About Synonycha grandis (Thunberg, 1781)
Mating in Synonycha grandis occurs one day after adult emergence. Mating sessions last between 2 and 3 hours, and multiple matings are very common. After mating, adult females lay eggs on leaf surfaces. The eggs are yellowish, spindle-shaped, and measure 5 mm in length. The grub has an elongate body with tapering ends. Its head is square-shaped with rounded margins, and the pronotum is wide, bearing two black tubercles at its extreme ends. The last abdominal segment lacks tubercles, but it has yellowish protrusible anal pads. The legs are slender and elongated. The dorsum is black, with yellow spots located on the mesothorax and metathorax, while the ventrum is yellowish black. First instar grubs are golden yellow in color, and darken to black as they mature. Second instar grubs begin moving and feeding on aphid nymphs and adults, and reach 8 to 12 mm in length during this stage. Third instar grubs have yellow spots on the dorsum, and a completely black pronotum. Two yellowish tubercles are located dorsally on the mesothorax. The first and fourth abdominal segments are yellow, while the second, third, and all remaining abdominal segments are black. Third instar grubs measure 12 to 15 mm in length. Fourth and fifth instar grubs are 16 to 18 mm long, and the final grub stage reaches 19 to 21 mm in length. In later grub stages, the pronotum is black with lateral tubercles, and the dorsal and lateral tubercles on the mesothorax and metathorax are yellow. The pupa is bright yellow when first formed, and later develops black spots on its dorsum. Freshly emerged adults are golden yellow with soft forewings, and remain in the pupal case until their forewings harden. Black spots become visible on the forewings after emergence. The elytra range from yellowish to red and bear black spots. The adult body is hemispherical and measures around 13 mm in length, with females growing larger than males. This species is distributed across China, India, Sri Lanka, Nepal, Indonesia, Japan, Malaysia, the Philippines, Taiwan, Australia, Trinidad and Tobago, the United States, and Hawaii.
