Tag Archives: beetle rearing

Beach Day for Beetles!

The largest-ever reintroduction of an endangered tiger beetle happened quietly in the morning of October 19th, 2017, on a foggy beach in the Connecticut river. These beetles are the rare Puritan Tiger Beetle, Cicindela puritana , or “PTB” as tiger beetle experts call it. This species is listed as federally threatened and state endangered due to a century of human use that has changed the Connecticut River’s flow. This change has reduced desired habitat, and left only one viable population of PTBs in New England. This reintroduction of more than 700 laboratory-reared PTB larvae is only part of a multi-year, team-project to establish sustainable populations of PTB in the Connecticut River.

Endangered Puritan Tiger Beetle male.

This project, which is supported by the Cooperative Recovery Initiative program and based at the Richard Cronin Aquatic Resource Center in partnership with Silvio O. Conte National Fish & Wildlife Refuge, unites a seasoned team of over 30 Federal & State wildlife officials, professional Biologists, Academic partners, students, and generous volunteers. Together, this group is pioneering methods to acquire land, captive-rear larvae, manage habitat, and use field-techniques to ensure the survival of PTB throughout one of the largest rivers in the Northeast.

Volunteers from the U.S. Fish & Wildlife Service, the Student Conservation Association, and the University of Massachusetts prepare a plot before larva reintroduction.

To restore a healthy river ecosystem that includes these tiny apex predators, lab-reared PTB reintroductions are key to establishing new populations. To do this, the PTB team uses aerial “butterfly” nets to carefully collect adult beetles from the single source-population. The adult beetles mate and lay eggs in the lab, which hatch into larvae that grow progressively larger through 3 growth phases, called instars. In the wild, it takes about 2 years for PTB larvae to reach their third instar, but in the lab, this time can be reduced to just a few months.

Rodger Gwiazdowski moistens the top layer of soil with river water at 1 of 7 reintroduction plots.

The reintroduction sites were carefully selected by the PTB team. Finding good habitat requires expertise to determine sediment size, beach slope, and the abundance and diversity of prey that PTBs prefer. To be reintroduced, PTB larvae are transported to the site, each in their own small sand-filled vial, and released into plotted-areas on the beach where they immediately dig vertical tunnels in the sand to develop through their instar stages. 

Volunteers release PTB larva into the sand.

Over the next 2 years, the PTB team will revisit the reintroduction sites to count the number of PTB burrows and adult beetles, which will indicate the success and survival rate of the lab-reared PTBs.

Stay tuned for 2018 updates on the PTBs!

Got loosestrife? Now’s the time to check!

Today Katrina Scheiner, biologist at Great Meadows National Wildlife Refuge in Sudbury, Mass., shares the refuge's efforts to control a highly invasive plant. Photo courtesy of Katrina.

Today Katrina Scheiner, biologist at Great Meadows National Wildlife Refuge in Sudbury, Mass., shares the refuge’s efforts to control a highly invasive plant, purple loosestrife. In this photo, Katrina is pulling another invasive plant, water chestnut. Photo courtesy of Katrina.

What is purple loosestrife? You’ve probably seen it, and right now it’s in full bloom.

It’s a tall plant with spires of bright purple flowers that grows in wet areas. It’s very pretty, very invasive, and very hard to get rid of.

Purple loosestrife is a tall invasive plant with magenta-colored flowers that adapts to wetland areas. Once established, the plant begins to compete with native plants reducing natural habitats for waterfowl and other species which depend on aquatic environments.

Purple loosestrife is a tall invasive plant with magenta-colored flowers that adapts to wetland areas. Once established, the plant begins to compete with native plants reducing natural habitats for waterfowl and other species which depend on aquatic environments. Credit: USFWS

Native to Europe, purple loosestrife was introduced to the U.S. in the early 1800s both on purpose, as a medicinal herb, and accidentally by way of contaminated ballast water on ships. It didn’t take long before loosestrife infested the eastern seaboard, and now it’s has spread through almost all of the U.S.

Purple loosestrife is remarkably difficult to remove for a number of reasons:

  • Each mature adult plant is capable of producing tens of thousands of seeds;
  • Its woody roots allow it to regenerate (so even after all your hard work, it might come back) and are difficult to pull up;
  • It grows in wet areas, so mowing is not always an option; and
  • Burning is not effective and may even damage native plants.

So how do we control this noxious weed? Many conservation organizations now use biological control.

Six different European insect species appear to be the most effective. They have been carefully studied to make sure that they don’t become an invasive problem themselves. They are host-specific, which means that they feed and reproduce solely on loosestrife.

Adult Galerucella beetle.

An adult Galerucella beetle. Credit: Katrina Scheiner, USFWS

Two of the most successful insects are the Galerucella calmariensis and Galerucella pusilla beetles. The adults and their larvae feed on the stems and leaves, stripping the plant of its foliage and reducing its ability to flower and set seed.

Larva on the purple loosestrife. Credit: Katrina Scheiner, USFWS

Larva on the purple loosestrife. Credit: Katrina Scheiner, USFWS

After obtaining permission from the state environmental conservation department to release beetles, organizations can purchase beetles from a supplier. If there is an existing beetle population, they can bolster the wild populations by raising beetles in a rearing facility. Raising your own beetles can engage local conservation partners, volunteers and even youth groups.

Partnering with the Sudbury, Assabet, and Concord Rivers Cooperative Invasive Species Management Area, Great Meadows National Wildlife Refuge of the Eastern Massachusetts Complex ran a beetle rearing facility for the second year in a row this past spring.

“Beetle rearing facility” may sound high-tech, but we’re just creating a mock wetland environment. Plastic kiddie pools provide the water, and potted loosestrife plants provide tasty food for our beetles. We dig up loosestrife root balls in early spring and plant them in pots in the pools and let them grow until they’re tall and leafy enough to support beetles. If your facility is in a publicly accessible spot (we housed ours at Assabet River refuge’s visitor center), having signs or other outreach materials lets visitors know why you are actively growing an invasive species!

Removing mesh nets, which protect beetles, to release the beetles from the loosestrife. Credit: Katrina Scheiner, USWFS

Removing mesh nets, which protect beetles, to release the beetles from the loosestrife. Credit: Katrina Scheiner, USWFS

After the plants are big enough, we slip fine mesh nets over them, supported by tomato cages or bamboo poles, and we collect wild beetles from local wetlands and add them to our netted pots. The nets keep the beetles in and predators out. Birds, amphibians and other insects all find Galerucella quite tasty, and we want as many of our beetle babies to survive to adulthood as possible.

Note the sign that we used to mark our plants. Credit: Katrina Scheiner, USWFS

Note the sign that we used to mark our plants. Credit: Katrina Scheiner, USWFS

After a little over a month of careful monitoring, the new generation of adults is ready for release! We grew 50 pots of loosestrife in our 2013 facility and estimate that we reared between 25,000 and 50,000 new adults. While that sounds huge, several thousand beetles are released for each infested acre.

Are you interested in starting your own beetle rearing facility? Right now is a great time to get started! Loosestrife is in full bloom, so now you can mark ideal sites to collect rootstock for your facility.

You collect the roots in early spring, when all that’s left are the dead sticks of the previous year’s growth. Flag each plant now, and collecting the roots in the spring will be a breeze!

Galerucella eggs. Credit: Katrina Scheiner, USWFS

Galerucella eggs. Credit: Katrina Scheiner, USWFS

Want to learn more? Visit our watershed blog or contact Amber Carr at amber_carr@fws.gov. Also be sure to check our Neponset River Watershed Association’s Flickr for hundreds of really great photos from their beetle raising efforts and all of their wonderful volunteers! You can also check out a similar effort led by our West Virginia Field Office.