Diversity in gas exchange and muscular activity patterns in insects studied by a respirometer‐actograph

Abstract

Summary Different events in insect gas exchange and muscular activity are described by a new system of automatic respirometers, a differential electrolytic microrespirometer‐actograph. This is very sensitive to volumetric changes caused by insect respiration and/or body movements. In this system, oxygen generation and its regulation are combined in the same current circuit. According to this principle, the oxygen consumed by the insect is continuously replaced by equal amounts of electrolytically produced oxygen. This simple laboratory‐made apparatus records simultaneously metabolic rate, the cyclicity of external gas exchange, rhythms of muscular ventilating and the pattern of other body movements, including abdominal pulsations not observable with the naked eye. The respirometer‐actograph described here is applicable also to the recording of the respiration of other terrestrial arthropods or other living organisms or tissues.

Tonic immobility in adult Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) evoked by mechanical and optical stimuli

“…The electrolytic microrespirometer we used was described in detail earlier (Kuusik et al, 1996;Tartes et al, 1999). An infrared gas analyzer (Infralyt-4, Dessau) was exploited for recording the CO2 -emission.…”

“…The mean metabolic rate can be calculated by averaging data over a shorter or longer period (see Tartes et al, 1999). During the baselines of the recording (e.g., between two peaks) the units VO2 (ml h"1) correspond roughly to the metabolic rate of the insect.…”

Interrelations of gas exchange cycles, body movements and heartbeats in the foragers of bumblebee Bombus terrestris (Hymenoptera: Apidae) at low temperatures

“…Metabolic rate, discrete CO2 releases and body movements were recorded by means of an electrolytic differential microres pirometer, where the consumed oxygen was replaced continu ously by adjusting the level according to pressure changes in the insect chamber (for more details see Kuusik et al, 1991Kuusik et al, , 1996Tartes et al, 1999Tartes et al, , 2000. In the present modification of this res pirometer, standard plastic tubes (Eppendorf, volume of 1.5 ml) were used as insect chambers, and were connected to the respirometric system by rubber tubing (inner diameter 0.5 mm).…”

The opening-closing rhythms of the subelytral cavity associated with gas exchange patterns in diapausing Colorado potato beetle, Leptinotarsa decemlineata

“…Taylor, 1977;Heusner et al, 1982). By contrast, our coulometric respirometry (a volumetric manometric system) was characterised by a continuously (uninterrupted) O 2 -compensating system (Kuusik, 1977;Kuusik et al, 1996;Tartes et al, 1999Tartes et al, , 2002. This setup has also been described by Lighton (2008).…”