The soybean aphid, Aphis glycines, is an economic pest of soybean plants across all midwestern states including Pennsylvania.  High population of soybean aphids can cause up to 20% yield loss.  Although the pest has a heteroecious holocyclic life cycle, the summer parthenogenic form is responsible for crop injury.  This research is focused on understanding how temperature influences the development of parthenogenic soybean aphids.  Soybean aphid development was observed under five temperatures (32˚C, 30˚C, 25˚C, 22˚C, and 16˚C) in growth chamber settings at 16:8 (L:D) hr. photoperiod and 50±10% ambient RH.  Neonate borne nymphs were placed on the youngest trifoliate leaf of a three-week-old soybean plant and the leaf was enclosed within a 60 x 15 mm Petri plate, without the removal of the leaf from the soybean plant.  Nymphal development was observed every 12±2 hours until adulthood, then every 24±2 hours.  The number of nymphal molts, number of offspring, and longevity were collected daily until soybean aphid death.  The average number of molts per nymph was 4 across all temperatures.  Nymphal development to adulthood occurred fastest at 30˚C.  Maximum adult longevity of soybean aphids was observed at 25˚C.