Thursday, May 30, 2013

Southern Leopard Frog

Young Southern Leopard Frog, Rana sphenocephala
The Southern Leopard Frog has a range throughout the eastern United States, reaching as far north as Nebraska and New Jersey. Although the color may vary within the shades of brown and green, the light line along the upper jaw and dorsal ridges, as well as the light spot on the tympanum, help distinguish this species.  The southern leopard frog can reach a length of 9 cm (3.5 in) and has a high, far-reaching jump. In some areas of its range, breeding can take place year round with metamorphosis occurring between 60 to 90 days.   This species has a distinctive laughing call to aid in identification.

Tuesday, May 28, 2013

American Dagger Moth

Caterpillar of American Dagger Moth, Acronicta americana
The American Dagger Moth caterpillar is densely covered in yellow to white hairs with black lashes on the first and third segment, plus an unpaired lash on the eighth segment. They feed on a variety of trees including box elder, elm, ash, oas, hickory, walnut, and other deciduous trees. The general rule of "never touching fuzzy caterpillars" applies to this species which has toxins in the hairs that can cause irritation. The caterpillars are generally seen close to June through October with two broods in the South. The small, gray moth is seen mostly in the eastern portion of North America from April to September.

Thursday, May 23, 2013


Radiation fog formation not long after sunrise.
A cloud is a concentrated suspension of tiny water droplets, but when formed at ground level, it is known as fog. There are six types of fog for which are determined by the way it is formed. When moist air is cooled below its dew point by contact with cold land surface which is losing heat by radiation, it is known as radiation fog, and is often seen near sunrise. A cool land mass where warm moist air, often from over water, can cause the air to saturate forming advection fog. All sea fogs are advection fogs as the oceans do not radiate heat similar to land, therefore it never cools sufficiently enough to produce radiation fog. Upslope fog is found within the mountain ranges as well as hillsides. A light wind pushes moist air up to a level where it becomes saturated and condenses, usually a good distance from the peak. The supercooling of water droplets forms a freezing fog. These water droplets remain in liquid state until touching a surface in which they can freeze. When the air temperature is well below freezing, generally near the poles, it causes the fog to be entirely composed of tiny suspended ice crystals.

Tuesday, May 21, 2013

Western Salsify

Western Salsify, Tragopogon dubius
Western Salsify, or Goat's-Beard, is a grass-like biennial originating from Eurasia and Northern Africa, now found throughout most of North America. As part of the Asteraceae family, this flower contains a milky sap to make it unpalatable for grazing, but has no known toxicity. It was a common food source during the Middle Ages, and brought to North America by settlers as both a food source and ornamental. Flowering occurs May through September with flowers opening in the morning and closing by midday. Western salsify prefers dry, open sites and is often found along the edge of fields.

Thursday, May 16, 2013

Giant African Millipede

♂ Giant African Millipede, Archispirostreptus sp.
A male Giant African Millipede is identified by the gonopods, or "modified legs". These are usually located on the seventh sternite of the body of the adult male form. For the female millipede, the vulvae is located under the second sternite where sperm may be stored for up to months. She will later make a nest of compressed soil below ground to lay hundreds of eggs, which remain unfertilized until that process. Although the female may guard the eggs until they hatch, she will abandon the young right after hatching.

Tuesday, May 14, 2013

Hackberry Butterflies

Texas Tawny Emperor (Caterpillar), Asterocampa clyton texana
The Hackberry Butterflies of the Asterocampa genus has three species found within North America: the Hackberry Emperor (celtis), the Tawny Emperor (clyton), and the Empress Leilia (leilia). The caterpillar stage of these butterflies has a distinct forked end and a head with two branched projections. As the common name of this genus implies, their host plants are within the hackberry genus, Celtis. In warm climates, there are three generations per year resulting in these butterflies being seen spring to fall.

Thursday, May 9, 2013

Clearwing Butterflies

Clearwing Butterfly, Ithomiini
The Ithomiini is a tribe of Neotropical butterflies within the subfamily of Danainae, along with the tribes Tellervini and Danaini, which together contain close to 400 species. The theories of both Batesian and Müllerian mimicry were developed thanks to this tribe which is known for the unpalatable adults. This is due to their sequestered dehydropyrrolizidine alkaloids, most coming from the nectar of Eupatorieae and the leaves and stems of Boraginaceae. As the males visit these sources more frequently, the role of these alkaloids may play a role beyond defense.

Scales are not completely absent as seen in the edges of the wings.
Belonging to the tribe Ithomiini, the clearwing butterflies capture the imagination with their translucent wings. Butterflies and moths are of the order Lepidoptera, or "scaly wing" as the wings are covered in hair-like structures called setae. These are overlapping pieces of chitin, referred to as scales, which give the wings color and distinction. In the clearwing butterflies, the scales are missing. One hypothesis points to the difficulty of spotting these butterflies when in flight as the sunlight goes through the wings. The glasswinged butterfly, Greta oto, is the most well-known, but is not the only species with the characteristic clear wings. 

Tuesday, May 7, 2013

Clearwing Moths

Snowberry Clearwing, Hemaris diffinis
The clearwing moths, often called hummingbird moths, are found throughout North America. Of the four species, the two most familiar are the Snowberry Clearwing, Hemaris diffinis, and the Hummingbird Clearwing, Hemaris thysbe. The coloration is best to differentiate the two as the snowberry clearwing is often confused for a bumblebee. The western Rocky Mountain Clearwing, Hermaris thetis, is similar to the snowberry, but the ranges are separate.

A bumblebee mimic with wing position as one way to differentiate.
The adults feed on nectar of a variety of plants including bluebells, verbena, lantana, lilac, thistles, and bee balms whereas the caterpillars are more restricted to snowberry, honeysuckle, dogbane, and members of the rose family. The cocoons of this genus are found within the leaf litter on the ground with two broods per year. Adults are found flying from March to September in the south, but with a shorter season in the north.

Thursday, May 2, 2013


Spittlebug froth, Cercopidae
Spittlebugs are the nymph stage of froghoppers, named for the mass of spittle used to protect themselves from drying out. In the family Cercopidae, these native pests often appear around May and June. The adult form, which does not produce spittle, is around July to August. They can be distinguished from leafhoppers by the shorter hind tibiae which have strong lateral spines. While the nymph stages may slow plant growth and distort plants, they do not cause enough harm to justify treatment. As a native species, the natural enemies, of which include parasitic wasps and fungal diseases, help control the population.