Obscure mealybugs exhibit a high degree of sexual dimorphism; females are flightless, larger, and longer-lived than the winged males, who cannot feed and die immediately after mating.

[4] The most distinctive feature of the obscure mealybug is the set of two to four exceptionally long caudal filaments growing from the posterior of large nymphs and adult females.

[8] Being in the order Hemiptera (so-called "true bugs"), obscure mealybugs undergo incomplete metamorphosis; nymphal young closely resemble adults in body shape, take six to nine weeks to mature, and retain the use of all six legs throughout their entire lives.

[7] Depending on temperature, obscure mealybugs may complete 2-3 generations per year;[11] females will lay clutches of several hundred orange eggs in cottony sacs, from which nymphs will hatch and emerge after about 5–10 days.

[12] The female obscure mealybug sex pheromone has the unfortunate property of sometimes attracting parasitic wasps (such as Tetracnemoidea peregrina), and is therefore a kairomone.

[14] The obscure mealybug has caused particularly substantial damage to vineyards in the Central Coast of California, where it is an introduced species and has no natural predators.

[3][15] Because of the high toxicity and strict regulation of organophosphate pesticides, some Californian vintners have imported natural parasites of the obscure mealybug from Chile, particularly Pseudaphycus flavidulus and Leptomastix epona.

[16] Such efforts have so far produced indeterminate results; the obscure mealybug is capable of encapsulating and killing the eggs of L. epona and L. dactylopii, for example, rendering those parasites ineffective.

In 1983 and Kaiser et al. 2001 find P. viburni to have taken residence in these pomes by that time in the season, at the calyx or distal end, and unreachable to sprays.