I'm afraid I have to go with Allen Dick on this one.

We are in a British Isles environment and have a number of apiaries in
areas which could be considered 'built up' (although it must be said
that they are in the edges of villages or small towns, not in cities, so
in the case of inner city beekeepers I have to bow to their knowledge of
their local conditions, of which I have no experience.)

We have never noticed any advantage in feeding late in the day, indeed
in evening the bees can be in a much worse temper than in the morning.

Much more important is how you do it. Heavily feed the small hive in a
group, yet do not feed the strong one which is fine for weight and you
have a recipe for trouble, but only during nectar dearths.

The use of contact feeders can also cause you a problem, as there is an
inevitable leakage every time the pail is inverted. In this case, and
given sufficiently high night time temperatures (which I doubt at this
time of year in the British Isles, even in the normally milder Irish
conditions) then the bees can tidy up the leakage overnight before the
opportunists find it in the morning.

OK, we are a bit further north than you, but at this time of year we
only feed fondant. It is clean, easy to use, and NEVER causes robbing.
The bees can use it even in the coldest weather when in tight cluster.
We never even consider syrup as an option in February, as in normal
conditions at this time of year they cannot work it other than
sporadically, and we will not start with it until mid March at least. In
a cold spring we can even be a month after that before using it.

Syrup, other than the thickest 70%+ solids invert types, can give
serious problems this early in the year. In our time we've seen
everything from dysentry to brood failure (similar to EFB), and all have
been down to syrup feeding too early. (Not something we are proud of,
but have to admit to making errors in that way, sometimes several times
before realising what we were doing wrong.)

Once the timing is right, good LEAKPROOF hive top or frame feeders cause
little trouble.

Someone mentioned bee type as also significant, and I can certainly say
that we have noticed that yellower bees seem to be far more persistent
robbers than dark bees. Most of our bees are mongrels anyway so
attributing this to specific races in our population would be
potentially misleading.

As regards robbing as a general topic, we have found that April and
September/October are the trouble months. Too early/late for a honey
flow, yet the colonies are active. Feeding has to be carried out with
care at these times. Give them ALL something at the same time (at least
all the strong and medium ones, you can get away with not feeding the
small ones, but certainly NEVER feed the small and omit the strong).
Small colonies should be protected by use of entrance reducers (even
down to single bee way in extreme cases). Someone mentioned giving back
wet supers, and that is something we noticed many years ago could cause
the bees to go absolutely crazy with robbing and which we now never do.
(Apart from the robbing there is also the question of workload in doing
it, and increased wax moth activity in dry supers to contend with, plus
one or two other important factors I won't go into as they could open up
a whole new thread.)

Get all the other factors right and time of day becomes of little
importance. It is, of course, feasible in a hobbyist situation to be
able to feed at dusk only, so if you see it as a help why not do it, but
like one or two others who have posted on this subject, we just cannot
do this. If we want to feed all our colonies in one working week we have
to do 300 a day, which means that the two men are out from early morning
till near dusk in spring to get it done.

This seems to be a debate involving some entrenched opinions, but I
guess the real thing in this is it depends how you do it.

Murray
--
Murray McGregor