Here in the identification service we don’t need a diary or calendar to know what time of year it is, in fact we don’t even have to look out of the window! We can tell the time of year by trends in the enquiries we get by email, phone, through the post or on our forum.
Many species of insect have a lifecycle that lasts for a year, with the larvae or nymphs around in one season, and the adults around in another. Last year we blogged about the amazing bee fly and how it is a sure sign that spring is on the way, but it’s not the only enquiry with a strong seasonal distribution.
I searched our database and the forum for enquiries right back through the mists of time to 1992 to collect data on 3 of our common seasonal species – bee flies (Bombylius sp.), the excellently named cockchafer (Melolontha melolontha) and house spiders (Tegenaria sp.).
Bee flies
These amazing little critters are around in April and May making the most of the spring flowers. The two species we see most often are the common bee fly (Bombylius major, see picture) and the dotted bee fly (Bombylius discolour). They have a fascinating life cycle and you can find out more about them here -
- http://www.nhm.ac.uk/nature-online/species-of-the-day/biodiversity/loss-of-habitat/bombylius-major/index.html
- http://www.nhm.ac.uk/natureplus/community/identification/blog/2011/04/07/body-of-a-bee-face-of-a-mosquito--spring-is-in-the-air
- http://www.nhm.ac.uk/natureplus/blogs/diptera-blog/2011/04/12/beeflies
Cockchafers
No, we didn’t make that name up, the common English name for Melolontha melolontha is indeed the cockchafer. Although they are beetles they are also commonly called May bugs, and you can see why from the graph above. These large beetles emerge as adults in May or June after living in the soil as larvae for 3-5 years. They are strong though inelegant fliers and are attracted to light, meaning they often fly through open windows and gatecrash evening barbeques! But don’t worry; they are not harmful to humans. Find out more here -
http://www.nhm.ac.uk/nature-online/life/insects-spiders/common-bugs/cockchafer/index.html
House spiders
There are several species of common house spider in the UK which are difficult to tell apart. However, they all belong to the genus Tegenaria. They are around all year, but are most commonly encountered between August and October when the fully grown males set out to find love. This is when they are most likely to run out from under your sofa or turn up in the bath – just in time for Halloween! You can find out more here -
http://www.nhm.ac.uk/about-us/news/2010/october/house-spiders-prefer-the-shed-shock85297.html
On a more serious note this little project shows how the identification service records are a mine of fascinating and potentially useful information. This data also shows that both bee flies and cockchafers emerged significantly earlier in 2011 than 2010, so it would be interesting to see how they fare in 2012 – keep your enquiries and observations coming in to our forum!