Pedro Guilherme Lemes

The impact of the Forest Stewardship Council (FSC) pesticide policy on the management of leaf-cutting ants and termites in certified forests in Brazil

• Key messageThe recommendations accompanying pesticide derogations from the FSC are not efficient for the management of leaf-cutting ants and termites in certified forest plantations in Brazil compared with chemical control using insecticides. FSC recommendations ignore the biological and ecological features of pests and forest plantations in Brazil when they set global rules for forest certification.

Cerambycidae and other Coleoptera Associated with Branches Girdled by Oncideres saga Dalman (Coleoptera: Cerambycidae: Lamiinae: Onciderini)

Abstract Species of Oncideres Serville, often referred to as twig girdlers, girdle tree branches prior to oviposition to promote larval development. The behavior creates a unique niche that is utilized by other beetle species. The objective of this study was to compare emergence of insects from branches girdled by Oncideres saga Dalman in an intercropping system and a monoculture of Acacia mangium Willd. in the Atlantic Rainforest of Minas Gerais, Brazil. Twenty-four Coleoptera species emerged from the branches: 17 Cerambycidae; three Cleridae; and one individual each from Cantharidae, Cucujidae, Elateridae, and Trogossitidae. Although branches from the intercropping system yielded more individuals, branches from the monoculture had higher species richness, including almost all of the cerambycid species and all of the potential predators. The use of girdled twigs may confer a reproductive advantage to subsequent cerambycid colonists, which are probably attracted to the volatiles released by the girdled branch. Beetles belonging to other families may prey on the Cerambycidae dwelling inside the branches. Potential predators may be ecologically important, contributing to the natural biological control of O. saga. Collecting and burning the infested branches is the technique most extensively used to control the twig girdlers. However, this also destroys beneficial organisms as well as the subsequent colonists that depend upon these branches.

Essential oils cause detrimental effects on biological parameters of Trichogramma galloi immatures

Essential oils from botanical extracts used for insect pest control should be both effective and have low impact on natural enemies. The objective was to evaluate the effects of ten essential oils on the biological and reproductive parameters in two Trichogramma galloi Zucchi (Hymenoptera: Trichogrammatidae) generations. The emergence F1 generation of T. galloi was reduced by more than 30% with Allium sativum, Carapa guianensis, Citrus sinensis, Neem and Syzygium aromaticum. Zingiber officinale reduced the T. galloi emergence of the F1 and F2 generations by between 30 and 99%. The longevity of the F1 generation was reduced by more than 50% with Z. officinale at the pre-pupae and pupae stages. All oils reduced the parasitism rate of the F1 generation in the egg-larva and pre-pupa stages. Allium sativum, C. guianensis and C. sinensis, Neem and Origanum vulgare reduced parasitism by between 30 and 79%. Zingiber officinale was slightly and moderately harmful to the F1 and F2 generations, respectively, for the T. galloi parasitism. The sex ratio of the two T. galloi generations was not affected by the essential oils. The low side effects of the oils on the F2 generation, except for Z. officinale (the most harmful oil), suggest that T. galloi developed some post-transgenerational tolerance/resistance mechanisms to these oils and/or their components. The A. sativum, C. guianensis, C. sinensis, Neem, O. vulgare, S. aromaticum and Z. officinale oils were not selective for T. galloi. Mentha piperita, Piper nigrum and Thymus vulgaris essential oils can be included in integrated pest management programs for this parasitoid.

Greenhouse gas emissions and carbon sequestration by agroforestry systems in southeastern Brazil

Agrosilvopastoral and silvopastoral systems can increase carbon sequestration, offset greenhouse gas (GHG) emissions and reduce the carbon footprint generated by animal production. The objective of this study was to estimate GHG emissions, the tree and grass aboveground biomass production and carbon storage in different agrosilvopastoral and silvopastoral systems in southeastern Brazil. The number of trees required to offset these emissions were also estimated. The GHG emissions were calculated based on pre-farm (e.g. agrochemical production, storage, and transportation), and on-farm activities (e.g. fertilization and machinery operation). Aboveground tree grass biomass and carbon storage in all systems was estimated with allometric equations. GHG emissions from the agroforestry systems ranged from 2.81 to 7.98 t CO2e ha−1. Carbon storage in the aboveground trees and grass biomass were 54.6, 11.4, 25.7 and 5.9 t C ha−1, and 3.3, 3.6, 3.8 and 3.3 t C ha−1 for systems 1, 2, 3 and 4, respectively. The number of trees necessary to offset the emissions ranged from 17 to 44 trees ha−1, which was lower than the total planted in the systems. Agroforestry systems sequester CO2 from the atmosphere and can help the GHG emission-reduction policy of the Brazilian government.