NewYorkScienceJournal,2010;3(3)
71
Foraging Behaviour of Apis Spp. on Apple Flowers in a Subtropical
Environment
Naveen C. Joshi and P.C. Joshi
Department of Zoology and Environmental Sciences
Gurukula Kangri University, Haridwar (U.K.) - 249404, India.
prakash127@yahoo.com
Abstract: Observations on foraging behaviour, time spent per flower and number of flowers visited per minute by
the two species of honey bee viz. Apis cerana and A. mellifera were made and a significant and nonlinear
relationship was found. The number of flowers visited by each bee was also examined and it was found that A.
cerana visited higher number of flowers than that of A. mellifera. Similarly the exotic A. mellifera carried heavier
pollen loads than the native bee A. cerana. The foraging activity of A. cerana was observed at a peak between 1100
to 1300 hrs and then a steady decline was recorded which abruptly decreased between 1700 to 1800 hrs. However,
in the case of A. mellifera, the increase was steady and reached its peak between 1300 to 1500 hrs. [New York
Science Journal 2010;3(3):71-76]. (ISSN: 1554-0200).
Keywords: Foraging, Apis mellifera, Apis cerana, pollen loads
1. Introduction
Foraging behavior is one of the important
characteristic of any insect. Bees can also be
classified as generalists or specialists depending on
their foraging habits. Bees that gather nectar and
pollen from a wide variety of flowers are generalists.
Bumble bees and honey bees are good examples of
generalists. Bees that depend on a single plant or a
small number of plants for pollen and nectar are
categorized as specialists. The criterion used to select
candidate pollinator species undoubtedly vary from
crop to crop, but some general rules apply. In
principle, promising pollinator species should show a
preference for foraging on flowers of the target crop
(Torchio, 1976; Maeta, 1978; Marquez et al., 1994).
Pollination of apples is more complicated as
compared to other fruits by the fact that five stigmas
have to be pollinated separately (as the transmitting
tissue of each style is separate; Pratt, 1988), otherwise
misshapen fruits result (Free, 1993).It is estimated
that bees accomplish more than 80 percent of the
total pollination by the insects. Honeybees are the
main pollinators responsible for over 98% of visits to
flowers of apple. They are among the most important
pollinating insects found within orchards and modern
agricultural systems (Williams, 1994; Morse and
Calderone, 2000; Sharma et al, 2004). Foraging rate
is one of the important factors to compare pollination
efficiency of different bee species. More is the
foraging frequency more is the pollination efficiency
(Singh et. al. 2006). Bees are the most important
pollinators, so understanding the scale at which they
forage has important ecological implications and
conservation applications (Greenleaf et. al. 2007).
The honeybee, A. mellifera is flower
constant, which means that on any foraging trip, it
focuses on only one kind of flower. Pollen is
transferred only between flowers of the same species
and this is one of the features that make honey bees
so popular for commercial pollination of crops. On
the down side, some scientists have expressed
concern that honey bees are too efficient in their
collection of nectar and pollen, leaving none in a
given local flower source for the foraging of other
pollinators (Buchmann and Nabhan, 1996; Hubbell,
1997). Consequent overcrowding stresses, however,
strongly debilitate the bee populations concerned;
nectar and pollen may not suffice to nourish all bees
introduced, which thus compete for the resources
available, or the bees may experience increased larval
mortality (Robinson et al., 1989; Kevan et al., 1995;
Strickler, 1996, 1997). In India foraging behavior of
Apis spp. has been recorded by different workers on
different crops in different localities (Gupta et. al.,
1984; Verma and Dutta, 1986; Kapoor and Dhaliwal,
1989; Negi and Joshi, 2006). This study has been
carried out in one of the most apple producing areas
of Uttarakhand state of India.
2. Materials and Methods
The study was carried out during April-June,
2009, which is the peak season of flowering of apple,
in one of the apple orchard (situated in Cheepa) in
district Nainital of Kumaon Himalayas situated in
