Temporal variation in the behavior of Pollinators

A pollinators living organism that moves pollen of flower male part (anther) to flower female part (stigma). It helps in bringing the male gametes to ovule for fertilization.

Temporal variation in the behavior of Pollinators

Insects are the major pollinators that mostly include flying insect of order hymenptora, diptera and lepidoptera. In hyminoptera bees are the major pollinators which are plainly adopted to pollination. Bees are usually fuzzy and they carry electrostatic charge that helps them in carrying pollen.

They have also specialized pollen carrying structure called as scopa which is mostly present on the hind leg or sometimes on the lower side of abdomen. Honeybees and the bumblebees and species that are related to them does not contain scopa but they have another modification on their hind leg called as corbicula (pollen baskit).

Most bees are attractive towards both nectar and pollen because they are rich source of nutrient and protein. While some attracted only towards nectar and when they are gathering nectar from the flowers pollen attach to their body that results in indirect pollination. Honeybees collect nectar and pollen when they travel from flower to flower. Bees collect the pollen by rubbing their body against the anther.

The pollen is collected in the pollen basket present in the hind leg. When these travel from flower to flower some of the pollen falls into the stigma of other flower. Nectar provide the energy while pollen provides the proteins. Others insects also act as excellent pollinators by visiting flower for either pollen or nectar, or both of them. Males of many hyminoptrus species rely on flowering plant as a source of energy.

Many bee flies and some tabanidae and nemestrinidae are adopted for the pollination of desert and subterranean for taking nectar and pollen. We also say that some flowers also are good pollinators and they cross pollinate the some plant like (Araceae) or (Zamiaceae).

Some species of ants also are study as pollinator but they are not mostly useful. Many thrips as well as midges are consider as minor pollinators. Some how the most important pollinators is consider as wild bees while second is hoverflies. The mosquitos(aedes communis) which are adult are also act as a pollinators but the feed upon nectar.

Many factors like abiotic parameters such as solar redaction, wind velocity, and biotic position between insect pollinated plant are the main resign for causing temporal vernation among pollinators. Different plants have different floral opening time period which attracts different pollinators.

Interspecific differences in timing of activity lead to the succession to the pollinators allow them to visit flowers at different time of the day at specific plant species. Variation in relative humidity and frequency of light is also a major factor in causing temporal variation because change in humidity causes variation in the opening of flower and pollen and nectar content.

Under normal condition the forager in honey bees are workers mostly more than 21 days old. Honeybees start foraging when the level of juvenile hormone in forager is affected by diurnal vernation. It was found in the different studies that honeybees mostly visit flowers for pollination when there is a low temperature a high relative humidity.

This was because with the increase in temperature the sucrose in nectar decreases in increase in temperature. The highest number of bees visit flowers mostly in the morning but in general they visit plant whole day.Mostly nectar collecting bees visit flowers in the middle of morning and in after noon with greater thermal comfort considering the high temperature.

Mostly lepidoptrus butterflies visit flowers during and after the mid of after noon due to specific light intensities. While mostly moths visit flowers after a sun set due to their nocturnal nature in a detail research study it was observed that different species of moth have different specific time period for foraging due to vernation in wavelength of light present.

For example noctuid moth visit flower just after the sun set, while pyralid moth starts foraging two to three hours after sun set and sphingid moth starts foraging in complete darkness in the present of moon light. Insect belonging to order diptera are observed to start foraging.

Early in the morning in very low temperature and high relative humidity because at that time due to high relative humidity the nectar is contain more moisture than in others parts of day because they contain sponging type of mouth part so they cannot consume solid food.

They are three main groups of the pollinators(insect) visiting the flowers Hymenoptera, Diptera and Lepidoptera. Hymenopterans (largely bees) were active between (05-19) hours daytime period. Their abundance, remained fairly high throughout the day, with three times of peaks comes in early morning, midday, and late afternoon. Butterflies foraging on the flowers of the plant is starts at about (07) hours, and closed around (1700) hours.

The presence of the group increasing slowly from the morning till prominent times of the peak at 1100 hours, then it started declining at the afternoon. Flies generally started foraging at flowers at about (0600) hours, and they carry on some of the activity at (1900) hours.

They exhibited a bimodal activity pattern, with a major peak at 0700 hours, a minimum around midday, and a secondary peak at (17) hours. Between (05) and (0700) hours, so that’s why latifolia flowers are visiting almost excilently by Hymenoptera. Between (0700 and 1000) hours is very important for Hymenoptera, Diptera and Lepidoptera because it is greater than other times period.

The pollinators are belonging mainly to four orders which are Hymenoptera, Diptera, Lepidoptera and Coleoptera. Most important species visuiting the coriander were Apisdorsata, pis.ceranaindica, Apismellifera, Apisflorea, Episyrphusbalteatus, Eristalistenax, syrphus species, Musca species and other Dipteran flies , the foraging speed of honey bees that is Apisdorsata and A. cerand are (10.22 and 5.47) seonds of a minute, respectively.

The foraging rate is found to be (5.53 and 10.43) um-bels per minutes for Apisdorsata and Apiscerena, respectively. Syrphid started foraging (8.23 AM) much earlier than the honeybees, Apisdorsata and Apiscerana (10.13AMand10.14).

This species have a diversity of  pollinator assemblage which are  based nearly eighty bees, flies, and butterflies species, and pollinators are different  broadly in verious components of pollinating effectiveness. The daily activity patterns of different pollinators are described here, and this information is then relate with data on their differential pollinating effectiveness.

To determine the daily profile of pollinating potential for the assemblage of insect (POLLINATORES) visitor. So that profile may be then  compared with the plant’s floral daily cycle opening and withering of flowers, and nectar and pollen availability. Specifically,  Which is the degree of matching between the daily floral cycle and the daily profile of pollination.

Temporal variation in climatic conditions is a regular occurrence for most early spring flowering plants in temperate regions, often producing variation in available pollinators. Evaluating the effectiveness and importance of pollinators to a plant population provides an indication of the relative influence of each visitor on a population’s reproductive success and selection on floral traits.

This study examined pollinator activity and its effect on seed set in a population of Phlox divaricata L. (Polemoniaceae), investigating variation over the 24-h day and the flowering season for two consecutive years. Eleven species, representing three orders of insects, were documented visiting the study population, although lepidopterans (four species, particularly Hemaris diffinis and Megalographa biloba) accounted for 90% of all visitation.

The highest visitation rates (and resulting seed set) occurred during the morning and afternoon diurnal time periods and the evening crepuscular time period. The relative frequencies of the different visitors varied over the 24-h in a day and between plants  flowering seasons. Most of the visitors that can  be checked were found to be effective pollinators.

Therefore a pollinators importance to reproductive success was generally dictated by its visitation frequency H.diffinis is the most valuable pollinator. So recent studies indicates that the importance of consider the  temporal variation in valuable effective pollinators in species shows the  variety of environmental  environmental conditions.

Authors:  1Faheem Shoukat, 2Muqarrab Ali and 2Muhammad Nazim

1Department of Entomology, MNS- University of Agriculture, Multan, Punjab, Pakistan.

2Department of Agronomy, MNS- University of Agriculture, Multan, Punjab, Pakistan.

By Muhammad Nazim

M.Sc.(Hons.) Crop Physiology, Department of Agronomy, MNS-University of Agriculture, Multan, Pakistan.