Pseudococcus meridionalis, a new species of mealybug found on grapes: biology, morphological and molecular characterization

Pseudococcidae includes many species of mealybugs that are important pests of a variety of crops, including fruits, forest and ornamental plants. The main damage is associated with their interference in international trade, because many species have quarantine status for several markets. While conducting a survey to describe the species of mealybugs associated to grapes in central Chile, we found individuals that presented unknown genetic sequences, and with a combination of morphological characteristics that did not correspond to any mealybug species thus far formally described. Here we present the molecular and morphological characterization of one of the species found: Pseudococcus meridionalis Prado. Additionally, in order to know its biology in laboratory and field conditions, we begun laboratory colonies in different substrates and also follow its biology on grapes for one season. In laboratory conditions we found poor development on potatoes and butter squash, the most common rearing substrates for mealybugs, with the best development on zucchini and quince. Fecundity on potatoes was relatively low (69.8 ± 8.1). In the field we found the development of three discrete generations, requiring approximately 590°D (10°C threshold). The population peaked in December, when 95% of the individuals were found on leaves and the rest on bunches. This biology differs from that of P. viburni, the most common species found on grapes in this region. We conclude that the use of both, molecular and morphological tools are key when describing mealybug species. Also, the distinct biology of this species in the field should be taken into account when designing integrated pest management strategies for mealybugs on grapes.  Funding: FONDEF D10I1208