Psylliodes

Latreille, 1829

flea beetles

Psylliodes is a large of comprising approximately 200 described worldwide. Members are characterized by enlarged hind adapted for jumping, a trait shared with other Alticini. Approximately half of all species are specialized feeders on Brassicaceae, with the remainder associated with roughly 24 other . Several species are economically significant agricultural pests, including the cabbage stem flea beetle (P. chrysocephala) and (P. affinis). The genus includes rare species such as the Lundy Cabbage Flea Beetle (P. luridipennis), a globally Critically restricted to a single island off the coast of England.

Psylliodes by (c) Andy Slater, some rights reserved (CC BY), uploaded by Andy Slater. Used under a CC-BY license.

Psylliodes by (c) portioid, some rights reserved (CC BY), uploaded by portioid. Used under a CC-BY license.

Psylliodes chrysocephala by (c) anasacuta, some rights reserved (CC BY), uploaded by anasacuta. Used under a CC-BY license.

Pronunciation

How to pronounce Psylliodes: //sɪˈlioʊdiːz//

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

Identification

Psylliodes are distinguished from related primarily by genitalic characters and subtle external that requires expert examination. The genus can be separated from the superficially similar Phyllotreta by differences in male and tarsal structure. Species-level identification within Psylliodes is challenging and typically requires examination of morphology, with many species showing subtle differences in coloration, punctation, and body proportions. The metallic bronze coloration of P. luridipennis is distinctive among British species.

Images

Habitat

vary by and association. Species feeding on Brassicaceae occur in agricultural fields, habitats, and natural areas where cruciferous plants grow. The P. luridipennis is restricted to steep, wind-sheltered slopes on the eastern side of Lundy Island where its host plant Lundy Cabbage (Coincya wrightii) grows. Psylliodes chrysocephala aestivates during summer in protected microhabitats to avoid heat and desiccation stress.

Distribution

distribution with recorded across Europe, Asia, Africa, and the Americas. The is particularly diverse in the Palearctic region. Specific distribution records include Denmark, Norway, and Sweden. The P. luridipennis is restricted to Lundy Island, Devon, England. Psylliodes chrysocephala occurs in northern Europe where it is a significant pest of winter oilseed rape .

Seasonality

of many are active during the growing season of their plants. Psylliodes chrysocephala adults aestivate during summer months, entering a state to survive heat and desiccation stress before resuming activity. The timing of activity is closely tied to host , with typically present during periods of active plant growth.

Diet

Herbivorous. Approximately 50% of feed on Brassicaceae; remaining species feed on plants from approximately 24 different including Capparaceae, Cleomaceae, Resedaceae, and Tropaeolaceae. mine stems, roots, and leaves; feed on foliage. Psylliodes chrysocephala feeds on winter oilseed rape (Brassica napus). Psylliodes luridipennis feeds exclusively on Lundy Cabbage (Coincya wrightii).

Host Associations

Brassica napus - winter oilseed rape; of P. chrysocephala
Coincya wrightii - Lundy Cabbage; exclusive of P. luridipennis
Brassicaceae - for ~50% of
Capparaceae - for some
Cleomaceae - for some
Resedaceae - for some
Tropaeolaceae - for some

Life Cycle

with , , , and stages. Eggs are laid in soil at the base of plants. Larvae are stem and , feeding internally on tissues. occurs in the soil. Adults emerge and feed on host plant foliage. In Psylliodes chrysocephala, adults enter during summer, a state characterized by altered metabolic regulation including transport dynamics mediated by specific transporter (Tret-1 and Tret-2).

Behavior

possess enlarged hind enabling -like jumping when disturbed, the characteristic giving the group its . Psylliodes chrysocephala adults undergo summer to avoid heat and desiccation stress, during which they exhibit reduced metabolic activity and altered distribution between and . Disruption of trehalose transport causes compensatory increases in feeding activity in pre-aestivation .

Ecological Role

that can significantly impact through larval mining and foliar feeding. Several are economically important agricultural pests of . The P. luridipennis represents a rare example of co- with its host plant, illustrating tight evolutionary specialization. Some species have been investigated as potential agents for thistles.

Human Relevance

Several are significant agricultural pests. Psylliodes chrysocephala (cabbage stem ) is a major pest of winter oilseed rape in northern Europe. Psylliodes affinis () damages potato . Psylliodes punctulatus and P. convexior are known as hop flea beetles. Psylliodes chalcomera has been investigated as a agent for musk thistle. The P. luridipennis is a priority and flagship species for conservation in Britain.

Similar Taxa

PhyllotretaBoth are in tribe Alticini with jumping hind legs and similar body form; distinguished by male and tarsal structure
AlticaAnother with enlarged hind ; Psylliodes generally smaller with different associations and genitalic