... clothing lice and head lice, Pediculus humanus ssp., and high sensitivity balances, it was shown that recently fed lice lost mass consistently as water ingested with the blood meal was excreted via the respiratory system. If all spiracles were occluded using petroleum jelly, mass/water loss was inhibited...

... is metabolically costly, and this cost persists for several days after thaw. Metabolic rate TCO 2 Hemolymph Respiratory quotient Spiracles CT min Insects overwintering in temperate regions may encounter temperatures low enough to freeze their body fluids. Although freezing is typically harmful...

... in the anterior body with emphasis on the arrangement of the pathways for airflow. The fly's head is preferentially supplied by cephalic tracheae originating from the ventral orifice of the mesothoracic spiracle (Sp1). The respiratory airflow during flight is a by-product of cyclic deformations of the thoracic...

...Stav Talal; Eran Gefen; Amir Ayali ABSTRACT Discontinuous gas exchange (DGE) is the best studied among insect gas exchange patterns. DGE cycles comprise three phases, which are defined by their spiracular state: closed, flutter and open. However, spiracle status has rarely been monitored directly...

...Lutz T. Wasserthal; Anja S. Fröhlich ABSTRACT The operation of the thoracic spiracular valves was analysed using anatomical and physiological techniques. Dense spiracular filter trichomes impede a diffusive gas exchange. However, the hinged posterior filter flap of the metathoracic spiracle (Sp2...

...Lutz T. Wasserthal ABSTRACT It is widely accepted that an efficient oxygen supply and removal of CO 2 in small flying insects are sufficiently performed by diffusion with open spiracles. This paper shows that in the tethered flying blowfly, gas exchange occurs by autoventilation and unidirectional...

.... A current model of insect spiracular control suggests that spiracles are controlled by two interacting feedback loops, which produce the discontinuous pattern. The flutter period is thought to be initiated by a critically low partial pressure of oxygen, while the open period is initiated by a critically...

... negative pressure periods, the tracheal partial pressure of oxygen ( P O 2 ) increases by 0.5 kPa. In the quiescent fly, tracheal P O 2 is rather high (17.5–18.9 kPa), although the thoracic spiracles remain constricted. Microscopic video recordings and reflectance measurements revealed that the dorsal soft...

... (spiracles closed) alternated with bouts of CO 2 emission and O 2 consumption (burst phase); no true ‘flutter’ phase was observed. Cycle duration decreased with increasing temperature in both hydrated and dehydrated individuals. Metabolic rates for this large, sluggish species are lower than those reported...