An insect’s surprising way of seeing, and other revelations

How can insects turn colors they can’t see?

Peppered moths are masters of camouflage. In the larval stage, they can change the color of their skin to blend into their settings—even without seeing those surroundings, a new study found. After raising more than 300 peppered moth larvae, U.K. researchers obscured the vision of some with black paint (which the larvae later shed, unharmed). The larvae were placed in boxes containing white, green, brown, or black sticks, and given time to adapt. When the researchers opened the boxes, they found that nearly all the caterpillars, with or without vision, had changed their body colors to match the sticks in their box. The researchers then moved the caterpillars into new boxes containing sticks of two different colors, and about 80 percent of the insects chose to rest on sticks that matched their body color. The researchers say their findings provide strong evidence that peppered moth larvae are capable of dermal photoreception—seeing with their skin. —Annie Roth

Whether or not their eyes could see, caterpillars in a study generally mimicked the colors of the sticks that they perched on.

Photograph by ILIK SACCHERI

Cement of the future?

The process for making cement creates so much greenhouse gas that if it were a country, it’d be the third largest emitter on Earth. That statistic is from MIT, where scientists devised a process that would produce cement using electricity, rather than by burning fossil fuels. In a water electrolyzer, current to the electrodes creates hydrogen and oxygen gases, an acid, and a base. When limestone is added to the acid, it’s dissolved and decarbonated—loses its CO2—and then can be used to make a key cement ingredient. —AR

To attract the ladies, a male moth flashes this

A male Creatonotos moth inflates his bushy behind only at mating time, and for one purpose: to lure females. The tubular organs are coated in bristles that emit pheromones. The more toxic plants the males eat as larvae, the bigger and more potent these organs will be. —Maya Wei-Haas

This male Creatonotos gangis moth displays the bristles of his inflated tubular scent organs. As larvae, Creatonotos eat plants full of toxins—pyrrolizidine alkaloids—which pumps up the potency of the organs’ scent. These toxic compounds help the plants naturally ward off predators. But some insects co-opt the defense, eating the plants to help them deter their own natural enemies and—like Creatonotos—to attract females.

Photograph by KHALID ABDULLAH SAID ALHADHRAMI

Medicinal uses are mushrooming

Patients in a pilot study felt decreased symptoms of anxiety and depression for at least one week after taking a large dose of psilocybin, the hallucinogen in magic mushrooms. The study findings, published in Scientific Reports, suggest that the drug may support an “enduring shift” away from negative moods and cravings. —Patricia Edmonds