| dc.description.abstract | Syrphid flies visit flowers to feed on nectar and pollen and provide an important pollination
service in many cropping systems. We previously observed that perimeter plantings of alfalfa
concentrate syrphid populations in trap-cropped June-bearing strawberry fields, but whether
this trap cropping strategy impacts syrphid visitation to strawberry flowers remains unknown.
This study examined whether trap cropping influences syrphid visitation to strawberry flowers
by comparing the proportion of strawberry pollen in the syrphid digestive tract. We expect that
the gut content of syrphids collected from strawberry fields with an alfalfa border will have a
higher proportion of strawberry pollen than those from fields with the weedy border. Although
syrphids are abundant in alfalfa strips, alfalfa and strawberry flower at different times, whereas
weeds present in the field border compete with strawberry. We conducted gut content analysis
on syrphids by dissecting syrphids and pulverizing their abdomen. Calberla’s staining solution
was added to visualize pollen under the microscope, allowing individual grains to be identified
and counted. We found no evidence that alfalfa perimeter plantings influence the average
proportion of strawberry pollen found in the digestive tract of syrphids. However, strawberry
pollen represented a significantly higher proportion of gut contents of syrphids collected from
the perimeter compared to those collected from strawberry fields, and there was a lower
proportion of strawberry pollen in syrphids collected in week two compared to week one and
three. Differences in strawberry pollen consumption and floral visitation may reflect patterns of
syrphid activity over time. Future research including direct observations of syrphid movement in
strawberry fields with an alfalfa border, studying the efficiency of syrphids as strawberry
pollinators, and analyzing week two samples to determine whether there was a particular type
of pollen other than strawberry that was high in proportion to strawberry pollen will provide
useful information about this vital, but understudied group of pollinators. | en_US |
