|Crop Knowledge Master|
Pseudococcus longispinus (Targioni-Tozzetti)
|Long tailed Mealybug|
Victoria L. Tenbrink, Research Associate
Arnold H. Hara, Entomologist
Beaumont Research Center
Updated by: J.M. Diez April 2007
Longtailed mealybug has a wide host range, including, air plant, asparagus, avocado, banyan, begonia, betel-nut, caladium, coconut and other palms, coffee, citrus, cycads, dracaena, gardenia, floral ginger, guava, heliconia, hibiscus, kamani, lilies, macadamia, mango, orchids, philodendron, pigeon pea, pineapple and other bromeliads, potato, sugar cane, soybeans, ti (Furness 1976, McKenzie 1967, Zimmerman 1948, Heu 1990).
Longtailed mealybug is widespread throughout the world. It is found outdoors in the warmer parts of America, Europe, and Africa. In northern latitudes it occurs in greenhouses (McKenzie 1967). First collected in Hawaii before 1900, it is present on the six major Islands (Zimmerman 1948, Hawaiian Terrestrial Arthropod Chlecklist 1992).
Mealybugs have piercing-sucking mouthparts. They feed by inserting slender mouthparts into plant tissues and sucking the sap. Plant parts may be spotted, curled, or wilted (Metcalf & Flint 1939). Infestations reduce the vigor and growth of foliage plants, which reduces the beauty of the plant and affects marketability (Hamlen 1975). Mealybugs are a quarantine problem on exported foliage and flowers. This is due to the fact that species cannot be accurately identified outside of the lab, so inspectors may treat all specimens as unknown species. Mealybugs are especially hard to wash out of floral ginger.
Longtailed mealybugs don't produce an egg sack (McKenzie 1967). Eggs are straw yellow at first and deepen in color before hatching. The eggs may hatch as soon as they are laid, giving the impression that young are born rather than hatching. Fewer eggs are laid when it is very hot or cool 77û F being optimum. From 20 to 240 eggs have been observed per female under lab conditions (El-Minshawy et al. 1974).
After hatching, the crawlers leave the mother. They are flattened, oval, light yellow, six-legged insects, with smooth bodies. Soon after beginning to feed, they exude a white, waxy covering over their bodies, giving them a mealy appearance (Metcalf & Flint 1939). After molting, differentiation between male and female begins. The male larvae stop feeding near the end of the second stage and migrate towards a protected place where they secrete waxy cocoons in which they complete development. The female goes through three stages to adulthood, but changes little in appearance besides growing larger, reaching 1/6 to 1/4 inch in length. The time in developmental stages varies with temperature. At 70ûF development lasts about a month for both males and females (El -Minshawy et al. 1974, Metcalf & Flint 1939).
The long-tailed mealybug has wax thread "tails" that are as long as or longer than the body. The female body is oval and covered with waxy filaments (McKenzie 1967). Females live 2 or 3 months. The male is a tiny, winged creature, necessary for reproduction but living only a few days (El-Minshawy et al. 1974, Metcalf & Flint 1939).
Females are wingless but freely mobile, though sluggish, and occur exposed on the foliage or twigs of the host. Females seek out a protected place to lay eggs (McKenzie 1967). All life stages of the female feed, as well as the male nymphs. Pupating and adult males do not feed.
Biological control -- Predators
Population resurgence after insecticide spraying in Australia suggests that natural enemies are an important control factor (Furness 1976). The lacewing, Sympherobius barberi (Banks) feeds on longtailed mealybugs and is established in Hawaii (Zimmerman 1948, Hawaiian Terrestrial Arthropod Checklist 1992). The coccineliid beetle, Cryptolaemus montrouzieri Muls. was introduced from Australia via California in 1894 to control green shield scale. It feeds on mealybugs as well as scales in California and Hawaii (Fullaway & Krauss 1945, Furness 1976). The C. montrouzieri larvae look similar to the female longtailed mealybug.
Biological control -- Parasites
The encyrtid wasp, Anagyrus fusciventris (Girault) parasitizes long-tailed mealybug in Australia (Furness 1976). This parasite is present in Hawaii on the six main Islands (Hawaiian Terrestrial Arthropod Checklist 1992).
A high pressure stream of water will dislodge mealybugs (Metcalf & Flint 1936) Wetting the mealybugs also encourages fungal pathogens. In the packing house, mealybugs are scrubbed from cut flowers and foliage destined for export.
Sanitation is important in field control. Infested material should not be used as mulch, but should be removed from the field and destroyed. Hot water dips successfully kill mealybugs; commodities vary in their tolerance to the treatment.
In Australia outbreaks of longtailed mealybug have been documented following use of chemicals to control other pests (Furness 1976). Complete control of longtailed mealybug by the use of insecticides is extremely difficult. Foliar sprays of insect growth regulators suppress mealybug populations and have low mammalian toxicity, which is an advantage for nursery personnel (Hamlen 1975). Dipping in a combination of pyrethroids and insecticidal soap is effective as a postharvest treatment for export material. Manual scrubbing before the dip is essential when the material comes into the packing house moderately to heavily infested with mealybugs.
Fullaway, D. T. & N. L. H. Krauss. 1945. Common Insects of Hawaii. Tongg Publishing Company: Honolulu. 228 pp.
Furness, G. O. 1976. The dispersal, age-structure and natural enemies of the long-tailed mealybug, Pseudococcus longispinus (Targioni-Tozzetti), in relation to sampling and control. Aust. J. Zool. 24: 237-47.
Hamlen, R. A. 1975. Insect growth regulator control of longtailed mealybug, hemispherical scale, and Phenacoccus solani on ornamental foliage plants. J. Econ. Ent. 68 (2): 223-226.
Hawaiian Terrestrial Arthropod Checklist. 1992. Gordon Nishida, Ed. Bishop Museum: Honolulu, Hawaii. 262 pp.
Heu, R. A. 1990. Distribution & Host Records of Agricultural Pests and Other Organisms in Hawaii. State of Hawaii Department of Agriculture: Honolulu. 34 pp.
McKenzie, Howard L. 1967. Mealybugs of California. University of California Press: Berkeley & Los Angeles.
Metcalf, C. L. & W. P. Flint. 1939. Destructive and Useful Insects, 2nd Ed. McGrawHill Book Company: New York. 981 pp.
Zimmerman, E. C. 1948. Insects of Hawaii Vol. S Homoptera: Sternorhyncha. University of Hawaii Press: Honolulu. 464 pp.