Thecabius

Koch, 1857

Species Guides

Thecabius populimonilis(Bead-like Cottonwood Gall aphid)

Thecabius is a of aphids in the Aphididae, Pemphiginae. occur in Europe and North America. At least one species, Thecabius affinis, exhibits dormancy with substantial lipid accumulation during . The genus contains at least two described species: T. affinis and T. anemoni.

Thecabius populimonilis by no rights reserved, uploaded by anthocyana. Used under a CC0 license.

Thecabius populimonilis by (c) giantcicada, some rights reserved (CC BY), uploaded by giantcicada. Used under a CC-BY license.

Pronunciation

How to pronounce Thecabius: /ˈθiːkəbiəs/

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Distribution

Europe and North America. GBIF records confirm presence in Denmark, Norway, and Sweden.

Life Cycle

Thecabius affinis exhibits dormancy in virginoparae, characterized by cessation of feeding and wax production, and accumulation of lipid reserves nearly double those of summer forms. Dormancy is induced by low temperatures (8°C), with offspring of summer forms entering within 1–3 weeks, typically at the second or third instar. Quiescent individuals resume feeding and wax production when transferred to warmer conditions (15°C), though developmental and reproductive rates remain reduced compared to summer forms.

More Details

Dormancy physiology

forms of T. affinis accumulate large quantities of triglycerides and phospholipids, in contrast to summer forms which contain small amounts of several neutral lipids. The mechanism of dormancy induction—whether direct temperature effect on the or indirect via the plant—remains unresolved.