During winter break, some adventurous students at the University of Maryland participated in a course that took them on a remarkable adventure to the rainforest in Belize to study Mayan culture and the fascinating creatures and plants in tropical ecosystems. By some strange coincidence, Bug of the Week happened to stow away on this tropical odyssey.
The Belizean jungle is a dangerous place for an insect. Hungry iguanas, motmots, and coatimundis search the vegetation for tasty insects. Insects have clever ways of escaping or dissuading other animals hoping to have them for dinner. Monarch butterflies and their larvae contain chemicals toxic to predators. Velvet ants pack a powerful sting. Their bright colors warn predators not to fool around with them. Many residents of the rainforest have evolved another way of reducing the risk of being eaten by a predator. They are cryptic and simply blend in with the background of their environment. On our visits to the jungle, we saw many examples of this cryptic life style.
Warriors and hunters often wear patterned clothing or pieces of vegetation to break up the outline of their body and blend in with the surroundings. This form of crypsis is called camouflage. While I rested against a tree in the rainforest, I noticed an almost imperceptible twitch as I brushed my hand across the tree's surface. Upon closer inspection, I discovered a remarkable katydid doing its best to resemble the mottled and lichen encrusted bark. This master of disguise certainly looked nothing like a tasty meal for a hungry bird or lizard passing by. Katydids like this one are relatives of the common bush katydid that we met in September of 2005 in "Katydid?". Most katydids make sound by rubbing a structure called a "file" on one wing against a second structure called the "scraper" on the other wing. The resultant vibrations produce the katydid's song. I noticed that our lichen-colored Belizean katydid had very tiny wings. I wonder if it sings very tiny songs. A short time later on the bark of another tree, I spotted a couple of small twigs that looked out of place. These were the legs and antennae of a well-camouflaged longhorned beetle.
As adults, longhorned beetles eat leaves and fruit, but the larvae have powerful jaws that enable them to bore through wood and feed on plant tissues beneath the bark of branches, trunks, and roots. We saw the larvae of longhorned beetles in February of 2006 in the episode called "Beetles roasting on an open fire". These boring larvae can be very damaging to plants and are commonly known as roundheaded borers. One final master of disguise was spotted by a student as it rested on the railing of a porch. The wings, body, and legs of this insect resembled the contorted remains of a dried and withered leaf. However, closer inspection revealed a remarkable jungle predator, a praying mantis. This form of crypsis, known as masquerade, occurs when an insect resembles an inanimate object that a predator would have no interest in consuming. In this case a hungry bird intent on finding a bug is unlikely to be interested in eating a dead leaf. Notice how the veins in the wings of the mantis resemble veins of a leaf and the tips of the mantis's wings curl as would a dried leaf. The dried leaf mantis is a relative of one we met in September of 2005 in "The Chinese praying mantid". It is a "sit and wait" predator meaning that it remains motionless and awaits a hapless and unsuspecting victim to pass nearby before striking and making its kill. Undoubtedly, masquerading as a leaf helps in this endeavor.
We thank Kristina for posing with the mantis for this Bug of the Week. The delightful bug book "The Insects" by P.J. Gullan and P.P. Cranston was the reference used for this week's episode.