In larval damselflies, the self-amputation (autotomy) of the caudal lamellae permits escape from predatory larval dragonflies. Lamellar joint size declines among populations with increasing risk of dragonfly predation, but the breaking force required for autotomy and the biomechanical factors that influence breaking force are unknown. If autotomy enhances survival in larval damselflies, then pr...

Several reports suggested that rice seedling nursery-box application of some systemic insecticides (neonicotinoids and fipronil) is the cause of the decline in dragonfly species noted since the 1990s in Japan. We conducted paddy mesocosm experiments to investigate the effect of the systemic insecticides clothianidin, fipronil and chlorantraniliprole on rice paddy field biological communities. C...

Dragonflies are bioindicator insects for the quality of aquatic environment, especially springs. This study aims to determine types dragonflies that live in Science Techno Park (STP) spring, Beleknehe village, Nekemese sub-district, Kupang District. STP is owned by Widya Mandiri Catholic University. research was conducted September 2022. Data collection consisted dragonfly samples and abiotic f...

Design smell detection is considered an efficient activity that decreases maintainability expenses and improves software quality. Human context plays essential role in this domain. In paper, we propose a search-based approach to optimize the selection of human evaluators for design detection. For purpose, Dragonfly Algorithm (DA) employed identify optimal or near-optimal evaluator’s profiles. A...

Motion processing in visual neurons is often understood in terms of how they integrate light stimuli in space and time. These integrative properties, known as the spatiotemporal receptive fields (STRFs), are sometimes obtained using white-noise techniques where a continuous random contrast sequence is delivered to each spatial location within the cell's field of view. In contrast, motion stimul...

Wing pitch reversal, the rapid change of angle of attack near stroke transition, represents a difference between hovering with flapping wings and with a continuously rotating blade (e.g. helicopter flight). Although insects have the musculature to control the wing pitch during flight, we show here that aerodynamic and wing inertia forces are sufficient to pitch the wing without the aid of the m...

Recent increases in air temperature have affected species phenology, resulting in the earlier onset of spring life-cycle events. Trends in the first appearance of adult dragonflies across Japan were analysed using a dataset consisting of observations from 1953 to 2005. Dynamic factor analysis was used to evaluate underlying common trends in a set of 48 time series. The appearance of the first a...

During gliding, dragonfly wings can be interpreted as acting as ultra-light aerofoils which, for static reasons, have a well-defined cross-sectional corrugation. This corrugation forms profile valleys in which rotating vortices develop. The cross-sectional configuration varies greatly along the longitudinal axis of the wing. This produces different local aerodynamic characteristics. Analyses of...

Respiration in the aquatic larvae of anisopteran dragonilies is of interest from a comparative point of view in that it utilizes a tidal ventilation mechanism in an aquatic medium. In most animals where water is the respiratory medium the flow over the respiratory surfaces is generally undirectional and this probably requires less energy for the extraction of a given amount of oxygen. Tidal or ...