First record and verification of Tyrophagus putrescentiae (Acari: Acaridae) causing direct damage on anthurium plants cultivated in vitro

Abstract

The population size at which Tyrophagus putrescentiae can produce damage on anthurium plants (Anthurium sp.), cultivated in vitro, was determined. Symptoms caused by these mites on the plants are described. Two anthurium varieties coded as ANMIRO and ANWHGE, were cultivated in a Murashige and Skoog medium for four weeks. The treatments for each variety were as follows: a) Absolute Control (AC), b) fungus inoculated in the cultured medium (CF), c) fungus on leaves + mites (FLM), d) fungus in medium + mites (FMM), and e) only mites (OM). Mite density within the vessels increased through time. Fifty-five days after the first evaluation, the highest amount of injury was observed in the treatments FLM, FMM, and OM. The observed symptoms were holes on the foliar lamina produced by the feeding of mites until complete plant deterioration. According to the prediction model, when there is an average population close to 62 mites per vessel, it would be expected to find 20% damaged. The probability of observing damage on the variety ANWHGE was 1.7 times higher than on the variety ANMIRO. Although T. putrescentiae is a known contaminant in tissue culture laboratories as it carries bacteria and fungi on its body, this is the first record of this species causing direct damage to plants cultivated in vitro.