Each year in Batangas, Philippines, a festival is held to help eradicate a major crop pest.  Guest contributor Karen Uy describes the festival, which centers on a cooking contest with a unique featured ingredient: June beetles (Leucopholis irrorata), or as locals call them, salagubang.  

I was first introduced to this insect as a young city girl living in Manila, Philippines.  At the time, I sincerely believed insects belong crushed to death under flip flops and never in one’s mouth.  So when my mother served beetles sautéed in soy sauce, my first thought was “No Way!”  After a long consideration, I decided to try one as a dare. To my surprise, the dare became an awakening experience as I realized eating the bugs was fun and tasty!  And, as the people of Batangas celebrate, eating June beetles provides a fun way to help manage an important pest.

In the Philippines, the salagubang is considered a serious pest of upland crops such as sugarcane and rice causing over 97 million peso (US $2 million) damage annually.  June beetles grow underground as grubs until they are 16-30 mm long, then emerge after the first rain of the season.  Therefore, entire plants are threatened as larvae feed on roots while adults eat leaves.  June beetles are strongly attracted to light and therefore could be caught using a light trap.  Be sure that what you collect to eat has not been exposed to harmful pesticides.

June beetles are also found in the US, and they are just as edible.  Although the bugs aren’t considered invasive in the US, the idea of eating other insects as a way to control populations may be worth serious consideration.

In fact, insects may represent a preferable protein source compared to meat because they have almost no fat and are packed with protein and other minerals.  For example, 100 grams of June beetles have ~13.4 g protein, 6 mg iron, and 22.6 mg calcium while lean ground beef has 27 g of protein, 3.5 mg iron, and no calcium.  The Batangas Salagubang festival is a reminder of a sustainable future where we can turn a negative into a belly-full of positive.

A table full of June Beetles, ready to be eaten! Photo Credit: Karen Uy

Americans and Canadians are hearing more and more about a long-established invasive plant called cheatgrass (Bromus tectorum), especially after this year’s fire season out west.  What’s the connection?  Among other problems, cheatgrass helps contribute to a longer fire season and more destructive fires, which may worsen in the future because this invasive grass seems to benefit from climate change.  Recently, NPR Science Friday featured an interview with several scientists and land managers about the ecological and economic effects of cheatgrass invasion.   My ears really perked up when I heard that cheatgrass can be used to make beer!  Read on, and then gather your brewing equipment while listening to the podcast of the interview (which is very easy to understand and features questions from the public audience).

Cheatgrass dominates large areas of the West

Cheatgrass is native to Eurasia, and was introduced to the USA in the late 1800s, probably via ship ballast (here is a brief history of cheatgrass).  Interestingly, cheatgrass may have first spread to the West because it was used as a packing material for railroad cars.  It easily established because the native herbaceous species had been greatly reduced by intensive livestock grazing, which cheatgrass can better tolerate.  Cheatgrass, like other invaders that we have mentioned on this website, produces huge amounts of seed (more than 5000 seeds per square meter- nearly 500 pounds of seed per acre!) which helps to maintain its dominance once established.  Cheatgrass also out-competes native species because it germinates earlier in the season.

And what about cheatgrass and wildfires?  As explained in the NPR podcast, cheatgrass senescences (stops its growth and dries up) 4- 6 weeks earlier than the native species, increasing the length of the fire season.  Cheatgrass is also incredibly flammable.  Invasion by cheatgrass and subsequent fires eliminate the native sagebrush communities, and the 50 or so animal species that rely on this community type, such as the sage grouse.

One method of controlling cheatgrass is to heavily graze with goats or sheep.  Another way is to re-establish the (perennial) native plant community, and to use biocontrol, such as a fungus which only infects cheatgrass.  As another of our recent posts emphasized, native species are best controlled with multiple methods simultaneously.

And what you have been waiting for… a final way to control cheatgrass (on a small level) is to turn the seeds into beer!  It is described as an amber ale, of a little over 5%.  Ira Flatow (the show’s host) says it is delicious!  Listen in to the podcast about fifteen minutes from the end, to get some detailed descriptions of the taste and some tips on how to start producing.  And be prepared for puns (“I think that Idaho cheatgrass beer would catch on like wildfire.”)

Today’s post was contributed by Dr. Christopher Patrick, an ecologist at the Smithsonian Environmental Research Center.

These fish fight hard, and the small ones (5-20 lbs) taste great!  For this reason they were introduced into lakes, reservoirs, and river around the United States during the 20^th century and have become a controversial invasive presence. 

The blue catfish Ictalurus furcatus is one of North America’s largest catfish.  Native to the Mississippi River drainage, these long-lived, fast growing top predators will consume anything in their path and can reach astonishing sizes in excess of 140 lbs.

Blue catfish at the Tennessee Aquarium. Photo courtesy of Wikimedia Commons.

In 1974, blue catfish were introduced into the James River in Virginia, a tributary of the Chesapeake Bay.  Authorities believed that the catfish would remain contained by high salinity levels down river, and would not be able to spread throughout the many rivers and tributaries that make up the largest estuary in the United States.  Today, the blue catfish can be found in increasing numbers in the Potomac River, another tributary of the Chesapeake, and there is fear that it is only a matter of time before these fish spread to the remaining uninvaded rivers in the Chesapeake Bay ecosystem.  While Blue Catfish cannot tolerate salinity levels in the lower reaches of the main channel, fish may get the opportunity to swim into the channel during major inundation events that reduce salinity levels, such as massive flows recorded on the Susquehanna River following Hurricane Irene in 2011.

Blue catfish have become very popular with local recreational and commercial anglers, while this is a good thing in an invasivore kind of way, Maryland DNR also the fear that misguided anglers could be moving fish to help speed their invasion.  Control efforts in Maryland have been largely unsuccessful so far, but new regulations may begin to have an effect on catfish numbers.

The next time you are in the Chesapeake Bay region, do your part by ordering some local blue catfish, and help eat these voracious invaders out of the Bay!

Nutria (Myocastor coypus), also known as the coypu or river rat, is a 12lb rodent native to South America that has been introduced to North America, Africa, Europe, and Asia and has become especially invasive in coastal regions of the US. They resemble a small beaver with a long, thin tail. Nutria were originally introduced to the US in 1899 to be used in fur farming and were deliberately released in Louisiana in the 1930’s to control invasive water plants. There are nutria populations established in many states, although control efforts have been especially focused in Louisiana, where nutria greatly damage coastal marshes by digging up soil to eat the base of plant stems, roots, and rhizomes. Control efforts have been successful, with a drop in wetland loss due to nutria destruction at nutria survey sites from 27,000+ acres/year in 1998 to just over 1,600 acres/year in 2011.

Chef Philippe Parolla was involved in a movement to popularize nutria for human consumption, but their rat-like appearance made many consumers hesitant to eat them. There are additional markets for nutria as guilt-free fur and as a dog treat ingredient.

Like the common dandelion, we like to call purslane a “gateway invasive” because it is so common throughout North America and represents an easy first target for novice invasivores. 

Purslane (Portulaca oleracea) is an annual succulent plant native to North Africa, the Middle East, and India.  It has been present in North America for a long time (possibly even predating Columbus) but its quick growth habit and ability to sprout up in poor soils and disturbed areas makes it a troublesome weed for gardeners and farmers alike.  Because it is a succulent plant, it is drought tolerant, so you may even have some in your backyard right now- even if the rest of the garden is dead!

Purslane usually grows in a sprawling manner, creeping along the ground.  It has bright green, fleshy leaves that grow to about the size of your thumb nail.  The stems tend to be reddish brown in color.  Purslane flowers are small, yellow, and short-lived.  Purslane only boasts a shallow taproot and puny supporting root system, so it is easily hand-pulled from the ground.

Purslane photo credit Ethel Aardvark c/o Wikimedia Commons

The silver lining of purslane invading your garden is that it is edible.  It is also a great source of omega-3 fatty acids.  Purslane can be enjoyed raw or cooked.  It is popular in traditional Mexican cuisine, and many recipes can already be found online (for example, here).  We’ve just collected a bounty while weeding out our own flowerbeds at home, so keep an eye out for our own recipe contribution soon!

***For recipes featuring this invasive weed, check out our Spicy Purslane Stir-Fry, Cool Cucumber Purslane Salad, and Purslane Relish!*** 

In the novel “A Tree Grows in Brooklyn,” the tree-of-heaven is described as follows: “No matter where its seed falls, it makes a tree which struggles to reach the sky. It grows in boarded up lots and out of neglected rubbish heaps. It grows up out of cellar gratings. It is the only tree that grows out of cement… survives without sun, water, and seemingly earth.”  Indeed it is one of the most stress tolerant (high pH, drought, salinity, air pollution, compact soil) and fast growing trees (more than one meter per year as a sapling!) found in North America, making it a formidable invader and a problem in forested and urban environments.

Tree of heaven (Ailanthus altissima), introduced from China in the 1700s, is short-lived (50 years) and usually gap-obligate (needing full sunlight).  It has invaded much of the USA from Iowa to Texas to Massachusetts and also along the West Coast (as well as throughout Europe, and southeast Australia), most commonly along roads, fence lines, and railroads, and at abandoned mines or dump sites.  Ailanthus can quickly colonize areas of natural forest that have been disturbed by fire, cutting, or heavy insect damage.  The tree outcompetes native forest hardwoods due to its fast growth, many seeds (hundreds of thousands!), and suppression of other species by releasing toxins from leaves and roots (called allelopathy, in which plants release chemicals to kill other plant species).  Ailanthus can grow in concrete and causes urban problems including damage to building foundations and sewer pipes (not to mention the awful smell of the male flowers).

Tree of heaven branch, from invasive.org

Ailanthus can often be identified simply by its extremely fat twigs with large buds, astonishing growth, and long (more than 12”) compound leaves with 11 to 25 leaflets.  However, its bark and leaflets may be confused with ash, black walnut, and other native species.  Ash has opposite rather than alternate leaflets and walnut species have fewer and fatter leaflets.  More good photos and descriptions can be found here and here.  An excellent general guide to native species and their invasive look-alikes is here.

The tree is incredibly difficult to eliminate once established.  If cut, the tree vigorously sprouts from the stump or roots, and combinations of mechanical, chemical, biological and thermal treatment may be needed (application is described here).  Young trees can be removed by hand pulling but you must be sure to remove all root fragments, which can sprout new trees, so pulling in wet soil is helpful.

As it has reached a high volume in some states, and requires high investment to eradicate, ailanthus is a good example of an invasive species that, while it cannot be eaten (sorry, no recipes!), has other uses and can be marketed, providing an economic incentive for land owners to manage this invasive.  In addition to larger scale uses such as pulpwood, the wood can be used as firewood- it is relatively hard and heavy, comparable to oak, ask, maple and hickory.  It must first be dried well for one to three months (preferably away from your home as it harbors carpenter ants!).  A very practical and interesting summary of other uses, and programs by the Department of Forestry in Virginia to test the properties of ailanthus wood, can be found here, and more recommendations are found here.  As these publications show, it can also be used to make charcoal for cooking some of the other tasty invasives found at Invasivore!

Here are some photos of ailanthus outside my work, in Italy.  It commonly colonizes the edges of walls and parking lots.  You can click for zoom ins.

You can see here the bright colored seeds this time of year.

Ailanthus tree 

This tiny seedling is growing right out of the wall. Not a bit of soil!

 This species profile is a guest contribution from Dr. Sean Hoban, a postdoctoral scholar and food blogger in Italy.  

“I still remember discovering a row of small trees with a fruit like a blackberry and leaves vaguely resembling sassafras on my path to school.  After a little research, I began to gather handfuls of fruit each day on my walk home.”  

White mulberry (Morus alba), a fast-growing (as a seedling, four feet per year!), deciduous, medium size (generally 10 to 20 m tall) tree, was introduced from northern China to North America from the 16^th to the 19^th century to feed silkworms.  Though my own row of trees still bore silken nests full of wriggling worms, the silk industry never came to fruition and white mulberry was here to stay, finding use as an ornamental tree and as supplemental feed for livestock in the dry season.  Due to its strong branches, it is also planted as a windbreak and apparently makes a great climbing tree.  It is tolerant of drought, poor soil, and pollution, so is common in urban environments.  Some homeowners plant mulberry because of its propensity to attract many birds- it is a favorite food of cardinals, robins, orioles, finches, thrushes and more.

White mulberry leaves (though considerable variation in leaf structure exists). Photo courtesy of Wikimedia Commons.

With widespread planting over more than two centuries, and continued distribution by nurseries, white mulberry has naturalized in semiurban and rural areas in most states and three Canadian provinces as well as central Asia and southern Europe.  A detailed description of its invasive occurrence, by region, is found here.  Rapid growth, aggressive and deep roots, tolerance of poor soils, and efficient dispersal mechanism (small mammals and birds eat the berries, spreading them far and wide) makes white mulberry a terrific invader.  White mulberry can be particularly difficult to eradicate once established.  If cut down, stumps can sprout and grow vigorously into a new tree.  It can form dense stands that exclude other plants.  One of the main recognized threats of white mulberry is to the native red mulberry (Morus rubra), found throughout the eastern hardwood forest.  The species are weakly differentiated genetically and ecologically, and are highly interfertile.  Therefore, the non-native is a direct and successful competitor for space, and is gradually replacing the native with hybrids- white mulberry and hybrids may now outnumber the native red mulberry!

Distinguishing the two species is difficult, but guides with excellent pictures of buds, bark and leaves can help.  One way you can control this invader is to make sure that your next nursery purchase is a native red mulberry rather than its invasive relative (and request that your nursery promote indigenous species in general).  Also, inquire with your local, state, or regional authorities to see if parks and roadsides are landscaped with natives.

If you are able to identify the white mulberries in your neighborhood or local woodlot, you can help limit reproductive success through delicious harvest!  Stay tuned for our tips on white mulberry harvest and preparation.

Popular worldwide as a food source, pet, and for educational purposes (who hasn’t dissected one?), the American bullfrog has also become a formidable invasive pest.  

brrrrrp... I'm invading an aquatic ecosystem near you. (Photo credit: Wikimedia commons)

The American bullfrog (Lithobates catesbeianus or Rana catesbeianus, depending on who you talk to) has a lot to offer.  It’s a large charismatic amphibian that can be kept as a pet, dissected in a science classroom, or eaten as a great source of protein.  Unfortunately, the many uses of American bullfrogs also led to considerable export over the last 200 years.  Native in the eastern United States, American bullfrogs have become invasive in western US and have also been established intentionally and unintentionally in over 40 countries around the world.  Their progress has been described as nearly unstoppable, and models suggest that climate change may only serve to exacerbate their invasion in some areas.

Where they have been introduced, American bullfrogs have had dramatic impacts due to their voracious appetites, prolific reproduction, and adept dispersal.  Tadpoles gobble up algae and can outcompete other organisms for valuable resources.  As adults, bullfrogs will eat whatever they can fit into their mouths- insects, small amphibians, other bullfrogs, rodents, snakes, even birds.  In addition to limiting resources for other species, bullfrogs turn a lot of those calories around into reproduction- a female can produce 20,000 eggs in a single clutch, and an average of around 5,000 of those will actually hatch.  Finally, bullfrogs can transmit chytrid fungus, a disease that has been plaguing amphibian populations worldwide.

With such dramatic impacts, it’s no wonder that the American bullfrog has found its way onto the IUCN list of the world’s 100 worst invasive species.  Even the folks over at “Save the Frogs!” don’t like them!  As a result, there’s a lot of interest in bullfrog control.  We recently got our hands on some frog legs, and coming up we’ll share a few ideas on how invasivores can do their part to quell this invasion.

Native to China, Russia, North Korea, and South Korea, the northern snakehead (Channa argus), is now found in many parts of the eastern United States and California preying on native fish populations.  Their introduction to the United States can be attributed to both release from the aquarium trade and live food fish trade.  One specific introduction in the year 2000 to a pond in Crofton, Maryland utilized both these pathways when a local resident purchased a pair of live snakehead to prepare a traditional soup remedy and instead kept them as pets.  Unable to keep up with their appetites, the pair of snakeheads was released and propagated like mad!

The scary face of the northern snakehead Channa argus.

In the waters of the Mid-Atlantic and the south (warmer relative to its native northern Asia), the northern snakehead can reproduce all year and grow to lengths greater than 1 meter (3 feet).  As adults, they prey mostly on fish but are capable of eating amphibians, birds, and small mammals.  However, as juveniles, they can be subject to predation by the invasive blue catfish (Ictalurus furcatus Lesueur, 1840).  Northern snakeheads are obligate air breathers which facilitates their hardiness and ability to survive a lengthy trip from Asia out of water. These traits make this invasive species so dangerous that the Maryland Department of Natural Resources has issued a mandate for fishers to kill upon capture.

Their overconsumption of native aquatic species will not only decimate native populations but will likely cause millions of dollars in damages as well.  A market already exists that is facilitated by consumption; can snakehead be another gateway to invasivory?  Chef Chad Wells is already preparing it for culinary masses!

I don’t care whether you call them invasive pigs, feral swine, or wild boars; just don’t call me late for dinner when this tasty beast is the main course! 

The feral pig Sus scrofa represents an interesting case study for the invasivore because they have a long history as both bounty and burden.  Wild pigs are descended from domestic livestock that was introduced around the globe during the human era of exploration.  Since being introduced in North America by Spanish explorers in the 1500s, wild pigs now occur in almost every state in the US.  Feral pigs can reach nuisance levels in their native central Europe and Asia, and introduced populations also occur in South America, throughout the Caribbean, in Sub-Saharan Africa, and Australia.  So there are probably feral pigs nearby as you read this!

A wild boar near you, ravenously looking for food. (Photo courtesy of Wikimedia Commons)

The popularity of feral pig hunting in North America has grown over time because wily feral pigs can provide a thrilling hunt (we recommend Mark J. Hainds’ Year of the Pig for an overview) and a bounty of meat.  Unfortunately, this popularity has led some hunters to release domestic pigs or maintain protected land to harbor feral pig populations, solidifying the establishment of invasive populations.  These activities are falling under increasing scrutiny in places like Michigan, Missouri, and Tennessee, where officials are trying to manage the negative impacts feral swine can impose.

The negative impacts of feral swine are far-reaching.  Because they are voracious omnivores, feral swine will readily consume small mammals, ground birds and eggs, reptiles, decaying matter, and plants.  Feral pigs seem to particularly enjoy plant roots, and their rooting behavior- churning up the earth with their tusks in search for food- can be particularly disruptive to local vegetation, including native plants and agricultural crops.  Feral swine can also carry diseases that can infect domestic livestock or other wildlife.  Finally, feral swine are very smart, making them escape artists who are also excellent at hiding.  While this contributes to the thrill of the feral pig hunt, it also makes eradication and control efforts difficult.

Feral pig rooting can dramatically impact landcapes. (Photo courtesy of hogstoppers.com)

With their dramatic impacts and popularity in sport hunting, feral swine are a regular feature in environmental news (for example, check out most of our Out to Eat! Weekly News Roundups).  We’re doing our part here at invasivore.org, and in the coming posts, we’ll be describing our experiences enjoying our first feral pig roast as well as sharing a recipe for delicious pulled feral pork sandwiches.