Islamic Republic Of Iran Ministry of Jihad-e-Agriculture Plant Protection Organization A Guide for Diagnosis & Detection Of Quarantine Pests Scarlet mealybug Pseudococcus calceolariae (Maskell) Hemiptera:Pseudococcidae Edited by: Ahmad Cheraghian Bureau of Plant Pest Surveillance and Pest Risk Analysis 2014
Pseudococcus calceolariae (Maskell) Hemiptera: Pseudococcidae Common name: Scarlet mealybug, Citrophilus mealybug, Currant mealybug Synonyms: Pseudococcus gahani Green 1915, Dactylopius calceolariae Maskell 1879 Pseudococcus citrophilus Clausen 1915, Pseudococcus fragilis Brain 1912 Erium calceolariae (Maskell) Lindinger1935, Pseudococcus similans Economic impact: P. calceolariae is an endemic pest throughout most of Australia, and is perhaps the most serious pest of citrus in South Australia (Altmann and Green, 1991). P. calceolariae is commonly found throughout the major fruit-growing regions in New Zealand, and may be very common locally on most fruit crops (Charles, 1993). It can be a severe pest, at least locally, in Italy (Laudonia and Viggiani, 1986). The introduction of natural enemies has reduced its importance in the Republic of Georgia (Yasnosh, 1995). Mealybugs are pests for several reasons. They may debilitate parts of the plant through sap depletion, transmit disease (Petersen and JG Charles, Horticulture and Food Research Institute of New Zealand Ltd, personal communication), or scar fruit, for example P. calceolariae feeding under the 'button' of citrus fruit causes a necrotic halo mark. A heavy infestation can cause fruit drop (Altmann and Green, 1991). More commonly, the presence of mealybugs in other perennial fruit crops leads to unacceptable growth of sooty mould fungi on honeydew deposits on the fruit, either as a deposit on the cheek (which is difficult to remove at packing) or around the stalk, calyx or sepals. For growers producing fresh fruit for export markets, the presence of mealybugs or sooty mould may be sufficient to limit the sale of that fruit to local markets at reduced prices. Some countries accept the fruit, but insist on fumigation, which is costly, and results in poorer quality fruit with a shorter shelf-life. P. calceolariae has recently been shown to be a vector of the closterovirus associated with grapevine leafroll disease, and is implicated in the spread of this disease in vineyards (Petersen and JG Charles, Horticulture and Food Research Institute of New Zealand Ltd, personal communication). Hosts: Major hosts: Abutilon (Indian mallow), Arachis hypogaea (groundnut), Brachychiton, Brassica, Ceanothus (white-thorn), Chenopodium (Goosefoot), Citrus medica (citron), Conium maculatum (Poison hemlock), Crataegus (hawthorns), Cydonia oblonga (quince), Daucus carota (carrot), Dodonaea viscosa (switch sorrel), Eugenia, Ficus, Fragaria (strawberry), Geranium (cranesbill), Hedera helix (ivy), Helianthus (sunflower), Heliotropium arborescens (cherry-pie), Hibiscus (rosemallows), Juglans regia (walnut), Laburnum anagyroides (laburnum), Ligustrum (privet), Lolium (ryegrasses), Malus domestica (apple), Malus sylvestris (crab-apple tree), Malva (mallow), Musa x paradisiaca (plantain), Nerium oleander (oleander), Pelargonium (pelargoniums), Pinus radiata (radiata pine), Pisum sativum (pea), Pittosporum tobira (Japanese pittosporum), Pittosporum undulatum (Pittosporum), Polyscias, Prunus (stone fruit), Pyrus communis (European pear), Rheum hybridum (rhubarb), Rhododendron (Azalea), Ribes sanguineum (Flowering currant), Rosa (roses), Rubus (blackberry, raspberry), Schinus molle (false pepper tree), Sechium edule (chayote), Solanum tuberosum (potato), Theobroma cacao (cocoa), Vitis vinifera (grapevine).
Geographic distribution: Asia:China, United,Georgia (Republic) Europe: Czechoslovakia (former -), France, Italy, Netherlands,Portugal, Spain, Ukraine, United Kingdom. Africa: Ghana, Madagascar, Morocco, Namibia, South Africa North America: USA, Mexico South America: Chile Oceania: Australia, New Zealand. World distribution map of Pseudococcus calceolariae (Maskell) Morphology: P. calceolariae is broadly similar to other species of Pseudococcus mealybugs. The body outline of the female is elongate-oval to oval, and all stages are covered with a rather coarse, powdery, white wax. There are 17 pairs of short white lateral filaments, and two relatively short and stout terminal filaments. The body is a dark purplish-red, and there are usually two distinct lines (of reduced wax cover) running along the back. These features may be sufficient to allow separation from other sympatric mealybug species (Cox, 1978). Morphological characterization and identification usually requires adult female specimens to be cleared and slide mounted for examination of the cuticular pores and setae under a compound microscope (Cox,1987; Williams, 1985). Adult female P. calceolariae are relatively large, and are 4-5 mm long immediately before oviposition. Male nymphs spin a silken cocoon from the end of the second instar. Third-instar males have small lateral wing buds, which become quite pronounced in the fourth instar. Adult males are tiny insects with one pair of wings and no mouthparts. Pseudococcus calceolariae (Maskell)
Pseudococcus calceolariae (Maskell)
Biology and ecology: Female P. calceolariae may each lay in excess of 700 eggs within a waxy ovisac. Neonate crawlers spend the first few days of their lives sheltering under the disintegrating ovisac before dispersing to feed. They usually do not move far from their feeding site for the first moult. At the end of the second instar, males spin a tubular, silken cocoon in which they develop through a short-lived third (about 2 days) and a longer-lived fourth nonfeeding instar (about 4 days) before moulting into a tiny, winged adult with a pair of stout, wax, terminal filaments. Females develop through three immature instars and undergo a final moult to the adult form. Males, at the end of the second instar, and females before oviposition, often seek out sheltered spots under bark or old vegetation for further development. Neither stage feeds from then on, so physical protection is more important than a food source. Mature female P. calceolariae produce a sex pheromone which attracts crawling males from short distances (as a scent trial) (Rotundo and Tremblay, 1981) or flying males from distances in excess of 1 m (Rotundo et al., 1980). The pheromone attracts large numbers of males in the field, and has been used to detect three seasonal male flight peaks in Italy (Rotundo et al., 1979). Adult females may mate almost immediately, but then spend up to several weeks maturing their eggs. Mature females commonly move to a protected site to oviposit over a period of up to 2 weeks. They cease feeding before oviposition, when they are little more than a convenient bag for their eggs. They die at the end of egg laying. Parthenogenesis has not been reported in this species, and experience suggests that sexual reproduction is obligate. The rate of development of P. calceolariae on any host is primarily dependent on temperature, and is similar to other cosmopolitan species of Pseudococcus, such as P. longispinus and P. affinis [P. viburni]. In the laboratory, generation time (from egg to egg) at 25 C is about 60 days (J. G. Charles, Horticulture and Food Research Institute of New Zealand Ltd, personal communication), similar to those reported in California (Smith and Armitage, 1931). In New Zealand, there are probably up to three generations per year (Charles, 1981), in Australia four generations per year (Smith and Armitage, 1931), and in California three to four generations per year (Clausen, 1915). Pseudococcus calceolariae (Maskell)
Symptoms: P. calceolariae feeds on the phloem of deciduous and evergreen plants in warm, temperate climates. Under these conditions, populations of P. calceolariae seldom reach sufficiently high levels to debilitate the plant, and the symptoms of attack are usually restricted to visual sighting of mealybugs or sooty mould. When P. calceolariae (or other mealybugs) shelter in fruit, for example within the calyx (pipfruit), around the stalk (pipfruit) or under fruit sepals (citrus, persimmons) they are often hidden from view, and cannot be seen without cutting open the fruit. Sooty mould fungi growing around the calyx or sepals on excreted honeydew are a good indicator of the presence of mealybugs in the fruit. Sooty mould on foliage may result from mealybugs or other Sternorrhyncha. Symptoms by affected plant part Fruits/pods: external feeding; honeydew or sooty mould. Growing points: external feeding; honeydew or sooty mould. Inflorescence: external feeding; honeydew or sooty mould. Leaves: honeydew or sooty mould. Roots: external feeding. Stems: external feeding; honeydew or sooty mould. Pseudococcus calceolariae (Maskell)
Means of movement and dispersal: Scales may be present on stems, leaves of infested plants. adults and eggs occurs through human transport of infested plant material. In host plant,infestations are often on stems, leaves and transport of this insect. Phytosanitary significance: P. calceolariae is often injurious to crops especially when the mealybug is introduced to new geographical areas without natural enemies, or as a result of injudicious chemical spraying techniques. Areas where the mealybug occurs but where the mealybug wilt of pineapple is absent are at risk from the introduction of mealybugs carrying the virus. Areas where only the parthenogenetic form occurs are also at risk from the introduction of the biparental form.p.calceolariae is quarantine pest for Iran. Detection and inspection: Mealybugs, including P. calceolariae, are best found by close examination of potential host plants. P. calceolariae is found above ground level, often in aerial parts of trees. On deciduous fruit trees, mealybugs are usually found on leaves during the growing season, and on fruit close to, or after, harvest. On citrus, they may infest the fruit at any stage from fruit set, depending largely on the morphology of the fruit 'button'. Time searches are probably the most effective way of quantifying mealybug populations in orchards, but no standard techniques have yet been published. Because they choose sheltered feeding spots, detection of mealybugs as quarantine pests almost always requires samples of fruit to be cut open and mealybugs to be removed for identification. Inspection host for Pseudococcus calceolariae (Maskell)
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