Did you know that there is a primitive group of the hymenoptera with free-living larvae that look very much like the caterpillars of the lepidoptera? Known as the Sawfly, there are morphological distinctions between them and the caterpillars and they can also be distinguished by this defensive posture adapted by the Sawfly larvae (Arge sp.) pictured here.
The mimicry that insects exhibit can be astounding. Walking around Shaw Nature Reserve this summer, I noticed quite a fresh and disgusting looking bird dropping on a small bush near the trail. Something made me take a closer glance and I discovered it wasn’t a poop at all, but a caterpillar. The caterpillar was an early instar of the Giant Swallowtail Butterfly (Family Papilionidae). These caterpillars feed on member of the citrus family, the Rutacea, and this individual was found on a small hop bush. Youngsters like this one will most often be found directly on the surface of a leaf (as poops are most likely to be found), while older stages are likely to be found on leaf petioles or slender branches. In citrus production areas of the south, these guys have the nickname “Orange Dogs” due to their dietary needs. They can be considered a pest in such situations. Unfortunately, I forgot that, if harassed these guys will evert a pair of bright red structures called osmeterium. The function of these organs appears to be defensive in multiple ways. Often brightly colored, they can look quite like the forked tongue of a snake, and go along with other morphological adaptations in some members of the swallowtails in making them appear like a snake. In addition, numerous chemical compounds can be released with the osmeterium that have been shown to repel ants and other potential insect predators.
Moving from bird droppings to the droppings of a caterpillar we come to this fascinating creature that is most often found on raspberry bushes. A member of the diverse family of beetles – the Chrysomelidae, this Warty Leaf Beetle (Pacybrachis nigricornis), will tuck in its appendages and drop, looking exactly like a caterpillar’s droppings, or “frass” (anyone remember the action figures from the 80s, the Rock Lords?).
Marshall, S.A. 2006. Insects Their Natural History and Diversity. Firefly Books Ltd.
Evans, A.V. 2014. Beetles of Eastern North America. Princetone University Press.
Damman, H. 1986. The osmeterial glands of the swallowtail butterfly Eurytides Marcellus as a defense against natural enemies. Ecol.Entomol. 11: 261-265.
Tonight we have a couple of native bees photographed this summer at Shaw’s Nature Reserve. I may very well be incorrect, but I believe the bee pictured above is a Mining bee in the family Andrenidae. I would love to know how much pollen is taken away in a season by these guys.
The final two photos show a sweat bee (Halactidae). These are quite challenging to photograph, but worth the effort.
How fascinating a beetle. Did you know this group of beetles begin their lives as kleptoparasites – stealing food from the the nests of solitary bees? As adults these beetles are primarily nectar and pollen feeders and use the specialized mouth parts visible in this photograph to collect their food – primarily from the flowers of Asteraceae. If that were not enough, these guys get their names from a defensive chemical they produce called cantharidin which can produce severe chemical burns and blisters when sprayed on skin and severe poisoning if ingested. This chemical has proven an effective treatment against diseases such as cancers and leishmaniasis. This guy was found at Shaw Nature Reserve.
The Snowberry Clearwing is a member of the Sphinx Moths (AKA Hawk Moths). Its name comes from the fact that one of this species important larval foods is the Snowberry plant. Sphinx moths are important pollinators and are often mistakenly identified as Hummingbirds or Bumble Bees due to their size and their habits of visiting flowers. Most Sphinx Moths are active nocturnally or at dawn and dusk, but the Snowberry Clearwing is diurnal. One Missouri favorite, the Missouri Evening Primrose of glade habitats, shares an obligate pollination mutualism with a species of Hawk Moth, meaning that no other animal can provide pollination services for this plant. This is a photography project someday in the future!
The caterpillars of these moths are known as “hornworms”, and they are just as fascinating as the adults. Included in this group is the Tobacco Hornworm, which is a notorious pest on tomato plants. A useful natural controller of hornworms are the parasitoid braconid wasps that lay their eggs on the developing moth and whose larvae then eat the caterpillar from the inside out.
Next time you are in the garden, take a closer look at that bumblebee or hummingbird. It might not be what you assume it to be!
That’s right! I am excited to announce that OZB will once again be presenting his work (~100 unique prints will be available) at Art at the Shaw Nature Reserve 9th Annual Show & Sale to be held the weekend of November 8th and 9th. I would love to meet and say hello to all of you who have given me support through our relationships via Flickr and A Thousand Acres of Silphiums over the years. There will be more than 20 artists, providing art in a wide variety of mediums, including one particularly pathetic photographer… 😉 Here are directions to the show…
Perhaps the most appropriately named warbler, this special bird is said to nest almost exclusively in pine trees and is one of the earliest nesting warblers within it’s range. These special birds were a thrill for us to find and watch. Closeup images of the male bird were taken at Big Spring State Park, while the nest was located in a Short-leaf Pine located on a parking lot within Shaw Nature Reserve.
The chicks were adorable and near-helpless, only able to open their gigantic craws at anticipation of a juicy insect meal.
During the time Steve and I strained our necks watching the child care from ~50 ft below, we were able to observe that when dad visited the nest he always approached from the side of the nest facing us as seen in the image below. Mom always visited on the opposite side, affording us poor looks. It was interesting to observe that both parents approached the nest in a slow and indirect manner, usually starting low in the nest tree or an adjacent neighbor. They would then hop from branch to branch, often in a spiral up the tree to reach the nest. I do not remember watching either parent make a direct flight to the nest.