Cyazypyr^(TM) Selectivity for Three Species of Phytoseiid for Coffee and Other Relevant Agricultural Crops in Brazil

Mites belonging to the family Phytoseiidae are the most important and most widely studied among predatory mites of phytophagous mites. The phytophagous mites Brevipalpus phoenicis (Geijskes, 1939) (Tenuipalpidae) and Oligonychus ilicis (McGregor, 1917) (Tetranychidae) on coffee (Coffea spp.), are frequently found in combination with the predaceous mites Iphiseiodes zuluagai Denmark & Muma, 1972;Euseius alatus DeLeon, 1966 and Amblyseius herbicolus (Chant, 1959) (Acari: Phytoseiidae), among others. The purpose of this research was to study the effects of the product CyazypyrTM (cyantraniliprole 100 OD) on these three species of Phytoseiidae, relevant to coffee, citrus and other agricultural crops in Brazil, following standard laboratory procedures. Mated female mites were exposed to fresh-dried residues on a glass surface, with 8 treatments, 5 mites per glass plate and 6 replicates, in a completely randomized experimental design. Each test lasted eight days, with a daily count of the surviving females and of eggs laid. CyazypyrTM, in all tested doses (75, 100, 125, 150, 175 and 200 g a.i./ha), was selective for the studied species, A. herbicolus, I. zuluagai, and E. alatus. Overall the treatments resulted in low mortality rates and negligible impact on the reproduction. Therefore, based on IOBC standards, CyazypyrTMcan be classified as not harmful (class 1) or slightly harmful (class 2), comparable to the agrochemical TalentoTM (hexythiazox 500 WP-12 g a.i./ha) equivalent to a harmless standard of selectivity in the laboratory. CyazypyrTM is therefore a complement to programs of integrated pest management, to preserve the populations of predatory mites in crops of coffee and citrus, among others, in Brazil.

Predatory Potential of Phytoseiulus macropilis(Banks)Preying on Tetranychus urticae Koch(Acari:Phytoseiidae,Tetranychidae)

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.

Study of Potassium Silicate Spraying in Coffee Plants to Control <i>Oligonychus ilicis</i>(McGregor) (Acari: Tetranychidae)

The southern red mite, Oligonychus ilicis (McGregor) (Acari: Tetranychidae) can cause a significant reduction in the photosynthesis potential and the growth of new coffee plants (Coffea spp., Rubiaceae). Studies suggest that the leaf spraying of silicon (Si) leads to increase plants resistance in order to reduce infestations of insect pests such as herbivores, borers, sucking insects and mites. The objective of this study was to evaluate the effect of leaf spraying of potassium silicate (K2SiO3) to control the southern red mite in coffee plants. Experiments were conducted in coffee plants (Coffea arabica L.), grown in a greenhouse, by means of completely randomized design with six treatments: Dose 0 (control), 2, 4, 6, 8 and 10 liters of silicate potassium ha-1 and five replications. Plants treated with potassium silicate, regardless of the applied dose, had a lower O. ilicis infestation compared to the control, not allowing the population increase, thus a smaller damage in coffee leaves. The silicon content in leaves was higher in plants treated with the highest dose of potassium silicate. It was observed that there was induction of defense molecules such as tannins and lignin in plants sprayed with potassium silicate. It was concluded that the potassium silicate applied in leaf spraying had positive effect on reducing O. ilicis attack in coffee plants, even being a dicot. Therefore, the applications of potassium silicate by leaf spraying can be used in programs of integrated management of the southern red mite in coffee, with a view to sustainable management and environmental protection.

Biological Control of Southern Red Mite,Oligonychus ilicis(Acari:Tetranychidae),in Coffee Plants

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.