Cassiadelges Havill & Brunet, 2025

Cassiadelges Havill & Brunet , subgen. nov.

Type species. Adelges (Cassiadelges) coccipus Havill & Brunet, by present designation.

Etymology. A noun in apposition stemming from the Latin cassida, meaning “helmet,” in reference to the prominent cephaloprothoracic shield in adult exules.

Diagnosis. Adult exulis. Feeds on Larix secondary hosts. Head and pronotum completely covered with plates fused into a cephaloprothoracic shield. Ventral spiracles present on abdominal segments II–VI. Only acuminate setae on abdominal segments VIII–IX.

Remarks. Monotypic, including only A. (Ca.) coccipus at present, pending the description of an additional species, A. (Ca.) nr. coccipus , collected from Larix in Sichuan, China ( Table 1 View TABLE 1 ). This additional species has fully developed legs in the adult stage, so lacking legs is not a diagnostic character of Cassiadelges . Annandina is the only other subgenus in Adelges with a complete cephaloprothoracic shield in the adult exulis stage. Cassiadelges differs from Annandina in feeding on Larix vs. Tsuga secondary hosts and by Annandina having knobbed setae on the distal abdominal segments.