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August 2020
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It's Probably Not a Murder Hornet
There's been a lot of buzz in the news about the Asian giant hornet (AGH), Vespa mandarinia, popularly dubbed the 'Murder Hornet'. The AGH are voracious hunters that preferring medium to large insects, and are a predator of the European honeybee, which could be devastating to the already-threatened western honeybee population.
See: Varroa mite, pesticide, environmental changes.
The AGH is a large bodied hornet that can grow to be 1.5 to 2 inches long. It has a large orange or yellow head, prominent eyes, and a yellow and black to brown striped abdomen, similar to a honeybee. The first confirmed U.S. report of AGH was in Washington state, December 2019.
There have been no confirmed reports of AGH in Texas. However, it does resemble some of our native Hymenopterans (wasps), including Cicada Killers, Pigeon Horntails, and Yellow Jacket Queens:
Cicada Killers can grow from 0.5 to 2 inches long; have a dull brown head with yellow patching, and a brown to black abdomen with incomplete yellow stripes. Pigeon Horntails can grow to be 1 to 1.25 inches long and have a narrow, elongated body and abdomen compared to that of the AGH. Yellow Jacket Queens can grow from 0.75 to 1 inch and have a predominantly orange abdomen with some black incomplete banding. Patterns vary by species but the bands on the abdomen will always be discontinuous compared to the AGH.
Entomologists in Washington are working with USDA APHIS in hopes to eradicate the invaders while the populations are small. Survey work is currently underway this season, with any positively identified wasp being tracked back to the hive and eradicated. The only confirmed populations of AGH thus far are in the Pacific Northwest of the U.S.
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Cicada Killer (Left) and Asian Giant Hornet (Right).
Pigeon Horntail (Left) and Asian Giant Hornet (Right).
Yellow Jacket Queen (Left) and Asian Giant Hornet (Right).
Credit for all images: Hanna Royals, Museum Collections: Hymenoptera, USDA APHIS PPQ, Bugwood.org
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USDA Investigates Packages of Unsolicited Seeds
About two months ago, mystery seed packets started showing up in mail all over the U.S. Since then, thousands of Americans have reported receiving unsolicited seed packets from China. The USDA has been working diligently with the Chinese postal service and E-commerce companies to determine the origin of the packets and stop the shipments. U.S. Customs and Border Protection officials are working with the USDA to intercept any future packages being shipped to the United States. Official USDA APHIS Reports
Seeds from two noxious weeds, water spinach and a dodder, were identified from two separate seed packages. Another single seed package contained larvae from a common leaf beetle pest. Other tests have concluded that packets contain a fairly common mixture of ornamentals, herbs, fruits, vegetables, and weeds. Officials continue to monitor the situation, as they remain concerned about the possible accidental introduction of invasive agricultural pests or diseases that could cause irrevocable damage to American crops.
At this point is believed that the mystery seeds were sent as part of a "bushing" campaign or scam, where a company ships cheap unsolicited packages and uses fake sales to improve rating in the marketplace.
Recipients are asked to not plant the seed or throw them away but to instead File a Report with USDA officials. After completing the report, you will then receive instructions on how to mail the seeds to the USDA. The USDA APHIS has collected over 900 seed packets, but this is only a fraction of the thousands of packets reported.
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Credit: Kylee N Kleiner, TRIES
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Beauty or the Beast: Spotting the Native from the Invasive
The Yellow Jessamine (Gelsemium sempervirens), nicknamed the Poor Man's Rope, is a beautiful evergreen vine and familiar Texas native that decorates many homes and gardens with its twisting limbs, dark-green foliage and fragrant yellow trumpet flowers. The Cat's Claw Vine (Dolichandra unguis-cati) is an invasive look-a-like and a rampant climber. The vine has bright yellow tubular flowers similar to those of the Yellow Jessamine and large glossy leaves. Cat's Claw vine can grow very large, and the stems can ultimately become tough and woody. Cat's Claw grows quickly, and if left unchecked it can grow to form a dense mat and smother native vegetation.
There are two simple ways to separate the Beauty from the Beast:
Leaves: Yellow Jessamine has simple leaves, with only a single blade. Cat's Claw vine has two compound leaves that are attached opposite each other on the stem with two leaflets, and a third middle tendril with three "toes" at the end that give the plant its "cat's claw" name.
Seed pods: The Yellow Jessamine seed pods grow no more than 1.5 inches long, while Cat's Claw vine pods grow between 9 to 30 inches. The pods are flat capsules similar to those of the trumpet creeper, Campsis radicans, which is in the same family.
If you think you have Cat's Claw vine growing in your yard, please see Management and Treatment Information.
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Cat's Claw Vine (Dolichandra unguis-cati). Credit: Forest and Kim Starr, Starr Environmental, Bugwood.org
Cat's Claw leaves with clawed tendrils. Credit: Photo: Sheldon Navie
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Nutria Make Headlines in Fort Worth and San Antonio
Nutria, or Myocastor coypus, are large, semi-aquatic beaver-like rodents that are dark- to yellowish-brown and about 2 feet long. They have large yellow-orange incisors and a long rat-like tail. Females can have two or three litters a year with up to 15 offspring per litter. They can eat up to 3 pounds per day and feed on various types of vegetation, causing significant ecological damage. Native to South America, this species was introduced to the US by fur traders.
In Fort Worth, groups of 20+ nutria were seen running through Krauss Baker Park. It is relatively uncommon to see so many nutria out in the open. By feeding the ducks, park visitors have kept the rodents well fed and have allowed them to thrive. TPWD officials reported seeing approximately 50 nutria in the park last year. The Parks Department have captured and euthanized 31 nutria so far. Officials hope the media coverage will spread the word about the nutria problem and how feeding wildlife can cause populations to increase artificially and casue further ecosystem damage.
In San Antonio, officials continue to receive reports of nutria in Mission County Park and around Padre Park. It seems nutria have been trapped along multiple segments of the River Walk, including the Mission Reach segment, the low water crossing at Padre Park, areas near the VFW, and close to Lonestar Blvd. The San Antonio River Authority hire specialists to place traps off the trails along the banks of the San Antonio River to catch nutria. Once trapped, they are euthanized. This year fewer than 10 have been trapped in the San Antonio River; 10 in 2019, 60 in 2018, and 32 in 2017.
Nutria are euthanized according to TPWD protocol. It may seem an extreme response, but relocation is not an option and without natural predators nutria can quickly overpopulate and destabilize the ecosystem. See: Nutria
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Nutria (Myocastor coypus). Credit: Royal Tyler, Pro Pest and Lawn Store, Bugwood.org
Nutria and ducks eating pet food left by park visitors in Fort Worth. Credit: WFAA-TV
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Invasive Spotlight:
Asian "Jumping Worms"
(Amynthas spp.)
Other names: Alabama jumpers, Asian crazy worms, snake worms
Most North American earthworms were wiped out over 10,000 years ago during a Pleistocene ice age. Forests evolved to rely on bacteria and fungi for leaf litter decomposition. Earthworm invaders arrived with the European settlers and thrived in the upper soil levels. Any surviving native earthworms remained in the deeper soil levels.
Asian jumping worms have invaded multiple states across the eastern and southeastern U.S. since the 1900s and are antive to Asia. Jumping worms prefer to live in the top few inches of soil and consume leaf litter. Most earthworms introduced from Europe are deep dwellers, that churn the soil while they move and feed.
Jumping worms are a type of earthworm in the genus Amynthas, named for the "jumping" or thrashing movement exhibited when disturbed. They have a milky or light-colored ring, or clitellum, that extends around the body. The color of the clitellum varies slightly by species, but it is always located toward the front-end of the worm. However, European earthworm (genus Lumbricus) bodies are pinkish and the clitellum is more "saddle-like", located farther back on the body. Jumping worms are 6 - 20 cm long, smooth, glossy but not slimy, and gray to brown. Jumping worms leave behind a loose, granular waste product that resembles coffee-grounds.
Jumping worms have an annual life cycle. Juveniles grow rapidly to sexual mature adults (60–90 days), then reproduce and die in the fall. They overwinter in cocoons and hatch the following spring. Jumping worms can live in densities 10x that of European earthworms. They exhibit a greater dietary flexibility, consume and process leaf litter quickly, and can outcompete other soil organisms, like millipedes. They can cover 17 acres in a single season, while the European worms grow slowly, live longer and typically only travel 30 feet per year.
Traits that make earthworms great in the garden are the same that make them detrimental to forest ecology. Experts are concerned about the high number of jumping worms and their swift consumption of leaf litter. The rapid alteration of topsoil can cause erosion and reduce the ability of the soil to absorb and hold water. Native plant germination and soil fungi ecosystems are disturbed by the pebble-like residue from Jumping worms, and leave ecosystems more susceptible to nutrient losses. Leaf litter has declined as much as 95% in some forest study areas. This could be detrimental to the insects, birds and other animals that rely on leaf litter.
Currently no viable control methods exist. The best way to "stop the spread" is preventative care:
• Be careful when moving and purchasing plants. Always check for worms.
• Only use compost or mulch that has been Heat Treated.
• Do not purchase jumping worms for fishing bait or composting.
• Clean soil and debris from tools and equipment, clothing and shoes, automobiles, etc. between use.
See: Stop the Spread, Helpful video
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Credit: Kylee N Kleiner, TRIES
Credit: Kylee N Kleiner, TRIES
Cocoons of Amynthas agrestis (Left) and Amynthas tokioensis (Right). Credit: Marie Johnston
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More News
August is Open Season for Hunting Invasive Insects
Texas A&M Forest Service gets ready for a busy season. This is the time of year when many highly destructive pests are emerging in their adult form to reproduce and lay eggs. One such pest on the Forest Service's most wanted list is the emerald ash borer, or Agrilus planipennis. phys.org.
Invasive Lionfish May Be a Selective Predator
The invasive lionfish, genus Pterois, has become a growing threat to the ecological balance as it has the capacity to dramatically alter marine ecosystems. To gather insight regarding its impact on reef communities, scientists evaluated the predatory behaviors and diet choices of lionfish. Their experiments revealed that most of them actively selected their prey species. sciencedaily.com
First Record of Invasive Shell-Boring Worm in the Wadden Sea Means Trouble for Oyster
In 2014, suspicions arose that the parasite worm Polydora websteri had found its way to the Wadden Sea. Researchers confirm that they have found the shell-borer in oysters near Sylt and Texel and that it has arrived in European waters. sciencedaily.com
Biodiversity May Limit Invasions: Lessons from Lizards on Panama Canal Islands
Introduced species can become invasive, damaging ecosystems and disrupting economies through unchecked population growth. Researchers at the Smithsonian Tropical Research Institute (STRI), are studying invading lizards on the tiny islands that dot Gatun lake. They discovered that islands with native lizard's act as another kind of reservoir, harboring the parasites that control invaders. The study provides evidence that biodiversity is better at making ecosystems more resistant to invasion. si.edu
Invasive South American Fish Known as the 'Vegetarian Piranha' Found in Tennessee
A Tennessee fisherman was quite surprised to reel in an unusual fish with human-like teeth. State officials later determined the fish was a South American pacu, Myloplus zorroi, a species related to the famously vicious piranha. phys.org
How Maths Modelling Helps Efforts to Eradicate Banana Bunchy Top Virus
Modelling the predicted movements of pervasive sap-sucking insects before they infest banana crops has the potential to become a key tactic in the fight against a devastating virus, according to new research. Banana bunchy top virus (BBTV) is an aphid-transmitted banana disease that has been in Australia since 1913. Researchers have designed a model that tracked the probability of a banana plant being infected by aphids that carried the disease. qut.edu
Native Hawaiian Tiger Cowries Eat Alien Invasive Species
Researchers have discovered the Hawaiian tiger cowrie, Cypraea tigris, is a voracious predator of sponges. Among preferred sponge prey is the invasive Orange Keyhole sponge (Mycale grandis) which can overgrow native coral. soest.hawaii.edu
Making the Most of a Tree Epidemic
A large portion of North America's 8.7 billion ash trees are now infested the emerald ash borer beetle, Agrilus planipennis. Cornel devised a plan for all the "worthless" wood. phys.org
Invasive Shrubs in Northeast US Forests Grow Leaves Earlier and Keep Them Longer
The rapid pace at which invasive shrubs infiltrate forests in the Northeastern United States makes scientists suspect they have an advantage over native shrubs. The first region-wide study of leaf timing, conducted by Penn State researchers with the help of citizen scientists, supports those suspicions. sciencedaily.com
New Study Shows Evolutionary Breakdown of 'Social' Chromosome in Fire Ants
Scientists from Queen Mary University of London have found that harmful mutations accumulating in the fire ant, Solenopsis invicta, social chromosome are causing its breakdown. The result has allowed them to become a highly invasive pest all over the world. qmul.ac.uk
Plant Size and Habitat Traits Influence Cycad Susceptibility to Invasive Species
A long-term study on cycads in Guam has revealed how rapidly non-native invasive species devastated the native Cycas micronesica species and the key factors that have influenced the plant's mortality. phys.org
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If you would like to highlight a successful invasive species project or nominate a special person to be highlighted in an upcoming iWire, please send the details to iwire@texasinvasives.org.
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Sentinel Pest Network and Invaders of Texas Workshops
Invaders of Texas workshops train volunteers to detect and report invasive species as citizen scientists. Workshops, which are free, are designed to introduce participants to invasive species and the problems they cause, cover aspects of invasive species management, and teach identification of local invasive plants, and to train participants to report invasive plants using the TX Invaders mobile application. The workshop is 7 hours long (usually on a Saturday, but scheduling is arranged with each individual host group). The workshop satisfies Master Naturalist training requirements.
Sentinel Pest Network workshops serve to increase the awareness and early detection of a set of particularly important invasive species, to help prevent their spread into Texas or their further spread within Texas. Participants learn to identify species such as the Emerald Ash Borer, Cactus Moth, Asian Longhorned Beetle, and other pests of regulatory significance, and to report them. The workshop is 3.5 hours long. The workshop satisfies Master Naturalist training requirements.
Upcoming Workshops:
--None scheduled--
For more information or to register to attend a free workshop, please visit the Workshop Page.
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