 We're in one of the rearing rooms within the insectry and this is where we rear our cul-cordies-butting midges as vectors of blue tongue virus. The reason we raise these midges is to find out more about the transmission of blue tongue virus which these midges can actually transmit to animals. Blue tongue is a notifiable disease that means it's quite a serious disease it's very easily transmitted so it's easy to pass on because the midges can fly a long way. It also causes a significant mortality in some sheep. We had a very large outbreak in northern Europe in 2006-07-08 and it was very economically damaging because you cannot move your animals away from infected areas, from infected zones, from protection zones and so you get a double impact. You get the direct effect of sick animals and some animals will die but also you then can't move your animals and trade with either internationally or within the country. Cul-cordies-butting midges are capable of spreading important livestock diseases so when they bite an animal they can pick up a virus and then subsequently when they've incubated that virus inside their bodies after that period of time can actually then pass on that virus to another individual animal and by understanding the behaviour of these insects and what they do on a day-to-day basis how they choose which animals they bite, how far they fly, we can build a picture of how the virus can be transmitted so given from one animal to another by these insects. So behind me you can see the rearing pans. Cul-cordies typically breed in damp organic matter so whether it's animal dung, leaf mold and we represent this by having this lovely concoction of liver powder and wheat germ and seeded with bacteria that the larvae can breed in. We get our female midges to lay eggs on a bit of paper and then we put that bit of paper there's eggs on inside one of these pans and the eggs hatch and the larvae wriggle free and then as they grow they get bigger and bigger they're still very small. Cul-cordies-butting midges are about two to four millimetres in length as adults the larvae aren't that much longer but they're very thin they look like tiny worms. When they're finished growing as larvae they then pupate they become a pupae or chrysalis and fortunately that chrysalis floats so we can actually raise level of the water collect all those pupae by a suction pump so we put the pupae into these little cardboard pots from whence they can emerge and we get about 500 individuals in one of these cardboard pots. In order to blood feed these insects we use this humatec unit here with little heater units if I can bring that to here. I want these to have a little reservoir of blood that fits over the top of here which heats it to 37 degrees. A little reservoir of blood that the midges can feed through a membrane and so the adult midges are in these pots. So we can feed these on blood that has not blood in the virus which we do for our rearing purposes but also on blood from a sick animal and see if they pick up the virus or we can mix a blood and virus mixture together and and then feed that to the midges or we can actually enter thoracically inoculate these midges to actually inject the midges with a virus suspension using a very fine glass needle that's drawn out capillary tube which we insert into the thorax just behind the wings or just behind the legs of the the midge inject a tiny amount of virus solution and then leave them to develop and we know that although these midges aren't very good at picking up virus they're very good at transmitting it so they're very good at passing it on and even one bite from one single effective midge is enough to transmit to pass on blue tongue into that animal and the animal may be sick. We can take our infected midges we've affected in restricted area and planarite building and we tend them to the isolation units and then we can place them on the on the sheep typically on the inner thigh hold it there for a short period and then the midges will feed through the mesh and contact the skin of the animal and then pass on that virus converted when we have an infected animal we can take naive insects from this lab into the isolation units and then feed those naive insects on the sick animal and see how many midges actually will pick up that infection again that varies with strain. So blue tongue was for a long time considered to be just a tropical disease and since 1998 we've had a few incursions into southern Europe then we had a significant outbreak in northern Europe in 2006 where the virus was being able to be passed on between livestock by our northern european midges and that virus arrived in the UK in 2007. Fortunately we were able to get a vaccine policy out and the vaccination rollout prevented that virus from expanding as it did in northern Europe and northern Europe because of significant issues for the livestock industry significant economic impact for the livestock industry. So the work we do here is it's about when these insects might arrive what damage they might do and by looking at the infection by looking at the behavior we can understand how and why and when blue tongue might get to the UK and the impact it might cause.