majors at brown university Polyphagous shot hole borer (pshb) plant heroes

Description: the polyphagous shot hole borer is a tiny invasive black beetle smaller than a sesame seed (2 – 2.5mm or 0.07 – 0.1inches long) that was recently discovered attacking many different types of trees in southern california. Brown university admissions video female beetles make tunnels, or galleries, in the trunks and branches of host trees and lay their eggs inside. Males are much smaller, do not fly, and don’t leave the galleries. The females vector (or carry from tree to tree) a fungus ( fusarium euwallaceae) that grows in their galleries, and the adult beetles and their larvae depend on it for food. While this fungus definitely helps the beetles out, it is really bad for the trees and clogs their water and food conducting tissues!

Habitat: so far, PSHB has been found infesting trees in neighborhoods, avocado farms, and several public gardens.

Because PSHB can attack so many different types of trees, native california woodlands are also at risk if the beetle continues to spread.

Host trees: part of the reason this bad guy is SO bad is that it has a huge appetite. In fact, it has been known to attack plants in 58 different families! Many of these plants are important parts of native california ecosystems, and others are planted widely across the U.S. In cities and neighborhoods. Brown university united states A few host species, like avocado and olive, are important in agriculture. Here is a list of plants that the beetles can reproduce in:

The facts: the polyphagous shot hole borer is an ambrosia beetle. You might think of ambrosia beetles as the “farmers” of the insect world! Rather than eating bark or wood like many of their cousins, these guys feed on fungus. Sanford brown university locations but, the cool part is that they grow the fungus themselves! Ambrosia beetles have special pits or dents in their bodies (called mycangia) that are used to carry the spores (think of these as the farmer’s seeds) of the fungi that they eat. When a female beetle finds a suitable tree, she chews a tunnel into the sapwood and “plants” the fungus as she digs. How to get into brown university the fungus grows into the tree’s wood and on the walls of the beetle galleries—a fresh crop of fungal food for both the adult and young beetles! The relationship between the beetle and the fungus is called ‘symbiotic,’ meaning that these two very different species depend on one another—the fungus provides a ready source of food for the beetle and the beetle provides the fungus with a free ride to new trees. How smart is that?

In their native homes, ambrosia beetles usually only attack sick or dead trees. However, when they are accidentally moved to new habitats, they may begin attacking healthy trees—this is what has probably happened with the polyphagous shot hole borer.

Signs and symptoms of PSHB attack can vary a lot depending on the type of tree, however, tiny beetle entry and exit holes (a bit smaller than the tip of a ballpoint pen) are usually present in the tree’s bark. Sawdust is often found around the holes or on the ground around the trunk; sometimes a sawdust “toothpick” can be seen sticking out of the beetle hole. In areas around the beetle holes, trees may have ‘bleeding’ symptoms (liquid oozing out of the bark), ‘gumming’ symptoms (blobs of goo coming out of the bark), or ‘sugar volcano’ symptoms (little cone-shaped piles of white powdery stuff on the bark). PSHB causes branches to die and can eventually kill the whole tree. Brown university international students financial aid branches can also be weakened by the beetles’ tunneling and break off, revealing webs of galleries filled with black fungus.