Citrophilus mealybug	-	Dispersal for all species combined
	Longtailed mealybug
	Obscure mealybug

Apart from the eggs, all stages of mealybugs are mobile. However, the tiny first instar or crawler plays a key role in dispersal and the adult males are winged. Crawlers hatch beneath the adult female (longtailed mealybug) or in the egg sac (obscure and citrophilus mealybugs) and then disperse over the host plant. This is especially important in spring, when crawlers move from the overwintering sites under bark to feed on the young leaves at bud burst, but also occurs with subsequent generations. Older stages (mainly 3rd instars) return to the bark in summer and autumn in the reverse process. In general, crawlers disperse to open feeding sites (e.g. on leaves) whereas second and later instars prefer to move to more sheltered sites. Crawlers are also primarily responsible for spreading the mealybug population to new host plants, of which there are many. This occurs through both crawling and wind dispersal, and they may also be carried on birds and other animals. Crawlers have been observed to walk more than 6 m in the laboratory. Second instar mealybugs are also dispersed by wind but the mobility of 3rd instars and adult females is confined to crawling. Studies of longtailed mealybug in Australia have shown that sticky traps in pear orchards catch wind-blown crawlers (89%) and second instars (11%). Greater numbers were caught as temperatures rose from 19 to 39°C and as wind speeds rose from 2 to 24 km/h. Crawler production by obscure mealybug is reported to vary through the day, reaching a peak around noon.

The effectiveness of insecticides for control of mealybugs can be improved by timing sprays to coincide with the production of exposed and dispersing crawlers. Insecticide timing and efficacy is needed to prevent older stages from dispersing to the calyx and stem end of fruits and establishing colonies there, usually from mid-January onwards.

The dispersal ability of male mealybugs appears to be less than their wings would suggest. In the Australian study, only 2 males of longtailed mealybugs were caught on just 2 of the 76 days of trapping and wind was not thought to assist them in dispersal. In their short lives, the primary function of males is to locate females for mating and studies with the males of citrophilus mealybug indicate an optimum wind velocity of 0.5 m/s for this behaviour. Under these conditions, the males move directly to a female sex pheromone source from 1 m away. They move against the wind in a zigzag (klinotactic) flying motion. In the field study of longtailed mealybug dispersal, males were trapped only on the rare days with no wind and they were more often seen walking in crevices on the bark, presumably seeking the scent trails of adult females.