Semester of Graduation
Fall 2024
Degree
Master of Science (MS)
Department
Entomology
Document Type
Thesis
Abstract
Common bed bugs (Cimex lectularius) are obligatory blood-feeding pests that have adapted well to survive in challenging environmental conditions. Known for their high tolerance to dehydration, low water loss, and high critical thermal maximum, they have become difficult to manage. Environmental factors, particularly temperature and humidity, play a significant role in their survival. However, with growing resistance to insecticides, integrated pest management (IPM) strategies are now essential for effective bed bug control. A key strategy in IPM involves combining insecticides with heat treatments. This method aims to overcome the limitations of heat treatment alone, as bed bugs may escape to cooler areas or survive short exposures to high temperatures. Applying insecticides either before or after heat treatment targets bed bugs that survive the initial heat or flee to untreated areas, enhancing overall control effectiveness.
Despite the common use of heat and insecticides together, there is limited research on how these methods interact, particularly regarding temperature and humidity’s impact on insecticide performance. This study investigates these interactions, focusing on the efficacy of combining heat and insecticides to manage bed bugs. Specifically, it examines three commonly used insecticides—bifenthrin, chlorfenapyr, and clothianidin—representing different chemical classes to understand their effectiveness in various environmental conditions.
The first objective was to identify lethal combinations of temperature and humidity that enhance bed bug mortality. Bed bugs, both from laboratory and field sources, were exposed to different temperatures (25 ºC, 37 ºC, 38 ºC, 39 ºC, and 40 ºC) and humidity levels (10%, 45%, and 90%) in controlled incubators, with daily monitoring over 10 days. These combinations provided insights into environmental conditions that can be optimized with insecticides in IPM strategies.
The second objective involved determining the LD₅₀ values for the three insecticides through topical bioassays. Following probit analysis, the LD₂₅ doses of each insecticide were then tested in combination with elevated temperature (38°C) and humidity levels (10% and 90%) to assess interaction effects using Mansour’s formula.
This study emphasizes the importance of prolonged exposure to lethal temperatures and humidity levels, as bed bugs can survive short exposures by fleeing from heated areas. By understanding how temperature and humidity influence insecticide efficacy, pest control professionals can improve treatment efficiency, reduce follow-up treatments, and enhance IPM outcomes for more effective bed bug management.
Date
11-1-2024
Recommended Citation
Shrestha, Bandana, "DETERMINING THE IMPACT OF LETHAL TEMPERATURE AND RELATIVE HUMIDITY WHEN COMBINED WITH VARIOUS INSECTICIDE CLASSES AGAINST A BED BUG (CIMEX LECTULARIUS) POPULATION." (2024). LSU Master's Theses. 6063.
https://repository.lsu.edu/gradschool_theses/6063
Committee Chair
Aaron R. Ashbrook