Biological pest control predatory midge "Feltiella acarisuga", and a ladybird "Stethorus punctillum". The bug "Orius insidiosus" has been successfully used against the two-spotted spider mite and the western flower thrips ("Frankliniella occidentalis"). Predators including "Cactoblastis cactorum" (mentioned above) can also be used to destroy invasive plant species. As another example, the poison hemlock moth ("Agonopterix alstroemeriana)" can be used to control poison hemlock ("Conium maculatum"). During its larval stage, the moth strictly consumes its host plant, poison hemlock, and can exist at hundreds of larvae per individual host plant, destroying large swathes of the hemlock. Not all biological control agents are directed at
What Is to Be Done? (Tolstoy) the same Biblical reference (Luke 3:10–14). What Is to Be Done? (Tolstoy) What Is To Be Done? (sometimes translated as What Then Must We Do?) is a non-fiction work by Leo Tolstoy, in which Tolstoy describes the social conditions of Russia in his day. Tolstoy completed the book in 1886, and the first English language publication came in 1887 as What To Do?. A revised translation with the current title was published in 1899. The English title was also used for two better-known works by Nikolai Chernyshevsky and Vladimir Lenin; Tolstoy's Russian title is similar but not identical to Chernyshevsky's