Avaliação da distribuição espacial e níveis de dano dos percevejos do género Orthezia em Moçambique

Abstract

Agribusiness in Mozambique has been prominent in several economic areas involving agricultural production, and is often associated with agriculture, livestock, fruit growing and floriculture. However, in recent years there has been a considerable increase in some populations of insects and other organisms associated with ornamental plants and some fruit trees, particularly citrus fruits. Among several insect populations, bugs belonging to the Ortheziidae family have been the most worrying. Orthezia is a generalist pest of ornamental and fruit plants, across its broad host range, which in the natural environment remained low. In this context, the need arose to assess the spatial distribution and damage levels of the pest in Maputo. The study was carried out in multiple locations, where the following parameters were measured at each sampling point: infestation level, population density, damage level and its intensity. The experimental design used for the analysis of variance was the Completely Causalized Design (CCD). Two species belonging to the Ortheziidae family (Insignorthezia insignis and Praelongorthezia praelonga) were identified in Maputo Province. The results obtained show that Duranta erecta and Citrus limon presented the highest levels of pest infestation with 89.1% and 100%, respectively, and are considered the main hosts of the pest. For Praelongorthezia praelonga on Citrus limon, a range of 60 to >80% of the damaged leaf area (350 to >450 bugs/leaf) was observed, with the value attributed to the most severe level, and for Insignorthezia insignis on Duranta erecta, this value was in the range of 40 to >80% of the damaged leaf area (220 to +450 bugs/leaf). The plants presented an attack degree that varied on average on a scale of 4 to 6 on a scale of 0 to 6, thus representing a level of damage that varied from high, severe and dead plant. 18 species of ornamental and fruit plants, distributed across 11 families, were also identified, considered as hosts and potential hosts of the pest. The occurrence of other species of predators and unidentified species has been recorded, which may be potential natural enemies of the pest(TRADUÇÃO NOSSA)