Brazilian Consensus on Photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection

Spinosad and the tomato Borer Tuta absoluta: a bioinsecticide, an invasive pest threat, and high insecticide resistance

The introduction of an agricultural pest species into a new environment is a potential threat to agroecosystems of the invaded area. The phytosanitary concern is even greater if the introduced pest’s phenotype expresses traits that will impair the management of that species. The invasive tomato borer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is one such species and the characterization of the insecticide resistance prevailing in the area of origin is important to guide management efforts in new areas of introduction. The spinosad is one the main insecticides currently used in Brazil for control of the tomato borer; Brazil is the likely source of the introduction of the tomato borer into Europe. For this reason, spinosad resistance in Brazilian populations of this species was characterized. Spinosad resistance has been reported in Brazilian field populations of this pest species, and one resistant population that was used in this study was subjected to an additional seven generations of selection for spinosad resistance reaching levels over 180,000-fold. Inheritance studies indicated that spinosad resistance is monogenic, incompletely recessive and autosomal with high heritability (h2 = 0.71). Spinosad resistance was unstable without selection pressure with a negative rate of change in the resistance level ( = −0.51) indicating an associated adaptive cost. Esterases and cytochrome P450-dependent monooxygenases titration decreased with spinosad selection, indicating that these detoxification enzymes are not the underlying resistance mechanism. Furthermore, the cross-resistance spectrum was restricted to the insecticide spinetoram, another spinosyn, suggesting that altered target site may be the mechanism involved. Therefore, the suspension of spinosyn use against the tomato borer would be a useful component in spinosad resistance management for this species. Spinosad use against this species in introduced areas should be carefully monitored to prevent rapid selection of high levels of resistance and the potential for its spread to new areas

Relative toxicity of insecticides to the parental spinosad-resistant strain and its derived strain after 15-generations of selection for spinosad resistance.

<p>All of the concentration-mortality curves followed the probit model based on the χ² goodness-of-fit test (<i>P</i>>0.05).</p

Dominance of spinosad resistance based on a range of spinosad concentrations including LC₅₀s from the susceptible parental strains and pooled F₁ progeny of reciprocal crosses estimated for the tomato borer <i>Tuta absoluta</i>.

<p>The concentration range used also discriminates for high spinosad resistance, as observed in the spinosad-selected strain. The estimated dominance (<i>h</i>) varies from 0 (completely recessive) to 1 (completely dominant), where 0.5 corresponds to co-dominance, 0<<i>h</i><0.5 corresponds to incompletely recessive and 0.5<<i>h</i><1.0 corresponds to incompletely dominant.</p

Direct test of monogenic inheritance for spinosad resistance in the tomato borer <i>Tuta absoluta</i> by comparing expected and observed mortality of the progeny of the backcrosses between the pooled F1 progeny of the reciprocal crosses and the (selected) spinosad-resistant strain.

<p>*Non-significant at <i>P</i>>0.05.</p

Synergism of spinosad toxicity in spinosad-susceptible and -resistant strains of the tomato borer <i>Tuta absoluta</i>.

<p>Synergism of spinosad toxicity in spinosad-susceptible and -resistant strains of the tomato borer <i>Tuta absoluta</i>.</p

LC₅₀s for spinosad with successive selections for spinosad resistance of the tomato borer <i>Tuta absoluta</i>.

<p>After 12 generations of spinosad selections, the selected line was split into two, one line maintaining selection and one line with interrupted selection.</p

Spinosad concentration-mortality curves (with observed data as symbols) for the (standard) spinosad susceptible strain, (selected) spinosad resistant strain, the F₁ progeny of the reciprocal crosses and the backcross progeny (pooled F₁ RC×spinosad-resistant) of the tomato borer <i>Tuta absoluta</i>.

<p>Spinosad concentration-mortality curves (with observed data as symbols) for the (standard) spinosad susceptible strain, (selected) spinosad resistant strain, the F₁ progeny of the reciprocal crosses and the backcross progeny (pooled F₁ RC×spinosad-resistant) of the tomato borer <i>Tuta absoluta</i>.</p