Host-use pattern for overwintering and reproduction of the ragweed beetle, Ophraella communa LeSage, was examined in Tsukuba, Japan. Many adults of both sexes were found overwintering inside the rolled parts of dead leaves of Xanthium canadense in November. These adults had already accumulated triacylglycerol as energy reserves, and were able to survive the winter and to reproduce in the spring. No eggs and larvae were found on X. canadense throughout the observation period, although overwintered adults were temporarily found in May. In contrast, reproduction occurs on Ambrosia artemisiifolia and A. trifida in late April. These results suggest that O. communa adults mainly use dead leaves of X. canadense as an overwintering shelter in Tsukuba, while they reproduce only on A. artemisiifolia and A. trifida in the spring. Such a seasonal migration between host plants may be important for the survival strategy.