Social Wasps in Exotic Forest Planting and Atlantic Rainforest in the Neotropical Region

Social wasps play an important role in communities, whether in natural or agricultural ecosystems, performing pollination and/or predation on other organisms, especially caterpillars, which reveals their potential for biological control. We register species of predatory wasps found in a eucalypt reforested area compared with a native rainforest. Five species of social wasps were found: Agelaia myrmecophila (Ducke), Mischocyttarus punctatus (Ducke), Polistes carnifex (Fabricius), Polybia liliacea (Fabricius), and Polybia striata (Fabricius), with higher numbers in the eucalypt monoculture than in the Atlantic rainforest, suggesting no negative impact of the monoculture on the population of that natural enemies

Relationship between chemical properties of the soil and the occurrence of Bacillus thuringiensis

The soil and other substrates such as mushroom compounds are the main sources of new Bacillus thuringiensis (Bt) isolates for Integrated Pest Management programs. This study describes the relationship between chemical properties of the soil (pH, OM, P 3+ , K 1+ , Ca 2+ , Mg 2+ , H 1+ +Al 3+ , B 3+ , Cu 2+ , Fe 2+ , Mn 2+ and Zn 2+ ) and the occurrence of Bt in Brazil. A total of 1,197 bacterial colonies were obtained, being 512 of them identified as Bt. The Bt index (iBt), which is the relation between Bt colonies and bacterial counts ranged from 0.18 to 0.86. The iBt may be expressed with the formula: iBt= -0.4 + 0.6Ca 2+ + 0.07Cu 2+ + 0.009Fe 2+ – 0.53Mg 2+ -0.12Mn 2+ + 1.26Zn 2+ . A cluster of samples with fewer colonies and a high negative correlation (antagonism) between Mn 2+ and Ca 2+ ; Mg 2+ and Ca 2+ ; Mg 2+ and Zn 2+ ; Mn 2+ and Zn 2+ and a high positive correlation (synergism) between Mn 2+ and Mg 2+ ; Zn 2+ and Ca 2+ was observed. The relationship between these elements and their effect on the Bt presence are discussed.O solo e outros substratos, como restos vegetais são as principais fontes de obtenção de isolados de Bacillus thuringiensis (Bt) para programas de Manejo Integrado de Pragas. Este estudo descreve uma investigação sobre a rela- ção entre algumas propriedades químicas do solo (pH, MO, P 3+ , K 1+ , Ca 2+ , Mg 2 +, H 1+ + Al 3+ , B 3+ , Cu 2+ , Fe 2+ , Mn 2+ e Zn 2+ ) e a ocorrência de Bt em solos do Brasil. Entre 1197 colônias bacterianas, 512 foram identificados como Bt. O índice de Bt (iBt), que é a relação entre o número de colônias de Bt e de colônias bacterianas, variou de 0,18 a 0,86. Os dados obtidos mostraram que o iBt pode ser representado pelo iBt da fórmu- la = -0,.4 + 0,6Ca 2+ + 0,07Cu 2+ + 0,009Fe 2+ - 0,53Mg 2+ - 0,12Mn 2+ + 1,26Zn 2+ . Observou-se o agrupamento das amos- tras com poucas colônias; uma correlação negativa elevada (antagonismo) entre Mn 2+ e Ca 2+ , Mg 2+ e Ca 2+ , Mg 2+ e Zn 2+ , Mn 2+ e Zn 2+ ; uma correlação positiva elevada (sinergismo) entre Mn 2+ e Mg 2+ , Zn 2+ e Ca 2+ . A relação entre esses elementos e o efeito dessa relação na presença de Bt são discutidos

Eucalyptus cloeziana AS A NEW HOST TO Hylesia paulex (LEPIDOPTERA: SATURNIIDAE) IN SOUTHEAST BRAZIL

An unidentified Lepidoptera species was found defoliating Eucalyptus cloeziana (Myrtaceae) in a cerrado area of Minas Gerais State, Brazil. Pupae of this insect, collected in the area, were brought to the laboratory and maintained in Petri dishes (9.0 cm x 1.5 cm) under 25 ± 2oC, relative humidity of 60 ± 10% and 12 hours photophase to obtain adults and eggs. This insect was identified as Hylesia paulex Dognin (Lepidoptera: Saturniidae), and, in that way, the objective of the present study was to register for the first time its herbivory in E. cloeziana plants. Newly-emerged caterpillars were reared in 10 plastic pots (500ml), with 30 caterpillars per pot and fed, daily, with fresh leaves of Eucalyptus cloeziana (Myrtaceae). The egg incubation period of H. paulex was 32.00 ± 1.19 days. The total duration of the seven instars of this insect was 67.83 ± 0.84 days. Hylesia paulex completed its life cycle with E. cloeziana plants, what proves its adaptability to this kind of exotic Myrtaceae in Brazil

Efeito do Silício em aspectos comportamentais e na história de vida de Tuta Absoluta (Meyryck) (Lepidoptera: Gelechiidae)

A tecnologia baseada no uso do silício diminui o uso de agrotóxicos, mantendo a qualidade de frutos e protegendo o ambiente. Este trabalho teve como objetivo avaliar a utilização de diferentes fontes e doses de silício em plantas de tomate sobre aspectos biológicos e preferência de oviposição da traça-dotomateiro (Tuta absoluta). O delineamento experimental foi em blocos casualisados contendo vinte e um tratamentos incluindo a testemunha, em cinco repetições [(Agrosilício® solo (t ha-1 de SiO2) - 0,45; 0,90; 1,35 e 1,80); (Agrosilício® foliar (t ha-1 de SiO2) - 2,0; 4,0; 6,0 e 8,0); (Sili-K® (l ha-1 de SiO2) - 0,5; 1,0; 2,0 e 3,0); (Ácido silícico foliar (% de SiO2) - 0,25; 0,50; 0,75 e 1,00); (Ácido silícico solo (% de SiO2) - 0,25; 0,50; 0,75 e 1,00) e controle]. Os parâmetros biológicos avaliados foram: duração das fases larval e pupal, sobrevivência de larvas e pupas e peso de pupas machos e fêmeas. A não preferência para oviposição de T. absoluta em plantas de tomateiro tratadas com silício foi avaliada através de testes com e sem chance de escolha. Não foram observadas diferenças na duração das fases larval e pupal, sobrevivência de lagartas e pupas, peso de pupas machos e fêmeas de T. absoluta e preferência de oviposição em indivíduos provenientes dos tratamentos com silício aplicado no solo e daquelas do grupo controle. Insetos obtidos dos tratamentos à base de silício aplicado via foliar apresentaram aumento na duração das fases larval e pupal, diminuição na sobrevivência de lagartas e pupas, diminuição do peso de pupas machos e fêmeas e diminuição na preferência de oviposição.The technology based on the use of silicon reduces pesticide use, keeping fruit quality and protecting the environment. This study evaluated the effects of different sources and levels of silicon applied on tomato plants, on biological and behavior characteristics of the tomato pinworm Tuta absoluta. The experimental outline was a randomized block with twenty one treatments, including control, in five replicates[(Agrosilício ® soil (t ha -1 of SiO 2 ) – 0.45, 0.90, 1.35 and 1.80); (Agrosilício ® leaves (t ha -1 of SiO 2 ) – 2.0, 4.0, 6.0 and 8.0); (Sili-K ® (l ha -1 of product) – 0.5, 1.0, 2.0 and 3.0); (Silicic Acid Leaves (% of SiO 2 ) – 0.25, 0.50, 0.75 and 1.00); (Silicic acid soil (% of SiO 2 ) – 0.25, 0.50, 0.75 and 1.00) and control]. The biological characteristics evaluated, were: duration of larval and pupal stages, survival of larvae and pupae and pupal weight of males and females individuals. The non-preference for oviposition of T. absoluta in tomato plants treated with silicon was evaluated through tests with choice and without choice trials. There were no differences observed in the length of larval and pupal stages, survival of larvae and pupae, pupal weight of males and females of T.absoluta and oviposition in individuals from the treatments with silicon applied to the soil and those in the control group. However, insects collected from treatments based on leaf application silicon showed an increase in the duration the larval and pupal stages, decreased survival of larvae and pupae, decreased pupae weight of males and females and a decrease in oviposition preference