Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 12, 1996
Publication Date: N/A
Interpretive Summary: Immersion of fruit fly larvae in hot water has been used to generate data used in modeling fruit fly mortality for quarantine treatments based on heat. However, there are many differences between immersing laboratory-reared larvae in hot water and heating wild larvae inside a fruit which make modeling fruit fly heat kill precarious. The objective of this research was to investigate two of these differences: rearing larvae on a semi- artificial diet or a fruit and heating larvae in water versus heating them in a fruit juice. Mature Caribbean fruit fly, Anastrepha suspensa, larvae were reared on a semi-artificial diet or grapefruits and then immersed in 43 degrees C water, grapefruit juice, or water with the same pH (3.2-3.7) as grapefruit juice for 6-30 minutes. The numbers of pupae formed and adults emerged were counted. Greater mortality occurred among larvae immersed in grapefruit juice than in water regardless of larval diet. Diet did not affect larval mortality.
Technical Abstract: Tephritid fruit fly larval mortality due to heat has been investigated by immersing immature fruit flies into heated water. It has been postulated that this information could be used to model the relationship between heat and fruit fly kill in fruits subjected to heat quarantine treatments, such as hot water immersion, vapor heat, and forced hot air. Third instar Caribbean fruit flies, Anastrepha suspensa (Loew), were reared on a semi-artificial diet or grapefruits and immersed in 43.0 + 0.05 degrees C tap water, grapefruit juice, or tap water with the same pH as grapefruit juice (using citric acid). LT(95) estimates were 20-31% lower for puparia and adults of third instars immersed in grapefruit juice than those immersed in heated water regardless of diet. Diet did not affect mortality of third instars immersed in heated water or grapefruit juice.