Hi Anne,
A few quick points first of all. The range of acceptable blood glucose readings where you are is wider than in the UK. Here, the NHS recommends diabetics try to remain between around 70 -130.
Having said that, the ideal level to aim for is around 90 as that is a typically healthy non-diabetic reading.
Your son's bedtime reading is above 150 (8.3 in UK money) and that's really too high on a regular basis. 200-300 (11.1 - 16.6) is much too high, high enough in fact to cause damage to much of the body.
As your son was diagnosed in April and his bg levels are now creeping upwards, this suggests he is coming to the end of what's known as the 'honeymoon period'. This is a time when the pancreas still has some remaining insulin producing capability, but can quickly be ended when bg levels are routinely too high. It's a dificult time and you'll need to be vigilant in monitoring his levels and adjusting his medication levels upwards to suit.
The other option is to have a close look at his diet and remove the foods which cause his blood glucose to rise so high. This can have a significant impact both on reducing average bg levels and also reducing the fluctuations between low and high.
I hope that helps, but please keep us posted.
All the best,
fergus