Sunday, July 10, 2011

Insects at Willowwood Arboretum

Yesterday I was at Willowwood Arboretum in southern Morris County. In addition to the formal mansion garden and a Japanese garden, the arboretum holds several acres of meadow habitat bordered by small patches of woodland. This makes the property an excellent place to look for insects, particularly in July and August when insect diversity is at its peak.

Overall, I recorded 17 species of butterflies in Willowwood's fields yesterday. Many were common butterflies, like this Red-spotted Purple. Red-spotted Purple is actually a subspecies, Limenitis arthemis astyanax, and shares the species designation with White Admiral, Limenitis arthemis arthemis. White Admiral tends to be more northerly than Red-spotted Purple, though both subspecies can be found in northeastern states.

Other common butterflies included this Great Spangled Fritillary, Monarchs, Common Wood Nymphs, and Pearl Crescents. The latter two were by far the most abundant butterflies I encountered yesterday. Strangely, I did not see any of the less common browns.

This American Copper was one of the less common species I observed. This species is widespread, but apparently its abundance is highly localized. It is also tiny, which makes it even easier to miss.

The meadows tend to be fairly dry, so the arboretum is not as rich in odonates as a wetter habitat would be. Still it is possible to see some pretty attractive species there. Above is my favorite dragonfly, the Twelve-spotted Skimmer. A lot of the dragonflies in the meadows cruise around fairly high off the ground, which makes them hard to photograph, and sometimes even hard to see.

Another of my favorite odes is the Ebony Jewelwing, a stunning metallic green damselfly with black wings. A few of these were active along the bank of a stream that borders one of the meadows.