Unaspis

MacGillivray, 1921

Unaspis is a of ( ) containing economically significant agricultural and horticultural pests. The genus includes at least 19 described , with several species infesting citrus (U. citri, U. yanonensis) and ornamental plants (U. euonymi). Species in this genus are characterized by their protective waxy coverings and feeding habits on tissues.

Unaspis by no rights reserved, uploaded by Johannes. Used under a CC0 license.

Unaspis euonymi by (c) Paul Cook, some rights reserved (CC BY), uploaded by Paul Cook. Used under a CC-BY license.

Pronunciation

How to pronounce Unaspis: /juːˈnæspɪs/

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Identification

Unaspis are distinguished by their hard, protective test (covering) formed from and secretions. The can be differentiated from related armored scale genera by morphological features of the female test and body structure; a to all 19 Unaspis species has been published. Specific identification requires examination of microscopic characters including pygidial margin structures and duct arrangements. U. citri produces a conspicuous , elongated test on citrus bark, while U. euonymi shows with females producing a , oyster-shaped test and males producing a narrower white covering.

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Habitat

occur in agricultural, horticultural, and urban environments where their plants grow. U. citri and U. yanonensis inhabit citrus groves and orchards. U. euonymi occurs in urban landscapes, gardens, and nurseries on ornamental shrubs. U. mabilis and U. lansivora infest lanzones (Lansium domesticum) trees in the Philippines.

Distribution

The has a broad global distribution corresponding to ranges. U. citri occurs in citrus-growing regions worldwide including North, Central, and South America, Europe (Azores), Africa, Asia (China, Southeast Asia), Australasia (Australia, New Zealand, Pacific Islands). U. euonymi is established in Europe, Asia, North Africa, and North and South America. U. yanonensis is distributed in East Asia (China, Japan, Korea) and has been reported in France. U. mabilis and U. lansivora are known from the Philippines.

Diet

; feed on sap from tissues. U. citri and U. yanonensis feed on Citrus species. U. euonymi feeds on Euonymus species, Prunus, Hibiscus, and other ornamentals. U. mabilis and U. lansivora feed on Lansium domesticum (lanzones).

Host Associations

Citrus - primary U. citri, U. yanonensis
Lansium domesticum - primary U. mabilis, U. lansivora
Euonymus - primary U. euonymi
Prunus - U. euonymi
Hibiscus - U. euonymi

Ecological Role

As pests, heavy cause premature leaf , , reduced fruit production, and tree mortality. U. lansivora has been documented causing tree death in lanzones plantations. The serves as for and agents including predatory (Chilocorus kuwanae, Cybocephalus nipponicus) and (Aphytis yanonensis, Coccobius fulvus, Aspidiotiphagus spp., Encarsia spp.).

Human Relevance

Several are economically significant agricultural pests. U. citri () and U. yanonensis (arrowhead ) threaten citrus production globally. U. euonymi is a major pest of ornamental Euonymus in urban landscapes. U. lansivora has emerged as a damaging pest of lanzones in the Philippines with potential significance. Management relies on , , and chemical interventions.

Similar Taxa

AulacaspisBoth are in with similar ; molecular data shows U. mabilis has 87.4% COI sequence similarity to Aulacaspis tubercularis, but phylogenetic analysis places Unaspis as a distinct clade.
LepidosaphesU. lansivora was initially misidentified as Lepidosaphes ulmi before being recognized as a distinct Unaspis ; both produce elongated coverings but differ in pygidial and duct .
ChionaspisU. euonymi was previously classified as Chionaspis euonymi; the Unaspis was erected based on distinct morphological features separating it from Chionaspis.