If tiny black bugs have invaded your outdoor garden and you're not sure what they are, don't fret. With today's technology and a large amount of information at your fingertips via the Internet, you're just a couple of clicks away from their identity. With proper identification, you can act accordingly; however, you may be surprised to learn that some insects are beneficial and are better left alone.
Examine the tiny black spots you are seeing on the leaves to be sure that they are in fact bugs. Some bugs leave behind black excretions. The black spots may be little balls or flecks, or it may be more like a shiny, sticky residue. Knowing what evidence the bugs leave behind helps identify the ones that are invading your outdoor garden.
Monitor the plants in your garden to notice which ones the bugs are attracted to. For example, if the tiny black bugs are attracted to your lettuce plants and little else, this will be a significant clue when identifying it. Note if there are any other insects nearby. They might be attracted to plants that have anthills or other bugs nearby.
Look at the leaves and stems for any other damage, such as tiny holes in the leaves or rotting in the stems. Take note if there is damage along the leaf edges or near the centre. Look to see if the leaves are browning starting on the outer edges or in the middle. Note if the bugs attack young or mature leaves.
Pick off a leaf with a bug on it and place the whole thing in a sealable plastic bag. Look to see if it is a larva -- a small wormlike critter. It will be easier to identify the adult bug, so look on the underside of the leaves or try in the morning when many bugs are most active. Capture the live bug for reference.
Examine the features on the bug. Notice if it has any spots or wings and note how many legs it has and the shape of its body. Look at the colours. Perhaps the bug is not completely black. Perhaps they are just black spots.
Compare all your observations to a university extension website or an insect identification book or garden book. Start by finding information for the plants which these tiny black bugs are invading. There is most likely a list of common pests specific to that plant to help you narrow your search. For example, tiny light-coloured bugs with black spots found mainly on your lettuce plants and feeding in the centre of the young leaves are most likely lettuce aphids.