Injury resulting from this type of feeding appears as light-colored, scratched, or bleached areas, known as stippling. Division of Agriculture and Natural Resources Host plants include citrus, apple, Nandina, Boston ivy, boxwood, cypress, hackberry, locust, maple, oaks, peaches and plums, pecan, pears, pine, Pittosporum, pomegranate, quince, rose, Verbena, walnut, willow, and other woody ornamentals. Oil sprays kill by suffocation. Nondiscrimination Statement. Staff-only pages Behind the female scale is a grooved, white egg sac containing hundreds of scale eggs. For examples of products containing Spinosad, please see Table 1. Foliage can be distorted by aphids or other Homoptera, caterpillars that web foliage, citrus thrips, citrus leafminer, citrus bud mite (in … Follow label directions for mixing. They also secrete an unattractive cottony wax. To maintain a healthy citrus tree, such as this orange tree (Citrus x sinensis), one must be observant of insect pests that injure the foliage, twigs, and fruit and treat the pest problem accordingly. Spray the trunk, limbs, and mature foliage with 2% horticultural oil solution to the point of run-off. For information on how to test the soil, please see the fact sheet HGIC 1652, Soil Testing. Allow potting soil in containers to become slightly dry between watering. Root damage. citrus long-horned beetle adult; photo courtesy of Pest and Diseases Image Library, www.bugwood.org Beetles Diaprepres root weevil adult; photo by Lyle Buss, Department of Entomology and Nematology, University of Florida On citrus trees, apply horticultural oil sprays when pests are present, and when temperatures are between 45 and 85 ºF. If pests are present during spring as new, tender growth appears, apply a 1% mixture spray (2½ tablespoons oil per gallon of water). If citrus fruit are present on the plants, apply horticultural oil sprays that are no stronger than 3 tablespoons per gallon of water. These brown citrus aphids are very similar in appearance to the black citrus aphid, which feeds on flowers buds and new foliage of citrus. Citrus under drought or nutrient stress are more susceptible to scale and other insect pest infestations, so maintain plant vigor. The mite has piercing-sucking mouthparts, which it inserts into plant tissue. They primarily feed on foliage and tender stems. For examples of canola oil products, please see Table 1. Avoid the temptation to over-fertilize trees and shrubs, as this can lead to increased pest problems. Citrus leafminer (Phyllocnistis citrella) is the larva of a small moth originating from south-east Asia and is commonly seen in backyard citrus trees. Apply a 1% oil spray (2½ tablespoons oil per gallon of water). Natural parasitoids are unable to keep this scale pest under control. There may be several generations per year. A sure sign of a heavy spider mite infestation is large amounts of webbing found around the terminal ends of upright branches. We cover most Citrus Pests & Diseases in this manual and include photos to make it easier for you to figure out what's wrong with your Citrus Tree. Indoor citrus houseplants may be taken outdoors during warm weather to spray with water or to allow rainfall to help dislodge mites. Chewing insects . Make a 2% solution by adding 5 tablespoons of horticultural oil per gallon of water. Canola oil sprays labeled for horticultural use can also be used to reduce the number of scale insect pests by suffocating all growth stages like the horticultural oil sprays do. Maintain good citrus tree health to reduce the chance and severity of scale infestation, and for the trees to better tolerate insect pests already present. This scale produces honeydew, which drips onto surrounding foliage. The honeydew is colonized by dark-colored sooty mold and results in foliage becoming blackened. However, they can become a year-round pest when containerized citrus plants are brought indoors during the winter. Besides being unattractive, sooty mold may interfere with photosynthesis and retard the growth of the plant. Mealybugs are more apt to be a problem with indoor citrus trees. The inconspicuous, immobile female scales are brownish-purple, oyster-shell shaped, and ⅟16– to ⅟11-inch long pests. Symptoms include green spots on fruit that do not color correctly and yellow spots on foliage. © 2016 Regents of the University of California, Division of Agriculture and Natural Resources. A heavy infestation may cause defoliation. If the citrus is a landscape plant, sprays are needed to stop the spread of this pest. Their Like all plants and trees, citrus trees can be affected by disease and insect damage. Citrus Whitefly. Make a 2% solution with 5 tablespoons of horticultural oil per gallon of water. Cottony cushion scale infestations can generally cause older trees to have reduced vigor, premature leaf drop, or twig death, but younger trees can be severely stunted or killed.