The Highland Biological Recording Group

The Bee-fly Bombylius major Progress (2004)

Jimmy McKellar

All of our projects give us a benchmark by which to gauge whether the subject under scrutiny is undergoing any changes to its advantage or detriment. When I first considered Bombylius major as a species worth recording I had little idea what the distribution or flight periods are in Highland or indeed Scotland. Several years have passed since I introduced this insect in Newsletter No. 12 (1999) and I have managed to amass over 100 records for Scotland, these give a much better idea of both distribution and flight periods.

The insect is not one of the easiest to find but once seen it is surprisingly easy to pick out as it is one of the few insects on the wing early in the year. This sun-loving insect only flies when the sun shines. Anecdotal evidence suggests that even very short periods of sunshine are enough to bring them out.

The Beefly larva is a kleptoparasite/predator in the nests of solitary bees, several species of which may frequent the same banks as the Beefly.

The beefly Bombylius major in typical posture, basking in the spring sun on semi-bare ground. The characteristic features of brown hairy body, patterned wings held in a 'V' shape, and the long proboscis are clear.

Photo © Jimmy McKellar

Distribution of Bombylius major in Scotland (10km square resolution), all records.

The last progress report in Newsletter No. 14 allows us to compare that map with this one. We have to be careful as the last map showed historical records but on this current map I have treated all records equally without differentiating between modern and historical records. Just as the historical/modern records are different so is the scale. This means not all records appear on the map as this map shows distribution on a 10km basis.

Even with the change in emphasis we can still see an improvement with the southern half of Scotland having good, if localised, coverage. The mainland west coast from Ayrshire to Skye has also gained enough records to allow us to say this species can be found locally there too. It is difficult to say if the absence from the northeast is genuine or a lack of recorders. It would be interesting to have recorders search this area.

Phenology: The chart on the right represents the relative abundance of individuals in each quarter of the months we have records for. Strangely there were no March records. The table clearly shows the marked reduction as we go into June. The unaccountable dip towards the end of May might be genuine or recorder bias. Only more records and searching will determine the true reason. This is a fairly small sample and it would be erroneous to place too much emphasis on the results. It does reflect the known flight period and therefore gives us a fairly good idea of the best times to search.

There are still a great many things I would like to know: What are the host species? How long does it take from egg to adult? Is the time taken always the same? Why are there no records from Arran, Mull, The Black Isle and the Northeast?

Records of Beeflies may be sent to: . Specimens of solitary bees associated with them - contact Murdo Macdonald . All the usual information, please. Time of day, weather and behaviour will also be useful.

Previous bee-fly articles in the Highland Biological Recording Group Newsletters may be of interest: