Effects of Temperature and Humidity on the Survival and Water Loss of Cimex hemipterus (Hemiptera: Cimicidae)

Abstract

The effect of temperature and humidity on the survival and water loss of the tropical bed bug, Cimex hemipterus (F.), was studied using two field-collected strains. Insects were exposed to temperatures ranging from 20 to 45 degrees C and relative humidities (RHs) of 33, 75, and 100%. C. hemipterus survived longest under the interaction of low temperature (20 degrees C) and high RH (75-100%). Survival and water loss were significantly affected (P < 0.01) by temperature and RH (either singly, or in interaction). Strain and sex significantly (P < 0.01) influenced bed bug survival, but not on water loss. Eggs, first instars, and adults reached their upper thermal lethal limit within 1 h at 39 degrees C, 44 degrees C, and 46 degrees C, respectively. The survival and water loss profiles showed that starved C. hemipterus started to die after losing 35-45% of their body weights.

Desiccation tolerance as a function of age, sex, humidity and temperature in adults of the African malaria vectorsAnopheles arabiensisPatton andAnopheles funestusGiles

“…Investigations of survival of dry conditions are typically undertaken at a given water content of the air and at a specific temperature to obtain an indication of the desiccation resistance or tolerance of a given species or population (Hoffmann, 1990;Gibbs and Markow, 2001;Gray and Bradley, 2005). By contrast, investigations of the effects of temperature × water interactions are uncommon (How and Lee, 2010;Kleynhans and Terblanche, 2011), and understanding interactions of this kind is generally considered a significant challenge in physiology (Chown and Nicolson, 2004;Gaston et al, 2009;Hoffmann, 2010).…”

“…Interactions among environmental variables are also unlikely to be consistent among age groups and sexes, given that responses to both temperature and water availability vary with age and sex (Bowler and Terblanche, 2008;How and Lee, 2010;Weldon et al, 2013). In several insect species, as they age, they become less tolerant of temperature extremes (e.g.…”

Mechanisms that contribute to the establishment and persistence of bed bug infestations

“…The rate of water loss observed in bed bugs is equivalent to that of many desert-adapted arthropods (Benoit and Denlinger, 2010;Chown and Nicolson, 2004;Hadley, 1994). Larvae (1" instar nymphs) are most susceptible while 5''' instars nymphs/males/females are most resistant to xeric conditions (Benoit et al, 2007;How and Lee, 2010a). Under severe dehydration conditions and warmer temperatures, P' instar larvae survive for only 3-4d.…”

“…Under severe dehydration conditions and warmer temperatures, P' instar larvae survive for only 3-4d. Larger instars (5''' instar nymphs and adults) are capable of surviving for a little over two weeks under warm, arid conditions (Benoit et al, 2007;Benoit et al, 2009b;How and Lee, 2010a). If environmental conditions are similar to those of human comfort standards (75% RH and 20-22°C), adult and 5'''-instar bed bugs are able to survive on average for A-G months with a maximum of a little over a year without water (Benoit et al, 2007;Benoit et al, 2009a;Benoit et al, 2009b;Omori, 1941).…”

“…The tropical bed bug, C hemipterus, is slightly more heat tolerant and slighdy less cold tolerant than the C. lectularius (How and Lee, 2010a, b). Eggs remain viable if held below 37°C throughout embryogenesis (Benoit, 2011;How and Lee, 2010a;Johnson, 1941;Omori, 1941). The cold tolerance of bed bugs for brief periods ( = 1 hour) is -14 to -16°C (Benoit et al, 2009a;Johnson, 1941;Usinger, 1966), but extended exposure to temperatures below freezing will result in death (Benoit, 2011;Usinger, 1966).…”