Borers: Trees Most Common Enemy
Perhaps the most common and harmful enemy to a tree’s health is generally known as a tree borer. Tree borers are insects, also called tunneling insects that burrow deep on or inside of trees to lay their eggs. These pests can be alarming for it can spread unnoticeable into nearby trees in a small period of time.
Borers can either beetles or clearwing moths. Its young larvae are the main culprits. It burrows deep into the tree gnawing vital transport tissues that cause affected parts of the trees like stems, twigs and even roots to slowly weaken and eventually death of the tree. Infestation sites also provide entry points for plant pathogens such as fungi, bacteria, protists, nematodes, and viruses that cause plant diseases.
Infestation
These insects emerge in the spring and summer and starting infesting trees. After their mating season, a female will find a suitable tree to lay her eggs. She will lay it on barks, often on crevices, or around wounds. The eggs will hatch 10 days to 2 weeks later. The young larvae will quickly burrow beneath the bark where they will feed and grow.
Signs
As tree borers dig deep into the tree they live tiny holes. These holes can be round or oblong. The presence of frass or sawdust-like material that can be seen below these holes is also an indication of infesting insects. They form long cylinder tunnels as they excavate deeper into the tree.
Prevention
It is important to take early measures when this insects are most vulnerable to insecticides. Proper timing is significant to get rid of newly hatched larvae before they tunnel into the bark. Once these young larvae are inside of the tree insecticides can no longer kill them. Once inside, they are hardly detected until serious damage has been done.
Pyrethroids like bifenthrin (Onyx) (Talstar) and permethrin (Astro) work well if sprayed properly-timed on barks. Be aware that some insecticides tend to harm not only the bad but also the good bugs. Chlorantraniliprole (Acelepryn) is an effective bee-friendly option.
Borers contribute to the development of disease and perhaps eventual death of the tree. To control these creatures, early detection and prevention play a vital role. Clean up wood from dead limbs and dropped fruits around the tree as it can attract these insects. Regularly pruning weak or damaged can eliminate the insects’ suitable area to lay its eggs. For a safer alternative, a spray made from oil is a good option.