Ariel Schalit / AP

Locusts land on a sand dune in Negev Desert, southern Israel, near the border with Egypt, March 5. A swarm of locusts crossed into Israel from neighboring Egypt Monday, raising fears that Israel could be hit with a biblical plague ahead of the Passover holiday. Israel sent out planes to spray pesticides over agricultural fields to prevent damage by the small swarm of about 2,000 locusts, said Dafna Yurista, a spokeswoman for the Agriculture Ministry. The ministry also set up an emergency hotline and asked Israelis to be vigilant in reporting locust sightings.

Scientists can learn a lot about the locusts swarming over Egypt and Israel just by looking at the pictures. Keith Cressman, senior locust forecasting officer for the U.N. Food and Agriculture Organization, is based hundreds of miles away in Rome — but he can tell that these particular bugs may be on their last legs.

"The few good pics I have seen of the locusts show that they are a brick red rather than pinkish," Cressman told NBC News in an email. "Both colors indicate they are immature adults, but the dark color suggests they are old and tired rather than young and hungry. Hence, the infestations arriving in northeast Egypt and Israel will probably come to nothing." That's the good news. The bad news is that other locust swarms could pose a more serious threat to the region's agriculture later this year. To get the details, check out the full story in Cosmic Log.

Ibraheem Abu Mustafa / Reuters

A Palestinian farmer displays locusts at a farm in Khan Younis in the southern Gaza Strip, March 5. Palestinian officials said locusts had not hit Gaza in several decades and numbers of locusts that reached Gaza on Tuesday were small but the Agriculture Ministry said they have taken all necessary steps to fight it if larger numbers hit the Gaza Strip.

Amir Cohen / Reuters

A swarm of locusts fly near Kmehin in Israel's Negev desert.

Ariel Schalit / AP

A locust on a sand dune in Negev Desert, southern Israel.

More about locusts:

• Locusts hit Egypt and Israel before Passover
• Gaddafi's fall leads to desert locusts' rise
• Locusts illustrate the science of swarming

Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.