From March to May these leafminers pupate in the new portion of the mine after an exit hole has been chewed. Arborvitae leafminer pupae face toward the tip of the damaged leaf. N.C. Adults are small (about 1/8 inch long), light gray moths with brown and black spots and slender antennae. New moths appear 3 to 5 weeks later in late spring or throughout the summer. Newly hatched larvae bore into the leaves and feed for the rest of the season. These entrance holes are … It may also attack juniper. N.C. This Factsheet has not been peer reviewed. Arborvitae leafminers are slender and found in the tips of arborvitae branches. Eggs are laid on the foliage, from which the larvae soon hatch, and then they chew their way into the leaves. Nearly fully grown arborvitae leafminers overwinter in mined foliage. Eggs are pinkish at first but turn darker as the embryo inside matures. Doing nothing should allow these parasites to reduce the population of leafminers naturally. Larvae sometimes leave old mines and begin new ones. Those clippings should be destroyed to prevent another generation of moths from emerging the following spring. Most of the eggs are laid around the first of June. Arborvitae leafminer moths are very small. The larvae mine from the tips of branchlets toward the bases and allow the frass to collect in the tunnels until winter. commitment to diversity. Cooperative Extension is based at North Carolina's two land-grant institutions, Its 1/8 inch long pupa is greenish but turns brownish-red as it matures inside the mined leaf. A familiar species is P. citrella, a major pest of citrus plants, causing leaf curls. Leaf miner moth Phyllocnistis spp. Publication date: Sept. 23, 2016 The arborvitae leafminer, Argyresthia thuiella, is a small (up to about ¼ inch long), green (sometimes with a reddish tinge) or brownish caterpillar with a dark brown or black head and a dark spot just behind the head (the cervical shield). At least 26 species of parasitic wasps have been reared from infected arborvitae leafminers. Later in the season, try pruning out dead tips. At times, whole shrubs may turn brown from their feeding. NC State University and NC Arborvitae leafminers overwinter as larvae in the mined leaves. Systemic insecticides such as imidacloprid are also recommended for control. Revised: Aug. 29, 2019. Heavily damaged leaves may drop from the plant prematurely. Its 1/8 inch long pupa is greenish but turns brownish-red as it matures inside the mined leaf. The tail segment has a group of six to eight short, stout hooks called the cremaster. commitment to diversity. When mining is resumed the following spring, the frass is expelled from the mine. This publication printed on: Nov. 26, 2020, Caterpillars on the Foliage of Conifers in the Northeastern United States (revised), Extension Plant Pathology Publications and Factsheets, North Carolina Agricultural Chemicals Manual, NC Arborvitae leafminers are tiny to very small caterpillars. Indians. For assistance with a specific problem, contact your local Cooperative Extension Center. A&T State University. A&T State University, in all 100 counties and with the Eastern Band of Cherokee Arborviate leafminer moths have a wingspan of 5/16 inch. Eggs are tiny and almond shaped with wrinkled sculpturing on one end. It has silvery and white iridescent forewings with brown and white markings and a distinct black spot on each wing tip. Pupae face the exit hole. Spraying with a pyrethroid insecticide labeled for residential landscape use should help control these adults. In extreme cases a heavily infested plant may be killed. The tips may die out completely. A closeup of a firethorn leaf miner moth. Most of these are from the Lepidoptera (moth), Symphyta (sawfly) or Diptera (fly) families, although there are a few exceptions from other genera. If more rapid suppression is desired, shake the foliage in June or July to see if the moths fly around the shrubs. Family Phyllocnistidae Adult wingspan: 6 mm This is a group of mainly host-specific and similar looking species, including many undescribed species. The adult is a very small moth that emerges to lay eggs in May and June. Thousands of different fly or moth larvae are considered to be leaf miners, and each variety has its own favored plant type. Source: davidshort. Although you'll likely never see the tiny adult insects, the females insert their eggs inside of plant leaves in the spring, and the hatched larvae grow and feed within the leaf … The arborvitae leafminer, Argyresthia thuiella, is a small (up to about ¼ inch long), green (sometimes with a reddish tinge) or brownish caterpillar with a dark brown or black head and a dark spot just behind the head (the cervical shield). The arborvitae leafminer apparently attacks all varieties of arborvitae (northern white cedar) but seems to prefer American pyramidal, globe, and golden arborvitae (about in that order). Citrus leafminer is a very small, light-colored moth, less than 1/4 inch long. Mined leaves turn yellowish or whitish and detract from the appearance of infested arborvitae. Read our Mature caterpillar present from April to June. After 2 or 3 days, females deposit eggs in the axils of branchlets or along leaf margins. A female may oviposit for 4 or 5 weeks. Receive Email Notifications for New Publications. The legs and abdomen are light brown. The adult moths are small (wingspan 5-6mm), silvery tan in appearance, and are active starting approximately mid-June into early July. "Leaf miner" is a catchall term for fly, moth and beetle larvae that feed inside of plant leaves, leaving winding tunnels or large blotches in their wake. — Read our Cooperative Extension prohibits discrimination and harassment regardless of age, color, disability, family and marital status, gender identity, national origin, political beliefs, race, religion, sex (including pregnancy), sexual orientation and veteran status. Arborvitae leafminers hollow out and kill the tips of arborvitaes. The hind wings and body are white, with long fringe scales extending from the hindwing margins.