Effects of Temperature and Nutrition on Growth Efficiency of the South American Locust ( Schistocerca cancellata) During the Sixth Instar

• Published in: The FASEB Journal
• Main Authors: Elliott, Deanna B., Youngblood, Jacob P., Angilletta, Michael J., Cease, Arianne J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Argentina; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1096/fasebj.2020.34.s1.04776

Throughout history, locust swarms have caused ecological and economic destruction in agricultural communities. Today, there are 20 species responsible for plagues on every continent excluding North America and Antarctica. In recent years, the South American species Schistocerca cancellata has wrought such devastation that Argentina and Bolivia were forced to declare states of emergency. Temperature and nutritional content of crops are known to be important variables in where a swarm will occur, but how these phenomena interact has not been studied. This experiment was intended to determine which temperature and dietary composition cause the highest growth rate in S. cancellata , based on the assumption that swarms may very well occur in places where the locusts are most likely to maximize their fitness. To this end, 180 locusts were separated into treatments composed of all combinations of three temperatures and three diets. Each treatment lasted the length of each animal’s 6 th instar. Temperatures were held at 25°C, 35°C, and 42.5°C, and diets with protein‐to‐carbohydrate ratios of 0P:42C, 14P:28C, and 35P:7C were fed. Once completed, waste was collected and weighed, and then compared to the mass of diet consumed in order to determine how much mass was retained. Additionally, the caloric content of the diets and waste was measured to calculate energy efficiency between treatments. The hottest treatments tended to result in the highest, fastest growth rate, while the cold treatments grew less and took significantly longer to reach adulthood. The diet highest in protein showed the most weight gain, while the on with no protein had very few survivors. The results of this study may help to predict where and when locust swarms will occur, based on weather and crop content in South America, and allow for precautions, such as chemical control measures, to take place in the probable affected areas. Support or Funding Information NSF LEAP Scholars Program