Preliminary studies on the effects of d-limonene to workers of the leaf-cutting ant Atta sexdens rubropilosa and its implications for control

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of the insecticides abamectin and lufenuron on eggs and larvae of Chrysoperla externa under laboratory conditions

The side effects of two insecticides/acaricides, abamectin and lufenuron, on the eggs and larvae of Chrysoperla externa (Hagen) were studied in the laboratory (25 +/- 2degreesC, 62 +/- 10% RH and 12-h photophase). The analytical methods used were those proposed by the International Organization for Biological Control (IOBC)-Working Group for 'Pesticides and Beneficial Organisms'. Chrysoperla externa egg viability was not affected by abamectin. Neonate larvae from abamectin sprayed eggs as well as first, second and third instar larvae that were directly treated, developed normally and yielded normal adults. Lufenuron presented no adverse effects on egg survival. However, lufenuron induced high mortality in neonate larvae from treated eggs. These neonates, as well as lufenuron treated first and second instar larvae could not molt. In the third instar, high pupal mortality occurred. The results showed that abamectin is innocuous and that lufenurom is toxic to Chrysoperla externa eggs and larvae.

Effect of bean genotypes, insecticides, and natural products on the control of Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) and Caliothrips phaseoli (Hood) (Thysanoptera: Thripidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Towards new botanical pesticides: the toxic effect of Eremanthus goyazensis (Asteraceae) leaves essential oil against Brevipalpus phoenicis (Acari: Tenuipalpidae)

This work reports the chemical characterization of Eremanthusgoyzensis essential oil and its toxic effect over Brevipalpus phoenicis. The essential oil displayed a major composition of sesquiterpenes (61.87%) including trans-caryophillene (26.81%) and germacrene-D (13.31%). The fumigation test indicated a promising bioactivity over adult B. phoenicis individuals at 24 h (2.03 µL/L of air) and 48 h (1.08 µL/L of air) of exposition. A brief discussion of essential oils composition and their singular role on the toxic effect over B. phoenicis is provided here. Our results may contribute to a new and profitable use of a species of Brazilian flora on agribusiness.

Suscetibilidade de operárias e larvas de abelhas sociais em relação à ricinina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Residue decay of insecticides applied with mineral oil on clementine fruits

Three insecticides (chlorpyrifos methyl, dimethoate and fenthion) were applied on clementine fruits with and without mineral oil to assess the effect of mineral oil on pesticide residues. In both experiments the residues on the fruits after the last treatment and at harvest time were not significantly different.

Comparison of different clean-up procedures for the determination of N-methylcarbamate insecticides in vegetable matrices by high-performance liquid chromatography with UV detection

Several clean-up procedures which included the use of glass chromatography columns (silica gel, alumina, Florisil, silanized Celite-charcoal), Sep-Pak cartridges and standard solutions were compared for the determination of the following N-methylcarbamate (NMC) insecticides: aldicarb, carbaryl, carbofuran, methomyl and propoxur. According to recovery results of the compounds after elution in a glass column, the most efficient systems employed 4.6% deactivated alumina and a silanized Celite-charcoal (4:1) as adsorbents, using dichloromethane-methanol (99:1) and toluene-acetonitrile (75:25) mixtures, respectively, as binary eluents. The recoveries of the compounds studied varied from 84 to 120%. Comparable recoveries (75-100%) for Sep-Pak cartridges in normal phase (NH2, CN) and reversed phase (C-8) were observed. Different temperatures were tested during the concentration step in a rotary evaporator, and we verified a strong influence of this parameter on the stability of some compounds, such as carbofuran and carbaryl. Recovery studies employing the best clean up procedures were performed at the Brazilian agricultural level in potato and carrot samples; Validation methodology of the US Food and Drug Administration was adapted for the N-methylcarbamate analysis. Their recoveries ranged between 79 and 93% with coefficients of variation of 2.3-8%. (C) 1998 Elsevier B.V. B.V.

Simplified multiresidue method for the determination of organophosphorus insecticides in olive oil

A simple and rapid method for the determination of 13 organophosphorus insecticides and their metabolites in olive oil by GC is described. The pesticide was extracted from oil with acetonitrile and no cleanup was needed. GC-nitrogen-phosphorus detection response factors of pesticides were affected by solvents and coextractive substances. Pesticides in hexane showed on average higher response factors. Standards were prepared in the residue-free oil extract solubilized in hexane to handle effects of matrix and solvent. The low amount of coextractive substances does not decrease the column efficiency, even after a few hundred analyses. Recovery at three fortification levels (ca. 0.1, 1.0 and 3.0 mg/kg) ranged from 74 to 118%, With coefficients of variation ranging from 1 to 16.

Determination of carbamate insecticides in apples, pears, and lettuce by LC with UV detector

A simple and rapid method was developed for determination of 8 carbamate insecticides and 10 of their metabolites in apples, pears, and lettuce by liquid chromatography with UV diode array detector. With this method no derivatization is needed. Carbamates not belonging to the N-methylcarbamate class and metabolites without the N-methyl group can also be determined.

Urban areas and isolated remnants of natural habitats: An action proposal for botanical gardens

The International Union for Conservation of Nature and Natural Resources (IUCN) and the World Wide Fund for Nature (WWF) advocates an increase of the number of botanical gardens throughout the world as one of the measures that can help to preserve the world's biodiversity. To implement this strategy, the present work brings forward a suggestion particularly suited to tropical regions: establishing municipal botanical gardens. It refers to the experience of a newly opened municipal botanical garden in Brazil, comparing its attractive power on visitors to that of other botanical gardens included in the Brazilian network of Botanical Gardens. It also presents considerations on in situ conservation in small remnants and on the importance of urban reserves to preserve the regional biodiversity and spread the conservationist philosophy. The present proposal promotes the participation of local communities making the public opinion more aware and active, besides being able to counterbalance proposals that support protecting the world biodiversity through interventionist actions. It assumes that, through actions planned and coordinated by regional and national botanical garden networks, the measure proposed can mitigate the anthropic actions exerted on important natural reserves all over the world.