like soybean and corn.Keywords: pheromones; Brazilian agriculture; pest control. introduÇÃo os semioquímicosOs insetos exercem suas relações ecológicas com o ambiente e com os outros organismos de várias maneiras, sendo uma das mais importantes a comunicação por meio de compostos químicos. Estes compostos no indivíduo receptor da mensagem química agem como gatilhos fisiológicos de reações comportamentais específicas. Em uma nomenclatura mais generalista estas substâncias são denominadas de semioquímicos. É através da detecção e emissão destes compostos que os insetos encontram parceiros para o acasalamento, alimento ou presa, escolhem local de oviposição, se defendem contra predadores e organizam suas comunidades, no caso dos insetos sociais.A origem semântica da palavra semioquímico está relacionada com a palavra grega semeîon, que significa sinal, portanto, são designados de semioquímicos (sinais químicos) os compostos utilizados na intermediação de relações entre os seres vivos. Os semioquímicos possuem duas classificações; a primeira está relacionada com a espé-cie do emissor e do receptor do sinal químico, e a segunda, de acordo com os resultados decorrentes desta comunicação.Quando os compostos são mediadores de comunicação intraespecífica, ou seja, emissor e receptor do sinal químico são da mesma espécie, este semioquímico é denominado de feromônio. No entanto, quando estes compostos intermedeiam comportamentos de indivíduos de espécies diferentes, relação denominada de interespecífica, estas substâncias são classificadas como aleloquímicos (Figura 1). 1 Entre os insetos, diferentes tipos de feromônios são reconhecidos através dos comportamentos que estes compostos produzem no receptor da mensagem. Os comportamentos mais comuns mediados por feromônio são: a atração de indivíduos do sexo oposto para acasalamento, denominados de feromôni...

Phthia picta is part of a complex of true bugs (Heteroptera) in Brazil that attack tomatoes, being particularly damaging because nymphs and adults feed on both leaves and fruit. Gas chromatography (GC) of aeration extracts of adult males vs. females revealed the presence of a male-specific compound. GC-electroantennographic detector experiments indicated that the antennae of females are highly sensitive to this male-specific compound. GC-mass spectrometry and GC-FTIR analyses suggested a methyl branched hydrocarbon structure for this compound. After synthesis of three different proposed structures, the natural product was indentified as 5,9,17-trimethylhenicosane, which was strongly attractive to females in Y-tube olfactometer bioassays. Analysis of dissected body parts of adults revealed that the pheromone is produced in the lateral accessory glands of the metathoracic scent gland of males only.

Edessa meditabunda is a secondary pest within the piercing-sucking stink bug complex that attacks soybean crops in Brazil. The behavioral responses of males and females to aeration extracts from conspecifics suggested the presence of a male-produced sex pheromone. Gas chromatographic (GC) analysis of male and female aeration extracts revealed the presence of two male-specific compounds in a ratio of 92:8. Gas chromatographic -electroantennographic detection (GC-EAD) assays indicated that the major component is bioactive for females, supporting the behavioral data. Analysis of the mass and infrared spectra of the male-specific compounds suggested that they were both methyl-branched long-chain methyl esters. On the basis of the mass spectra of the respective hydrocarbons obtained by micro derivatizations, the structures of these methyl esters were proposed to be methyl 4,8,12-trimethylpentadecanoate (major) and methyl 4,8,12-trimethyltetradecanoate (minor). An 11 step synthetic route that was based on a sequence of Grignard reactions, starting from cyclopropyl methyl ketone, was developed to obtain synthetic standards with a 7.9 % overall yield for the major compound and a 9.9 % yield for the minor. The synthetic standards co-eluted with the natural pheromones on three different GC stationary phases. Y-tube olfactometer assays showed that the synthetic standards, including the major compound alone and a mixture of the major and minor compounds in the proportion found in natural extracts, were strongly attractive to females.

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