Two-spotted rose chafer

Systematic position: The two-spotted rose chafer (Protaetia bipunctata) belongs to the order Coleoptera and the family Scarabaeidae. This species is closely related to the common rose chafer and occupies a similar ecological niche, acting as a specialized consumer of flowering plant parts during its adult stage, which poses a significant agricultural challenge.

Host plants: As a polyphagous insect, the beetle affects a wide range of fruit and ornamental woody plants. Primary hosts include apple, pear, cherry, plum, and peach trees. Furthermore, it causes severe damage to vineyards and various flower gardens, where it feeds on petals and reproductive parts, thereby directly reducing fruit set and aesthetic value.

Biology and life cycle: The insect undergoes complete metamorphosis. Adults typically emerge in late spring when temperatures rise. They are highly active during sunny hours. The larval stage is spent in soil rich in decaying organic matter, leaf litter, or compost piles. Unlike some other scarabs, the larvae of this species generally feed on humus and decaying wood, not living roots.

Damage and economic importance: The primary economic damage is caused by the adults. They exhibit high voracity when consuming floral organs, stripping flowers of their stamens, pistils, and petals. This prevents pollination and subsequent fruit development. In addition to damaging flowers, adults often chew irregular holes in developing fruits, which creates entry points for fungal pathogens and leads to fruit decay.

Control measures: Management of Protaetia bipunctata is complicated by its activity during the flowering period, limiting chemical options. Key strategies include:

• Manual collection of beetles in the early morning when they are lethargic.
• Maintenance of garden hygiene to remove rotting wood and compost, which serve as breeding sites.
• Use of pheromone or light traps during the adult emergence phase.
• Avoidance of broad-spectrum pesticides during peak pollination times to protect beneficial insects.