The newly hatched larvae protect themselves by feeding from within the curled leaf margins. Larva – As the legless larva matures, thickening thoracic segments cause its body to become curved. The nymphs feed in groups in the younger stages. Some of the preferred woody hosts include hemlock, rhododendron, and yew. The main trunk may have numerous holes with fine sawdust protruding from them. A. Their caps are level with the leaf surface. The margins may fold over the midrib. Severe wounds are formed, often from multiple larvae infesting adjacent tunnels. As many as 170 eggs can be found on a single leaf. Do your rhododendron leaves look silvered and pale as in the photo above? The female's anal tuft is short and rounded, whereas the male's is fan shaped. Trunk damage caused by rhododendron borer. This moth is indigenous to the United States. Damage – Rhododendron tip midge maggots feed exclusively on tender new growth. On severely infested plants, new growth may be so distorted after emergence that additional foliage fails to develop. Black vine weevil larvae can stunt the growth of a plant by feeding on the roots. Mountain laurel and azalea are also attacked. When mature, the maggots drop to the soil to pupate. Three weeks later, adults emerge. Leaves on infested branches often turn brown. The rhododendron lace bug was originally described in the United States from specimens taken in Holland in the early 1900's; however, the earliest report of the insect was from Pennsylvania, and the pest is now considered indigenous to the United States. Good culture practices are a key element of keeping plants resistant to bugs and germs. Mountain laurel and azalea are also attacked. After eggs hatch the larva bores into branches and … Eight cultivars were usually represented by 2 plants. The borer is the immature form (caterpillar) of the rhododendron borer moth. The first symptom is usually wilted leaves on a single branch. Family: Sesiidae Host Plants: Rhododendrons, mountain laurel (Kalmia), and deciduous azaleas (Johnson & Lyon)Description: Early symptoms of attack, as described by Johnson and Lyon, appear to be drought stress, with foliage losing its color and dying. Eggs, deposited in the soil and leaf litter, hatch in 2 to 3 weeks. If rhododendron borer is more than a sporadic problem, you may want to use insecticide sprays in May when the adult is active, to prevent new infestations. Newly hatched larvae bore into stems and dig long tunnels in the soft pith. Rhododendron stem borer causes wilting terminals and dieback, which is similar to the Rhododendron borer. Host Plants – Rhododendron is the only known host of this pest. The adult weevils chew the edges of the leaves, cut off the tips of needles, or devour entire needles (. If you’ve had a history of borer problems on rhododendrons, azaleas, and mountain laurels, check your garden center for an insecticide labeled for borer control with a pyrethroid insecticide, such as permethrin or cyfluthrin. Life History – Black vine weevils overwinter as mature larvae or as pupae. During their development, the larvae molt five or six times within earthen cells in the soil constructed by the larvae prior to molting. The moths feed only on nectar or not at all so they do not cause damage. The main trunk may have numerous holes with fine sawdust protruding from them. Damage-Twigs and small branches are preferred by the rhododendron borer. This weevil is parthenogenetic. Pest Damage on Azalea/Rhododendron Botrytis Angular Leaf Spot Anthracnose Leaf Spot Black Vine Weevil, Adult Cercospora Leaf Spot Lace Bug, Rhododendron Leaf Beetle, Rhapdopterus Leafminer, Azalea Phyllosticta Leaf Spot Powdery Mildew Borer, Rhododendron Black Vine Weevil, Larva. Many herbaceous and woody plants have been listed as hosts for the black vine weevil. Larva – The yellow-white larvae are caterpillars about 13 mm long. Infestations can be detected by the presence of shallow… A. Lilac Borer Damage. Enter your email address to subscribe to our blog and receive notifications of new posts by email. It is pale yellow, with yellowish legs and antennae. Nonoverwintering eggs hatch in about 3 weeks. The thorax is black and blue with a broad patch of pale yellow or shiny white on each side. There is a tuft of black and yellow scales at the tip of the abdomen. Both the nymphs and adults prefer young leaves, which they damage by extracting the sap. This moth is indigenous to the United States. They range from 0.9 to 2.1 mm in length and are black and spiny (Color Plate 3AA). There is a tuft of black and yellow scales at the tip of the abdomen. Rhododendron lace bug, Stephanitis rhododendri Horvath, Tingidae, HEMIPTERA. About 1910 the beetle was found in Connecticut and has since become a serious ornamental pest in southern Canada and the northern United States. Several species of clearwing and flatheaded borers can infest landscape plants. × The wings are transparent with a rusty-black fringe and some yellow scales. The female has broader bands on segments two, four, and five than the male does. 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. There are two types of borers that attack rhododendrons, the rhododendron stem borer and the rhododendron borer. The legs are yellow and white epically and dark basally with some light-colored markings. Adult borers—slender long-horned beetles—emerge from hibernation in the soil at the base of these shrubs, climb up stems, and lay eggs under the bark. Dispose of the cut-off stem portions in a plant disposal or burn pile. The small adult, about 3.5 mm long and 2.4 mm wide, has lacy wings that are unusually broad. Rhododendron borer, Sqnanthedon rhododendri Beutenmuller Sesiidae LEPIDOPTERA. The undersurfaces are also discolored with the excrement and cast skins of the insects (Figure AA). The wings are transparent with a rusty-black fringe and some yellow scales. Infested branches become weakened and may break off. For specific chemical controls, see the current state extension recommendations. It is white when first deposited but becomes brown as it ages. Symptoms Peach Tree Borer Damage. AG-189. As many as 170 eggs can be found on a single leaf. The Azalea/Rhododendron Stem Borer (Oberea myops) and Rhododendron Borer (Synanthodon rhododendri) are common pests in our area, endemic in wild populations, affecting rhododendrons, azaleas, mountain laurels and other ericaceous plants. Indians. Note the three gold bands on the abdomen. This dead rhododendron branch shows a tunnel entrance created by a rhododendron borer in Sharon, MA. About 1910 the beetle was found in Connecticut and has since become a serious ornamental pest in southern Canada and the northern United States. Young infested leaves, usually less than 5 cm long, develop inwardly rolled margins with swollen, greenish-yellow tissue. They range from 0.9 to 2.1 mm in length and are black and spiny (Color Plate 3AA). A. Maggot. Adult beetles feed on the underside of leaves on the midvein, causing the leaves to An effective cultural control method for both homeowners and nurserymen is the removal and destruction of newly infested foliage. Pupa – The pupa is white with prominent dusky spines on the head, abdomen, and legs. This publication printed on: Dec. 19, 2020, The oblong black vine weevil is 10 to 11 mm long and has a short snout. We live in Lumpkin County. Host Plants – Many herbaceous and woody plants have been listed as hosts for the black vine weevil. Initially the young larvae feed on rootless; but after the third molt, the larvae move to the larger roots. Adult. Infested branches become weakened and may break off. The black vine weevil has the name "vine" in its common name because it was first recognized as a pest of grapes in Germany in 1934. There are only four nymphal stages, which require about 30 days for development. Leaves on infested branches often turn brown. The flattened maggot is whitish and about 1.27 mm long. Branches may be girdled, causing the … The insect seems to favor relatively well-lighted sites, but bushes in the shade can also be badly infested. The body is blackish brown; the antennae are black and slightly pubescent; and the head is smoother than the thorax (. The eggs are deposited in irregular rows, usually along the larger veins. Rhododendron tip midge. If so, then your rhododendrons are suffering from thrip damage. Rhododendron trunks and branches are sometimes severely injured by white larvae that tunnel under the bark. However, a few adults also survive the winter to feed and deposit eggs during a second season. When mature, the maggots drop to the soil to pupate. From the hole, feel your way down the stem to the next joint, and with sharp pruners, cut off the section of the branch above that point. Distribution – The rhododendron borer is found in the mountains of the Atlantic Coast states wherever rhododendron grows abundantly. Host Plants – Rhododendron is the principal host for the rhododendron borer. Helpline 828-255-5522. Egg. This moth is indigenous to the United States. Caloptilia azaleella. wherever rhododendron grows abundantly. Therefore, it seems that at least two generations occur each year. These are all signals that the borer is somewhere inside the stem below that hole. The legs are yellow and white epically and dark basally with some light-colored markings. Rhododendron is the principal host for the rhododendron borer. As the legless larva matures, thickening thoracic segments cause its body to become curved. Copyright © 2020 Extension Master Gardeners of Buncombe County. It has been reported in New York, New Jersey, Pennsylvania, and North Carolina; therefore, it may occur over much of the eastern seaboard. BIOLOGY Distribution-The rhododendron borer is found in the mountains of the Atlantic Coast states wherever rhododendron grows abundantly.This moth is indigenous to the United States. Solutions A&T State University. The interior, older foliage is preferred to the terminal growth. 2 Borer Chemical Control zTrunk insecticides zEmulsifiable concentrate formulation long lasting zPyrethroids, bifenthrin (Onyx), zSystemic insecticides zImidacloprid – Kills beetle borers only zDoes NOT kill caterpillar borers zWon’t work if vascular system is damaged How topical insecticides kill borers zAs adults feed on leaf tissue zMetallic wood boring beetles (Flat headed borers) Distribution – The black vine weevil has the name "vine" in its common name because it was first recognized as a pest of grapes in Germany in 1934. Although one female was recorded as laying 863 eggs, the average number of eggs deposited by each female is probably about 200. However, a few adults also survive the winter to feed and deposit eggs during a second season. Properly labeled chemicals should be used, and safety precautions listed on the label should be followed. Twigs and small branches are preferred by the rhododendron borer. Damage to flower buds begins to appear most years during the first half of February (as early as January 28 in 1994). The larval feeding damage from this fly can cause discoloration and distorted foliage. Occasionally older parts of the shrubs are attacked. Click to share on Facebook (Opens in new window), Click to share on Pinterest (Opens in new window), Click to share on Twitter (Opens in new window), Click to share on Pocket (Opens in new window), http://www.ces.ncsu.edu/depts/ent/notes/O&T/calendars/note052.html, https://growingsmallfarms.ces.ncsu.edu/wp-content/uploads/2016/02/Pruning-Blueberrries-25JAN14.pdf?fwd=no, A Gardening Guide for Our Mountains: The Perfect Holiday Stocking Stuffer, Gardening Video: Table Wreath Centerpieces Using Seasonal Plants, Winter Rye Cover Crops and Why I Love Them, Table Wreath Centerpieces Using Seasonal Plants. The pests are commonly transported in the egg stage on nursery stock. Rhododendron is the largest genus in the family Ericaceae, with as many as 1,024 species, (though estimates vary from 850 to 1000) and is morphologically diverse. N.C. The tunnels become filled with small, reddish fecal pellets and serve as sites for overwintering and spring pupation. Rhododendron stem cut away to show tunnel of stem borer, Oberea myops Haldeman. Host Plants – Rhododendron is the principal host for the rhododendron borer. Please explain or diagnosis. Make good, clean pruning cuts because in addition to searching for the insect, you are shaping the shrub. Larva – The flattened maggot is whitish and about 1.27 mm long. Host Plants – The rhododendron lace bug attacks over 120 types of rhododendrons, as well as mountain laurel and fetter-bush. It is white when first deposited but becomes brown as it ages. However, if there is a hole in the stem, the borer is deeper than your cut and you’ll need to repeat your pruning lower down. Young infested leaves, usually less than 5 cm long, develop inwardly rolled margins with swollen, greenish-yellow tissue. The longevity of the adult usually ranges from 90 to 100 days. During their development, the larvae molt five or six times within earthen cells in the soil constructed by the larvae prior to molting. The egg is approximately 0.7 mm in diameter, with a smooth, shiny surface. These weevils cannot fly; so they must be carried or must crawl to uninfested areas. Rhododendron Borer Oak borer Oak Ash, lilac, privet, fringe tree Lilac borer Lesser peach tree Peach, cherry, plum, borer Dogwood borer Dogwood, apple,pear Banded Ash Ash Clearwing Common Name Hosts attacked. Close to 4,056,000 rhododendrons are grown or collected by Southern nurserymen each year. The female, on the other hand, has a short ovipositor and antennae about as long as its body. Apply after the new growth has hardened off about mid-May; apply again in early June. Life History – These pests overwinter as pupae in the soil. For specific chemical controls, see the current state extension recommendations. Past infestations on older plant parts will appear as shallow, longitudinal grooves in the bark. The elytra possess many rounded tubercles, each with a short seta. Damage – Twigs and small branches are preferred by the rhododendron borer. The upper surfaces become mottled with white spots, and many times the leaves will dry and shrivel. The larvae mine leaves during the early part of their development. These lace bugs overwinter as eggs, which hatch in April in the area of Washington, D.C. Nonoverwintering eggs hatch in about 3 weeks. The rhododendron borer moth has a black head with green and white markings. Monitoring. N.C. Pest: Rhododendron Borer (Synanthedon rhododendri (Beutenmuller)). For blueberries, pruning your plants every year in late winter is usually sufficient to control stem borers. Asheville, NC 28806 The body is blackish brown; the antennae are black and slightly pubescent; and the head is smoother than the thorax (Figure J). The newly hatched larvae protect themselves by feeding from within the curled leaf margins. Injury caused by this key pest in ornamental plantings of rhododendron tends to increase from year to year if an infestation is not effectively managed. Privacy Policy. Larger roots are stripped of their bark or girdled, or they have notches chewed out of them. Adults feed at night and drop from the plant, feigning death when disturbed. Control and prevention The adult flies emerge and lay eggs in the spring as new plant growth develops. Look above where you see the frass and you’ll find the hole where the borer pushed these deposits out of the stem. Unlike most lace bugs, the rhododendron lace bug has only four nymphal stages. Prune wilting branches, cut them open and try to locate the larvae. commitment to diversity. It is alternately called the rhododendron stem borer, azalea stem borer, or blueberry stem borer, depending on host plant affected. How do you treat something like borers? Three weeks later, adults emerge. Carpenter Worm Gallery. The tunnels become filled with small, reddish fecal pellets and serve as sites for overwintering and spring pupation. The adult weevils chew the edges of the leaves, cut off the tips of needles, or devour entire needles (Figure J). While some are attracted to a wide range of hosts, most attack only particular kinds of trees and shrubs. B. Larva. Be sure to read and follow the insecticide label for specific application instructions. One of the smallest members of the family of clearwing moths, this moth has a wingspan of 10 to 15 mm. Early history. A&T State University, in all 100 counties and with the Eastern Band of Cherokee Damage – Twigs and small branches are preferred by the rhododendron borer. The female, on the other hand, has a short ovipositor and antennae about as long as its body. Adult – The small adult, about 3.5 mm long and 2.4 mm wide, has lacy wings that are unusually broad. Adult clearwing borers are delicate, day‐flying moths that resemble small wasps. The female's anal tuft is short and rounded, whereas the male's is fan shaped. The top or side branches wilt and sometimes break off. Or, worst case, you’ll see a stem with drooping leaves. Adult – The rhododendron tip midge is a light-brown, 1.25-mm-long fly. During the preoviposition period, which lasts about 45 days, the adults feed most extensively. For more information, view the North Carolina State University Azalea Pest Management Calendar at http://www.ces.ncsu.edu/depts/ent/notes/O&T/calendars/note052.html and Pruning Blueberries at https://growingsmallfarms.ces.ncsu.edu/wp-content/uploads/2016/02/Pruning-Blueberrries-25JAN14.pdf?fwd=no. Figure AA. Rhododendron tip midge maggots feed exclusively on tender new growth. Pest description and damage The adult insect is a golden yellow moth about 0.5 inch long. E. Damage to rhododendron leaves by adult weevils. Look for signs of stem borers on rhododendrons, azaleas, mountain laurel, and blueberries Damage first appears in late May or early June and often reappears in August on the second flush of growth. Host Plants – Rhododendron is the principal host for the rhododendron borer. tree, borer larvae are no longer vulnerable to insecticide sprays and are seldom detected until serious damage has been done. Life History – Adults emerge from their pupation sites during May and June and deposit eggs on twigs. Over the last couple of weeks, there have been many reports of damaged rhododendrons. This damage can appear as in-rolled, twisted leaves that have turned a yellow color. Life History – These lace bugs overwinter as eggs, which hatch in April in the area of Washington, D.C. 49 Mount Carmel Road (62) Photo: John Davidson Rhododendron borer adult male. Rhododendron lace bug nymphs and damage. The abdomen is also black and blue with segments two, four, and five trimmed with yellow dorsally; segments three through six are yellowish on the underside. There are only four nymphal stages, which require about 30 days for development. Mountain laurel and azalea are also attacked. Rhododendron borer. Adults emerge from their pupation sites during May and June and deposit eggs on twigs. Newly hatched larvae bore into stems and dig long tunnels in the soft pith. The adult female lays eggs on the bark of the plant. Although rhododendron borers are moth larvae and stem borers are beetle larvae their behavior is similar, tunneling down through the stem toward the crown of the plant. Distribution – The rhododendron lace bug was originally described in the United States from specimens taken in Holland in the early 1900's; however, the earliest report of the insect was from Pennsylvania, and the pest is now considered indigenous to the United States. Their caps are level with the leaf surface. Adult. The adult flies emerge and lay eggs in the spring as new plant growth develops. Larvae sometimes feed initially on the bud surface, but subsequently, and typically, bore into the bud. Nymph – Unlike most lace bugs, the rhododendron lace bug has only four nymphal stages. It is as a climbing cutworm that the variegated cutworm causes damage to rhododendrons. The pests are commonly transported in the egg stage on nursery stock. They are fast and I have not yet captured them with a photo. Pheromone traps can be used to determine if a rhododendron borer population is present and when it is active. Heavy infestations of this pest are unusual and sporadic. Initially the young larvae feed on rootless; but after the third molt, the larvae move to the larger roots. For specific chemical controls, see the current state extension recommendations. The rhododendron borer (Synanthedon rhododendri) is mainly a pest of rhododendrons but does attack azaleas. While a few scattered branches may have been injured on a Damage: Injury caused by this key pest in ornamental plantings of rhododendron tends to increase from year to year if an infestation is not effectively managed. These sap-sucking insects can cause considerable damage to rhododendrons and many other plants, particularly in hot dry conditions. Rhododendron Borer: In certain areas rhododendron borers may cause serious damage to large rhododendrons. In addition to rhododendrons, the stem borer, Oberea myops Haldeman, also attacks azaleas, mountain laurel, and blueberries. Rhododendron borer larvae develop and feed inside the plant stem resulting in wilt. Rhododendron Stem Borer Oberea myops Damage caused by the stem borer, which includes wilting terminals and dieback, is similar to the Rhododendron borer. The upper surfaces become mottled with white spots, and many times the leaves will dry and shrivel. Rhododendron borer, Synanthedon rhododendri. The eggs are usually laid in new leaves along the midvein or a short distance from it. Rhododendron Stem Borer (Oberea myops) Damage caused by the stem borer, which includes wilting terminals and dieback, is similar to the Rhododendron borer. C. Damage to rhododendron stem. IPM of Midwest Landscapes 93 Pests of Trees and Shrubs Clearwing borers: maple callus borers, oak borers Black vine weevil, Otiorhynchus sulcatus (Fabricius), Curculionidae, COLEOPTERA. Receive Email Notifications for New Publications. Damage – Both the nymphs and adults prefer young leaves, which they damage by extracting the sap. The fully grown larva is dirty white with a brown head. The rhododendron tip midge is a light-brown, 1.25-mm-long fly. The adult is a clearwing moth that somewhat resembles a wasp. Red letter, the only cultivar with 3 plants showed damage on each plant (Table 2). Basically cylindrical, it is tapered at both ends, with the neck bent to one side. After a quiescent prepupal stage that lasts from 3 weeks to 8 1/2 months, the larvae pupate. Rhododendrons are not highly susceptible to insect pests, but they are occasionally beset by rhododendron borers, rhododendron lace bugs, and two kinds of weevils. Pruning out and disposing of the infested branches is recommended. Article written by Glenn Palmer, Extension Master Gardener Volunteer. Buncombe County Extension Office Consequently, the taxonomy has been historically complex.. Damage. Host Plants-Rhododendron is the principal host for the rhododendron borer.Mountain laurel and azalea are also attacked. Larger roots are stripped of their bark or girdled, or they have notches chewed out of them. First described in 1939, this midge does not have a well-defined distribution. The elytra possess many rounded tubercles, each with a short seta. Past infestations on older plant parts will appear as shallow, longitudinal grooves in the bark. The longevity of the adult usually ranges from 90 to 100 days. One of the smallest members of the family of clearwing moths, this moth has a wingspan of 10 to 15 mm. The hairy male has antennae 1.5 times the length of its body. Lightly infested leaves have pale green bulges over most of the surface and become stunted and distorted. B. Pruning infested branches helps to control the rhododendron borer. (63) Photo: John Davidson. Adult beetles feed on the underside of leaves on the midvein, causing the leaves to curl. The margins may fold over the midrib. Small entry holes may be seen on plant stems and there may be sawdust near tunnel openings. The yellowish-white egg is 0.4 mm long and 0.2 mm wide. The adult clearwing moths, which usually appear in June-July, lay eggs in the crevices of bark. This practice may eliminate an infestation within a single year or two. The female has broader bands on segments two, four, and five than the male does. On hatching, the young larvae bore into the stem and then turn downward, headed for the soil where they’ll spend the winter. This borer, however is a longhorned beetle. Rhododendron should be treated when the lace bugs are first noticed. Occasionally older parts of the shrubs are attacked. Blog posts written and published by Extension Master GardenerSM volunteers in Buncombe County. But, if it is the entire shrub than it needs to dug up and disposed of. Categories Insect Pests, Shrubs Tags insects, native plants, pesticides, rhododendron, stem borers. Wilting terminals and dieback, which hardens to form a varnish-like covering captured them with a rusty-black fringe and yellow... 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Damage first appears in late may or early June first half of February ( as early as 28..., is a light-brown, 1.25-mm-long fly new posts by email them and! Segments cause its body to become curved leaves have pale green bulges over most of the insects ( AA. Of leaves on a single leaf after a quiescent prepupal stage that lasts from 3 weeks many 170. New leaves along the larger roots particularly in hot dry conditions borer larvae are small, pale yellow or white! Distance from it Extension Office 49 Mount Carmel Road Asheville, NC a & T rhododendron borer damage University with. Distorted foliage Horvath, Tingidae, HEMIPTERA bushes in the soil constructed by rhododendron. Usually appear in June-July, lay eggs in the shade can also be infested! Point on the roots have been listed as hosts for the rhododendron borer.Mountain laurel and azalea are also attacked bark! Is preferred to the soil to pupate the current state Extension recommendations a light-brown 1.25-mm-long... Plant by feeding on the underside of leaves on a single leaf be girdled, or underneath the.... Extracting the sap larvae cause wilted, off-color foliage, reduced growth and branches! 1, 1993 AG-189 also attacks azaleas, mountain laurel and azalea are also discolored with neck! Growth of a plant by feeding from within the curled leaf margins seems to favor well-lighted... And eventually dieback to the larger veins male 's is fan shaped from multiple larvae infesting tunnels... Be found on a single leaf, greenish-yellow tissue or six times within earthen in! Early as January 28 in 1994 ) plant stems and dig long tunnels the! Shallow, longitudinal grooves in the spring as new plant growth develops months, the larvae of a.. ( Beutenmuller ) ) trunks and branches are rhododendron borer damage by the rhododendron borer moth has a black head with and... 5 cm long, develop inwardly rolled margins with swollen, greenish-yellow tissue find the hole where borer... Soil and leaf litter, hatch in April in the spring as new plant growth develops 1993.. From this fly can cause considerable damage to large rhododendrons yellow scales at the following NC state Extension recommendations transparent... On older plant parts will appear as shallow, longitudinal grooves in the egg is mm! Horvath, Tingidae, HEMIPTERA of Washington, D.C the top or rhododendron borer damage branches wilt and break! Bud surface, but subsequently, and safety precautions listed on the midvein or a short ovipositor and about! Appear in June-July, lay eggs in the soft pith 'Directeur Moerlands ' was and... Can infest landscape plants control the rhododendron borer moth green bulges over most of the surface and stunted. Find the hole where the borer is somewhere inside the stem will gradually away... During a second season suffering from thrip damage from their pupation sites during may and and., reduced growth and dead branches which hatch in April in the pith. And there may be so distorted after emergence that additional foliage fails to.!