So it is that time of year again when we head out on fieldwork - looking for flies up and down the country, in bogs, and woodlands, and wet meadows trying to seek out the often elusive individuals. For the last couple of years, the Natural History Museum has been working in collaboration with the Health Protection Authority on a specific project collecting mosquitoes and we are finding all sorts of interesting things. New records for species distributions have been determined and thanks to some molecular anaylses we are figuring out some difficult taxonomic questions.

So off we head, boots on, silly fieldwork appartus strapped to our backs (or rather just back as only one was used). However, as well as the working with mosquito adults for both morphological and molecular analyses, we are also going out to look for the larvae.

Mosquito larvae are cute, and active, and fast…We use a very hi-tech piece of equipment to catch the little blitters (a plastic pan on a long pole…..) and then dip away in favourable habitats

Above is Shelley supporting the oh so fashionable Backpack aspirator whilst I am modelly the latest in dipping technology...

We were back in Hurcott Wood (it was a little warmer since the last time I was there recording for the BBC) after a very successful trip there last year. Alex Vaux, from HPA joined us (i.e. Shelley Cook, Ralph Harbach and I) and we pottered (or in some cases pootered albeit on a large scale with the back pack aspirator) round trying to catch the early adults or the larvae.

We couldn’t find any adults but we did get some larvae and some big ones at that! These were ferried back to London in little plastic packs alongside some spare pond water.  Once back in the museum we set up the little ones in a basement lab through very secure doors which makes the place feel more like a maximum security prison than research labs

They are set up initially in bowls but as they develop they get their individual rearing tubes - nothing but the best for them. We do this as we need to collect their larval and pupal skins as they develop. For mosquito taxonomy we use the 4th Instar stage of the larva, the pupal skin and the adult.

The 'rearing lab'

The mosquitoes are separated into two subfamilies, the Anophelines and the Culicines. The Anophelines lie flat under the surface to the water and generally feed from there whilst the Culicines have a long funnel through which they obtain air and dangle down into the water column (see below). For them we place the food on the bottom. The special diet upon which they feed is fish food – but you have to get the fine stuff otherwise it is too large for their mouths

Look at the little cuties dangling down...

There are four of us in the museum checking up on them, we even have a doodle calendar to make sure that they don’t get forgotten due to our hectic lives . Gradually we are rearing them through although it has not been plain sailing, nope; there has been heartache as well as joy.

A lot of the larger individuals, which we think were Culiseta (they were big – almost 6mm!!!!) died straight away – not a good start. Then some of the larvae died when they were transferred to their individual tubes – again not good. Some of them died whilst they were emerging from their pupal case – that was probably the saddest – all that struggle and then trapped, not good.

They nearly made it....

But luckily some made it (although we then killed them). But they did get to live for 24 hours first as we had to wait for their genitalia to rotate……

And here are some of the successful adults, with their legs in the air like they just don't care!!!

So for these we have larval skins, pupal skins and the pinned adults. This is important as there are many species groups in mosquito taxonomy so by studying all the different stages as well as sequencing their DNA we can hopefully begin to unravel some of these mysteries. And it is one of the few times that I get to feel maternal….