Williams, 1960
Diagnosis
Scale cover of adult female elongate, narrowly mussel-shaped, about 2.5 mm long, slightly convex, pale to reddish-brown, with pale brown terminal exuviae LETAPL1.jpg . Scale cover of male not documented, probably similar to that of female but smaller and narrower, with terminal exuviae.
Body of slide-mounted adult female elongate, about 1.0 mm long, more than 1.8x as long as wide, and membranous, with a rounded head; head without obvious lateral tubercles; eye not developed into a spur; lateral marginal spurs present on margins of prepygidial segments I, II and III, each spur sharply pointed and sclerotized, not containing any macroduct openings LETAPS.jpg . Pygidium with median lobes with a pair of gland spines between them, not yoked, and without club-shaped basal scleroses; perivulvar pores present LETAPP1.jpg ; with 6 marginal macroducts on each side of pygidium. A minute dorsal duct (as small as a ventral microduct) opening just anterior to each second lobe; another, similar, duct often present on the midline just anterior to median lobes LETAPD.jpg .
Host range
Lepidosaphes tapleyi is a fairly polyphagous species that has been recorded from hosts belonging to 8 plant families (Borchsenius, 1966; Williams and Watson, 1988). In Africa and Asia it is particularly common on mango (Williams and Watson, 1988). Hosts include species of: Agave, Capsicum frutescens, Ceratonia, Citrus, Cocos nucifera, Compositae, Dovyalis, Eucalyptus, Ficus, Hibiscus, Jasminum spp., Laurus nobilis, Lycopersicon esculentum, Mangifera indica, Nerium, Olea, Plumeria, Psidium, Punica, Rosa, Sterculia and Tristania.
Affected plant stages: vegetative growing, flowering and fruiting stages
Affected plant parts: on leaves LETAPL1.jpg ; when infestations are heavy it spreads to fruits and branches
Biology and ecology
On guava in Egypt, L. tapleyi went through five generations a year (Swailem, 1974). A few females of the last generation began to oviposit in December, but most entered diapause and did not resume activity until March. Populations were much reduced by unfavourable weather, particulrly by hot winds, and large numbers fell from the trees when the leaves dropped in April. Swailem, 1973, recorded that in Egypt, overwintering females began to oviposit in late May and continued to lay eggs until the temperature rose in July and August. Oviposition was resumed when the temperature dropped. Females laid 8-35 eggs each (average 20). The crawlers settled mainly on the upper surface of the leaves, especially on the parts of the trees exposed to the sun. After hatching, the two immature female stages averaged 15-35 and 9-26 days, respectively, and the immature stages of the males after hatching averaged 30-52 days. Adult females lived for 55-120 days and adult males for 1-2 days. Males formed 30.8, 42.2, 45.4 and 24.9% of the population in March, June, September and December, respectively.
Crawlers are the primary dispersal stage and move to new areas of the plant or are dispersed by wind or animal contact. Mortality due to abiotic factors is high in this stage. Dispersal of sessile adults and eggs occurs through human transport of infested plant material.
Economic impact
Lepidosaphes tapleyi was described as causing severe but local damage on sisal (Agave sislana) beside dusty roads in Tanzania (Williams, 1960). Specimens collected on tomato in Kiribati were reported causing damage (Williams and Watson, 1988). In Egypt, heavy infestations of guava caused premature leaf drop; small, poor quality fruit; and weakened trees (Swailem, 1973).
Detection and inspection methods
Examine leaves of the hosts listed above, for elongate, narrowly mussel-shaped, slightly convex, pale to reddish-brown scale covers, each with pale brown terminal exuviae.
Natural enemies
Parasitoids:
- Aphytis chrysomphali, in Egypt
- Encarsia citrina, in Egypt
Distribution
See Lepidosaphes tapleyi distribution.
Microscopic examination of slide-mounted adult females is required for authoritative identification to species.
Lepidosaphes camelliae Hoke (camellia scale) LECAMS.jpg could be misidentified as L. tapleyi, but differs in having no sclerotized spurs on the margins of abdominal segments II-IV; usually 4 or 5 submarginal and submedian ducts on each side of segment VI; and the marginal and submarginal ducts are almost the same size LACAMP.jpg. In contrast, L. tapleyi LETAPS.jpg possesses sclerotized spurs on the margins of abdominal segments II-IV; usually only 2 submedian ducts on each side of segment VI; and the submarginal ducts are obviously smaller than the marginal ducts LETAPP1.jpg. Lepidosaphes camelliae is known from USA (Alabama, Arkansas, Connecticut, Delaware, Florida, Georgia, Louisiana, Massachusetts, Maryland, Missouri, Mississippi, North Carolina, New York, Oklahoma, Oregon, South Carolina, Texas and Virginia), Mexico, China (Guangdong, Hunnan) and Japan (Tao, 1999; Nakahara, 1982; Kawai, 1980) on leaf undersides of species of Camellia, Cleyera, Cupressus, Ilex, Ligustrum, Magnolia, Rhaphiolepis and Ternstroemia (Tao, 1999; Danzig and Pellizzari, 1998; Kosztarab, 1996; Miller, 1996; Nakahara, 1982). Lepidosaphes camelliae is occasionally a serious pest on camellia and holly in Florida (Dekle, 1976). Heavy infestations cause yellow and orange leaf discolouration and premature drop (Johnson and Lyon, 1991). This species has 4-5 generations per year in California, where it is considered to be a 'B'-rated pest on camellias, holly, cuttings and small plants (Gill, 1997). Scale cover of adult female mussel-shaped, slightly convex, light or dark brown, with yellow terminal exuviae; scale cover of male similar to that of female but smaller and narrower, with green-gold terminal exuviae (Davidson and Miller, 1990). Female scale cover LECAML1.jpg ; male and female scale covers LECAML2.jpg ; female scaleLECAML3.jpg ; habit sketch LECAML.jpg
Lepidosaphes pallida (Maskell) (Maskell scale) LEPALLL.jpg
LEPALLL1.jpg and L. pallidula (Williams) are morphologically very similar species. They are currently the subject of research (D.J. Williams, D.R. Miller and R.C. Henderson, personal communications), so their respective distributions and host ranges are not precisely known at present. Lepidosaphes pallida and L. pallidula could easily be misidentified as L. tapleyi, but differ in having antennal setae more or less fused into a single, thick seta on each antenna; a marginal spur on either side of each of abdominal segments II and III that is blunt and little sclerotized; and abdominal segments III and IV each with 3-6 marginal gland spines on either side. In contrast, L. tapleyi LETAPS.jpg has 2 separate, curved setae on each antenna; a marginal spur on either side of each of abdominal segments II and III that is sharply pointed and well sclerostized; and abdominal segments III and IV each with usually only 2 marginal gland spines on either side. Lepidosaphes pallida is a Holarctic species that feeds on conifers, sometimes damaging them, and occurs in the USA, Bermuda, New Zealand (Charles and Henderson, submitted) and possibly some countries in the Far East (Japan? Kawai, 1980). It is a 'B'-rated pest in California, although it is uncertain whether it still occurs there (Gill, 1997). Lepidosaphes pallida (known as L. newsteadi) was a serious pest in Bermuda in the 1940s, when it killed 60% of the native Juniperus bermudiana forest and adversely affected the tourist business; however, it has since been displaced by Carulaspis minima and is now very uncommon (Hodgson and Hilburn, 1991).
Lepidosaphes pallidula LEPALD~2.jpg is a tropical/subtropical species known from southern Asia and possibly elsewhere (Japan? Kawai, 1980); it feeds on many species of broad-leaved plants. Both the photographs used here are from Japan. Colony LEPALD~1.jpg
Comments
Lepidosaphes tapleyi is a tropical species of uncertain origin. It was described from Sudan and Tanzania, but the species is known from southern Asia and may be widespread there (Williams and Watson, 1988). It has not been recorded from Europe, the Western Hemisphere, Australia, or from many of the Pacific islands.
Asia
Brunei Darussalam: The Natural History Museum collection, London, UK
China
Hong Kong: The Natural History Museum collection, London, UK
India
Andhra Pradesh: The Natural History Museum collection, London, UK
Kanataka: The Natural History Museum collection, London, UK
Punjab: The Natural History Museum collection, London, UK
Uttar Pradesh: The Natural History Museum collection, London, UK
Indonesia
Irian Jaya: present (Williams and Watson, 1988)
Malaysia: The Natural History Museum collection, London, UK
Oman: The Natural History Museum collection, London, UK
Pakistan: The Natural History Museum collection, London, UK
Singapore: The Natural History Museum collection, London, UK
Southern Asia: present, no further details (Williams and Watson, 1988; Danzig and Pellizzari, 1998)
Africa
Central Africa: present, no further details (Danzig and Pellizzari, 1998)
East Africa: present, no further details (Williams and Watson, 1988)
Egypt: present, no further details (Swailem and Awadullah, 1974)
Kenya: The Natural History Museum collection, London, UK
Nigeria: The Natural History Museum collection, London, UK
Senegal: The Natural History Museum collection, London, UK
Sudan: present, no further details (Williams and Watson, 1988; Danzig and Pellizzari, 1998)
Tanzania: present, no further details (Williams and Watson, 1988; Danzig and Pellizzari, 1998)
West Africa: present, no further details (Williams and Watson, 1988)
Oceania
Kiribati: present (Williams and Watson, 1988)
Tuvalu: present (Williams and Watson, 1988)