Tamarixia

Mercet, 1924

Tamarixia is a of small in the , primarily known as parasitoids of (, superfamily ). The genus was established by Mercet in 1924 and contains approximately 50 described distributed worldwide. Most species are , though at least one species has been recorded as an . Several species, particularly T. radiata and T. triozae, are important agents used in programs for citrus and solanaceous .

Occurence de Tamarixia radiata dans le monde by Philippe GC Souza ,Owusu F. Aidoo ,Priscila KB Farnezi ,William K. Heve ,Paulo AS Junior ,Marcelo C. Picanço ,Kodwo D. Ninsin ,Fred K. Ablormeti ,Mohd Asif Shah ,Shahida Anusha Siddiqui etRicardo S. Silva. Used under a CC BY 4.0 license.

Tamarixia radiata hole in host nymph cuticle.png by Jeffrey W. Lotz,. Used under a CC BY 3.0 us license.

Tamarixia radiata by Jeffery W. Lotz. Used under a CC BY 3.0 us license.

Pronunciation

How to pronounce Tamarixia: /tæməˈrɪksiə/

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Identification

Tamarixia are small typically measuring 1-2 mm in body length. They can be distinguished from other eulophid by their association with and specific patterns. Species-level identification requires examination of morphological characters including segmentation, body coloration, and genitalic structures. T. radiata, the most extensively studied species, has a distinctive dark body with legs and antennae.

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Habitat

Tamarixia are found in agricultural and natural environments where their occur. Specific include citrus orchards (T. radiata), tomato and potato fields (T. triozae), and areas with host plants of various psyllid species. Rearing conditions for programs typically use potted host plants maintained at 25±2°C with 70±10% and 14L:10D .

Distribution

The has a distribution with recorded from North America, South America, Europe, Asia, Africa, and Oceania. T. radiata is to India and Pakistan and has been to California, Brazil, and Reunion Island for . T. triozae is native to North America. T. poddubnyi has been recorded from Iran, representing an extension to the Middle East.

Diet

Tamarixia feed on and obtained through host-feeding . stages develop as on . T. radiata develops preferably on 3rd to 5th nymphs of , with adults also feeding on and younger nymphs. T. triozae parasitizes nymphs of Bactericera cockerelli on tomato and other solanaceous .

Host Associations

Diaphorina citri - , primary of T. radiata
Bactericera cockerelli - tomato/potato , of T. triozae
Trioza eugeniae - of T. dahlsteni
Trioza neglecta - of T. poddubnyi on Elaeagnus angustifolia
Bactericera tremblayi - of T. monesus and T. tremblayi
Murraya paniculata - associated orange jasmine, used for rearing D. citri in programs
Citrus sinensis - associated sweet orange, in
Solanum lycopersicum - associated tomato, for B. cockerelli and T. triozae
Capsicum annuum - associated chili pepper, alternative for T. triozae studies

Life Cycle

Tamarixia have short times typical of small . T. radiata completes development from to in approximately 9 days under optimal conditions (25°C). Females lay eggs under or on ; develop as (most species) or (at least one species). occurs on or near the . T. radiata is an parasitoid, killing the host during development. T. triozae is , continuing to produce eggs throughout adult life.

Behavior

Female Tamarixia exhibit -feeding in addition to , consuming host to obtain nutrients for production. A single T. radiata female can eliminate up to 500 through combined feeding and parasitism over her lifetime. Host deprivation followed by feeding on or water can enhance for releases. are susceptible to many used in citrus production, with varying by —adults are most susceptible, most tolerant.

Ecological Role

Tamarixia serve as important agents of pests, particularly those vectoring . T. radiata is the primary used against , of Huanglongbing (), and has achieved rates up to 70% in release areas. The contributes to natural suppression of psyllid in both and ranges, forming a component of in citrus and solanaceous cropping systems.

Human Relevance

Several Tamarixia are commercially mass-reared and released for . T. radiata has been released in California since 2011, with over 200,000 released at more than 400 sites by 2014; it is also used in Brazil with six bio-factories producing for release. T. triozae has been imported to New Zealand for potential of Bactericera cockerelli. The has been subject to extensive testing to evaluate environmental safety prior to release. Research on optimizing rearing methods, diet for maintenance, and integration with chemical control.

Similar Taxa

Diaphorencyrtus aligarhensisAnother of in the ; distinguished by different family placement and endoparasitic development
Psyllaephagus of ; distinguished by -level differences and typically endoparasitic lifestyle
CirrospilusEulophid that may attack similar ; distinguished by different host associations and morphological characters

More Details

Biological Control Safety

range testing of T. radiata sourced from Pakistan demonstrated high specificity to , with minimal risk to non-target . Only Bactericera cockerelli (potato psyllid) showed any at levels below 5%, supporting regulatory approval for release in California.

Insecticide Susceptibility

T. radiata is susceptible to many used in citrus production, including , , and neonicotinoids. The pupal stage shows greatest , while are most vulnerable. Selective insecticide use is recommended to preserve in integrated management programs.

Augmentative Release Strategies

Research on T. triozae indicates that pre-release diet affects efficacy. fed water for one day before release show rapid increase suitable for high pest , while -fed adults are better for shipment and establishment when pest densities are low.