Trioza

Förster, 1848

psyllids, jumping plant-lice

Trioza is the of in the , comprising sap-sucking with worldwide distribution. in this genus exhibit diverse associations, ranging from agricultural to trees. Several species are economically significant: Trioza erytreae transmits (Huanglongbing), T. apicalis is a major pest of carrot in northern Europe, and T. brevigenae is an pest of ornamental Ficus in California. The genus is characterized by distinct morphological features and complex involving seasonal between summer hosts and sites.

Identification

Trioza can be distinguished from other by their patterns and structure. typically possess transparent with characteristic ; for example, T. brevigenae adults measure 2.6-2.8 mm with reddish and greenish to brownish bodies. often produce distinctive waxy filaments. Specific identification requires examination of male and female genitalia and is best confirmed by taxonomists.

Habitat

varies by : T. apicalis occupies agricultural fields with carrot and overwinters on coniferous trees (primarily Norway spruce); T. erytreae occurs in citrus-growing regions with mild temperatures and high precipitation; T. brevigenae infests ornamental Ficus microcarpa in urban landscapes; T. magnoliae inhabits Persea bay trees in southeastern USA.

Distribution

Worldwide distribution with regional variation: T. apicalis occurs in northern and central Europe (Denmark, Fennoscandia, and other European countries); T. erytreae is to Africa (Angola, Cameroon, Ethiopia, Kenya, Madagascar, South Africa, and others) and parts of the Middle East (Saudi Arabia, Yemen), in Europe (Spain, Portugal including Madeira and Canary Islands); T. brevigenae reported from India and invasive in southern California; T. magnoliae occurs in southeastern USA.

Seasonality

T. apicalis shows distinct seasonal : overwintered migrate to carrot in spring, occurs June-July, summer generation develops, and departure from hosts peaks early September before . T. erytreae activity patterns correspond to mild seasonal temperatures in its range.

Diet

Phloem-feeding on vascular tissues. T. apicalis feeds on Daucus carota (carrot), Coriandrum sativum (coriander), and Petroselinum hortense (parsley); T. erytreae feeds on Citrus spp. and other Rutaceae; T. brevigenae feeds on Ficus microcarpa; T. magnoliae feeds on Persea spp.

Life Cycle

T. apicalis has a complex with two : overwintered migrate to carrot in spring, live only 2-3 days on carrots, lay during June-July; develop through multiple on carrots; summer generation adults emerge and depart hosts in early September to overwinter on conifers. Other Trioza show variation in generation number and strategies.

Behavior

T. apicalis exhibits precise spring timing synchronized across central and northern Europe, possibly cued by long-day rather than local temperature. of this show very short residence time on summer (2-3 days). T. erytreae transmits Candidatus Liberibacter bacteria causing . of some species produce waxy filaments for protection.

Ecological Role

Several are significant agricultural pests and . T. erytreae is a vector of (Huanglongbing) caused by Candidatus Liberibacter africanum and can experimentally transmit Candidatus Liberibacter asiaticum. T. apicalis causes direct damage to carrot through phloem feeding that induces leaf curling. Some species appear to have limited impact on plants.

Human Relevance

High economic impact through agriculture and horticulture. T. erytreae is listed as an A1 by EPPO and is a quarantine pest for CPPC and OIRSA; its introduction has prompted prohibitions on citrus imports. T. apicalis is a major pest of carrot in northern Europe. T. brevigenae threatens ornamental Ficus plantings in California. T. magnoliae causes aesthetic damage to bay trees but has limited economic impact.

Similar Taxa

BactericeraFormerly included now transferred out (e.g., Trioza albiventris moved to Bactericera albiventris); distinguished by and characters
SchedotriozaFormer Trioza tasmaniensis transferred to Schedotrioza tasmaniensis; differs in associations and morphological details