Leaf Miners

Question 1

Arborvitae Leaf Miner Damage Identification

Answer 1

browning appears late winter - foliage tips will be hollow and contain frass and may also contain larvae, often misdiagnosed as winter injury. chemical control for the adults prior to egg laying, generally mid June

Question 2

Arborvitae Leaf Miner

Answer 2

adult moths are small and silvery tan, begin being active mid june to early july. lay eggs on the foliage, larvae hatch and chew into the leaves. feed until autumn where they overwinter in the mines, resume feeding in the spring and pupate by late may. pupate within the mine, browning of the foliage does not appear until late January / February

Question 3

Birch Leaf Miner

Answer 3

attack most birches, form blotch mines and consume partial or full leaves, adults are black and fly like, larvae are yellowish white and legless - can sometimes be seen if leaves are held up to the sunlight

Question 4

Birch Leaf Miner Lifecycle

Answer 4

two generations per year, adults emerge mid may, females deposit one egg at a time in slits made on the leaves, larvae hatch and create kidney shaped mines, feed for two weeks then drop to the ground and pupate - 2-3 weeks pupae begin second generation, overwinter in the soil

Question 5

Birch Leaf Miner vs Bronze Birch Borer

Answer 5

NO RELATION; damage due to bronze birch borer starts at the top of the tree and ends of the branches before moving inward, leaves damaged by leaf miners will be scattered throughout the tree

Question 6

Birch Leaf Miner Control

Answer 6

try to catch before damage - systemic pesticides like acephate, soil imidacloprid injections previous fall to control them in the spring - typically done for aesthetics

Question 7

Holly Leaf Miner

Answer 7

very common, generally caused by two species. adult of both is a small black fly and larvae is a maggot that feeds and leaves yellowish or brown winding trails / blotches - can also distort leaves and leave tiny brown dots; leaves yellow and drop

Question 8

Holly Leaf Miner Signs

Answer 8

early signs - small raised bumps on the leaves where the egg has been inserted into the leaf by the female, young maggots leave light green serpentine tunnels that get progressively wider as the maggot grows, can scrape back the leaf tissue to see

Question 9

Holly Leaf Miner Life Cycle

Answer 9

one generation per year; larvae overwinter in the leaves on the trees or ones that have fallen, adults emerge in mid may to late june and begin laying eggs in about 10 days; females make a slit in the leaf and deposit an egg inside the leaf

Question 10

Holly Leaf Miner Control

Answer 10

healthy plants / sanitation, acephate or imidacloprid beginning in mid May when the adults begin to emerge, generally will require two follow up sprays, can also apply imidacloprid to the soil in the early spring