Pests? Spider mites?

At this point, I'd pull the fruit, and then pull the plant out of the container to inspect the roots. That potting mix looks very dense, so I'd suspect the roots are either dead or impaired in some way.

I'd repot in a porous, free draining mix, water thoroughly, and place the tree in bright shade for a week. If it bounces back, move gradually back into the sun. Resume fertilizing two weeks after the repotting.

I would also thoroughly Neem treat the tree as a general precaution. Of course, keep it out of sunlight when spraying with Neem.

Josh

Josh gave the perfect advice...! Please do as he instructed and you should see your tree bounce back before summers end..

Where or what Zone do you live in? If you don't do anything at the moment, at least take it out of the sun)

By the way, welcome and what a cute baby in your arms!

What is the composition of the potting soil that you are using? I doubt it is insects, this is something cultural (watering, soil, heat, etc.). Does not look good, but if you isolate the cause, it can bounce back..., and in the current growing season. Is it sitting in a saucer btw?

Many thanks for the responses. Will tru to repot tomorrow with a free draining mix. Will also take all of the fruit off.

We live in the UK so weather is good at the moment for grow and warm weather.

Was in a saucer for the photo was easier to rest it on!!!!

Also, thanks for the welcome and yes she is rather cute even if I am a little biased

Craig, great idea doing it tomorrow! That is going to do wonders right away, Try and not disturb the roots too much and rinse away gently all the older soil if you can. Make sure to fill the new soil in between all the roots even if you have to shake the soil into them.

It's not important at this time until the roots are repaired and actually taking up moisture to have that tree in sun, especially hot sun. If it were mines, I would do as Josh says and keep it in shade until you see those leaves perk up..

If you can, keep the tree out of the sun starting now..))

What's the temps like over there now? Is it just great summer is finally coming. Nice to see another citrus nut across the pond. Please keep sharing and keep us posted on every step of the way?

Mike