Navegando por Autor "Lima, Eraldo R."

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Avaliação do comportamento reprodutivo e do feromônio sexual sintético de Mocis latipes (Guenée) (Lepidoptera: Noctuidae)
(Anais da Sociedade Entomológica do Brasil, 1998-03) Lima, Eraldo R.; Vilela, Evaldo F.; Sanchez, Germán R.
Durante a escotofase, fêmeas de Mocis latipes (Guenée) pousaram em superfícies verticais e iniciaram o comportamento de chamamento aos machos, abaixando levemente as asas, levantando o final do abdômen e protraindo o ovipositor. As fêmeas começaram a chamar a partir do 2º dia de idade, sendo o pico de chamamento no 4º dia. O início do chamamento aconteceu na 2ª hora da escotofase e o máximo de indivíduos chamando aconteceu na 3ªhora. As proporções entre os componentes (Z,Z,Z)-3,6,9-heneicosatrieno e o (Z,Z)-6,9-heneicosadieno de 70:30 e 60:40 mostraram ser as mais atrativas aos machos de M. latipes em túnel-de-vento. Os machos iniciaram a resposta às fêmeas 24 h após a emergência, na 3ª hora da escotofase. São descritas as seqüências de corte e cópula e apresentada uma análise comparativa do comportamento reprodutivo de M. latipes e Anticarsia gemmatalis (Hübner).
Coffee leaf volatiles and egg laying by the coffee leaf miner Leucoptera coffeella
(Crop Protection, 2008-06) Magalhães, Sérgio Tinôco V.; Guedes, Raul Narciso C.; Lima, Eraldo R.; Demuner, Antonio J.
Recent reports of coffee genotypes resistant to one of its key pests in the Neotropical region, the leaf miner Leucoptera coffeella (Lepidoptera: Lyonetiidae), sparked studies trying to recognize the underlying causes of resistance. An association between increased egg laying by the leaf miner and increased caffeine levels in coffee leaves was recently recognized. However, since caffeine is not volatile, its effect on egg laying is likely aided by a volatile compound. This was the hypothesis tested here. Coffee leaf volatiles from 12 coffee genotypes were collected, analyzed (gas chromatograph coupled with a mass spectrometer (CG/MS)) and tested for electrophysiological activity (EAG). The active volatiles thus recognized were subjected to partial correlation against the density of eggs laid by the leaf miner in each coffee genotype. The volatile showing significant positive correlation, p-cymene, was subjected to an attraction test in a four-arm olfactometer confirming its biological activity and providing evidence of its role stimulating egg laying by the coffee leaf miner.
Evaluation of porous silica glasses as insect pheromone dispensers
(Journal of the Brazilian Chemical Society, 2008) Tiboni, Aline; Coracini, Miryan D. A.; Lima, Eraldo R.; Zarbin, Paulo H. G.; Zarbin, Aldo J. G.
This work demonstrates the viability and advantages of using porous silica glass as an insect pheromone dispenser, in order to control insect population in agriculture. Pieces of so-called Porous Vycor Glass (PVG) were impregnated with pheromones of different insects (both consisting of a single compound or a mixture of compounds). Studies were conducted to characterize the impregnated-PVG and to determine the pheromone release ratio under laboratory conditions. The practical application was verified in two different plantation areas, using the PVG impregnated with pheromone from Grapholita molesta (Lepidoptera: Tortricidae) and Leucoptera coffeella (Lepidoptera: Lyonetiidae), the main pests of apple and coffee plantations in Brazil, respectively. The release rate was dependent on the interaction between the molecules of the impregnated pheromone and the surface of the PVG pores. A good performance of the porous glass was observed, similar to that of rubber septa commercially used as pheromone dispensers.
Female sex pheromones in the host races and hybrids of the fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae)
(Chemoecology, 2009-02-11) Lima, Eraldo R.; McNeil, Jeremy N.
The three major pheromone components found in gland extracts of both rice and corn strain Spodoptera frugiperda virgin females were Z9-14:Ac, Z11-16:Ac and Z7-12:Ac, However, both the concentrations and relative proportions of the compounds varied significantly between strains as a function of female age and the time during the scotophase that the glands were extracted. The concentration of Z9-14:Ac found in the glands of hybrid females, coming from corn × rice and rice × corn crosses differed significantly, but in both cases did not differ significantly from that of maternal line females. The results suggest that synthesis is controlled, at least in part, by the W chromosome. Given the intraspecific variability reported in other species of Lepidoptera, both with respect to female pheromone production and male responsiveness, it would appear rather unlikely that these differences alone would be sufficient to ensure reproductive isolation of the two strains.
Feromônios de insetos: tecnologia e desafios para uma agricultura competitiva no Brasil
(Química Nova, 2009) Lima, Eraldo R.; Zarbin, Paulo H. G.; Rodrigues, Mauro A. C. M.
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.
Identification (GC and GC-MS) of unsaturated acetates in Elasmopalpus lignosellus and their biological activity (GC-EAD and EAG)
(Journal of Separation Science, 2004-12-15) Jham, Gulab N.; Silva, Alexsandro A. da; Lima, Eraldo R.; Viana, Paulo
Two insect colonies of Elasmopalpus lignosellus were reared in our laboratory, the first being initiated from pupae obtained from a cornfield in the region of Sete Lagoas, Minas Gerais and the second from a cornfield in the region of Goiânia, Goiás. From the two colonies, two extracts were prepared from the pheromone glands of virgin E. lignosellus females. The extract obtained from the first colony was designated as extract 1 while the extract obtained from the second colony was designated as extract 2. Extract 1 was analyzed by gas chromatography-mass spectrometry (GC-MS) with (Z)-9-hexadecenyl acetate [(Z)-9-HDA] and (Z)-11-hexadecenyl acetate [(Z)-11-HDA] being identified and confirmed by the formation of DMDS derivatives. In addition, a third acetate, which could be either (E)-8-hexadecenyl acetate [(E)-8-HDA] or (E)-9-hexadecenyl acetate [(E)-9-HDA] was detected by GC-MS. Extract 2 was analyzed by gas chromatography (GC) and gas chromatography-electroannetography (GC-EAD) revealing the presence of (Z)-11-HDA and (Z)-9-TDA. In addition, the same compounds elicited a response with the E. lignosellus male antenna obtained from the second insect colony. Electroantennography (EAG) screening with the male E. lignosellus antenna (obtained from the second insect colony) was conducted with the 23 possible tetradecenyl acetates (TDA) and 22 hexadecenyl acetates (HDA) as standards. Out of the 23 TDA isomers evaluated, only (Z)-9-TDA elicited a response and out of the 22 HDA [(Z) and (E) isomers gamma2 to delta13] evaluated only (Z)-11-HDA elicited a response. The acetate compositions of two extracts obtained from insects originating from the two states (Minas Gerais and Goiás) of Brazil were different from one another as well as from that obtained from insects in Tifton, GA, USA. The bioactivity data (GC-EAD) of the extract 2 differed from those reported for the Tifton, GA, USA population. These data suggest polymorphism in relation to the insect populations found in Brazil and in the USA. The possibility of the existence of an E. lignosellus sub-species cannot be ruled out.
Identification of acetates in Elasmopalpulus lignosellus pheromone glands using a newly created mass spectral database and kóvats retention indices
(Química Nova, 2007-07) Jham, Gulab N.; Silva, Alexsandro A. da; Lima, Eraldo R.; Viana, Paulo A.
Based on a specially created mass spectral database utilizing 23 tetradecenyl and 22 hexadecenyl acetate standards along with Kóvats retention indices obtained on a very polar stationary phase [poly (biscyanopropyl siloxane)] (SP 2340), (Z)-9-hexadecenyl acetate, (Z)-11-hexadecenyl acetate and (E)-8-hexadecenyl acetate were identified in active pheromone extracts of Elasmopalpus lignosellus. This identification was more efficient than our previous study using gas chromatography/mass spectrometry with a dimethyl disulfide derivative where we could only identify the first two acetates. The acetate composition of the pheromone gland differed from region to region in Brazil and from that from the Tifton (GA, USA) population, suggesting polymorphism or a different sub-species.
Insecticide toxicity to Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) females and effect on descendant generation
(Ecotoxicology, 2008-10-18) Vianna, Ulysses R.; Pratissoli, Dirceu; Zanuncio, José C.; Lima, Eraldo R.; Brunner, Jay; Pereira, Fabrı́cio F.; Serrão, José E.
The effect of nine insecticides used in tomato production was evaluated on adults of two Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae) populations from Rive and Afonso Cláudio, Espírito Santo State, Brazil. The experiment was developed in an acclimatized chamber at 25 ± 1°C, 70 ± 10% relative humidity and 14 h photophase. Eggs of Anagasta kuehniella (Lepidoptera: Pyralidae), previously immersed in insecticides solutions were offered to females of both T. pretiosum populations. Bacillus thuringiensis, lufenuron and triflumuron had lowest negative effects on parasitism and viability of individuals of these populations; however, abamectin and pyrethroids (betacyflurin 50 and 125 g/l and esfenvalerate) insecticides reduced parasitism rates. T. pretiosum emerged from A. kuehniella eggs treated with esfenvalerate but were not able to parasitize non treated eggs of this host. B. thuringiensis, lufenuron and triflumuron may be used in integrated pest management programs to control tomato pests, because they have moderated negative effect on parasitoid wasps.
Note on gynandromorphism in the eucalyptus defoliator Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae)
(Anais da Academia Brasileira de Ciências, 2007-02-21) Bernardino, Aline S.; Zanuncio, Teresinha V.; Zanuncio, José C.; Lima, Eraldo R.; Serrão, José E.
The brown moth Thyrinteina arnobia (Stoll, 1872) (Lepidoptera: Geometridae) is an important pest in Brazilian eucalyptus plantations. A gynandromorph individual of T. arnobia was found in a population of this pest in a laboratory rearing and it is described.
Pupal period affects calling behavior of the wheat moth, Pseudaletia sequax (Lepidoptera: Noctuidae)
(Ethology, 2008-04-09) Almeida, Ângela A.; Lima, Eraldo R.; Reis Jr, Ronaldo
The effects of pupal period and age on calling behavior of virgin females of Pseudaletia sequax were determined. Calling behavior of groups of females of similar age of pupation was observed every 10 min for six calling days. Females were considered calling when they assumed a characteristic position: wings and abdomen elevated, displaying the ovipositor and presumably releasing pheromone. Calling behavior was discontinuous. Females with a shorter pupal period took more time to start calling than females with a longer pupal period and called for a longer period. On the first day of calling, females took more time to initiate calling, on average during the seventh hour of the scotophase, whereas on the second day of calling, most females initiated calling during the fifth hour of the scotophase. On subsequent days of calling, the average time to initiate calling changed to the fourth hour of the scotophase. The mean time of calling per day decreased significantly with the number of days since first calling, and the mean number of calling bouts increased with days since first calling.
Queen adoption in colonies of the leaf-cutting ant Acromyrmex subterraneus molestans (Hymenoptera: Formicidae)
(Behavioural Processes, 2005-08-31) Souza, Danival J.; Lucia, Terezinha M.C.Della; Lima, Eraldo R.
Bioassays were conducted in both laboratory and the field to determine if monogynous colonies of Acromyrmex subterraneus molestans (Myrmicinae, Attini) adopt queens from other colonies of the same subspecies. The results suggest that the adoption of fertilized queens is a possible mechanism to explain the occurrence of colonies with multiple queens in this subspecies. Only minor workers were able to discriminate queens from other colonies and were aggressive toward them. Therefore, queen recognition differs among subcastes.
Sex pheromone of Lonomia obliqua: daily rhythm of production, identification, and synthesis
(Journal of Chemical Ecology, 2007-03) Lima, Eraldo R.; Zarbin, Paulo H. G.; Lorini, Lisete M.; Ambrogi, Bianca G.; Vidal, Diogo M.
The sex pheromone of Lonomia obliqua Walker (Lepidoptera: Saturniidae) was studied in the laboratory. All female calling occurred during the scotophase. Most females (70.6%) called first within 24 hr of eclosion. Calling varied with age of female, with older (5- to 6-day-old) females calling earlier in the scotophase and for longer durations than younger (0- to 1-day-old) females. The sex pheromone gland of 1- to 3-day-old virgin females was extracted during the calling peak. A Y-olfactometer bioassay showed significant attraction of males to a filter paper containing the female gland extract. Gas chromatographic-electroantennogram detection (GC-EAD) analysis of the extract indicated the presence of at least two possible pheromone components. Gas chromatographic-mass spectrometric analysis of the major GC-EAD-active peak indicated a hexadecenyl acetate; chemical derivatization indicated Δ11 unsaturation. Synthetic samples of (E)- and (Z)-11-hexadecenyl acetate were obtained by coupling 10-bromo-1-decanol and 1-hexyne, utilizing lithium chemistry. The comparison of the retention time of dimethyl disulfide derivatives of the natural compound, to those of synthetic chemicals, confirmed the natural compound as (E)-11-hexadecenyl acetate. The minor component was identified as the related alcohol, (E)-11-hexadecenol. The ratio of the two components in female extract was 100:35. Preliminary tests of males in a Y-olfactometer showed that their response to a mixture of the two compounds was not significantly different from that to gland extract.