Programmed loss of flight ability in the early adult life of the blowfly Phormia terrae novae as a possible mechanism of intraspecific niche building with respect to the duration of life

Energy consumption during insect flight and bioinspiration for MAV design: A review

The excellent biological characteristics of insects provide an important source of inspiration for designing micro air vehicles (MAVs). Insect flight is an incredibly complex and energy-intensive process. Unique insect flight muscles and contraction mechanisms enable flapping at high frequencies. Moreover, the metabolic rate during flight can reach hundreds of times the resting state. Understanding energy consumption during flight is crucial for designing efficient biomimetic aircraft. This paper summarizes the structures and contraction mechanisms of insect flight muscles, explores the underlying metabolic processes, and identifies methods for energy substrate identification and detection, and discusses inspiration for biomimetic MAV design. This paper reviews energy consumption during insect flight, promotes the understanding of insect bioenergetics, and applies this information to the design of MAVs.

Behavioural, morphological, and metabolic maturation of newly emerged adult workers of the bumblebee, Bombus impatiens

Newly emerged adult holometabolous insects must still complete considerable morphological, metabolic, and neural maturation. Despite this, adults have frequently been documented to fly prior to finishing maturation and attaining peak physiological capacity. In some species, flight is limited by the unfurling of the wing, while in other species it may be limited by biochemical capacity. We charted maturation trajectories of adult bumblebee workers (Bombus impatiens) for both morphological and flight muscle metabolic capacities, and compared these to the first age at flight. Workers began regular flights as soon as two days after emergence. The unfurling of the wings was completed well before first flights and before any other studied factor, suggesting this did not initially limit flight. Wing beat frequencies, measured as a struggling response to grasping the hindlegs, were about 90% mature by two days old, and did not significantly change after three days. Conversely, by the initiation of flight, the mean enzyme maturation was only 63% completed relative to adult enzyme capacity, though specific enzyme profiles ranged from 42% to 73%. Maximum ADP-stimulated mitochondrial respiratory activity on pyruvate and proline matured along a similar time frame to glycolytic capacity, reaching its maximum three days after emergence. Bumblebees, as other adult insects, thus begin flights prior to fully maturing.

Fifteen years of Phormia - on the value of an insect for the study of aging

The blowfly Phormia is currently used for studying various aspects of aging. In the context of comparative life history studies this fly can be characterized as an example of an 'r' selected type with a short life span and explosive reproduction. This is in contrast to the mecopteran fly Panorpa which shows senescence even under free living conditions and represents the 'K' selected type. A sudden drop of flight performance, low levels of enzyme activities at the end of life and specific kinetic adaptations of single enzymes are part of the 'aging syndrome' of Phormia. In the context of general aging investigations Phormia proved to be a suitable model system. This is shown in several examples covering the age variation of oscillating glycolysis, the influence of the cell redox state on purified enzymes, and treatment with geriatrics.

Age dependent changes of a biochemical rhythm--the glycolytic oscillator of the blowfly Phormia terraenovae

1. By monitoring changes of fluorescence of NADH the frequencies, amplitudes and maximum slopes of the glycolytic oscillator of Phormia were analyzed in 5, 9, 15 and 21-day-old male flies. 2. In order to evaluate the possible existence of circadian rhythms within the oscillatory system, all determinations were repeated eight times/day. 3. In addition, the activities of three key enzymes of glycolysis, PFK, GAPDH and PK, which are central to the glycolytic oscillator were measured with respect to age and day time. 4. With increasing age the amplitudes of oscillations increased together with the maximum slopes of the oscillatory waves. The frequency appeared to be independent of age. 5. Variations of enzyme activities over the day indicated an age dependent circadian rhythm which, due to the simultaneous activity changes of the three measured enzymes, was not reflected in the whole oscillatory system. 6. The results suggest that modifications in the allosteric regulation of enzymes are responsible for the age dependent changes of the glycolytic oscillator.

The quantitative relationship between life span, food ingestion, egg production, mating, and flight-activity of protein-fed blowfly Phormia terrae novae females

The age-dependent variations in the amount of food ingestion, egg production, and flight activity of protein-fed female Phormia terrae novae were analyzed. Also the influence of mating and forced physical performance on the time course of these parameters and on life span were tested. In virgin females, the life span with the investigated factors is generally delayed, together with mean and maximum life span. In comparison to mated females virgin females exhibit a 40% prolongation of mean life span and ingest more sugar with a later intake maximum. Their egg production starts 5 days later (Day 10) but reaches only half the amount occurring in mated females. Flight performance is generally higher in virgin females, reaching its maximum 2 days later (Day 14), with a more gradual decline instead of the sudden drop in flight performance seen in mated flies. Females receiving their food by flight only ("forced fliers") show a shorter mean life span (which is more pronounced in virgin flies). The maximum of sugar intake shifts forward to an earlier point after eclosion, and the amount is reduced by about 30% over the entire life span. Similarly, the egg production rate reaches lower values and tends to have an earlier maximum in comparison to corresponding groups that had access to sugar on the cage floor. The results further support the hypothesis that Phormia exhibits a strictly programmed aging pattern. Its time course depends on reproduction sufficiency and physical performance. Both factors act to shorten life expectation.