An experimental study of free flight kinematics in a miniature parasitoid wasp, Trichogramma cacoeciae

Miniature insects must flap their wings differently from larger ones because of their small size. However, the combined effects of miniaturization, wing apparatus structure and phylogenetic position on the flight mechanics are complex and remain underinvestigated. We examined the flight kinematics and performance of one of the smallest membranous-winged wasps, Trichogramma cacoeciae, including both forewing and hindwing motion. Trichogramma cacoeciae, despite having essentially membranous wings, is capable of flying at the same high speed and acceleration as similarly sized insects with bristled wings. Its kinematics is characterized by high-amplitude U-shaped power strokes and prolonged recovery strokes. Сomparative analyses of distantly related miniature insects demonstrate that wing kinematics reflect phylogenetic relatedness and wing morphology as significantly as the body size. It is, therefore, necessary to take into equally careful consideration the effects of size, phylogeny and wing morphology.