Douglas Grützmacher

Monitoramento de agrotóxicos em dois mananciais hídricos no sul do Brasil

The objective of this study was to evaluate and to monitor the presence of pesticides in the waters of the Sao Goncalo channel and the Piratini river located in the southern region of the State of Rio Grande do Sul. During the rice growing season, water samples were collected five times, three samples from the river Piratini and four from the Sao Goncalo canal. The methodology used for the analysis of residues of quinclorac, carbofuran and clomazone was the High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD) and for residues of the pesticides fipronil and betacyfluthrin, the Gas Chromatography with Electron Capture Detection (GC-ECD) was used. Results show that from sowing to harvesting the quantity of pesticide residues in water decreased. It was also observed that, at the lowest point (Laranjal), a greater number of analyses contaminated with residues was detected (11 samples with some type of pesticide). Insecticide carbofuran and herbicide quinclorac were pesticides that presented residues more frequently (16 and 15 times, respectively). Clomazone and fipronil were present in each of the 7 samples with residues and betacyfluthrin was not detected at any site.

Seletividade de formulações de glyphosate aplicado nos estádios imaturos de Trichogramma pretiosum

The selectivity of eight commercial herbicide products with glyphosate formulations (Roundup®, Roundup® WG, Roundup® Transorb, Polaris®, Gliz® 480 CS, Glifosato Nortox®, Glifosato 480 Agripec® and Zapp® Qi) registered in Brazil, was assessed in relation to the immature stages of the egg-parasitoid Trichogramma pretiosum, as well as to their effects on the emerged adults, under laboratory conditions (temperature 25±1 °C, relative humidity 70±10%; photophase 14 hours and brightness 500 lux). The bioassays consisted of herbicide spray at the concentration of 14.4 mg L-1 of equivalent gliphosate acid on eggs of Anagasta kuehniella containing the immature stage egg-larva, pre-pupa and pupa of T. pretiosum. Reductions observed in adult emergence, compared to the control, were used to measure the effects of the treatments. Eggs from the host A. kuehniella were presented to the adults of the parasitoids emerged from the sprayed pupae, with the parasitism of T. pretiosum being evaluated in each treatment compared to the control. No significant harmful effect was observed for any of the herbicides assessed when sprayed at the different immature stages of development of T. pretiosum, in agreement with IOBC. The parasitism of the adults emerged from eggs sprayed at the pupa stage was not affected either.

Diagnóstico da exposição ocupacional a agrotóxicos na principal região produtora de pêssego para indústria do Brasil

The peach culture is extremely susceptible to the attack of pests and diseases. Aiming to avoid yield losses, peach growers apply pesticides. The objective of this research was to characterize some farms and obtain data to better diagnose the reality about the occupational exposition to pesticides in the peach culture. The methodology was based on spontaneous interviews carried out on farms with 135 peach growers. The results show that in general the peach culture is practiced on small farms where the predominant labor comes from the family. The purchase of agrochemicals is made via accredited shops, but without an agronomic prescription. Among the cited pesticides, the fungicide Carbendazim (Derosal 500) and insecticide (Perfekthion) are not labeled in Brazil for the peach culture. The use of personal protective equipment (PPE) standard is an uncommon practice among applicators.

Persistência de agrotóxicos indicados na produção integrada de pêssego a Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae)

The persistence (duration of harmful activity) of five insecticides indicated in the Integrated Peach Production (IPP) was evaluated by adult exposure of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) to insecticide residues on plant leaves at different time intervals after treatment using the International Organization for Biological and Integrated Control of Noxious Animals and Plants (IOBC) based on the suggested methodology.The results obtained in relation to the disease persistence will permit to classify the pesticides, commercial formulation/active ingredient (g or mL commercial formulation 100L), Dipterex 500/ trichlorphon (300), Sumithion 500 CE/fenitrothion (150) and Tiomet 400 CE/dimethoate (120) as slightly persistent (5-15 days); the insecticide Malathion 1000 CE/malathion (200) as moderately persistent (16-30 days) and the fungicide Kumulus DF/sulphur (600) as persistent (>31 days) to T. pretiosum adults.

Consumo foliar de cultivares de arroz irrigado por Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Mean foliage consumption by fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) was measured, for each sex and instar, in laboratory conditions, on rice leaves of cultivars BR-IRGA 410 and Embrapa 6-CHUI. No significant difference of total leaf consumption was observed among caterpillars that developed males or females. Differences were observed among instars with the seventh one being responsible for the higher total consumption. Duration of larval stage was not different for males and females on both cultivars but significant differences were observed in the duration of different instars, independently of sex. The seventh instar was the longest and represented the higher daily consumption. Average daily consumption was similar to male and females in the instars tested, in both cultivars, and increased considerably after the fifth instar.

Variabilidade genética interespecífica em formigas cortadeiras do gênero Acromyrmex que ocorrem no Estado do Rio Grande do Sul

At present, a few number of taxonomists work on identification of leaf cutting ants. Morphological-based methods do not always produce a reliable identification, due to the strong polymorphism observed even in the same colony. This fact leads to hypothesize that, besides those variations, others may also occur related to geographic distribution of the ants. Six Acromyrmex species were sampled at four locations in the State of Rio Grande do Sul and analyzed by RAPD and AFLP. Fifty UBC primers, originated from the University of British Columbia, were evaluated to select a set of primers that could be useful for species identification and genetic variability studies. Only 13 primers, which amplified fragments of all species, were selected. Although the selected primers produced fragments that allowed various ways for identification of A. heyeri, A. ambiguus, A. crassispinus, A. striatus, A. laticeps and A. aspersus, only UBC 354, UBC348 and UBC356 primers allowed a reliable identification showing the most visible fragments. Results by dendogram and morphological-based identification, showed that A. striatus and A. laticeps are less related to the other species. However A. ambiguus e A. crassispinus are the most genetically related ants in the State of Rio Grande do Sul. The results indicate that a reliable identification of Acromyrmex can be carried out by RAPD and AFLP, yet allowing verification of genetic distance between species.

INFLUÊNCIA DO CULTIVO DE Eucaliptus SOBRE A COMUNIDADE DE FORMIGAS CORTADEIRAS NAS REGIÕES SUL E CAMPANHA DO ESTADO DO RIO GRANDE DO SUL, BRASIL

O Rio Grande do Sul vem recebendo nos ultimos anos investimentos significativos, com o plantio de florestas de eucalipto para producao de celulose e papel, principalmente a regiao Sul e Campanha do estado. Uma das principais pragas desta cultura sao as formigas cortadeiras, onde cada especie apresenta habitos proprios, exigindo metodos de controle diferenciados. Nesse sentido, os objetivos deste trabalho foram: (i) identificar as especies de formigas cortadeiras que ocorrem nos florestamentos de eucalipto na Metade Sul do estado do RS, ( ii ) determinar as especies predominantes e ( iii ) verificar a distribuicao geografica na cultura de eucalipto nos municipios estudados. Para tal, o levantamento foi realizado em areas de cultivo de eucalipto, distribuidas em cinco municipios da regiao (Rio Grande, Arroio Grande, Piratini, Pinheiro Machado e Bage). Foram realizadas tres coletas em cada municipio, uma antes do plantio, cujas areas constituiam-se de campos nativos destinados ao pastoreio de gado com vegetacoes arbustivas de pequeno porte e duas nos dois primeiros anos subsequentes ao cultivo, compreendendo o periodo de maio de 2006 a marco de 2008. Ao todo foram encontradas sete especies: Acromyrmex ambiguus ( Emery , 1887), Acromyrmex heyeri ( Forel , 1899); Acromyrmex balzani Emery , 1890; Acromyrmex lundi ( Guerin , 1838); Acromyrmex lobicornis ( Emery , 1887); Acromyrmex crassispinus ( Forel , 1909) e Acromyrmex striatus (Roger, 1863). As especies A. ambiguus e A. heyeri foram as mais frequentes em todas as coletas, sendo a primeira predominante em todas as avaliacoes. A. lundi e A. lobicornis foram consideradas de baixa frequencia, mas de ocorrencia em todas as avaliacoes, enquanto que A. landolti balzani ocorreu apenas no municipio de Arroio Grande e A. lobicornis somente nos municipios de Bage e Pinheiro Machado. Palavras chave: Formigas cortadeiras, Acromyrmex , Florestamento , Analise faunistica . ABSTRACT The state of Rio Grande do Sul (RS), in the southernmost region of Brazil, has received significant investments for eucalyptus plantations in recent years. The regions of the Campanha , as well as the southern part of the state have increased the area sown to this species, with focus on the pulp and paper industries. One of the most important pests to eucalyptus is the leaf cutter ant, from which there are several species each showing specific habits which require different control methodologies. Regarding this issue, the objective of this work was ( i ) to identify the different species of cutter ants that occur at the eucalyptus plantations in the southern half of RS and (ii) their relative importance, as well as (iii) to establish their geographical distribution across the different counties. Data recording from eucalyptus plantations were carried out in five different counties (Rio Grande, Arroio Grande, Piratini , Pinheiro Machado and Bage ), at three different times e.g. the first before planting and the remaining two distributed through the first two years of the plantation, one on May 2006 and the second on March, 2008. In total seven species were recorded: Acromyrmex ambiguus (Emery, 1887), Acromyrmex heyeri ( Forel , 1899); Acromyrmex landolti balzani Emery, 1890; Acromyrmex lundi (Guerin, 1838); Acromyrmex lobicornis (Emery, 1887); Acromyrmex crassispinus ( Forel , 1909) and Acromyrmex striatus (Roger, 1863). A. lundi and A. lobicornis were considered to be of low frequency, however, with presence in all three sampling dates. A. landolti balzani was recorded only at the county of Arroio Grande whereas A. lobicornis was recorded only at the Bage and Pinheiro Machado sites. The A. ambiguus and A. heyeri were the most frequent species across sampling dates and sites, with the former being the prevailing species through all the experimental period. Key words: leaf-cutting ants, forestry, Acromyrex , faunistic analysis