NEWARK — Deep inside a large warehouse near the nation's second-busiest seaport, Rebecca Flinn stands guard against an army ready to invade the U.S. and cause untold amounts of destruction in New Jersey, New York and beyond.

With a flashlight attached to her forehead, Flinn opens a cargo container packed with 1,200 bags of rice from India that just entered the Port of Newark, and begins to sift through dozens of bags looking for a black spot the size of a pinhead.

"We want to make sure there are no hitchhikers," she says.

The hitchhikers Flinn is searching for are khapra beetles, one of the biggest threats to wheat, rice, flour and other grains.

Flinn and other agricultural inspectors with U.S. Customs and Border Protection are the first line of defense against invasive critters and plants from other countries — some of which have managed to make their way into New Jersey recently and caused havoc.

In just the past five years, New Jersey has been invaded by the spotted lanternfly and emerald ash borer beetle — both from Asia — which threaten millions of New Jersey's trees. Scientists have also recently discovered the longhorned tick from Asia, which poses a threat to animals.

None of this is surprising to state officials, considering that New Jersey is a state at the center of global trade and domestic shipping, with the Port of Newark, nearby ports in Philadelphia and Wilmington, Delaware, and some of the busiest interstate highways in the nation, including Routes 95 and 80.

In short, there are plenty of places for critters to enter New Jersey and quickly spread.

Stopping them is seemingly insurmountable due to the sheer volume of cargo.

The story continues after this photo gallery:

At Newark's seaport alone, 3.7 million containers arrived in 2018. The Newark branch of U.S. Customs won't divulge how many containers they physically inspect, but estimates nationally put the figure at 5 percent or less.

The inspectors try to identify trends: what bugs are coming in, where they are coming from, what products they are attaching themselves to. That allows for more targeted inspections of containers identified as high-risk.

Despite all their preparation, customs officials say they don't always know what to expect when they pry open a 20-foot-long container stuffed to the brim. And even then they often can inspect only the first few bags stacked near the container's door.

Pests from multiple countries can easily hitchhike in the same container, since products from one country can be loaded into a container from another country. So if rice from India is loaded into a container that's been in China, you could potentially have khapra beetles from India and spotted lanterflies from China in the same shipment bound for the U.S.

When there's a pest outbreak like the recently discovered spotted lanternfly, bulletins go out to all the ports of entry with photos of the bug. Many of New Jersey's more recent invaders are believed to have started their infestation in other parts of the U.S. before migrating to the Garden State.

"We've been fortunate enough that it hasn't taken a hold in the United States," Basil Liakakos, head of the agricultural inspection team at the Port of Newark, said of the khapra beetle. "We have done a good job of keeping them out."

On the day Flinn looks for the khapra beetle in the container stuffed with rice, she will also inspect oranges from Spain, pottery from China, ginger from Brazil and cumin seeds from India.

Flinn cuts open a bag of cumin seeds and finds a small piece of onionweed, an invasive species that can sap minerals and nutrients from the soil, denying them to native plant species.

"It's something we definitely get used to spotting," Flinn said. "They are very prolific. They will take over native habitats and push out all the native plants."

As she spreads rice from India on a table, Flinn notices what appears to be a black dot. It's a bug of some kind, possibly a khapra beetle, that will be taken for identification to a nearby lab.

If a khapra beetle is found dead or alive, the container is sent back or its contents are destroyed. "It's so prevalent in other countries and it's so harmful to us that those are the only choices," Liakakos said.

Invaders from afar

New Jersey has its share of new invaders, old invaders and invaders poised at the border ready to enter the state. Some of these critters may be out in force in the coming months as the weather warms.

Among them: