Numbers
Nine greenbug biotypes that damage small grains have now been identified.
Identification
Mature female greenbugs are winged or wingless, pear-shaped, about 1/16-inch long, pale green, and marked with a darker green stripe down the middle of the back and black tips on the legs and the two appendages (cornicles) on the back of the abdomen. (TAMU)
Greenbugs are small (1.3 to 2.1 mm), elongate oval shaped aphids with head and first part of thorax straw to pale green and with light to medium green abdomen. A darker green stripe down the middle of the top surface of the abdomen is most visible on last instar nymphs and adults. The antennae are uniformly dusky. The cornicles or siphunculi are pale with slightly flared and darkened tips. Winged aphids are produced as crowding and damage symptoms increase. (UF)
Range
The greenbug is thought to be Palearctic in origin and is now found in North, Central and South America, Europe, Africa, the Middle East and Asia
Food
The host range of greenbug includes 70 graminaceous species (Michels 1986). The aphid develops on species in the genera Agropyron (wheatgrass), Avena (oat), Bromus, Dactylis, Eleusine, Festuca (fescue), Hordeum (barley), Lolium, Oryza (rice), Panicum, Paspalum, Poa, Sorghum (sorghum), Triticum (wheat) and Zea (maize).
Life Cycle
Greenbugs reproduce without mating (i.e., parthenogenesis) in warm or mild climates. Females mate with winged males in areas with cold winters to produce overwintering eggs. Nymphs are produced directly from the female in Florida. Greenbugs pass through three instars directly into the adult stage (i.e., no pupal stage) in seven to nine days at temperatures of 60 to 80°F. Adult greenbugs produce one to five nymphs per day.
Remarks
The greenbug has been recognized as a major pest of small grains for over 150 years.
Internet References
Greenbug - Featured Creatures, Univ. Florida
