Book excerpt: "Insects are seldom mentioned in history texts, yet they significantly shaped human history. The Silken Thread: Five Insects and Their Impacts on History tells the stories of just five insects, tied together by a thread originating in the Silk Roads of Asia, and how they have impacted our world. Silkworms have been farmed to produce silk for millennia, creating a history of empires and cultural exchanges; Silk Roads connected East to West, generating trade centers and transferring ideas, philosophies, and religions. The western honey bee feeds countless people, and their crop pollination is worth billions of dollars. Fleas and lice carried bacteria that caused three major plague pandemics, moved along the Silk Roads from Central Asia. Bacteria carried by insects left their ancient clues as DNA embedded in victims' teeth. Lice caused outbreaks of typhus, especially in crowded conditions such as prisons and concentration camps. Typhus aggravated the effects of the Irish potato famine, and Irish refugees took typhus to North America. Yellow fever was transported to the Americas via the trans-Atlantic slave trade, taking and devaluing the lives of millions of Africans. Slaves were brought to the Americas to reduce labor costs in the cultivation of sugarcane, which was itself transported from south Asia along the Silk Roads. Yellow fever caused panic in the United States in the 1700s and 1800s as the virus and its mosquito vector migrated from the Caribbean. Constructing the Panama Canal required defeating mosquitoes that transmitted yellow fever. The silken thread runs through and ties together these five insects and their impacts on history"--