Within the spring of 2018 on the Montreal Insectarium, Stéphane Le Tirant acquired a clutch of 13 eggs that he hoped would hatch into leaves. The eggs weren’t ovals however prisms, brown paper lanterns scarcely greater than chia seeds.
They have been laid by a wild-caught feminine Phyllium asekiense, a leaf insect from Papua New Guinea belonging to a gaggle referred to as frondosum, which was identified solely from feminine specimens. Phyllium asekiense is a shocking leaf insect, occurring each in summery greens and autumnal browns. As Royce Cumming, a graduate scholar on the Metropolis College of New York, places it, “Lifeless leaf, stay leaf, semi-dried leaf.”
Mr. Le Tirant, the collections supervisor of the insectarium since 1989, focuses on scarab beetles; he estimates that he has 25,000 beetles in his non-public assortment at house. However he had at all times harbored a ardour for leaf bugs and had efficiently bred two species, a small one from the Philippines and a bigger one from Malaysia. A Phyllium asekiense — uncommon, lovely and, most essential, residing — could be a treasure in any insectarium.
Within the insect-rearing laboratory, Mario Bonneau and different technicians nestled the 13 eggs on a mesh display on a mattress of coconut fibers and spritzed them typically with water. Within the fall, and over the course of a number of months, 5 eggs hatched into spindly black nymphs. The technicians handled the infant nymphs with utmost care, transferring them from one tree to a different with out touching the bugs, solely no matter leaf they clung to.
“Different bugs, we simply seize them,” Mr. Le Tirant mentioned. “However these small leaf bugs have been so treasured, like jewels in our laboratory.”
The technicians supplied the nymphs a buffet of aromatic guava, bramble and salal leaves. Two nymphs refused to eat and shortly died. The remaining three munched on bramble, molted, munched, molted, and molted some extra. One nymph grew inexperienced and broad, similar to her mom.
However to Mr. Le Tirant’s befuddlement, the opposite two grew slender and sticklike and even sprouted a pair of wings. They bore a curious resemblance to leaf bugs in Nanophyllium, a wholly completely different genus whose six species had been described solely from male specimens.
Mr. Le Tirant emailed an image to Mr. Cumming, who confirmed what had now turn out to be apparent: The 2 species in truth have been one and the identical. The hatchlings had solved a century-old thriller of the lacking Nanophyllium feminine.
“Since 1906, we’ve solely ever discovered males,” Mr. Cumming mentioned. “And now we’ve our ultimate, stable proof.”
Mr. Cumming and Mr. Le Tirant just lately united the long-lost mates — broad-leafed females and slender males — in a single species, Nanophyllium asekiense, in the journal ZooKeys.
It’s truly fairly frequent for leaf bugs — that are a household within the broader order of stick bugs — to be identified from only one intercourse. Many stick bugs show excessive sexual dimorphism, with females unrecognizable from their male companions.
In 2018, Paul Brock, a scientific affiliate on the Pure Historical past Museum in London who edited a tough draft of the brand new paper, solved the same thriller in stick bugs. He and his colleagues described the primary male Acanthoxyla, a genus of supermodel from New Zealand that was considered completely feminine, from a specimen discovered on a automobile in Cornwall, England.
“Leaf bugs are a selected problem as they’re so occasionally discovered within the wild,” Dr. Brock mentioned.
Leaf bugs are nearly unimaginable to see in nature, and scientists can’t examine what they’ll’t see. Mr. Cumming, one of many world’s few specialists on leaf bugs, has by no means seen a leaf insect within the wild, solely specimens in captivity or museums. Dr. Brock has seen wild stick bugs, however by no means a wild leaf insect.
Mr. Le Tirant, who has gone on many insect-collecting journeys, has seen just one leaf insect within the wild. Whereas looking with a neighborhood collector in Malaysia, Mr. Le Tirant found it after hitting a tree together with his giant accumulating internet, which shook free many leaves and one leaf insect. “If I used to be alone, I might by no means have seen a single leaf insect,” he mentioned, shaking his head at his fortune. Mr. Le Tirant took the insect again to Montreal, the place it lived and died and nonetheless resides, in a drawer within the insectarium.
Even when somebody might distinguish a leaf insect from its arboreal brethren, there’s an nearly zero likelihood the insect could be within the firm of its mate, not to mention in flagrante delicto. Whereas the winged males flit from tree to tree, the flightless females spend their complete lives excessive up within the cover, out of attain and sight, swaying within the breeze as leaves will do. “By likelihood, one is likely to be blown out of a tree,” Mr. Cumming mentioned.
How, then, to match leaf bugs to their mates? With area commentary a nonstarter, entomologists resorted to hypothesizing. Twenty years in the past, Dr. Brock was the primary to recommend that the feminine mate to Nanophyllium may very well be discovered within the frondosum group. He was inspecting a pair of female and male leaf bugs from Papua New Guinea whose uneven legs regarded curiously related.
“This may be a easy process these days, by endeavor DNA bar coding,” Dr. Brock mentioned. However he lacked sufficient proof: The feminine was lacking her forelegs, and just one species of Nanophyllium had been formally described.
In 2017, Mr. Cumming determined to see if he might show Dr. Brock’s speculation. He and Mr. Le Tirant spent a number of years poring by way of museum specimens, which has resulted in 21 newly described leaf insect species. Mr. Cumming, Mr. Le Tirant and colleagues spent two years writing a paper figuring out the shared morphology of frondosum females and Nanophyllium males. The similarities have been small however sure — two nodes behind the top, and leaflike lobed legs.
Their paper had already handed peer overview when Mr. Le Tirant’s nymphs grew up and unexpectedly supplied unshakable proof. “We needed to rewrite every little thing,” Mr. Cumming mentioned. Mr. Brock is delighted the puzzle has been solved finally.
On the Montreal Insectarium, the 2 male Nanophylliums flew day and night time for 4 months and died earlier than their feminine sibling matured. She lived for 9 months, laying 245 eggs in Easter egg pastels: blues, yellows and beiges. “To have eggs from one feminine in so many colours?” Mr. Le Tirant mentioned. “That’s one thing very particular, one thing I’ve by no means seen prior to now for a leaf insect.”
Only a few of her eggs have hatched, and no nymphs survived. However Mr. Le Tirant has stored all of her eggs, hatched and unhatched, on pins and in jars.
Though the pandemic has prevented Mr. Cumming and Mr. Le Tirant from assembly in particular person, they’ve turn out to be quick associates and can quickly end a grander undertaking revising the evolutionary historical past of leaf bugs.
Mr. Le Tirant nonetheless marvels at his luck — of the eggs hatching, and of turning into acquainted with Mr. Cumming just a few years earlier than Mr. Le Tirant might need retired, giving Mr. Le Tirant the prospect to review the alluring bugs close to the tip of an extended profession dedicated to beetles. “You could possibly examine rocks your complete life, or you might examine diamonds,” he mentioned. “What a wonderful insect.”