Insect Science (2022) 29, 1361-1372

Tomer Urca, Eran Levin and Gal Ribak (2022)
Metabolic cost of flight and aerobic efficiency in the rose chafer, Protaetia cuprea (Cetoniinae)
Insect Science 29 (5), 1361-1372
Abstract: Rose chafer beetles (Protaetia cuprea) are pollinators as well as agricultural pests, flying between flowers and trees while foraging for pollen and fruits. Calculating the energy they expend on flying during foraging activity faces the challenge of measuring the metabolic rate (MR) of free-flying insects in an open space. We overcame this challenge by using the bolus injection of ¹³C Na-bicarbonate technique to measure their metabolic energy expenditure while flying in a large flight arena. Concurrently, we tracked the insects with high-speed cameras to extract their flight trajectory, from which we calculated the mechanical power invested in flying for each flight bout. We found that the chemical (metabolic) energy input converted to mechanical flight energy output at a mean efficiency of 10.4% ± 5.2%, with a trend of increased efficiency in larger conspecifics (efficiency scaled with body mass to the power of 1.4). The transition in the summer from a diet of pollen to that of fruits may affect the energy budget available for foraging. Starved P. cuprea, feeding on apples ad libitum, increased their body mass by an average of 6% in 2 h. According to our calculations, such a meal can power a 630-m flight (assuming a carbohydrate assimilation efficiency of 90%). Pollen, with a low water and carbohydrate content but rich in proteins and lipids, has a higher caloric content and should assimilate differently when converting food to flight fuel. The high cost of aerial locomotion is inherent to the foraging behavior of rose chafers, explaining their short flight bouts followed by prolonged feeding activity.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Full text of article

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
population dynamics/ epidemiology

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Protaetia cuprea	Fennel (Foeniculum vulgare)	Israel