Answer: Beetles such as Japanese beetles on roses can usually be repelled by using a neem-based spray according to directions. Handpicking is also effective but a bit time-consuming; it works best in early morning or evening when the beetles are moving slowly. On the other hand, rugosa roses are very sturdy plants and I would not expect a beetle attack to kill the plant. You might decide that the damage is "acceptable" and not do anything about it except ignore it.
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