The weather does influence their mood - lots (even if living in an airconditioned home , they can sense pressure changes I think, and get clues from then brightness of the light coming in the windows.
Hand feed him. IS EASY all you need are a set of fingers.
If you are feeding crickets , pull a big hopper leg off, and squash the head and give the cricket a bit of squeeze to get some yumminess out, then hold the skinny end hopper leg and push the fat end between the lips (near the snout), dragon will eat the leg will get the idea there is food , the firmly press the head end of the cricket against the lips (at about the same place) if some yumminess comes out and stays on the nose , chi, lips, he'll lick it off, more than likely if he's hungry he'll eat the cricket.
Do this for a few feeds and he'll soon get the hang of being handfed by fingers.
Be prepared to be accidentially nipped on the finger tips if you don't move the finger tips away in time though - a risk worth taking IMO.
I know of a very experienced local breeder here who advocates using a stiff plastic (coated) card with hole cut to pass the food which is folded in half, he slips the folded end of the car between the lips of poor eaters, opens the mouth by opening the folded card, and in goes the food items through the hole, out comes the card and the lizard chews and swallows the food.
Other option is to puree the food insects and use a feeding syringe and large bore crop needle.I'd be using a feeding syringe like
http://vetafarm.com.au/product/reusable ... g-syringe/ and maybe a 10G crop needle
http://vetafarm.com.au/product/medicati ... op-needle/ to get the food into the dragon.
In a pinch , a disposable 10ml syringe and a 14G drawing up needle (NOT SHARP !) will work, you might need to enlarge the syringe hole to about 3mm with a drill to make it easier to get food through it though.
I've done this for an injured wild juvenile water skink (who was tiny , 10g), in Lucky's case I used a small 5ml syringe and a catheter tube (the plastic tube from inside a catheter needle) as he was too small for even an 18G crop needle and he had an injured lower jaw as well as loosing an eye , was attacked by next door's cat (he got mealworm lavae and pupae meat and cricket meat)..
Inadequate UVA will result in depressed apetite in a beardie, as will being too cold.
Check temperatures (day and night) if too cold , his metabolism will be very slow.
Check the UV light ( how old is it ? ) Needs a light that produces very high levels of UVA (about 30%) and UVB (at least 10%).
You might need an apetite boosting suppliment like HerpaBoost to get him eating.