|Description:||Under a moderate magnification of 437X, this scanning electron microscopic (SEM) image depicted some of the morphologic details found on the exoskeletal surface of an unidentified hornet discovered in the suburbs of Decatur, Georgia. In this particular view, we see a close-up of the numerous sensorial “hairs”, or “setae”, which adorn almost the entire exterior, providing the hornet with data indicative of changes encountered in its environment such as chemical, thermal, and tactile queues. These setae are composed of chitin, unlike mammalian hair, which is composed of the molecule keratin. Also note the shingle-like arrangement of the hornet’s exoskeletal surface from which the setae originate.|
Chitin is a molecule made up of bound units of acetylglucosamine, joined in such a way as to allow for increased points at which hydrogen bonding can occur. In this way chitin provides increased strength, and durability as an exoskeletal foundation. This chitinous exoskeleton gives rise to a myriad of morphologic shapes, including these “scales”, setae, antennae, legs, and mouthparts.
This hornet was a member of the Phylum Arthropoda, i.e., Arthro = jointed, and poda = legs, and the class Insecta, for it possessed three pairs of these jointed extremities. The hair-like setae provided the hornet with data indicative of changes encountered in its environment such as chemical, thermal, and tactile queues.