Scirtothrips

Shull, 1909

leaf-feeding thrips, citrus thrips, chilli thrips

Species Guides

Scirtothrips dorsalis(chilli thrips)

Scirtothrips is a of leaf-feeding thrips in the Thripidae, established by Shull in 1909. The genus includes economically significant pest such as the (S. dorsalis), citrus thrips (S. citri), and South African citrus thrips (S. aurantii), which damage agricultural crops through piercing-sucking feeding on tender leaves, buds, and fruit. Species exhibit diverse associations ranging from highly host-specific forms on Australian Acacia to broadly pests. The genus has undergone taxonomic revision, with Labiothrips synonymised under Scirtothrips.

Scirtothrips by no rights reserved, uploaded by Jesse Rorabaugh. Used under a CC0 license.

Scirtothrips dorsalis by no rights reserved, uploaded by 余世文. Used under a CC0 license.

Sd adult spread by Aderksen at English Wikipedia. Used under a CC BY-SA 3.0 license.

Pronunciation

How to pronounce Scirtothrips: //skɪrˈtoʊθrɪps//

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Identification

identification requires examination of morphological characters including body coloration, setal patterns, wing venation, and antennal segmentation. Australian species have been distinguished through identification keys based on S. albomaculatus and S. akakia species-groups. Distinguishing Scirtothrips from other thrips involves characteristics of the pronotum, forewing structure, and abdominal tergite chaetotaxy. Specific identification typically requires slide-mounted specimens and reference to taxonomic revisions.

Images

Habitat

vary by : Australian species predominantly occupy arid zones, with three species (S. dorsalis, S. dobroskyi, S. tenor) in northern tropical areas. Agricultural pest species occur in cultivated systems including citrus groves, tea plantations, strawberry fields, and blueberry orchards. in Florida occupy woodland borders adjacent to crop fields.

Distribution

Native range includes Australia (with most to arid areas), Asia (India, China, Southeast Asia, Japan, Korea), and Africa (South Africa, Egypt). established in North America (Florida, California, Hawaii, Texas), Central America and Caribbean (Barbados, Jamaica, Puerto Rico, Saint Lucia, Saint Vincent and the Grenadines, Trinidad and Tobago), South America (Suriname, Venezuela), and Oceania (Papua New Guinea, Solomon Islands). S. aurantii introduced to Queensland, Australia.

Diet

Phytophagous; piercing-sucking feeding on plant sap. Specific feeding targets include tender leaves, buds, and fruit of plants. S. dorsalis feeds on tea leaves and strawberry plants. S. citri and S. aurantii feed on citrus fruit and foliage. S. perseae specialises on avocado. Feeding damage produces characteristic : pale thin lines parallel to leaf midvein, distorted buds, brownish damaged tissues, 'sand paper' and 'silvered' corky lines on fruit surfaces.

Host Associations

Camellia sinensis (tea) - primary S. dorsalis; major pest causing 12–15% crop loss in Indian tea plantations
Citrus spp. (citrus) - primary S. citri, S. aurantii; fruit scarring renders produce unmarketable
Fragaria × ananassa (strawberry) - primary S. dorsalis; important economic pest in Florida
Vaccinium spp. (blueberry) - primary S. dorsalis; target of current research
Persea americana (avocado) - primary S. perseae; specialised association
Acacia spp. - Multiple Australian ; S. albomaculatus and S. akakia species-groups
Allocasuarina spp. - Australian
Brachychiton spp. - Australian
Hakea spp. - Australian
Kunzea spp. - Australian
Cycads (two genera) - Australian
Tree ferns - Australian
Vitis rotundifolia (muscadine grape) - reproductive S. dorsalis in Florida woodland borders
Prunus caroliniana (Laurel cherry) - reproductive S. dorsalis in Florida
Celtis laevigata (sugarberry) - reproductive S. dorsalis in Florida
Bidens pilosa (Spanish needles) - reproductive S. dorsalis in Florida
Ludwigia peruviana (Peruvian water primrose) - reproductive S. dorsalis in Florida
Ambrosia spp. (ragweed) - reproductive S. dorsalis in Florida
Liquidambar styraciflua (sweetgum) - reproductive S. dorsalis in Florida
Quercus nigra (water oak) - reproductive S. dorsalis in Florida

Life Cycle

Development from to varies by plant and temperature. Laboratory studies on S. dorsalis at 25°C ± 2°C, 70–80% RH, 12L:12D demonstrated cultivar-specific variation: total developmental period shortest on TV1 tea cultivar, longest on TV23. Includes egg, larval, and adult stages. Larvae reared individually on leaf material with regular replacement. Adult female longevity and reproductive parameters vary significantly among host cultivars.

Behavior

Exhibits weak capability and aggregated distribution across plant . establishment linked to climate change, deforestation, and over-reliance on chemical in agricultural systems. Host selection behaviour disrupted by herbivory-induced plant volatiles.

Ecological Role

Major agricultural pest causing significant economic damage through direct feeding injury. S. dorsalis established as key pest in tea plantations of north-eastern India over five decades. S. citri and S. aurantii threaten citrus production in multiple regions. S. dorsalis in Florida strawberry and blueberry production. Some Australian appear restricted to native flora with limited agricultural impact.

Human Relevance

Economic pests requiring in citrus, tea, strawberry, and blueberry production. Research targets include programs, cultivar screening, , and plant defense inducers. Subject of classical and efforts. serves as model organism for studying herbivore-induced plant volatiles and selection disruption.

Similar Taxa

Thrips (genus)Both in Thripidae; distinguished by pronotal structure, wing venation, and abdominal chaetotaxy patterns
Frankliniella (genus)Common thrips in same ; Scirtothrips typically with more pronounced leaf-feeding damage and distinct antennal structure

More Details

Taxonomic history

The Labiothrips Bhatti & Mound has been synonymised with Scirtothrips. The New Zealand S. pan was removed from the Australian list as a misidentification.

Species diversity

Twenty-one recognised from Australia including eleven newly described species. Two new species-groups distinguished based on S. albomaculatus and S. akakia, both with multiple species on Acacia.

Research significance

Current research focuses on S. dorsalis in southern highbush blueberries, including spray studies, cultivar resistance screening, and grower surveys. modelling using parameters demonstrates cultivar effects on growth and .