Exorista

Meigen, 1803

uzi fly

Species Guides

Exorista is a of tachinid flies comprising approximately 70 described distributed across multiple subgenera. The genus includes both beneficial biocontrol agents and economically significant pests of . Species such as E. sorbillans (uzi fly) are major constraints on silk production, causing up to 80% crop loss in outdoor operations through endoparasitic larval development. Other species have been evaluated for of agricultural pests, including E. larvarum for rearing and E. deligata for control of tea loopers. The genus exhibits diverse associations, primarily targeting Lepidoptera.

Exorista larvarum by no rights reserved, uploaded by Jean-Paul Boerekamps. Used under a CC0 license.

Exorista.larvarum.-.lindsey by James K. Lindsey. Used under a CC BY-SA 3.0 license.

Exorista larvarum, Sontley, North Wales, Aug 2015 (22931883541) by Janet Graham. Used under a CC BY 2.0 license.

Pronunciation

How to pronounce Exorista: //ɛkˈsɔrɪsta//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Exorista are tachinid flies distinguished from related by combinations of bristle patterns, abdominal coloration, and male genitalic structures. Subgeneric classification relies on chaetotaxy of the scutellum, leg bristling, and wing venation patterns. Species-level identification requires examination of the male terminalia and often association records. The genus lacks the prominent facial carina found in some related exoristine genera.

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Habitat

occur in diverse associated with their lepidopteran , including agricultural , forests, and environments. E. sorbillans is closely tied to rearing facilities and outdoor semidomesticated sericulture systems. E. deligata has been recorded from tea plantations in India. typically occurs in soil or substrate near host habitats.

Distribution

distribution with records from Europe (Denmark, Norway, Sweden), Asia (India, China, Japan), and other silk-producing regions. E. sorbillans occurs in all major silk-producing countries. E. japonica is distributed in East Asia. Specific distributions vary by ; many species have restricted ranges while others are widespread.

Diet

of E. sorbillans have been observed feeding on 8% glucose solution in laboratory conditions. Natural adult feeding habits are poorly documented. Larvae are endoparasitic and do not feed independently.

Host Associations

Bombyx mori - primary for E. sorbillans; endoparasitic development inside larvae
Antheraea mylitta - for E. sorbillans; tasar
Samia cynthia ricini - for E. sorbillans;
Antheraea assamensis - for E. sorbillans; muga ; up to 80% seed loss reported
Hyposidra talaca - for E. deligata; Indian tea looper; larval-pupal endoparasitoid

Life Cycle

Larvae are developing inside lepidopteran . E. sorbillans: laid on larval body surface, maggots penetrate and develop internally, mature maggots exit host by cutting hole in cocoon case, pupate in soil. Infested silkworms die in late larval, pre-pupal, or pupal stage. E. deligata: stages (larva, pre-pupa, pupa) observed inside developing pupa of host with complete host consumption. Post-parasitic maggots collected from infested cocoons undergo to pupae then .

Behavior

E. japonica uses visual and olfactory cues to locate herbivore-infested plants. E. sorbillans females preferentially oviposit on larvae, laying 1-3 per . endosymbionts in E. sorbillans influence reproductive through and sex ratio distortion. longevity not significantly affected by Wolbachia status.

Ecological Role

Dual role as biocontrol agents and agricultural pests. E. sorbillans causes 15-20% yield loss in silk industry, up to 40% overall crop loss and 80% in outdoor seed . Damaged cocoons become commercially unreelable. E. deligata shows potential as agent against tea looper pests, causing mean 25.4% pupal mortality. E. larvarum has been evaluated for mass rearing and .

Human Relevance

Major economic impact on industry in Asia. E. sorbillans (uzi fly) is a primary pest requiring integrated management including -based controls (Ocimum gratissimum, thymol, carvacrol), physical barriers, and (Trichomalopsis uziae). Research has explored -based suppression and rearing techniques for E. larvarum. Some studied for of crop pests.

Similar Taxa

AnthraxBombyliid flies also parasitize tiger larvae; distinguished by wing venation, , and larval attachment position on
BillaeaTachinid with similar associations; separated by facial profile, scutellar bristling, and male terminalia structure

More Details

Wolbachia symbiosis

E. sorbillans harbors endosymbionts essential for normal . Infected females show ~17% higher . Removal causes (88-90% embryonic mortality), sterility in uninfected crosses (64-70% mortality), and male-biased sex ratios (~2:1). Represents mutualistic controlling reproductive physiology.

Subgeneric classification

divided into 9+ subgenera (Exorista, Adenia, Exoristella, Fauniodes, Podotachina, Ptilotachina, Spixomyia, Tricoliga) based on morphological characters including scutellar chaetotaxy, leg bristling, and abdominal structure. Numerous remain unplaced to subgenus.