The vine louse Phylloxera vastatrix became a “pest” as it was transferred from North America and from France to Germany during the 1870s. Embodying the “invading alien,” it assumed a cultural position that increasingly gained importance in Imperial Germany. In this process, the minute insect, living invisibly underground, was made visible and became constitutive of the scientific-technological object, “pest,” pertaining to a scientific discipline, modern economic entomology. The “pest” phylloxera emerged by being made visible in a way that enabled control measures against it. Thus, visibility functioned as a prerequisite for control measures. I differentiate between social visibility and physical visibility, as well as between social control and physical control of the “introduced pest.” The object phylloxera emerged at the intersection of techniques of social control such as surveillance, techniques of physical control such as disinfection, and representational practices of the sciences such as mathematics and graphics. The space of its visibility was not the vineyard as property of a vintner but the vineyard as national territory, where German (viti-) culture was defended against foreign infiltration and destruction. Many vintners had alternate visions of the grapevine disease, they resented the invasion and destruction of their vineyards by government officers, and thus they did not participate in the social and epistemic constitution of the “pest.” By 1914, the “introduced pest” had not yet become an effective “machinery.” However, the “pest” as an object of scientific knowledge emerged together with economic entomology. The field became organized as a discipline in Germany in 1913, forty years after the phylloxera had first aroused the minds of some worried Wilhelmians, and, together with its nationalistic images, the field of “pest” control became organized towards a redefinition of German society and its perceived dangers.