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Beginner

This pest affects:

Scientific Name
Pseudococcus comstocki

Identification
Eggs

• Elliptical
• 0.3mm in length
• Bright orange-yellow with a waxy coating

Nymphs

• Oval, 1.2-2.5 mm in length, females are larger than males
• 3 (male) to 4 (female) instar stages
• Wingless
• Orange-yellowish to reddish-brown
• Covered in thin waxy coating with no body filaments

Adults

• Female: Oval, 5mm in length, wingless, segmented body, reddish-brown but covered in white wax, 17 pairs of soft spines with posterior pair being the longest
• Male: Gnat-like, 1mm in length, veinless wings, reddish-brown, two posterior filaments as long or longer than body

Damage

• Sap-feeders that congregate on leaves or fruit (calyx and stem ends)
• Secrete honeydew that promotes growth of sooty moulds
• Fruit drop can occur if feeding along stem

Often Confused with
Scales - leathery waxed secretion forming a shell; adult females remain sedentary

Period of Activity
The overwintering eggs hatch from mid-April through May up to petal fall in pear. Nymphs that hatch from the overwintering eggs are active from early May to early July. Adult females and males emerge at the same time, from late June to mid-July. Adult females are present for a total of four to six weeks and lay eggs for approximately one week after mating. Males survive for only a few days after emerging.

Second- (summer) generation eggs are laid from mid-June through late July, and the overwintering eggs from mid-August into October. The summer generation eggs have an incubation period of about 11 days. Second-generation nymphs and adults are present from about mid-July to mid-September and late August to mid-September, respectively.

Scouting Notes
Examine terminal growth for crawler activity periodically throughout the summer. By placing double-sided tape around different branches at increasing heights up the tree, crawler and adult female movement towards the fruit can be monitored.  The presence of ants can be used as an indicator, as well, since honeydew attracts ants.

Thresholds
There are no thresholds nor a good monitoring method for mealybugs. 

Advanced

This pest affects:

Scientific Name
Pseudococcus comstocki

Identification
Eggs

• Elliptical
• 0.3mm in length
• Bright orange-yellow with a waxy coating

Nymphs

• Oval, 1.2-2.5 mm in length, females are larger than males
• 3 (male) to 4 (female) instar stages
• Wingless
• Orange-yellowish to reddish-brown
• Covered in thin waxy coating with no body filaments

Adults

• Female: Oval, 5mm in length, wingless, segmented body, reddish-brown but covered in white wax, 17 pairs of soft spines with posterior pair being the longest
• Male: Gnat-like, 1mm in length, veinless wings, reddish-brown, two posterior filaments as long or longer than body

Damage

• Sap-feeders that congregate on leaves or fruit (calyx and stem ends)
• Secrete honeydew that promotes growth of sooty moulds
• Fruit drop can occur if feeding along stem

Often Confused with
Scales - leathery waxed secretion forming a shell; adult females remain sedentary

Biology
Comstock Mealybug is a sporadic pest of peach and pear in Ontario.

Comstock Mealybug has two generations, each taking 60 to 90 days to complete, depending on seasonal temperatures. The egg is the primary overwintering stage, though some nymphs and adult females from the second generation overwinter, and their eggs being laid in the spring rather than the previous fall.

Eggs are laid in jumbled masses along with the white waxy filamentous secretions in protected places such as under bark crevices, near pruning cuts, and occasionally in the calyx of fruit. First generation nymphs (crawlers) appear at bloom and migrate from the oviposition sites to their feeding sites on terminal growth and leaf undersides of trees. As the nymphs approach the adult stage, they tend to congregate on older branches at a pruning scar, a node, or at a branch base, as well as inside the calyx of pears. Adult females may lay several hundred eggs on the leaves, fruit or twigs in a protective ovisac which is covered with wax filaments. Males are very short-lived and unlikely to be seen in the field unless captured in pheromone traps.

Period of Activity
The overwintering eggs hatch from mid-April through May up to petal fall in pear. Nymphs that hatch from the overwintering eggs are active from early May to early July. Adult females and males emerge at the same time, from late June to mid-July. Adult females are present for a total of four to six weeks and lay eggs for approximately one week after mating. Males survive for only a few days after emerging.

Second- (summer) generation eggs are laid from mid-June through late July, and the overwintering eggs from mid-August into October. The summer generation eggs have an incubation period of about 11 days. Second-generation nymphs and adults are present from about mid-July to mid-September and late August to mid-September, respectively.

Scouting Notes
Examine terminal growth for crawler activity periodically throughout the summer. By placing double-sided tape around different branches at increasing heights up the tree, crawler and adult female movement towards the fruit can be monitored.  The presence of ants can be used as an indicator, as well, since honeydew attracts ants.

Thresholds
There are no thresholds nor a good monitoring method for mealybugs. 

Management Notes
If infested fruit is found at harvest, trees should be examined during the dormant period for the presence of white cottony masses under rough bark, in pruning scars and in cankers on the larger branches and trunk.

Oil spray targeted for scales may suppress this pest at early instar stages when mealybugs have only a thin wax covering. When the infestation is severe, a special spray is recommended.