Small black beetles...?

(Garden novice)

Moved into new house and have not had a chance to really tackle the garden yet.

While pottering about in the back garden, I noticed loads of small black beetles underneath the leaves of an acer.

No photo I'm afraid but here goes...

Pinhead sized (approx), Black, Body shape is similar to a pear/teardrop shape with its head at the narrow end. There is loads of them - maybe 50 per leaf I examined. Harmless bugs or harbinger of doom for the acer?

Will get pics when possible.

Thanks for any help.

Cheers,

Slips

 

Slips, are you sure it isn`t aphids? your best bet anyway would be to spray with a systemic insecticide. David.