2018) The invasive red palm mite, Raoiellaindica Hirst (Acari: Tenuipalpidae), in Brazil: range extension and arrival into the most threatened area, the Northeast Region, ABSTRACT Raoiella indica Hirst (Acari: tenuipalpidae), commonly known as the red palm mite (RPM), is an invasive polyphagous pest, which has emerged as a threat to agriculture in the Americas. In the Americas, the mite has not only spread quickly, but also greatly extended its host range in the new areas where it has been observed. We present here new records of the RPM in Brazilian states, with focus on its arrival into the most threatened area, the Northeast Region. Coconut and banana are important crops in this region of Brazil and represent the main threatened crops by this pest. These new records of RPM reinforce the idea that this species is already widely distributed throughout Brazil eight years after its introduction into the extreme North state of Roraima. Comments on the possible economic, social and environmental impacts are presented. ARTICLE HISTORY

Raoiella indica Hirst (Acari: Tenuipalpidae) is a pest species that has expanded not only in geographical distribution but also in the number of host plants. Control measures are still being evaluated in recently invaded countries. In some countries and for some crops, spraying with botanical extracts has been used to reduce R. indica populations. Laboratory and field studies point to the predatory mite Amblyseius largoensis (Muma) (Acari: Phytoseiidae) as promising for combating R. indica. However, this predator has not yet been commercially available. Thus, the present study aimed to evaluate the potential of another predatory mite Neoseiulus barkeri Hughes, a commercially available generalist predator as a biological control agent of R. indica. The consumption and oviposition rate of N. barkeri were determined across the developmental stages of R. indica. The predation and oviposition capacity of N. barkeri and A. largoensis when fed R. indica eggs in the laboratory were compared. In the field, releases of the predator N. barkeri at densities of 900, 600 and 300 predators per plant were compared to spraying with botanical extracts such as cottonseed oil and azadirachtin to control R. indica. Our results suggested that N. barkeri is an effective predator to control R. indica. The consumption of N. barkeri was inversely related to the life stage of R. indica, and all developmental stages of R. indica enabled the reproduction of N. barkeri. The predation and oviposition of N. barkeri were higher than those of A. largoensis, and the releases of N. barkeri at densities of 900 and 600 predators/plant resulted in significant reductions in R. indica populations.

Fruit bagging is an efficient mechanical control technique used in fruit growing. However, to date, few studies have evaluated the efficacy of bagging in the cultivation of vegetables, including tomato crops. The objective of this study was to evaluate the effectiveness of bagging of tomato flowers and/or fruits using a non-woven fabric (NWF) for the control of Helicoverpa spp., Neoleucinodes elegantalis, and Tuta absoluta, to evaluate the effect of this technique on the final yield, and determine the optimal period for bagging. Tests were conducted in a commercial crop of staked ‘Valerin’ tomato plants located in the municipality of Ubajara, Ceará State, Brazil. The experimental design was randomized blocks with a 2x4 factorial design (sprayed versus unsprayed plants, and both plant groups were bagged with NWF bags at different growth stages [flowers bagging, bagging of bunches of fruits with a diameter of 1.5cm, bagging of bunches of fruits with a diameter of 3.0cm, and unbagged bunches (control)], with five repetitions. We evaluated the number of fruits per bunch, number of bunches per plant, weight of each fruit, longitudinal and transverse diameter, percentage of bored fruits, yield loss caused by insect infestation, and final yield. Bagging of ‘Valerin’ tomato bunches with NWF bags was effective for the control of N. elegantalis, and productivity increased by 21.5% when bagging was done in bunches of fruits with a diameter of 1.5cm compared with unbagged fruits; therefore, this growth period was the most suitable for bagging.

Raoiella indica Hirst (Acari: Tenuipalpidae) is a polyphagous pest widely dispersed worldwide and a particular threat to crops from the Arecaceae family. Control measures are still being evaluated in recently invaded countries. A possible control strategy for this pest is the use of predatory mites. A recent study has suggested Neoseiulus barkeri Hughes (Acari: Phytoseiidae) as a potential biological control agent of R. indica. In the present study we determined the prey stage preference of N. barkeri when offered different stages of R. indica besides its functional response and numerical over its prey stage preferred. The predatory mite N. barkeri showed a marked preference for eggs over other stages of the prey. The regression analysis indicated that the predatory mite N. barkeri exhibited a Type II functional response. The prey density needed to start the oviposition was 10 R. indica eggs. The number of eggs laid by N. barkeri females increased with an increase in the prey density and tended to stabilize when prey availability was greater than 80 R. indica eggs, with average oviposition of 2 eggs/female. Our study suggests that N. barkeri shows potential to reduce populations of R. indica, especially at low prey densities. However, further studies are needed to investigate whether R. indica supports the development of immature stages of N. barkeri.

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