Greenhouses were created to provide the perfect environment for plant growth. Nurturing plants to grow quickly is the key to profitability in the greenhouse. The perfect plant environment is also the optimal condition for many biotic pests and diseases. They can also thrive along with their plant food source. The two most commonly observed viruses in greenhouse production are Impatiens Necrotic Spot Virus (INSV) and Tomato Spotted Wilt Virus (TSWV). The primary vector of spread is Western flower thrips and a few additional thrips species. Given the continual arrival of plant material from numerous sources, it is possible for a virus to also be imported. Thus once a virus situation arises in a greenhouse, thrips can spread the disease to other plants. Both INSV and TSWV can manifest in a wide range of species, and the signs of a virus infection can vary among plants. Therefore, it is important to identify the symptoms of a virus. This guide is meant to be the first step in the diagnostic process, aiding in the initial identification of the problem and later confirmation by testing.