Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Reaction Orders for Thermal Mortality of Third-Instars of Mexican Fruit Fly (Diptera: Tephritidae)

Authors
item Hallman, Guy
item Wang, Shaojin - WASHINGTON STATE UNIV.
item Tang, Juming - WASHINGTON STATE UNIV.

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 9, 2005
Publication Date: December 12, 2005
Citation: Hallman, G.J., Wang, S., Tang, J. 2005. Reaction orders for thermal mortality of third-instars of Mexican fruit fly (Diptera: Tephritidae). Journal of Economic Entomology. 98:1905-1910.

Interpretive Summary: The Mexican fruit fly, Anastrepha ludens (Loew), attacks a number of fruits including grapefruit, orange, avocado, and mango from extreme southern Texas to Costa Rica. Heat may be used as a disinfestation treatment to enable shipment of Mexican fruit fly hosts from infested to non-infested areas. Heat treatments are difficult to research because many factors can affect efficacy of heat. Modeling could facilitate heat disinfestation treatments. To provide information for modeling heat phytosanitary treatments, third instar (late larvae) Mexican fruit flies were heated with an aluminum heating block between 44 and 50 degrees C for time intervals up to those causing 100% mortality. At 44 and 50 degrees C, respectively, 100% mortality was achieved at 100 and 2 minutes. Mortality was modeled using thermal death kinetics. Mexican fruit fly had a lower threshold for heat-induced mortality than shown in a previous study with the Mediterranean fruit fly. This type of information being gathered for fruit flies could lead to the development of generic heat treatments, which are available for other major quarantine treatments, such as cold storage, methyl bromide fumigation, and ionizing irradiation.

Technical Abstract: Mexican fruit fly, Anastrepha ludens (Loew), is a quarantine pest of a number of fruits including citrus, avocadoes, and mangoes, from extreme southern Texas to Costa Rica. To provide information for modeling heat phytosanitary treatments, third instars were heated with an aluminum heating block between 44 and 50 degrees C for time intervals up to those causing 100% mortality. At 44 and 50 degrees C, respectively, 100% mortality was achieved at 100 and 2 minutes. Each 2 degree C increase in temperature resulted in a ¾th reduction in the amount of time required to achieve 100% mortality. Mortality was modeled using thermal death kinetics, and the most suitable reaction order was the 0.5th. The thermal death activation energy was 560.7 kJ/mol, which is very similar to the value found for Mediterranean fruit fly, Ceratitis capitata (Wiedemann) in a previous study, indicating similar models of action for heat mortality. However, the Mexican fruit fly had a lower threshold for heat-induced mortality, resulting in less time at all temperatures studied to achieve 100% mortality compared with the Mediterranean fruit fly. This type of information being gathered for fruit flies could lead to the development of generic phytosanitary heat treatments, which are available for other major phytosanitary treatments, such as cold storage, methyl bromide fumigation, and ionizing irradiation.

Last Modified: 9/22/2014
Footer Content Back to Top of Page