Abstract: In population dynamics the study of both, the
abundance and the spatial distribution of the populations in a
given habitat, is a fundamental issue a From ecological point of
view, the determination of the factors influencing such changes
involves important problems. In this paper a mathematical model to
describe the temporal dynamic and the spatiotemporal dynamic of the
interaction of three populations (pollinators, plants and herbivores) is
presented. The study we present is carried out by stages: 1. The
temporal dynamics and 2. The spatio-temporal dynamics. In turn,
each of these stages is developed by considering three cases which
correspond to the dynamics of each type of interaction. For instance,
for stage 1, we consider three ODE nonlinear systems describing
the pollinator-plant, plant-herbivore and plant-pollinator-herbivore,
interactions, respectively. In each of these systems different types of
dynamical behaviors are reported. Namely, transcritical and pitchfork
bifurcations, existence of a limit cycle, existence of a heteroclinic
orbit, etc. For the spatiotemporal dynamics of the two mathematical
models a novel factor are introduced. This consists in considering
that both, the pollinators and the herbivores, move towards those
places of the habitat where the plant population density is high.
In mathematical terms, this means that the diffusive part of the
pollinators and herbivores equations depend on the plant population
density. The analysis of this part is presented by considering pairs of
populations, i. e., the pollinator-plant and plant-herbivore interactions
and at the end the two mathematical model is presented, these models
consist of two coupled nonlinear partial differential equations of
reaction-diffusion type. These are defined on a rectangular domain
with the homogeneous Neumann boundary conditions. We focused
in the role played by the density dependent diffusion term into
the coexistence of the populations. For both, the temporal and
spatio-temporal dynamics, a several of numerical simulations are
included.
Abstract: The butterflies are ecologically very important insects. The adults generally feed on nectar and are important as pollinators of flowering plants. However, these pollinators are under threat with their habitat loss. One reason for habitat loss is spread of invasive plants. However, there are even beneficial exotic plants which can directly support for Butterfly Conservation Action Plan of Sri Lanka by attracting butterflies for nectar. Stachytarpheta jamaicensis (L.) is an important nectar plant which attracts a diverse set of butterflies in higher number. It comprises a violet color inflorescence which last for about 37 hours where it attracted a peak of butterflies around 9.00am having around average of 15 butterflies. There were no butterflies in early and late hours where the number goes to very low values as 2 at 1.00pm. it was found that a diverse group of butterflies were attracted from around 15 species including 01 endemic species, 02 endemic subspecies and 02 vulnerable species. Therefore, this is a beneficial exotic plant that could be used in butterfly attraction and conservation however with adequate monitoring of the plant population.
Abstract: An experiment was conducted to determine the effect
of pollination on seed quality of rapeseed in Chitwan, Nepal during
2012-2013. The experiment was designed in Randomized Complete
Block with four replications and five treatments. The rapeseed plots
were caged with mosquito nets at 10% flowering except natural
pollination. Two-framed colonies of Apis mellifera L. and Apis
cerana F. were introduced separately for pollination, and control plot
caged without pollinators. The highest germination percent was
observed on Apis cerana F. pollinated plot seeds (90.50%
germination) followed by Apis mellifera L. pollinated plots (87.25 %)
and lowest on control plots (42.00% germination) seeds. Similarly,
seed test weight of Apis cerana F. pollinated plots (3.22 gm/ 1000
seed) and Apis mellifera L. pollinated plots (2.93 gm/1000 seed) were
and lowest on control plots (2.26 gm/ 1000 seed) recorded. Likewise,
oil content was recorded highest on pollinated by Apis cerana F.
(36.1%) followed by pollinated by Apis mellifera L. (35.4%) and
lowest on control plots (32.8%). This study clearly indicated
pollination increases the seed quality of rapeseed and therefore,
management of honeybee is necessary for producing higher quality of
rapeseed under Chitwan condition.