Heliothis virescens

Heliothis virescens, commonly known as the tobacco budworm, is a moth of the Noctuidae family found throughout the eastern and southwestern United States along with parts of Central America and South America. It is a major pest of field crops including tobacco (as its common name suggests) and cotton. However, it is able to thrive on a wide variety of host plants ranging from fruits, vegetables, flowers, and weeds. Control of this pest has proven to be particularly difficult due a variety of factors, but widespread insecticide and pesticide resistance have proven particularly concerning. The tobacco budworm is found throughout the eastern and southwestern United States and has been collected in states such as Louisiana and Florida. However, it has also been spotted in California and even in New England and southern Canada during the later summer months as it disperses northward annually. Generally, Heliothis virescens spends the winter in the Southern states, but it has been seen to survive northern climates in sheltered areas such as greenhouses. H. virescens is also widely found in the Caribbean and has been spotted in Central and South America. More specifically, Virginia, North Carolina, South Carolina, Georgia, Florida, Texas, Colorado, Mexico, Guatemala, Panama, Brazil and the Antilles all have H. virescens populations. Heliothis virescens larvae are a field crop pest, attacking a wide variety of crops. As its common name suggests, it is widely described as attacking tobacco plants of the Nicotiana species, but it also favors cotton, alfalfa, clovers, soybean, and flax plants. In addition to crop plants, it is a common pest of vegetables and fruits such as cabbage, cantaloupe, lettuce, pea, and tomato plants. Aside from plants that are grown for agricultural reasons, H. virescens larvae also attack flower crops such as geranium and a large variety of weeds. After eggs are laid on the host plant's leaves and hatch, the larvae may chew small holes in the leaves before they reach the buds. They then damage the bud or growing tip of the plant. The leaves that expand from the buds are often ragged and distorted as a result. Host plant preference seems to differ by region or habitat. In Mississippi, cranesbill is the key early season host plant. In Texas, cotton is the principle host plant, but wild tobacco, vervain, ruellia, and mallow are all important hosts as well. Studies in Florida show that H. virescens prefer tobacco more highly than other field crops and vegetables, but cabbage, collards, okra, and tomato were all still attacked. However, it is notable that cotton was not present in this study. Movements between host plants throughout generations of H. virescens have been observed in a widespread number of environments. For example, in Georgia, the first two generations of H. virescens of the year (in around April and May) develop primarily on toadflax, but the third generation (in June and July) prefers deergrass. Future generations (between July to October) prefer beggarweed to other host plants. Other recorded food plants include Penstemon laevigatus, Desmodium species, Lespedeza bicolor, Medicago lupulina, Geranium dissectum, Rhexia species, Rumex species, Physalis species, Lonicera japonica, Lupinus species, Ipomoea species, Jacquemontia tamnifolia, Passiflora species, Sida spinosa, Helianthus species, Linaria canadensis, and Abutilon theophrasti.