Anyone who has had a treasured palm tree annihilated by palmetto weevils (Rhynchophorus cruentatus) knows the pain of losing a long-lived tree from the home landscape. These large, native weevils are adept at working unnoticed inside a palm to the point of terminal damage. Typically, by the time you notice that the tree is declining and fronds begin to turn brown there is likely no hope of salvaging the situation. By then the larval grubs have already damaged the tree’s growing bud to the point of no return. At this stage the recommended procedure involves removing the tree, cutting it up and burning it to prevent the invading long-snouted critters from moving over to neighboring palms.
Color and size of adults is quite variable.
However, as frustrating as this is, if we step back and look at the bigger picture it is apparent that even our most aggravating native insect pests are part of the natural web of life and local plants have adapted to survive these “give and take” relationships on the population scale.
Palmetto weevils establish in a new tree when adult females lay their eggs in the crown of the tree and larvae hatch to burrow into the soft terminal bud. It is larval feeding that does the lethal damage. Larvae are large, white, legless grubs that can reach lengths of six-seven centimeters. When larvae are mature they create a cocoon inside the tree from tree fibers and pupate there before hatching into adults to start the cycle over. Grubs can be found in any part of the tree but really need the softer, growing parts for food, such as in the base of the living fronds and the terminal bud.
Weevil damage at base of frond.
The condition created by these burrowers is often referred to as “popped neck,” where the top of a palm tree dies and caves over. If you are in the process of removing a dying or dead palm due to the crown dying it would be a good idea cut through the top section with a chainsaw to see if weevil damage is evident in large (about ½ inch) diameter tunnels. If a live specimen of an adult can be captured in a jar it would be worth a visit to your local Extension office for a positive identification to make sure you aren’t dealing with another similar species of non-native weevil that has not been documented in Florida yet. The red palm weevil (Rhynchophorus ferrugineus) has now been found in the U.S. at Laguna Beach, California. Coloration varies by individual bug but a positive i.d. can be obtained by sending the specimen to UF’s laboratory in Gainesville. For further information on palmetto weevils refer to the EDIS fact sheet at this web link.
“Imitation is the sincerest of flattery,” wrote Charles Caleb Colton. Colton was a sometimes cleric, essayist, wine merchant and gambler who bounced around Europe and North America during the early nineteenth century. It is likely many of his financial lenders hoped the public would not imitate his borrowing practices.
Aside from his few literary works and the catchy phrase above, he was most noted for running up debts then leaving for parts unknown.
Eye spots on a Luna Moths wings are meant to deceive potential predators into believing they are seeing another predator. Photo by Les Harrison.
Imitations are not looked upon kindly when lazy students, or journalists for that matter, complete an assignment by borrowing blocks of text. Plagiarism is a flunking and firing offense with career-ending potential.
The concepts of imitation and mimicry date back to the earliest written records of ancient Greece. The philosopher Plato used mimicry to define beauty and truth, and as a contrast to the negative aspects of life.
For the denizens of north Florida’s untamed regions, mimicry is a form of imitation which assures the survival of some. Survival always beats the alternative.
Insects are particularly effective at using several forms of mimicry to survive and reproduce in a very hostile environment where big hungry creatures always are on the prowl for their next meal. Eyes and disguise are the top tactics for continuation of the species. Multiple eyes on the bug’s face are common in the insect world. Large, eye-like spots on the rear of the bug are an effective form of defensive mimicry used by several local caterpillars species.
The saddleback caterpillar is a good example of how this deception is carried. There are two color-coordinated eye-like spots on the rump of this caterpillar. These spots are exponentially larger than the saddleback’s real eyes, which are barely visible without the aid of magnification. An approaching predator will quickly notice the blankly staring spots and likely recall the last encounter with this appropriately named creature.
Mature larvae of the saddleback caterpillar, Acharia stimulea (Clemens). Photo by Lyle J. Buss, University of Florida.
It is worth noting the saddleback caterpillar has more defensive weapons systems than an Ageis missile cruiser. The novice predator that attempts to dine on this colorful, plump morsel will always remember the experience.
In addition to insects and caterpillars, some spiders have eye-spots on their thorax. Depending on the circumstances, the hunter can easily become the hunted.
Juvenile water moccasins or cottonmouths are brightly patterned with a yellow tail tip that they wiggle mimic insects attracting small prey such as lizards, toads, and frogs. Photo courtesy of J. D. Wilson and the University of Georgia.
Another mimicry tactic is camouflage, the ability to blend into the background and avoid detection. Millions, if not billions, of dollars of hunting clothing is sold annually to provide deer and turkey hunters that perceived advantage over their potential trophy animal. Moths are quite adept at using this technique to hide in plain sight. In the wild they almost always rest or lay eggs on surfaces which closely resemble their color scheme.
The last form of mimicry occasionally seen is the lure. This method attracts the prey to its demise. A prime example is employed by young water moccasins which have a sulfur-yellow tipped tail. The tail is shaken to resemble a wounded insect as the snake hides in the leaf litter. The unwitting victim is surprised, no doubt, to discover its status as a menu item.
