alula

• 指双翅目昆虫翅膀基部与平衡棒之间的小型鳞片状结构，或鸟类翅膀第一指上的一小簇小而硬的羽毛。

A noun referring to a small, scale-like structure found between the base of the wing and the haltere in two-winged flies, or a tuft of small stiff feathers on the first digit of a bird's wing.

1. Bird anatomyC2formalscientific

   A small, feathered projection on the first digit (thumb) of a bird's wing, also known as the bastard wing, which helps with slow-speed flight and landing.

   小翼羽

   • The alula allows birds to fly at very slow speeds without stalling.
   • During landing, the bird extends its alula to increase lift.
   • Ornithologists study the alula to understand avian flight mechanics.

   同义词bastard wing

2. Insect anatomyC2formalscientific

   A small, scalelike structure located between the base of the wing and the haltere in certain two-winged flies (Diptera).

   翅瓣

   • The alula in flies is a small, membranous lobe near the wing base.
   • Entomologists use the shape of the alula to identify different fly species.
   • The function of the alula in Diptera is still being researched.

   同义词calyptersquama