Agriculture Reference
In-Depth Information
numbers and diurnal activity patterns can be easily accessed by visually
inspecting the hives. Although not commonly used by farmers, scale hives
can yield important information on hive conditions and activity, the tim-
ing of nectar flow and the interaction between bees and the environment
In most developing countries, crops are produced mainly by small-
scale farmers. Here, farmers rely more on unmanaged, wild insects for
crop pollination (Kasina et al., 2009). To identify the most important pol-
linators for local agriculture, data on visitation rate alone does not neces-
sarily suffice. Crop species may be visited by several species of insects,
but several studies have shown that only a few visiting species may be effi-
cient pollinators. An effective pollinator is good at collecting, transporting
and delivering pollen within the same plant species.
In a recent review, Hegland et al.
(
2009) discussed the consequences of
temperature induced changes in plant-pollinator interactions. They found
that timing of both plant flowering and pollinator activity seems to be
strongly affected by temperature. Insects and plants may react differently
to changed temperatures, creating temporal (phenological) and spatial
(distributional) mismatches-with severe demographic consequences for
the species involved. Mismatches may affect plants by reduced insect visi-
tation and pollen deposition, while pollinators experience reduced food
availability. We have found three studies investigating how increased tem-
peratures might create temporal mismatches between wild plants and their
pollinators. Gordo and Sanz (2005) examined the nature of phenological
responses of both plants and pollinators to increasing temperatures on the
Iberian Peninsula, finding that variations in the slopes of the responses
indicate a potential mismatch between the mutualistic partners. Both
Apis
mellifera
and
Pieris rapae
advanced their activity period more than their
preferred forage species, resulting in a temporal mismatch with some of
their main plant resources (Hegland et al.,
2009). However, Kudo et al.
(2004) found that early flowering plants in Japan advanced their flower-
ing during a warm spring whereas bumble-bee queen emergence appeared
unaffected by spring temperatures. Thus, direct temperature responses and
the occurrence of mismatches in pollination interactions may vary among
species and regions (Hegland et al.,
2009).
