Strong gusts and an abundance of parched brush fed the Westhampton brush fire that scorched 600 acres in the pine barrens this weekend, Suffolk and state officials said Sunday.

The cause of the fire remained a mystery but Suffolk County Executive Ed Romaine said more focus is needed on ending the decade-old infestation of Southern pine beetles, tiny invasive insects that that have killed tens of thousands of trees across Long Island.

Experts say the loss of tree shade allows for new growth and as a result, more brush to feed a fire.

The Southern pine beetle is “killing the pine barrens,” Romaine said Sunday at a news conference to provide updates on the fire, which started in Center Moriches about 1 p.m. Saturday and spread to East Moriches, Eastport and Westhampton.

“Go to out to Amagansett … take a look at how many dead trees there are,” he said.

Why do Southern pine beetles raise concerns about more brush fires?

The dead trees do not by themselves increase the fire risk, according to Kathy Schwager, an ecologist with the Brookhaven National Laboratory, where nearby forests have been extensively damaged by the beetles. Forest fires generally ignite and burn leaves, dried grasses, smaller brush; it’s generally not the taller mature trees that catch, Schwager said, except in the case of extremely intense wild fires.

But the dead trees open up the forest canopy, bringing in more sunlight and a flush of new growth. As that vegetation dies out, especially if there’s a drought, there’s a whole lot of combustible material lying on the forest floor.

While the pine beetle was not a significant factor in the Westhampton brush fire, said Amanda Lefton, the acting commissioner of the state Department of Conservation, at the news conference, the DEC is attempting to stem the beetles’ onslaught, including with prescribed burns.

How did they get here?

The pine beetles were once confined to the Southern United States, but warmer winters have allowed them to spread north. They first appeared on Long Island in 2014 and have now moved as far as Cape Cod. In these parts, the preferred host is the pitch pine — which unfortunately is the most common species in Long Island’s ecologically fragile pine barrens.

These tiny insects burrow under the outer bark of the trees, laying eggs and building tunnels that interfere with the movement of water and nutrients. An infestation can quickly kill a healthy tree and in short order can turn whole stands of evergreens to sickly orange, then brown and gray.

What can be done?

State and federal foresters have been felling dead trees and even strips of live ones, to create breaks that they hope the beetles cannot cross. These efforts have not been highly successful.

Experts say the best strategy for minimizing the risk of very hot, uncontrolled blazes is to periodically burn off some of the dry fuel scattered about the woodlands. For a long time it was standard policy to suppress any fire that erupted, but in the past few decades foresters have caught up with centuries of Native American forest management practices, and have recognized the critical ecological role of natural fires.

State and federal foresters have conducted prescribed burns to mimic these natural processes and clear away some of the dry tinder.

But ecologists warn that global warming will bring more dramatic swings of very wet and very dry weather, which in turn will lead to exuberant growth followed by desiccated fuel — and that will make the job more challenging.