Direct coupling: a possible strategy to control fruit production in alternate bearing

Do Phagostimulants, Alone or Combined with Ammonium Acetate, Di-Ammonium Phosphate, and Acetic Acid, Effectively Attract Both Sexes of Peach Fruit Flies, Bactrocera zonata (Diptera: Tephritidae)?: Insights from Laboratory and Field Bioassays

Laboratory and field assays of three sets of experiments were conducted to evaluate the impact of different phagostimulants alone and in combination with other phagostimulant lure sources, such as ammonium acetate, DAP, and acetic acid, on the attractancy of both sexes of B. zonata. In the first experiment, the laboratory olfactometer study revealed that out of eleven phagostimulants, banana, mulberry, mango, guava, molasses, and protein hydrolysate exhibited moderate attractancy (15.2-60.2%) to B. zonata. Unexpectedly, banana and protein hydrolysate were demonstrated to be highly attractive phagostimulants for starved female B. zonata (53.6% and 60.2%, respectively). In the field study, none of the tested phagostimulants exhibited high attractancy; however, banana, mulberry, protein hydrolysate, guava, mango, and molasses demonstrated moderate attractancy (5.6-35.6%) to B. zonata. In the second experiment, out of five phagostimulant-mixtures, phagostimulant-mixture-4 proved highly attractive (40.5-68.6% and 45.5-51.2%), followed by phagostimulant-mixture-3, which proved to be moderately attractive (17.0-22.5% and 28.4-36.1%) to B. zonata in olfactometer and field studies, respectively. In the third experiment, out of five phagostimulant-AdMixtures, phagostimulant-AdMixture-4 demonstrated strong attractiveness in the olfactometer (41.6-68.7%) and field studies (52.7-58.7%) for B. zonata, while the rest of the AdMixtures demonstrated moderate to no attractiveness for B. zonata. So, phagostimulant-AdMixture-4 with GF-120 could be used in the development of a phagostimulant bait station which attracts the maximum B. zonata population and ultimately provides pest-free fruits to the farmers.

Period-3 dominant phase synchronisation of Zelkova serrata: border-collision bifurcation observed in a plant population

The population synchrony of tree seed production has attracted widespread attention in agriculture, forestry and ecosystem management. Oaks usually show synchronisation of irregular or intermittent sequences of acorn production, which is termed 'masting'. Tree crops such as citrus and pistachio show a clear two-year cycle (period-2) termed 'alternate bearing'. We identified period-3 dominant phase synchronisation in a population of Zelkova serrata. As 'period-3' is known to provide evidence to imply chaos in nonlinear science, the observed period-3 phase synchronisation of Zelkova serrata is an attractive real-world phenomenon that warrants investigation in terms of nonlinear dynamics. Using the Hilbert transform, we proposed a procedure to determine the fractions of periods underlying the survey data and distinguished the on-year (high yield year) and the off-year (low yield year) of the masting. We quantified the effects of pollen coupling, common environmental noise and individual variability on the phase synchronisation and demonstrated how the period-3 synchronisation emerges through a border-collision bifurcation process. In this paper, we propose a model that can describe diverse behaviours of seed production observed in many different tree species by changing its parameters.

Dispersal of allergenic pollen from Cryptomeria japonica and Chamaecyparis obtusa: characteristic annual fluctuation patterns caused by intermittent phase synchronisations

Trees produce pollen during specific times of the year. Pollen can induce pollinosis, a type of allergic rhinitis, in humans. In Japan, allergenic pollen is mainly dispersed from February to May. Using data collected at 120 observation sites managed by the Japanese Ministry of the Environment, we studied the annual patterns of airborne allergenic pollen. The allergenic pollen showed an alternating ON-OFF cycle, but the length of the cycle differed among regions. We used an in-phase/out-of-phase analysis to quantify two characteristic features of the synchronisation. The degrees of phase synchronisation were strong in eastern and weak in western Japan. The pattern of allergenic pollen dispersal throughout Japan is typical intermittent synchronisation. This is the first study to evaluate allergenic pollen's distribution from a phase synchronisation viewpoint.