Don’t let the brilliant color of this gorgeous Saica assassin bug fool you. The hook at the tip of its beak spells trouble for small creatures on the rainforest floor.
Among the spoils of a decimated colony of some unidentified sucking insects, this handsome assassin bug poses for a bug geek.
Last week we traveled to the rainforests of Belize to meet beguiling stingless bees. This week we continue our adventure in the rainforests of Belize where we meet two members of the assassin bug clan. In some of the most-watched previous episodes, we saw a ferocious assassin bug called the wheel bug dispatching stink bugs and impaling caterpillars with its terrifying proboscis. While strolling through an orchard at the Toucan Ridge Ecology and Education Society we came upon a magnificent plantation of Inga trees. These beautiful trees, native to the American tropics, are favorites among foresters and coffee plantation owners by virtue of their rapid growth, delicious edible fruit, and ability to improve poor soils with magical nitrogen-fixing properties. In addition, some species have extrafloral nectaries, small glands that produce sugar-rich nectar to attract beneficial insects. Not only do these nectaries deliver an element of protection to Inga but they also provide a modicum of pest control to crops like coffee trees growing nearby. Despite their admirable growth characteristics and ecosystem services, Inga trees are not immune to their own pest problems. On several of the Inga trees patches of flocculant white wax coated the undersurfaces of leaves. Coatings of white wax are a telltale sign of sucking insect pests like scales, whiteflies, aphids, and mealybugs. We found oodles of white wax, but search as we might all the wax-producing insects had vanished. Roaming around the leaves were several pretty pale green, long-legged bugs with rows of black spots along their backs and patches of yellow-orange adorning heads, legs, and derriere. We could not pin down the identity of this beauty, but it had a strong resemblance to assassin bugs in the genus Zelus we met in a previous episode.
See the dense forest of tiny hairs on the forelegs of this assassin bug. Like biological Velcro they help the bug snare its prey. And look at that terrifying hooked beak, perfectly designed for impaling its victims. We found this gorgeous predator wandering the rainforest floor perhaps in search of a tasty invertebrate for lunch. On the leaves of a nearby Inga tree, other pretty assassin bugs rested amidst the waxy remains of a disseminated colony of sucking insects. As we tried to record this predator, it did its best to escape the nosy lens of the camera.
At the Mayan ruin of Xunantunich, students discover Mayan history, culture, and insects of the tropical rainforest.
Nearby, at the edge of the Inga orchard, a brilliant red assassin bug in the genus Saica prowled the leaves and grasses on the ground looking for something to stab with its extraordinary beak. Little is known about the feeding habits of these slender legged assassin bugs. Some of their relatives prey on spiders and other ground dwelling invertebrates. These assassins amble about on middle and hind legs thereby freeing up their front legs to capture prey. Their modified prey-capturing legs are called raptorial legs. The upper segments of the assassin bug’s forelegs were festooned with hundreds of small prickly hairs designed to help grasp hapless victims destined to fill the belly of the beast. But as I had a closer look at this tiny terror, I marveled at its beak, the business end of the assassin bug. Unlike other assassin bugs I know that have powerful but unremarkable beaks, this one had a baleful hook at the tip of its proboscis. All the better to impale and subdue its prey I suppose. So many tiny wonders are to be found in the tropical rainforests of Belize.
Acknowledgements
We thank Drs. Dan Gruner and Paula Shrewsbury and the hearty crew of BSCI 339M: Tropical Biology and Maya Culture for providing the inspiration for this episode of Bug of the Week. Special thanks to assassin bug genius Tom Henry for help identifying this week’s stars. The fascinating references “Saica Amyot & Serville, 1843 (Reduviidae, Emesinae, Saicini): taxonomic revision and phylogenetic analysis with morphological characters” by Valentina Castro-Huertas and Maria Cecilia Melo, “Extrafloral nectaries of associated trees can enhance natural pest control” by M.Q. Rezende, M. Venzon, A.L. Perez, I.M. Cardoso, and Arne Janssen, and “Evolution of the assassin’s arms: insights from a phylogeny of combined transcriptomic and ribosomal DNA data (Heteroptera: Reduvioidea)” by Junxia Zhang, Eric R. L. Gordon, Michael Forthman, Wei Song Hwang, Kim Walden, Daniel R. Swanson, Kevin P. Johnson, Rudolf Meier & Christiane Weirauch, were consulted to prepare this episode.