The two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae), is considered one of the most important species of pest-mites because it is cosmopolite and polyphagous. This species has been described as attack...The two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae), is considered one of the most important species of pest-mites because it is cosmopolite and polyphagous. This species has been described as attacking over 1,100 plant species in 140 families of economic importance. On the other hand, Phytoseiulus macropilis (Banks) (Phytoseiidae) is a predatory mite of group I, specialist as predatory mite from the Tetranychus genus. Thus, the objective of this work was to evaluate predatory potential of P. macropilis in its different stages—nymphs, female and male adults—preying on T. urticae also in different stages—eggs, larvae, nymphs, and adults—and to know the functional and numerical responses in lab studies. Both the experiments were carried out on arenas made of Jack-bean leaflets’ discs [Canavalia ensiformis (L.)—Fabaceae] with 3 cm in diameter over agar-water at 3% inside 5 cm in diameter uncapped Petri dishes. To know the predatory activity, forty T. urticae and one predatory mite were placed in each arena with the respective phases of the developmental life cycle to be evaluated. To know the potential of predation, the no killed mites were counted after 24 hours. To know the functional and numerical responses, immature T. urticae in densities of 1 to 300/arena were offered for P. macropilis. The results for the predatory potential showed that larvae and male adult of T. urticae were the most killed stages, and the female predatory mites were the one that consumed most prey. The functional response showed a positive and significant correlation, suggesting a type II functional response (convex), a cyrtoid curve rising at a decreasing rate to a plateau, where the consumption remains constant regardless of prey density.展开更多
The species of mite Oligonychus ilicis (McGregor) (Tetranychidae) is an important pest of dicotyledonous plants, cosmopolitan and polyphagous, reported in seven countries from four continents, feeding on 34 plant spec...The species of mite Oligonychus ilicis (McGregor) (Tetranychidae) is an important pest of dicotyledonous plants, cosmopolitan and polyphagous, reported in seven countries from four continents, feeding on 34 plant species of 15 families. The spider mite O. ilicis is known in Brazil as coffee red spider mite, and as southern red mite most in other countries. In Brazil O. ilicis has been reported as the second most important pest of “Conillon” coffee, Coffea canephora Pierre & Froehner, in the state of Espírito Santo. Depending on the number of mites per leaf of arabica coffee, Coffea arabica L., the rate of potential photosynthesis can be reduced by 37% to 50%. In the present study, it was investigated the potential of the two predatory mites which, among others, naturally occurs in coffee plantations, Euseius alatus DeLeon and Amblyseius herbicolus (Chant) (Phytoseiidae), in the control of O. ilicis in coffee plants. It was used potted coffee plants in this research, with approximately 100 cm high, growing in a greenhouse covered with transparent plastic and shading material of 50% sun protection factor, and with fine mesh on all the sides. Results showed that both species of predatory mites, A. herbicolus and E. alatus, are efficient in reducing the mobile phases—larvae, protonymphs, deutonymphs and adults—of the southern red mite O. ilicis. So, the importance of conservation and increase number of these predatory mites in the field coffee growing is essential for implementing the southern red mite integrated management tactic, since these species are of natural occurrence in coffee plants.展开更多
基金the Conselho Nacional de Desenvolvimento Científico e Tecnológico—National Council for Scientific and Technological Development—CNPq for the financial support and the fellowships granted
文摘The two-spotted spider mite, Tetranychus urticae Koch (Tetranychidae), is considered one of the most important species of pest-mites because it is cosmopolite and polyphagous. This species has been described as attacking over 1,100 plant species in 140 families of economic importance. On the other hand, Phytoseiulus macropilis (Banks) (Phytoseiidae) is a predatory mite of group I, specialist as predatory mite from the Tetranychus genus. Thus, the objective of this work was to evaluate predatory potential of P. macropilis in its different stages—nymphs, female and male adults—preying on T. urticae also in different stages—eggs, larvae, nymphs, and adults—and to know the functional and numerical responses in lab studies. Both the experiments were carried out on arenas made of Jack-bean leaflets’ discs [Canavalia ensiformis (L.)—Fabaceae] with 3 cm in diameter over agar-water at 3% inside 5 cm in diameter uncapped Petri dishes. To know the predatory activity, forty T. urticae and one predatory mite were placed in each arena with the respective phases of the developmental life cycle to be evaluated. To know the potential of predation, the no killed mites were counted after 24 hours. To know the functional and numerical responses, immature T. urticae in densities of 1 to 300/arena were offered for P. macropilis. The results for the predatory potential showed that larvae and male adult of T. urticae were the most killed stages, and the female predatory mites were the one that consumed most prey. The functional response showed a positive and significant correlation, suggesting a type II functional response (convex), a cyrtoid curve rising at a decreasing rate to a plateau, where the consumption remains constant regardless of prey density.
基金the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico—National Council for Scientific and Technological Development—CNPq,and Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior—Coordination for the Improvement of Higher Education Personnel—CAPES,for financial support and fellowships granted.
文摘The species of mite Oligonychus ilicis (McGregor) (Tetranychidae) is an important pest of dicotyledonous plants, cosmopolitan and polyphagous, reported in seven countries from four continents, feeding on 34 plant species of 15 families. The spider mite O. ilicis is known in Brazil as coffee red spider mite, and as southern red mite most in other countries. In Brazil O. ilicis has been reported as the second most important pest of “Conillon” coffee, Coffea canephora Pierre & Froehner, in the state of Espírito Santo. Depending on the number of mites per leaf of arabica coffee, Coffea arabica L., the rate of potential photosynthesis can be reduced by 37% to 50%. In the present study, it was investigated the potential of the two predatory mites which, among others, naturally occurs in coffee plantations, Euseius alatus DeLeon and Amblyseius herbicolus (Chant) (Phytoseiidae), in the control of O. ilicis in coffee plants. It was used potted coffee plants in this research, with approximately 100 cm high, growing in a greenhouse covered with transparent plastic and shading material of 50% sun protection factor, and with fine mesh on all the sides. Results showed that both species of predatory mites, A. herbicolus and E. alatus, are efficient in reducing the mobile phases—larvae, protonymphs, deutonymphs and adults—of the southern red mite O. ilicis. So, the importance of conservation and increase number of these predatory mites in the field coffee growing is essential for implementing the southern red mite integrated management tactic, since these species are of natural occurrence in coffee plants.
