Vários fitovírus são capazes de influenciar o comportamento e desenvolvimento biológico de seus insetos vetores de modo a favorecer sua disseminação entre plantas hospedeiras, mas pouco se sabe a respeito dos efeitos de infecções virais sobre moscas-brancas Bemisia tabaci (Genn.), uma vez que se trata de um complexo de espécies, que transmite vírus de diferentes gêneros com distintos modos de transmissão. Considerando-se a importância de B. tabaci como praga e vetora e o grande prejuízo causado a diversos cultivos devido à transmissão de fitovírus, o presente trabalho teve como objetivos: a) Investigar a preferência para pouso e o comportamento arrestante de B. tabaci MEAM 1 (Middle East-Asia Minor 1) em plantas de tomate não infectadas e infectadas com o crinivírus Tomato chlorosis virus (ToCV) transmitido de modo semipersistente, e o begomovírus persistente-circulativo, Tomato severe rugose virus (ToSRV); b) Avaliar os efeitos diretos e indiretos de ToCV sobre o desempenho biológico de B. tabaci MEAM 1 c) Comparar o comportamento alimentar de adultos não-virulíferos de B. tabaci MEAM 1 em plantas de tomate não infectadas e infectadas com ToCV ou ToSRV, utilizando-se a técnica de Electrical Penetration Graph (EPG); d) Correlacionar as atividades estiletares de B. tabaci MED (Mediterranean) com a inoculação de ToCV em tomateiro. Verificou-se que plantas infectadas com ToCV não exercem atração sobre B. tabaci MEAM 1; há efeito direto quando o inseto está virulífero; no entanto, este efeito não parece favorecer a disseminação de ToCV. Já ToSRV exerce efeito direto que favorece sua disseminação, pois insetos virulíferos são mais atraídos por plantas não infectadas. A mosca-branca exibe comportamento arrestante em plantas de tomate sadias, e tende a deixar plantas infectadas com ToCV ou ToSRV, sugerindo que tais vírus reduzem a qualidade nutricional da planta hospedeira. Em relação ao desenvolvimento biológico do inseto, observou-se efeito direto de ToCV apenas de alongamento da duração do primeiro ínstar ninfal, e efeito indireto negativo sobre a viabilidade da fase ninfal, pois apenas 32% das ninfas eclodidas chegaram à fase adulta em plantas infectadas, contrastando com 77% em plantas não infectadas. Nos ensaios de EPG, verificou-se que a infecção de plantas de tomate por ToCV ou ToSRV não influenciou o comportamento alimentar do vetor de modo a favorecer a transmissão desses vírus, pois afetou apenas parâmetros não relacionados às atividades floemáticas. A transmissão de ToCV está principalmente associada à salivação nos elementos de floema (forma de onda E1) (52,2% de plantas infectadas), mas pode ocorrer com baixa frequência antes de E1 (3,5%). Entretanto, há maior eficiência de transmissão quando os indivíduos realizam vários episódios de E1+E2 (ingestão de seiva nos vasos do floema). Os dados obtidos na presente tese ajudam a esclarecer um pouco mais as complexas relações entre B. tabaci e diferentes fitovírus, e como as respostas comportamentais podem variar em função do modo de transmissão. / Several phytoviruses are capable of influencing the behavior and biological development of their insect vectors in order to promote their spread among host plants, but information about the effects of viral infections on whiteflies Bemisia tabaci (Genn.) is not available, since it is a species complex, which transmits vírus belonging to different genus with distinct transmission modes. Considering B. tabaci importance as a pest and a vector and the great damage caused to several crops due to the transmission of phytovirus, the present work had as objectives: a) To investigate the preference for landing and the arrestant behavior of B. tabaci MEAM 1 (Middle East-Asia Minor 1) in non-infected and infected tomato plants with semi-persistent crinivirus, Tomato chlorosis virus (ToCV) and the persistent-circulative begomovirus, Tomato severe rugose virus (ToSRV); b) To evaluate the direct and indirect effects of ToCV on the biological performance of B. tabaci MEAM 1 c) To compare the feeding behavior of non-viruliferous B. tabaci MEAM 1 in non-infected and ToCV or ToSRV-infected tomato plants using the Electrical Penetration Graph (EPG) technique; d) Correlate the stylets activities of B. tabaci MED (Mediterranean) with the inoculation of ToCV in tomato. It has been found that ToCV-infected plants do not exert an attraction on B. tabaci MEAM 1; there is a direct effect when the insect is viruliferous, however, this effect does not seem to favor the spread of ToCV. ToSRV has a direct effect that favors its dissemination, as viruliferous insects are more attracted to non-infected plants. The whitefly exhibits an arrestment behavior on non-infected plants, and tends to leave plants infected by ToCV or ToSRV, suggesting that such viruses reduce the nutritional quality of the host plant. In relation to the biological development, we observed a direct effect of ToCV only on the first ninfal instar, and a negative indirect effect on nymphal viability, since only 32% of the initial individuals reached adulthood in ToCV-infected plants contrasting with 77% in non-infected plants. In the EPG tests, it was verified that the infection of tomato plants by ToCV or ToSRV did not influence the feeding behavior of the vector in order to favor the transmission of these viruses, since it affected only parameters not related to the phloem. The transmission of ToCV is mainly associated to salivation in the phloem elements (waveform E1) (52,2% of infected plants), but may occur in a low proportion before E1 (3,5%). However, there is a greater efficiency of transmission when individuals perform several episodes of E1 + E2 (phloem sieve elements). The data obtained in this thesis help to clarify a little more about the complex relationships between B.tabaci and different phytovirus, and how the behavioral responses may vary depending on the mode of transmission.

La présent étude examine aspect de l'écologie chimique de la Pyrale du maïs (Ostrinia nubilalis, Hübner, Lepidoptera: Crambidae). L’isolement reproducteur des phérotypes et leur spécialisation à la plante hôte ont reçu une attention particulière. Toutes les expériences ont été conçues pour avoir des informations pertinents sur le plan écologique des signaux chimiques libérés ou perçu par la Pyrale du maïs pendant la période de reproduction. La plupart des travaux en cadre de cette thèse dans des conditions naturelles et en tenant compte de tous les traits comportementaux de la Pyrale. Premièrement, le paysage chimique du champ de maïs a été étudié pour connaître les signaux chimiques rencontrés par une femelle de Pyrale du maïs qui est à la recherche d’une plante hôte. Les mélanges des volatiles qui composent l'environnement olfactif du champ de maïs a été identifié et leurs rôles discutés selon la biologie et le comportement d’oviposition de la Pyrale du maïs.Deuxièmement, en tenant compte de la périodicité du comportement de la Pyrale du maïs nous avons étudié les modifications circadiennes des profils des volatiles libérés par les plantes individuelles du maïs et par le champ du maïs.Troisièmement, le fidélité d’hôte plantes de la Pyrale du maïs a été étudié. Les volatiles libérés par différentes plantes hôtes au moment de vol d’oviposition ont été identifiés et le comportement de ponte a été étudié dans le tunnel du vol.Quatrièmement, les signaux chimiques impliqués dans l'isolement reproducteur des phérotypes de la Pyrale du maïs a été étudié. Nous nous sommes concentrés sur la phéromone mâle produite par les pinceaux androconiaux et sur leur rôle dans le comportement de cour. / The present PhD study investigates the aspect of chemical ecology in the European corn borer (ECB, Ostrinia nubilalis Hübner, Lepidoptera: Crambidae): pherotypes reproductive isolation and host plant specialisation.All the experiences were designed to have ecologically relevant information about the chemical signals released or perceived by ECB moth during the reproduction period. Most of the work was conducted close to natural conditions and taking into account all the behavioural traits of ECB.First we investigated what can be the chemical landscape of maize field for host-seeking ECB moth. The whole volatile blends that make up the olfactory environment of maize field biotope was identified according to the ECB oviposition behaviour (Paper I). Secondly taking into account the diel periodicity of ECB behaviour we studied the diel changes of volatile profiles released from maize plant and from maize field (Paper II). Thirdly, we studied the process of host fidelity within the ECB host plants. The volatiles released from different host plants at the time of ECB oviposition flight were identified and the oviposition behaviour was studied in wind tunnel to evidence the host plant preferences of ovipositing females (Paper III). Fourthly, we address the question on assortative mating in ECB pherotypes and we investigated the chemical signals involved in the reproductive isolation in ECB pherotypes. We focused on the male pheromone produced by hairpencils and on courtship behaviour (Paper IV).

O sul de Minas Gerais é a principal região produtora de morangos (Fragaria x ananassa Duch.) no Brasil. O ácaro-rajado, Tetranychus urticae Koch (Acari: Tetranychidae), é considerado uma das principais pragas do morangueiro no Brasil e em vários países. Uma prática importante na cultura do morango refere-se à cobertura de solo, usualmente realizada com filme de polietileno, porém além de ser caro gera resíduos muito persistentes no ambiente. Objetivou-se com este trabalho comparar a resistência de oito genótipos de morango (\'Albion\', \'IAC Guarani\', \'IAC Princesa Isabel\', \'Oso Grande\', IAC T-0104, IAC 12, IAC 4 e IAC 1.13) ao ácaro-rajado; determinar o efeito da cobertura de solo (com a polpa de café desidratada, conhecida como palha de café) nas pragas/ patógenos e ácaros predadores desta cultura; comparar a ocorrência de pragas, patógenos e inimigos naturais entre um cultivo orgânico e outro convencional de morango. Os resultados obtidos indicaram que \'IAC Princesa Isabel\', IAC T-0104 e IAC 12 são resistentes, IAC 1.13 e IAC 4 apresentam resistência moderada e \'IAC Guarani\', \'Oso Grande\' e \'Albion\' são suscetíveis ao ácaro-rajado. \'Oso Grande\' e \'Albion\' são bastante utilizadas pelos produtores do sul de Minas Gerais. O uso de palha de café aumentou o número de predadores edáficos, tanto no solo dos canteiros (campo) e em vasos (laboratório) como em folíolos de morangueiro. O Gamasina Proctolaelaps pygmaeus (Müller) (Melicharidae) foi visto sobre morangueiros, principalmente no período noturno. Maior número de ácaro-rajado e maior severidade de doenças foram observados em plantas cultivadas em solo coberto com polietileno. Além disso, foi maior o nível de infecção de ácaro-rajado pelo fungo Neozygites floridana (Weiser e Muma) em plantas cultivadas em solo coberto com palha de café. Não foi observada diferença significativa entre a produtividade da cultura em solo coberto com polietileno e em solo coberto com palha seca de café. Os resultados da comparação da ocorrência de ártropodes e patógenos entre sistema orgânico e convencional mostraram menor ocorrência de ácaro-rajado e predadores em cultivo de morangueiro convencional, porém ocorrência considerável de tripes, mosca-branca e mofo cinzento. A incidência de dendrofoma e mancha de pestalotia foi a mesma nos dois sistemas de cultivos. Os resultados sugerem a conveniência de se continuar o processo de desenvolvimento dos genótipos que se mostraram menos afetados pelo ácaro-rajado, para que estes possam no futuro ser utilizados pelos produtores, e a condução de estudos complementares, que avaliem o desempenho de cultivos em sistema orgânico que incorporem o uso da palha de café para a cobertura do solo. / The southern of Minas Gerais is the main region producing strawberries (Fragaria x ananassa Duch.) in Brazil. The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is considered one of the main strawberry pests in Brazil and in several countries. An important practice in strawberry cultivation refers to soil cover, which is usually made with polyethylene film, but it is expensive and generates very persistent residues in the environment. The objective of this study was to compare the resistance of eight strawberry genotypes (\'Albion\', \'IAC Guarani\', \'IAC Princesa Isabel\', \'Oso Grande\', IAC T-0104, IAC 12, IAC 4 and IAC 1.13); to determine the effect of soil cover (with dehydrated coffee pulp, known as coffee straw) on the pests mites/ pathogens and predatory mites of this crop; to compare the occurrence of pests, pathogens and natural enemies between an organic and a conventional strawberry crop. The results indicated that \'IAC Princesa Isabel\', IAC T-0104 and IAC 12 are resistant, IAC 4 and IAC 1.13 are moderately resistant, and \'IAC Guarani\', \'Oso Grande\' and \'Albion\' are susceptible to the two-spotted spider mite. \'Oso Grande\' and \'Albion\' are widely used by producers in the southern of Minas Gerais. The use of coffee straw increased the number of edaphic predators, both in the soil beds (field) and in pots (laboratory) as well as in strawberry leaflets. The Gamasina Proctolaelaps pygmaeus (Müller) (Melicharidae) was seen on strawberry leaftlets, mainly in the nocturnal period. Higher numbers of the two-spotted spider mites and disease severity were observed in plants grown on soil covered with polyethylene. In addition, the level of the two-spotted spider mite infected by the fungi Neozygites floridana (Weiser and Muma) was higher in plants cultivated in soil covered with coffee straw. No significant difference was observed between yield in soil covered with polyethylene and in soil covered with dry coffee straw. The results of the comparison of the occurrence of arthropods and pathogens between the organic and conventional systems showed fewer occurrences of the two-spotted spider mites and predators in conventional strawberry cultivation, but considerable occurrence of thrips, whitefly and gray mold. The incidence of dendrophoma and leaf spots caused by pestalotia was the same in both cropping systems. The results suggest the convenience to continue the development process of the genotypes that were less affected by the two-spotted spider mite, which could be used in the future by producers, and the conduction of complementary studies to evaluate the performance of crops in organic system that incorporate the use of coffee straw as soil coverage.

Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-04-12T12:45:11Z No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-04-13T11:08:09Z (GMT) No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-13T11:08:09Z (GMT). No. of bitstreams: 2 Dissertação - Vinícius Silva de Alvarenga - 2018.pdf: 1904835 bytes, checksum: bbe0e840d010a67f148c91a849dbbf10 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-03-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Understanding how interactions between trophic levels structure species composition is one of the main goals of ecological studies. Mechanisms that explain the compositional structure of parasitoid insects usually neglect the direct and indirect effects of plants’ characteristics, which can also determine the compositional structure of their host herbivore insects. In this context, our goal was to evaluate how plants’ characteristics (abundance, floral phenology, and phylogenetic distance) and herbivores’ compositional similarity determine parasitoids’ compositional similarity. As study system, we used Asteraceae species, flower-head feeding insects, and parasitoids. Using path analysis, we considered parasitoids and herbivores’ similarities, in qualitative (Sørensen similarity), quantitative (Bray-Curtis similarity), and phylogenetic proximity (taxonomic Sørensen similarity) terms. In general, we demonstrated that herbivores’ similarity is the major predictor of parasitoids’ similarity. Even though the effects of plants’ characteristics explained the smallest part of the variation in parasitoids’ similarity, these characteristics had inconsistent relative importance among the similarity indexes used here. Thus, our results indicate that although plant species constitute a potential additional barrier for the parasitoids of endophagous herbivores to find their insect hosts, herbivore parasitoids in flower heads of Asteraceae do not see the plant species in this way. The parasitoids respond mainly to the compositional variation of their insect hosts in the plant species that the latter consume. Therefore, we show how the composition of the upper trophic levels in this tri-trophic system is structured directly and indirectly by antagonistic interactions. / Entender quais fatores influenciam a variação na composição de espécies em sistemas multitróficos é um objetivo fundamental em ecologia. Entretanto, estudos sobre a composição local de insetos parasitoides geralmente negligenciam a importância relativa das características de plantas consumidas por seus insetos herbívoros hospedeiros. Neste contexto, nosso objetivo foi avaliar os efeitos diretos e indiretos, mediados pela similaridade de herbívoros, da distância filogenética, da sincronia do período de floração e da similaridade de abundância das plantas sobre a similaridade de parasitoides. Como sistema de estudo, usamos espécies de Asteraceae, herbívoros endófagos de capítulos e insetos parasitoides. Usando análises de rotas, consideramos as similaridades de herbívoros e parasitoides entre pares de espécies de plantas em termos qualitativos (similaridade de Sørensen), quantitativos (similaridade de Bray-Curtis) e filogenéticos (similaridade de Sørensen taxonômica). Em geral, demonstramos que a similaridade de herbívoros é o principal determinante da similaridade de parasitoides. Mesmo que as características das plantas tenham explicado a menor parte da variação na similaridade de parasitoides, essas características tiveram importâncias relativas inconsistentes entre os índices de similaridade usados. Dessa forma, nossos resultados indicam que, apesar das espécies de plantas constituírem uma barreira adicional potencial para os parasitoides de herbívoros endófagos encontrarem os seus hospedeiros, os parasitoides de herbívoros em capítulos de Asteraceae não as enxergam dessa forma. Estes parasitoides respondem principalmente à variação composicional dos seus hospedeiros nas plantas que estes últimos consumem. Logo, demonstramos como as composições dos níveis tróficos superiores nesse sistema tri-trófico é estruturado diretamente e indiretamente por interações antagônicas.

Onion thrips (Thrips tabaci) and Iris Yellow Spot Virus (IYSV) constitute a pest complex of global concern for allium growers. Yield losses due to onion thrips alone can be heavy, and in tandem with IYSV, these losses can be complete. This study was one phase of a multi-phase research project intent on exploring the potential drivers of thrips and virus infestation in onion. Preliminary observations in participating growers’ fields in northern Utah pointed towards a potential link between weedy field borders and thrips/IYSV infestation in onion. Field work was carried out at the Kaysville experiment station examining the possible relationships between thrips and IYSV incidence in onion and the presence of adjacent weed populations. This research was conducted with the intent of guiding growers’ decisions regarding field border management, and to provide additional insights into onion thrips behavior. While implications for growers remain unclear, thrips preferences regarding host plant utilization were identified, as well as preliminary evidence of additional plant species capable of hosting IYSV.

Host-Associated Differentiation (HAD) is the formation of genetically divergent hostassociated lineages maintained by ecological isolation. HAD is potentially an important route to ecological speciation in parasites including many insects. While HAD case studies are accumulating, there is a dearth of negative results in the literature making it difficult to know how common the phenomenon really is or whether there are specific traits of parasites which promote HAD. To address these two problems, studies are needed which both publish negative results (i.e., parasites not showing HAD) and test for HAD in multiple parasite species on the same pair of host species (i.e., control for host plant effects). In this study, HAD was tested in three species of herbivorous insects and one parasitoid species on the same two host tree species: pecan and water hickory. The insects were selected based on the presence or absence of two traits, parthenogenesis and endophagy. A test for HAD was considered “positive” when population substructure was explained by host-association. To test for the presence of HAD, insects were sampled sympatrically to eliminate geographical isolation as a confounding factor, sampling was replicated spatially to assure that HAD persisted, and multiple loci were sampled from each individual. Genetic data was analyzed using cluster analyses. HAD was found in both pecan leaf phylloxera and yellow pecan aphid but not in pecan bud moth or in the parasitoid of the yellow pecan aphid, Aphelinus perpallidus. Interestingly, both taxa showing HAD are parthenogenetic and both taxa not showing HAD reproduce sexually. Species showing HAD were tested for the presence of a pre-mating reproductive isolating mechanism (RIM) which could be maintaining HAD despite the potential for gene flow. Selection against migrants to the alternative host was tested in yellow pecan aphid using a no-choice fitness experiment. The overall contribution of this RIM to total isolation was positive and ranged from 0.614 to 0.850. The RIM of “habitat preference” was tested in pecan leaf phylloxera using a dual-choice preference experiment. In this species, preference was only detected for phylloxera originating from water hickory suggesting that host discrimination ability may be a less important factor promoting differentiation in phylloxera.

The present PhD study investigates the aspect of chemical ecology in the European corn borer (ECB, Ostrinia nubilalis Hübner, Lepidoptera: Crambidae): pherotypes reproductive isolation and host plant specialisation.All the experiences were designed to have ecologically relevant information about the chemical signals released or perceived by ECB moth during the reproduction period. Most of the work was conducted close to natural conditions and taking into account all the behavioural traits of ECB.First we investigated what can be the chemical landscape of maize field for host-seeking ECB moth. The whole volatile blends that make up the olfactory environment of maize field biotope was identified according to the ECB oviposition behaviour (Paper I). Secondly taking into account the diel periodicity of ECB behaviour we studied the diel changes of volatile profiles released from maize plant and from maize field (Paper II). Thirdly, we studied the process of host fidelity within the ECB host plants. The volatiles released from different host plants at the time of ECB oviposition flight were identified and the oviposition behaviour was studied in wind tunnel to evidence the host plant preferences of ovipositing females (Paper III). Fourthly, we address the question on assortative mating in ECB pherotypes and we investigated the chemical signals involved in the reproductive isolation in ECB pherotypes. We focused on the male pheromone produced by hairpencils and on courtship behaviour (Paper IV).

Made available in DSpace on 2015-03-26T13:30:46Z (GMT). No. of bitstreams: 1 texto completo.pdf: 315546 bytes, checksum: 7c3954ee8525d69ec5427b4b0a3dbabb (MD5) Previous issue date: 2006-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The present thesis had the aim to study the importance of the host plant to the reproductive behavior of L. coffeella. At first, the following aspects were evaluated: (i) the effect of the reproductive condition of females in response to host plant volatiles; (ii) if mating proportion, initiation time and copulation duration are affected by the presence of volatiles in the host plant; (iii) and if females of L. coffeella, under no choice conditions, may be able to lay eggs in an alternative host. The efficiency of the mating disruption technique of males as a control method for this insect was also studied. In addition, the efficiency of PB-Rope dispensers was tested under low population conditions of adults in the field. These PB-Rope dispensers were used in order to saturate the environment with synthetic sexual pheromone and consist of a polyethylene tube containing 200 mg of 5,9-dimethylpentadecane, produced by Shin-Etsu Chemical Co. Ltd (Tokyo, Japan). In order to do so, the following hypotheses were tested: (i) that the PB-Rope dispenser provokes disorientation in males of L. coffeella in the areas treated with pheromone and (ii) that mating disruption leads to a decrease of lesions caused to the genus L. coffeella. In the first work, it was evidenced that only the volatiles emitted by the plant do not comprise relevant clue for females to spot their host. Nevertheless, they play an important role during the mating process. When another non-host plant was offered to the females as an oviposition site, it was observed that there was a considerable reduction in the number of laid eggs, indicating that females use cues of the host plant for oviposition. In the second work, the number of males captured in the pheromone traps in the treated area was reduced in relation to the control areas; however, the damage that this insect causes to the plantation was not different between the treated areas and the control areas. In this case, it was not possible to quantify the efficiency of the technique because the same levels of mined leaves and eggs were found in both areas. / Nesta tese foi estudada a importância da planta hospedeira no comportamento reprodutivo de L. coffeella. Inicialmente avaliou-se: (i) o efeito da condição reprodutiva das fêmeas em resposta aos voláteis da planta hospedeira; (ii) se a proporção de acasalamento, tempo de início e duração da cópula são afetadas pela presença de voláteis da planta hospedeira; (iii) e se fêmeas de L. coffeella, em condições de não escolha, podem ovipositar em hospedeiro alternativo. Foi estudada também a eficiência da técnica de confusão sexual de machos como método de controle deste inseto. Foi testada a eficiência dos liberadores de feromônio PB-Rope em condições de baixa população de adultos em campo. Estes liberadores PB-Rope foram usados para saturar o ambiente com feromônio sexual sintético e consistem de um tubo afilado de polietileno contendo 200 mg de 5,9-dimetilpentadecano, fabricados pela Shin-Etsu Chemical Co. Ltda (Tókio, Japão). Para isto testaram-se as hipóteses: (i) de que nas áreas tratadas com feromônio, o liberador PBRope provoca desorientação nos machos de L. coffeella e (ii) que a confusão sexual leva a redução das injúrias causadas ao cafeeiro por L. coffeella. No primeiro trabalho, ficou evidenciado que os voláteis sozinhos emitidos pela planta não constituem pista relevante para as fêmeas localizarem seu hospedeiro, porém têm papel importante durante o acasalamento. Quando ofereceu-se às fêmeas outra planta não hospedeira como sítio de oviposição, pode-se observar uma redução considerável no número de ovos depositados, indicando que as fêmeas usam pistas da planta hospedeira para a oviposição. No segundo trabalho, o número de machos capturados nas armadilhas de feromônio nas áreas tratadas foi reduzido em relação às áreas controles, mas, o dano deste inseto à lavoura não foi diferente entre as áreas tratadas e áreas controles. Neste caso, não foi possível quantificar a eficiência da técnica porque os mesmos níveis de folhas minadas e ovos foram encontrados em ambas as áreas.

The post-embryonic development of Caligo illioneus (Cramer, 1775) (Lepidoptera, Nymphalidae, Brassolinae) feeding on leaves of Heliconia bihai (L.) L. (Heliconiaceae), in laboratory. This study involved the following aspects: determination of larval (duration the instars, in days) and pupal stadia; the sex ratio and the viability of the eggs under laboratory conditions. Eggs and larvaes of C. illioneus were collected in leaves of H. wagneriana Petersen and maintained in the laboratory to register the dates of biological events (hatching, ecdysis, death, pupation and emergence of adults), and larvae behavior. The post-embryonic period (in days, average ± standard error) was 54,58 ± 0,44. The larval period had 40,00 ± 0,43 days and this period were represented by five instars: L1= 7,88 ± 0,23; L2= 6,42 ± 0,16; L3= 5,19 ± 0,25; L4= 7,04 ± 0,19 and L5= 13,46 ± 0,28 (the active larval period was 12,46 ± 0,28 followed by an one day prepupal period). The pupal instar was 14,58 ± 0,20 and the inactive period of the post-embryonic development was 15,58 ± 0,20. Were obtained 26 adults (the sex ratio was 0,46), that represented 56,52% of the eggs viability and 76,47% of the neonates. The morphometric analysis indicates that it is possible estimate the larval development phase based on the width of cephalic capsules, considering intervals values (in mm): L1= 1,457―1,605; L2= 1,951―2,272; L3= 3,139―3,488; L4= 4,970―5,600; L5= 7,423―8,557. The biological control agents, that naturally parasitized the imatures (egg and pupae) of C. illioneus were specimens of Conura maculata (Fabricius, 1758) (Hymenoptera: Chalcididae: Chalcidini) pupae parasitoids and a singly puparium (Diptera). For one egg were recorded specimens of Eulophidae (Hymenoptera) egg parasitoids. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Desenvolvimento pós-embrionário de Caligo illioneus (Cramer, 1775) (Lepidoptera, Nymphalidae, Brassolinae) alimentando-se de folhas de Heliconia bihai (L.) L. (Heliconiaceae), em laboratório. Este estudo foi desenvolvido visando os seguintes aspectos: a determinação dos estádios (duração de instares, em dias) dos períodos larval e pupal; a razão sexual e a viabilidade dos ovos, em condições de laboratório. Ovos e larvas de C. illioneus foram coletados em folhas de H. wagneriana Petersen e acompanhados em laboratório para o registro dos eventos biológicos (eclosão, ecdises, mortes, pupação e emergência dos adultos) e observação do com portamento de cinco larvas. O período pós-embrionário teve uma duração (média ± erro-padrão), em dias de 54,58 ± 0,44. O período larval foi de 40,00 ± 0,43 dias, sendo representado por cinco instares: L1= 7,88 ± 0,23; L2= 6,42 ± 0,16; L3= 5,19 ± 0,25; L4= 7,04 ± 0,19 e L5= 13,46 ± 0,28 (sendo o período larval ativo de 12,46 ± 0,28, seguido de apenas um dia de prepupa). O período pupal foi de 14,58 ± 0,20 e o período inativo do desenvolvimento pós-embrionário foi de 15,58 ± 0,20. Ao final do acompanhamento, foram obtidos 26 adultos (razão sexual de 0,46), o que representou uma viabilidade de 56,52% do total de ovos e de 76,47% dos neonatos obtidos. A análise morfométrica demonstrou que a indicação da fase de desenvolvimento larval de C. illioneus pode ser realizada com base na largura das cápsulas cefálicas, considerando os seguintes intervalos (em mm): L1= 1,457―1,605; L2= 1,951―2,272; L3= 3,139―3,488; L4= 4,970―5,600; L5= 7,423―8,557). Os agentes de controle biológico que naturalmente parasitaram os imaturos (ovo e pupa) da espécie C. illioneus foram parasitóides de pupa: Conura maculata (Fabricius, 1758) (Hymenoptera: Chalcididae: Chalcidini) e um único pupário de Diptera. Apenas um ovo estava parasitado por espécimes da família Eulophidae (Hymenoptera).

By warning signalling prey advertises its unpalatability to the predators. Typical examples are true bugs (Heteroptera) combining optical and chemical signals. The aim of this study was to find out the effectiveness of chemical defence against wild-caught adults of great tits (Parus major) and blue tits (Cyanistes caeruleus) and towards hand-reared juveniles of great tits. The tested prey were adults and larvae of two invasive species of genus Oxycarenus (Heteroptera: Oxycarenidae) (aposematic O. lavaterae, non-aposematic O. hyalinipennis), adults of Horvathiolus superbus (Heteroptera: Lygaeidae) and crickets (Gryllus assimilis) as a control prey. We were focusing on the influence of seed bugs to the initial reaction, the learning process and to the displays of discomfort behaviour in tits. Reactions affected by the tit species, age and sex were compared in adults. Juveniles were divided into two independent experimental groups, one group was offered adults of genus Oxycarenus, the second was offered sunflower (Helianthus sp.) or Digitalis sp. seed fed adults of H. superbus. The first bug offered did not elicit an initial aversive reaction in tits, but birds reacted aversively to the bugs after having further handling experience. All juveniles, contrary to the adult tits, attacked at least one bug...