Mitochondrial formation in the developing flight muscles of the Colorado beetle

Life cycle traits of Lethocerus deyrollei (Hemiptera: Belostomatidae), in central Japan: possibility of inoculation in extinct areas

The life cycle of Lethocerus deyrollei (Vuillefroy) in Sayo-cho, Hyogo, Japan (35 ° 00' N, 134 ° 21' E), was studied in terms of flight, reproduction, and energy allocation as well as developmental zero (t0) and required heat units (K) for a generation. Counts of bugs attracted to electric lighting showed that L. deyrollei flew most frequently in July, the second half of the mating season. The weight of flight muscle showed no significant yearly change despite a conspicuous difference in the flight activities. Fat content in the abdomen was low during summer, when oviposition activity reached a high level in females. Thereafter, lipid accumulation increased to mid-October when flight to an overwintering site took place. The lipid reservoir in late summer may be critical for surviving winter but no significant decrease was observed during overwintering. The number of eggs in the ovary indicated univoltism because no females had mature eggs late in the year. t0 and K were calculated based on laboratory rearing at different temperatures. Thus, estimated K (635 degree days) and local heat mass suggest a univoltine life cycle in Sayo-cho. The possible areas for successful inoculation of L. deyrollei were examined on the basis of available heat mass and day length in places where the species is extinct or not observed. Based on the estimated K and critical day length for reproductive maturation, Niigata and Tokyo fulfill suitable conditions of the Sayo population to complete a univoltine life cycle.

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.