Long Beach trees show a spread of infestation: Reported cases of Tuliptree Scale insects up from previous year as the city works to treat infected trees.

Daniel Green | Signal Tribune
Trees located along Magnolia Avenue appear to show signs of Tuliptree Scale infection. The City of Long Beach documented around 120 reported cases last year of the infection but currently has between 350-400 cases. Over time, this infection can lead to leaves turning yellow, dropping prematurely, or branch dieback–– where branches begin to slowly die.

Over the past year, residents walking down the streets of Long Beach may have noticed a change among some of the trees in their neighborhoods. What were once picturesque sights are now covered with large scaly bumps or excess of dew dripping from branches.

While this odd occurrence may not seem serious on the surface, the cause can be detrimental to the tree and potentially lead to its death.

The infection comes from an insect known as Tuliptree Scale, which feeds on tulip or magnolia trees, both commonly found in Long Beach.

According to Arthur Cox, Long Beach public service bureau manager, the city documented 120 reported cases last year but currently has between 350-400 cases.

“It started in the downtown area, and it moved to the north and west and was in the west side [of] Wrigley,” Cox said. “We’re experiencing an infestation, basically, citywide right now.”

Tuliptree Scale, or Toumeyella liriodendri, is a type of scale insect that survives by spreading to trees and attaching itself to branches, where it sucks sap from the tree. This can harm the tree by depriving it of vital nutrients. Over time, this can lead to leaves turning yellow, dropping prematurely, or branch dieback, where branches begin to slowly die.

Young trees are a common target for Tuliptree Scale, and if the infestation is left untreated, the host can potentially die.

The scale will commonly gather on a branch in bunches, causing a tree to look as if it is covered in warts. Residents may notice bumps along branches that can range from grey to light pink.

Another sign is a large amount of what is known as “honeydew,” a waste byproduct that the scale will emit. The dew can also harm the tree by allowing for the growth of mold that harm the tree by blocking sunlight, a necessity for the tree’s photosynthesis process.

In response to the spread of the insect, the city set aside $100,000 for the treatment of Tuliptree Scale. The city is already treating infected trees and is studying the best course of treatment, according to Cox.

“We treat the trees with an insecticide that requires irrigation. and then the tree takes the insecticide and it does its action on the pest,” Cox said. “We’re […] currently looking at how many cycles that needs to take in order to show the improvement that we need to have. [The] worst-case scenario is we’re removing the tree.”

For owners of trees that are susceptible to infestation, Cox recommends watching for symptoms and alerting the city as soon as possible.

“The first thing, is they look at the symptoms. The symptoms are going to be honeydew, which is a sticky substance that is going to fall from the tree and stain the ground,” Cox said. “We need to get that call when that starts to happen.”

When the call is received the city will study any tree to determine the health of the tree and discuss a treatment plan with the owner. Cox stressed that the best thing property owners can do is be engaged and help the infected tree by constant watering, which helps the insecticide circulate through the tree.

Catching the infestation in its early stages is the best way to save an infected tree and helps increase the chance of survival.

“Success is if we catch it early and we put it into a treatment program. Then the process is not fighting a major infestation,” Cox said. “We are treating trees that have a major infestation. The trees that are being removed are the trees are beyond what we think is that recovery area–– where there [is] severe dieback and leaf loss and the tree is no longer sound or have the potential to survive. Those are the removal candidates.”

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Daniel Green, Production Manager

Daniel is a California-raised journalist with a degree in Journalism from California State University Long Beach. He began his writing career at Cerritos...