|Abstract or Summary
- Nomia melanderi Cockerell is one of the most efficient pollinators
of alfalfa in Eastern Oregon.
Emergence begins in June, usually reaches its peak in early
July, and may continue into early August. Male emergence precedes
female emergence by four or five days. For the first few weeks of
this time, the males spend the morning hours patrolling the nesting
area. As each new female bee emerges, many males attempt to
mate with her , but most contacts are unsuccessful. Soil temperature
and moisture are the prime factors influencing emergence.
After mating has been accomplished, the female bee forages
in the field and returns to the bee bed in the afternoon to begin nest
construction. The male also spends the afternoon in the field, returning
to spend the night in clusters on plants on, or in the vicinity of
the bee bed. Some crawl under the loose soil crust, paper, sticks,
rocks, or enter burrows for the night.
The female, after digging herself under the soil surface,
spends the nest two or three days roughing out cells. On the third,
fourth or fifth day she begins to collect pollen. She usually forages
on blossoms close to the nest, tripping about 96 percent of those
visited. The female gradually increases her foraging range, moving
progressively further from the nest as she ages. The time required
to complete each pollen collecting trip varies considerably, but
averages close to 35 minutes. It takes from seven to 11 trips to
complete one pollen ball and this may require from 5 1/2 to 9 hours.
The female trips the alfalfa blossom by forcing its head
against the standard petal while its legs are braced against the wing
Mortality is evidenced by an abrupt decline in the number of
Eggs of Nomia melanderi require from 2 1/2 to 3 days to hatch.
The larva passes through five instars. The fifth instar defecates
after all the pollen has been consumed, and transforms into the
prepupa, which passes through the winter. The following spring the
prepupa transforms into the pupa which shortly develops into the
The alkali bee uses major and minor landmarks for orientation. Larger landmarks such as haystacks, trees, fences,
roads , and ditches are used to locate the bee bed. Then smaller
markers such as soil clods, sticks, etc. are used to locate the
individual burrow opening.
Preliminary studies suggest that the alkali bee is able to distinguish
among yellow, green, blue, white and gray colors.
Temperature is usually the limiting factor in the initiation of
morning activity, whereas light intensity appears to determine the
time of flight cessation in the evening.