Emeralds in New Jersey

I probably need to collect more species of emerald (Somatochlora) than any other group or family. They are often frustrating to catch and I have several species where I've caught one sex but not the other. Most emeralds are northern in range but so far I've done most of my field work in the south. Next summer I plan to spend a lot of time chasing them.

A handful of emerald species are primarily southern. Last year I collected a Calvert's Emerald S. calverti female in Florida and this year in Texas I saw but failed to net any Texas Emeralds S. margarita. A couple of these southern species, Fine-lined S. filosa and Treetop S. provocans, range up the East Coast reaching their known northern limit in New Jersey. Although a relatively small State, New Jersey boasts an impressive odonate list. Southern emeralds are found in the sandy pine habitats in the south and northern range emeralds are found in the bogs and higher elevation of the northwest corner of the State

One of these northern species at it's southern limit is Kennedy's Emerald S. kennedyi. On May 30, 2008 I got to visit a super secret location in Sussex Co. NJ as part of the survey to monitor their population. The bog is protected but it needs active management to keep it from becoming another red maple swamp.

On Sunday, July 13, 2008 I visited the Peaslee Wildlife Management Area in southern New Jersey seeking Treetop Emerald. I visited a couple of sites from Bob Barber's Dragonflies and Damselflies of Cumberland County published by the New Jersey Audubon Society. The publication is 14 years old so it has been interesting and sometimes frustrating trying to revisit some of the listed locations. I'm not sure if I found the first spot I was looking for. If I was in the right place then Cedar Branch is dry and I did not see anything flying in the area. I had driven 2 and a half hours to get there and the morning was slipping away and it was getting hot. I tried a couple of other places but ended up on Hunters Mill Road, the border between Cumberland and Cape May Counties. Driving slowly down the dirt road I saw one of the most exciting sights in dragonflying, the silhouette of an emerald flying overhead.

I pulled over and got out my net. The dragonfly circled appropriately high for a species called Treetop Emerald. I came as prepared as I could bringing all my net handle extensions. From the end of the handle to the top of the hoop, my net was nearly 12 feet long but at that length very difficult to handle and swing. But I needed every inch to catch the first emerald, a young male Treetop.

For the next couple of hours I drove slowly back and forth along the road. Spot an emerald, pull over, assemble the net, try to catch the dragonfly. Repeat. They all seem to be young male Treetops with brown not green eyes. I saw one that seemed to have the slightly different shape of a female but failed to catch her. Activity died as the temperature climbed. I could see that the dragonflies were landing high up in the trees. Interestingly I caught a mature male flying low back and forth over the road at 1 PM.

I hoped that they would resume flying in the late afternoon but I had to pass a couple of hours. I revisted the spot on the Manumuskin River where I caught Fine-lined Emerald in September last year. Didn't see any emeralds there but lots of skimmers (Libellulidae). I tried to catch a strange looking Common Whitetail Plathemis lydia. I assume it was a male, its abdomen had a pied look with just patches of white. It's hind wings had the pattern of a female with dark wing tips but the fore wings had the usual male pattern with a dark stripe at mid wing. I chased it down the railroad track but it eventually flew off into the swamp.

I drove back to Hunters Mill Road and found more emeralds flying after 4 PM. I caught and released another young male Treetop then caught a young male Fine-lined. So both species were present. I tried to concentrate on catching females since I lacked examples of both species. I saw a couple but they tended to fly even higher than the males. As the afternoon turned towards evening I watched one feed until she finally hung up high in a tree presumably for the night. I considered staying overnight with family in Philadelphia and returning the next morning. But I didn't have my laptop, scanner, or any other supplies and I would have to try to keep my specimens alive until the next evening. I decided to head home which turned out to be the right decision since a storm front brought rain overnight through the next morning.

Trip mileage: 374 miles


Kennedy's Emerald young male
Treetop Emerald young male
Treetop Emerald mature male
Fine-lined Emerald young male
Hunters Mill Road