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The ability of an organism to defend itself and protect its offspring is closely related to the evolutionary success of the organism. In this study, we examined the responses of red palm mite, Raoiella indica Hirst, to predation risk using cues from the predator Amblyseius largoensis (Muma). Females of A. largoensis were used for the production of cues for 4 h in two types of bioassays, a choice and no-choice tests. The oviposition rate of R. indica was evaluated until to 96 h. In addition, a walking behavior test was conducted (distance/time walked and resting time). For both tests, a control treatment without cues was done. In the no-choice bioassay, the oviposition rate of R. indica decreased by 55% when the cues were present. In the choice bioassay, the oviposition rate was similar to the control treatment, however most of the eggs were deposited in the site without cues. The walking behavior of R. indica was not affected by the presence of predator cues in no-choice bioassay. In choice bioassay, R. indica stayed longer in sites without cues. A. largoensis cues seem to be strong signs of predation risk affecting R. indica oviposition when there is no-choice, even after 96 h. R. indica shows that it is able to identify the cues of A. largoensis. We clearly evidenced the anti-predation behavior of R. indica, showing the trade-off between predation risk and reproduction on A. largoensis cues. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Organisms are adapted to recognize environmental cues that can provide information about predation risk or competition. Non-vagrant eriophyoid mites mainly avoid predation by using habitats that are difficult for predators to access (galls or confined spaces in plants) such as the meristematic region of the coconut fruit, which is inhabited by the phytophagous mites Aceria guerreronis and Steneotarsonemus concavuscutum. The objective of this study was to investigate the response of A. guerreronis to cues from the predators Neoseiulus baraki and Amblyseius largoensis in coconut fruits, cues from conspecifics (A. guerreronis injured) and cues from the phytophage S. concavuscutum. The test was carried out through the release of about 300 A. guerreronis on coconut fruits previously treated with cues from predators, conspecific or heterospecific phytophagous. We also observed the walking behaviour of A. guerreronis exposed to the same chemical cues using a video tracking system. The infestation of fruits by A. guerreronis was greater in the presence of predator cues and reduced in the presence of S. concavuscutum cues, but cues from injured conspecifics did not interfere in the infestation process. In addition, the cues also altered the walking parameters of A. guerreronis: it walked more in response to cues from predators and the heterospecific phytophage. Aceria guerreronis spent more time in activity in the treatments with clues than in the control treatment. These results suggest that A. guerreronis recognizes cues from predators and competitors and modifies its behaviour to increase its fitness. [ABSTRACT FROM AUTHOR]