Photo: Jim Baker, North Carolina State University, Bugwood.org. Photo: Bruce Watt, University of Maine, Bugwood.org. Adult Japanese weevils feed during the day and will drop from the plants when disturbed. Cottony camellia scales, Pulvinaria floccifera, are cream to tan, elongate oval, and relatively flat.They are also called cottony taxus scales as this scale is a fairly common pest of yew. Adult beetles feed for two to three weeks before laying eggs. The best control option for residents with only a few plants is to prune out (cut below active larvae) and destroy wilting branches in late summer or early spring before adults emerge. Most adult scales do not move, they look like brown or white “tortoise shells” on branches or foliage. In spring, adults emerge from the soil and fly to the tips of branches where they lay eggs in new developing leaf tissue. Curled leaf tips in June indicate the completion of the first generation. Sooty mold will also accumulate on the leaf surfaces and bark, much like it does during aphid feeding. They vary in appearance depending on age, sex, and species. Azalea lace bug damage. This borer prefers rhododendron, but occasionally attacks deciduous azalea and mountain laurel. Apply either spray when caterpillars are numerous and young (less than 3/4 of an inch long). Two-banded Japanese weevil (actual size is 3/16 inch). Consider hand–removal by squishing the scales to prevent populations from increasing. NPS Photo. Inspect the tape closely using a hand lens, if possible; look for the crawlers, which get trapped on the tape and look like yellow or orange specks. 'Patty Bee': Has scaly foliage, like an azalea, that turns maroon in winter. Plan to spray the shrub once the number of crawlers trapped begins to decline. Damage usually begins in early May on old leaves and later appears on new growth. Flowers 5-merous, usually in terminal corymbs. Management. Some cultivated varieties (Southgate series Rhododendrons) are more tolerant of high heat and humidity. A common shrub, also known as Cascade Azalea, found in the park on open slopes and meadow edges above 3,500 feet (1,066 meters). Photo: John Davidson, University of Maryland. Ask the Expert: what would get the white fungus off azaleas , leaf the azalea has white on them , on the leafs is it a fungus , what can spray on them will mild soapy water work. Whitefly adults and nymphs feed on the underside of the foliage. We embody the University's land-grant mission with a commitment to eliminate hunger, preserve our natural resources, improve quality of life, and empower the next generation through world-class education. Management: Look for caterpillars when chewing damage occurs. Spinosad, a biorational insecticide (which has the least toxic classification), may also be used on young and older caterpillars. Photo: University of Maryland Extension, Rhododendron Borer (adult). Rhododendron gall midge immatures spend the winter and early spring in the soil where they complete development and pupate. The larvae live in the soil and feed on roots and may also girdle the plant at the root crown, causing the plant to wilt and die. The second generation mines begin in July. Preferred host plants are azaleas, but they may also attack witch hazel, sumac, apple, red oak, and andromeda. The borer causes wilting of leaves and twig dieback. The caterpillars feed in groups when young and disperse as they mature. They were introduced to the European Alps and thus the name, Alpine Rose (Rhododendron histru… As larvae mature they curl the tips of the leaves with silk and feed inside the curl. Mature larvae are about 1/4 inch long, “C-shaped”, legless, and white with brown heads. Mature larvae are about 1/2 inch long, white with brown heads. Hosts include andromeda, azalea, rhododendron, hawthorn, poplar, willow, and most recently, blueberry in the Pacific Northwest. Interior leaves usually show most damage. Systemic insecticides applied to soil are also highly effective but follow cautionary warnings on label to protect pollinators visiting azaleas and rhododendrons. All stages occur on the undersides of leaves. A scale infestation is indicated by sooty mold on leaves, yellowing of leaves, and twig dieback. Insecticidal soap may also be used. The borer causes wilting of leaves and twig dieback. Heavy infestations of lace bug may cause leaves to turn yellow and then brown. The larvae are “C-shaped”, legless, and white with brown heads. Decide what tool you need for your rhododendron size. Young females have a dark stripe down the middle and mottling at the sides. This tiny fly attacks the new growth of rhododendrons. This borer, however, is a longhorned beetle. This scale is most obvious from May through June when white egg sacs may be found in twig forks. Azalea leafminer overwinters as pupae in the leaf mines. Buds with several to many imbricate scales. Inspect plants for signs of early damage and remove curled leaves promptly. Scales appear as mounded white lumps on rhododendrons in early summer and early fall. Damage on new foliage will be evident in May and July. Preferred host plants are azaleas, but they may also attack witch hazel, sumac, apple, red oak, and andromeda. Scales are so unusual looking that most people don’t recognize them as insects. Do not apply horticultural oil within 30 days of a sulfur application; avoid applications on drought-stressed plants, and on windy days or when temperatures are below 32 degrees Fahrenheit or above 90 degrees F. Follow manufacturer recommendations for preparation and dilution rate, typically 1 to 3 percent, and test out the material on a small, inconspicuous part of the shrub before applying it more broadly. Photo: John Davidson, University of Maryland. Older and more established rhododendrons may need a chainsaw to cut through the large woody branches, especially toward the middle of the plant. All types of fruit and ornamental trees, shrubs. Healthy shrubs can usually withstand some amount of scale feeding, but a heavy infestation can force leaves to wilt, turn yellow and drop prematurely. Susceptible cultivars include those of Rhododendron catawbiensis and R. maximum. Mature larvae are 1/2 inch long and yellowish brown. If hand removal is not feasible, spray shrubs with. Signs of beneficials insects may be active lady beetle adults or larvae, lacewing larvae, or parasitoids indicated by small circular holes on the immature whiteflies. Various scales attack azaleas and rhododendrons, but one of the most common is azalea bark scale (Eriococcus azaleae). Small shrubs may be defoliated in heavy infestations. Adults are present in June and July. The azalea bark scale, Eriococcus azaleas, is a prominent pest of rhododendron, azalea, and huckleberry (Vaccinium spp.). Beneficial nematodes may be effective in controlling larvae in the soil. Apply either spray when caterpillars are numerous and young (less than 3/4 of an inch long). Azalea whitefly damage. There is one generation per year in Michigan. Mature larvae are 1/2 inch long and yellowish brown. The second generation mines begin in July. Beneficial nematodes are not effective on these borers. There are as many of four generations of azalea lace bug during the growing season and into the fall. Weevils can be hand-picked and dropped into a container of soapy water for disposal. Description. Azalea Bark Scale, Eriococcus azalea: This insect prefers azalea or rhododendron but can infest andromeda, maple, willow, poplar and other plants. Damage is indicated by the presence of blotch mines in leaves of azalea beginning in May. Fully developed larvae drop to the ground where they will pupate. Overwintering immature scales (nymphs) are less than ⅛-inch long, gray, and are usually found in twig forks. There is one generation a year and all stages overwinter in the soil. Photo: M. Raupp, University of Maryland. Females produce white, waxy egg masses in late June to early July. Photo: David Held, Auburn University, Bugwood.org. They may be injected into the active borer tunnels. It has been reported in the Eastern US, as well as Belgium and Russia. Heavy infestations cause the margins of terminal leaves to cup. Adult weevils are about 3/8 inch long and black with faint yellowish flecks. Plant azaleas in partial sun (morning sun and afternoon shade). Stressed plants are more susceptible to lace bug feeding. Continue changing the double-sided tape and observing crawler numbers. If control is necessary, use a registered insecticide when damage begins in mid-June. As with black vine weevil, soil drenches of entomopathogenic nematodes may reduce populations of grubs in the soil. Photo: John Davidson, University of Maryland, Azalea Leafminer (late instar). Immature lace bugs ( nymphs ) are less than ⅛-inch long, overwinter on the underside the! Females appear totally white when they produce their white, waxy egg sacs and for reddish crawlers in late into! Generally does not kill hosts, rather it causes aesthetic damage present on the developing leaf tissue white egg.... Andrena ( Andrena ) cornelli two to three weeks before laying eggs the... They are inside the branches margins of terminal leaves to curl and the complete... L ’ Ecluse commonly cause black fungus on rhododendron adequate control of light bark scale infestations active borer.! Of lace bug feeding the curled leaf tips in June indicate the completion of the borer. Mites, nematodes, scale, rhododendron borer red with a 4 % rate horticultural! 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