Valid Names Results

Unaspis yanonensis (Kuwana, 1923) (Diaspididae: Unaspis)

Nomenclatural History

Common Names

Ecological Associates

Hosts:

Families: 2 | Genera: 2

Foes:

Families: 10 | Genera: 28

Geographic Distribution

Countries: 19

Keys

  • DaoBeWa2023: pp.1024, 1027-1028 ( Adult (F) ) [Diaspididae on citrus in Indochina and southern China.]
  • NiuFe2019: pp.579 ( Adult (F) ) [Species of Unaspis]
  • Watson2015a: pp.437 ( Adult (F) ) [slide-mounted adult females of Unaspis]
  • Zeng2000: pp.51 ( Adult (F) ) [Key to Chinese species of Unaspis]
  • LiuWa1996: pp.43 ( Adult (F) ) [Unaspis species in China]
  • Danzig1993: pp.306 ( Adult (F) ) [Key to species of Unaspis]
  • Chen1983: pp.29 ( Adult (F) ) [Key to species of Unaspis]
  • Chou1982: pp.67 ( Adult (F) ) [Key to Chinese species of Unaspis]
  • Takagi1961: pp.16 ( Adult (F) ) [Key to Japanese species of Unaspis]
  • Balach1954e: pp.289 ( Adult (F) ) [Key to species of Unaspis]
  • Rao1949: pp.65 ( Adult (F) ) [Key to species of Unaspis]
  • Kuwana1926: pp.41 ( Adult (F) ) [Key to species of Prontaspis] Key as: Prontaspis yanonensis

Remarks

  • Systematics: Unaspis yanonensis is similar to U. citri, but can be distinguished from it by having 48-64 macroducts on each side of the pygidium, 1 gland spine between the pygidial lobes, strongly diverging median lobes and 51-79 gland spines on each side of the body anterior of segment 4. U. citri has 18-35 macroducts on each side of the pygidium, 2 gland spines between the 2nd and 3rd lobes and between the 3rd and 4th lobes, slightly diverging median lobes and 27-39 gland spines on each side of the body anterior of segment 4 (Blackburn & Miller, 1984a).
  • Structure: Female scale 2.5-3.6 mm long, oyster-shell shaped, wax blackish brown, margin paler, dorsomedial longitudinal ridge wrinkled on sides. Exuviae terminal, brownish yellow. Male scale elongate, 1.3-1.6 mm long, felted, white, 2 or 3 longitudinal ridges. 1st exuviae brownish yellow, situated at anterior end of cover. Adult female body elongate, pygidium with 3 pairs of definite lobes, 4th lobes weakly indicated. Median lobes with conspicuous, paraphysislike sclerotization or yoke, median margins diverging apically and with conspicuous notches, medial margin noticeably longer than lateral margin. 2nd lobes bilobed, slightly smaller than median lobes, protruding beyond apex of median lobes, without notches. 3rd lobes bilobed, without notches. 4th lobes inconspicuous, simple or bilobed, represented by low series of notches (Blackburn & Miller, 1984a).
  • Biology: The overwintering population of Unaspis yanonensis consists of 2nd instar larvae and full grown male larvae and juvenile and mature female adults. In early May the 1st brood begins to hatch (Ohgushi & Miyasita, 1963). Unaspis yanonensis typically has between two and four generations annually in China, Japan, and the Mediterranean region. In Korea, the overwintered females start to produce their progenies (first generation) in mid-May. New female adults of the first generation start appearing in late June and peak in mid-July. The second generation female adults, occur starting in mid-September, and gradually increase in number until late October. (Kim, et al., 2010)
  • Economic Importance: Miller & Davidson (1990) list this insect as a serious and widespread pest. It is a very destructive pest of Citrus spp. in Japan (Watanabe, 1958). Huang & Zhang (1990) found that "machine oil emulsions" controlled 77 to 94% of immatures and adult females. Sprays of petroleum spay oil and lime sulfur were most effective against first and second instar nymphs, but later stage nymphs tended to produce abnormal scale covers which left them more open to attack by predators. (Kim, Seo and Choi, 2010) Two and three peak models have been developed by Kim, et al., 2010, to predict crawler occurrence in citrus orchards.
  • General Remarks: Detailed descriptions and illustrations by Kuwana (1926) and Blackburn & Miller (1984a).

Illustrations

Citations