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Selective agrochemicals including herbicides that do not affect non-target organisms such as natural enemies are important in the integrated pest management (IPM) programs. The aim of this study was to evaluate the herbicide toxicity, selectivity and hormesis of nicosulfuron, recommended for the corn Zea mays L. (Poaceae) crop, on 10 Trichogrammatidae (Hymenoptera) species. A female of each Trichogramma spp. or Trichogrammatoidea annulata De Santis, 1972 was individually placed in plastic test tubes (no choice) with a cardboard containing 45 flour moth Anagasta ( = Ephestia) kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. Parasitism by these natural enemies was allowed for 48 h and the cardboards were sprayed with the herbicide nicosulfuron at 1.50 L.ha, along with the control (only distilled water). Nicosulfuron reduced the emergence rate of Trichogramma bruni Nagaraja, 1983 females, but increased that of Trichogramma pretiosum Riley, 1879, Trichogramma acacioi Brun, Moraes and Smith, 1984 and T. annulata females. Conversely, this herbicide increased the emergence rate of Trichogramma brasiliensis Ashmead, 1904, T. bruni, Trichogramma galloi Zucchi, 1988 and Trichogramma soaresi Nagaraja, 1983 males and decreased those of T. acacioi, Trichogramma atopovilia Oatman and Platner, 1983 and T. pretiosum males. In addition, nicosulfuron reduced the sex ratio of T. galloi, Trichogramma bennetti Nagaraja and Nagarkatti, 1973 and T. pretiosum and increased that of T. acacioi, T. bruni, T. annulata, Trichogramma demoraesi Nagaraja, 1983, T. soaresi and T. brasiliensis. The herbicide nicosulfuron was "harmless" (class 1, <30% reduction) for females and the sex ratio of all Trichogrammatidae species based on the International Organization for Biological Control (IOBC) classification. The possible hormesis effect of nicosulfuron on Trichogrammatidae species and on the bacterium Wolbachia sp. (Rickettsiales: Rickettsiaceae) was also discussed.

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The aim of this study was to evaluate the effect of the herbicide mixture nicosulfuron + atrazine on 10 trichogrammatid species. A female of each trichogrammatid was placed in a test tube (no-choice) with a card with 45 Anagasta kuehniella eggs. Parasitism was allowed over a 48 h period, then the cards were sprayed with a solution containing nicosulfuron (30 g ha) + atrazine (1500 g ha), besides the control (distilled water). The nicosulfuron + atrazine mixture increased the Trichogramma atopovirilia and T. pretiosum female emergence. The percentage of T. acacioi, T. atopovilia and T. pretiosum male parasitoids emerged was higher in the control, and for T. demoraesi and Trichogrammatoidea annulata with nicosulfuron + atrazine. Sex ratio of the trichogrammatids was similar with nicosulfuron + atrazine.

Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays), despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested by T. urticae (clean plants clean) and, 30 infested by the spider mite. Infestation of maize plants by T. urticae reduced the conspecific female adult survival. However, no change in the survival of immature or reproduction was observed. These results suggest the induction of induced direct resistances in maize by T. urticae. This is first report of direct resistance induction in Z. mays by the two-spotted spider mite T. urticae.

Information on selective herbicide, including glyphosate that does not affect non-target organisms such as natural enemies, are important in integrated pest management programs in maize. The dose 13.94 L ha-1 of glyphosate was evaluated in females on 10 Trichogrammatidae species. A female of each Trichogrammatidae species was individually positioned per test tube with a card containing approximately 45 Anagasta kuehniella Zeller, 1879 (Lepidoptera: Pyralidae) eggs. For 48 h parasitism was allowed, and later the cartons were sprayed with the herbicide or with distilled water, for the control treatment. The glyphosate showed variable effects for parasitoids. The emergence of T. acacioi females was lower but that of T. atopovilia, T. demoraesi, and T. pretiosum higher with the glyphosate. The sex ratio of T. galloi was lower and that of T. bruni, T. brasiliensis, T. demoraesi, and T. soaresi higher with glyphosate. This glyphosate was innocuous to all Trichogrammatidae species females based on the classification adopted internationally.

ResumoAvaliou-se o potencial antimicrobiano dos óleos essenciais de alfavacão (Ocimumgratissimum L.) e de cravo-da-índia (Syzygiumaromaticum L.) em carne moída de ovinos contaminadas experimentalmente com S. aureus ATCC 25923. Ambos os óleos em estudo foram utilizados na concentração de 400 µL/g, e nos tempos de exposição de zero, cinco, 15 e 60 minutos. Os óleos essenciais analisados apresentaram atividade antimicrobiana na presença matriz alimentar utilizada. O óleo essencial do cravo-da índia apresentou maior efeito inibitório no tempo de 60 minutos em relação aos demais tratamentos (p≤0,001), sugerindo que o aumento do tempo de exposição potencializou o efeito antimicrobiano.Palavras-chave: Ocimumgratissimum L. e Syzygiumaromaticum L., condimentos, produtos naturais. AbstractThe antimicrobial potential of the essential ails of alfavacão (Ocimum gratissimum L.) and indian clove (Syzygium aromaticum L.) were evaluated i in minced sheep meat experimentally infected with S. aureus ATCC 25923. Both of the oils under study were used study were used at a concentration of 400 microlitres/g, and the exposure times were zero, five, 15 and 60 minutes. The essential oils analyzed showed antimicrobial activity in the presence of the food matrix used. The essential oil of Indian clove showed greater inhibitory effect on the time of 60 minutes compared to the treatments (p ≤ 0.001), suggesting that increasing the exposure time enhances the antimicrobial efficacy of the product.Keywords: Ocimum gratissimum L., Syzygium aromaticumL., condiments, natural products. IntroduçãoAs indústrias alimentares e farmacêuticas demandam por uma busca contínua de novos e melhores agentes antimicrobianos, especialmente tendo em vista o aumento da resistência aos antibióticos convencionais. Uma das áreas de grande interesse é o uso de extratos de plantas e em particular os seus óleos essenciais, que além de possuírem atividades antimicrobianas, podem reduzir a expressão de fatores de virulência pelos microorganismos, como por exemplo, as enterotoxinas A e B e α-toxina produzidas por S. aureus (Smith-Palmer et al., 2004).Comparados ao uso de aditivos sintéticos, a utilização de plantas, especiarias, frutos e óleos essenciais com ação antimicrobiana ainda demandam pesquisas no que se refere aos seus efeitos na alimentação humana, ao odor marcante e ao alto custo para obtenção dos mesmos em escala comercial, conforme apresentado em uma ampla revisão literária descrita por Tajkarimiet al., (2010).Tendo em vista a importância que a culinária utilizando carne de ovinos tem alcançado no país, pelas suas características nutricionais e políticas de incentivos à produção desta proteína *Recebido em 12 de setembro de 2013 e aceito em 7 de janeiro de 2014.