This paper records the first report of Megastigmus transvaalensis Hussey (Hymenoptera: Torymidae) in Brazilian peppertree, Schinus terebinthifolius Raddi (Anacardiaceae) drupes in Sorocaba, state of São Paulo, Brazil. This wasp is an invasive species and was found damaging S. terebinthifolius drupes in urban areas (35.0±15.8%), natural forests (21.5±10.2%) and restoration areas (15.8±8.4%). The bioecology and damage caused by M. transvaalensis in the S. terebinthifolius drupes warrants further study focused upon the management of this phytophagous wasp. Megastigmus transvaalensis has a potential to be disseminated throughout Brazil and is posing a threat to the natural regeneration of S. terebinthifolius in the native forests and restoration areas and ecological regions of this country.
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Megastigmus transvaalensis Hussey (Hymenoptera: Torymidae) parasitizes drupes of Rhus genus plants in Africa and Schinus (Anacardiaceae) in South America. This exotic wasp damages Schinus terebinthifolia Raddi drupes in native forests and ecological restoration areas in Brazil. The objective of the present study was to investigate the precipitation, temperature and relative humidity effects on M . transvaalensis flight activity, and to determine the parasitism rate and sex ratio of this wasp on S . terebinthifolia plants. The study was conducted with yellow sticky traps and S . terebinthifolia drupes collected in an ecological restoration area, from August 2014 to September 2015, in the Sorocaba municipality, São Paulo state, Brazil. Megastigmus transvaalensis populations were negatively correlated with maximum and minimum temperatures and precipitation, with population peaks at the end of May 2015, with 927 insects per evaluation (48.8 adults per trap). The M . transvaalensis sex ratio was higher in the laboratory (0.42) than in the field (0.08). The parasitism rate of S . terebinthifolia drupes by M . transvaalensis ranged from zero to 36.3% under natural environmental conditions. Megastigmus transvaalensis can be monitored with yellow sticky traps. Damage by M . transvaalensis in S . terebinthifolia drupes may decrease the germination of the seeds and the establishment of this plant in native and restoration ecological areas.
Areas planted with Eucalyptus urophylla S.T. Blake variety platyphylla F. Muell. (Myrtaceae) expand annually in most regions of Brazil. Many lepidopteran species defoliate this plant, but with damage varying per species. The objective of this study was to identify the pest status of lepidopteran defoliators based in the faunistic analysis of these insects and of their natural enemies on E. urophylla variety platyphylla plantations in a representative producing region of Brazil. Adult moths of lepidopterans and of their natural enemies were captured using a light trap, installed every two weeks, from September 2016 to August 2018. A total of 183, 10, three and 139 lepidopteran species was captured and classified as primary, secondary, without defined importance to eucalypt plants and non-identified with 1,419, seven, 465 and 876 individuals, respectively. Two primary pest species were constants, two accessories and six accidentals and all secondary ones were accidentals. Six primary pest species were common and dominant and four non-dominants. Faunistic indices indicated the main lepidopteran species that should be monitored in pest management programs. Seven hymenopteran species (65 individuals), three dipterans (49 individuals) and two hemipterans (four individuals) were the natural enemies collected using light traps. The monitoring of lepidopteran pests with light traps can contribute to the management and to reduce damage and control costs for these species, besides identifying natural enemies for biological control programs in Eucalyptus plantations.
The aim of this study was to evaluate the quality of starch produced by plants that suffer damage caused by M. fryanus, analyzed by colorimetric and morphological indices. Colorimetric data were composed of luminosity indices, “a” and “b” chroma coordinates and darkening index. For morphological data, the perimeter and area of starch granules extracted from cassava roots were analyzed. The variables were summarized in a principal component analysis and the axes scores retained for interpretation were correlated with the damage caused by the M. fryanus. From these analyses and observing the main effects, linear regression models for the variables were determined, according to the level of damage caused by the pest. The damage caused by M. fryanus in the roots strongly influenced the indices related to starch colorimetry, hence, under conditions of greater damage, the tendency of the chroma coordinates to vary toward red and yellow was observed and a decrease in starch luminosity occurred, inversely proportional to the increase in darkening. Similar to what was observed in the colorimetric data, a drop in the size of starch granules was noted in the roots, which suffered greater damage from the pest.
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