November 2023
Male-Killing Insect Virus

The scientific world of endless discovery is a marvelous thing. The scientific process is not all about being right or wrong, but about supporting or negating findings so as to strengthen an observation (or hypotheses). For those unfamiliar with this wacky world, many things can seem confusing, magical, or topsy-turvy. In this world, “negative” results can be good and should never be discounted, peer evaluation can be a helpful tool, and “mundane” repetition is key. The road to progress and discovery spits you out onto a busy highway, where you never know when you will be stalled or re-routed. However, one of the greatest things for those with ever curious, grouping minds, is that you never know what will place you back on that road towards an on-ramp.

A group of scientists at Minami Kyushu University, Miyazaki, Japan, experienced one of those great moments in science this month, when they stumbled upon a new discovery that could aid pest and invasive insect population control. They found a male-killing virus, called SIMKV, inside tobacco cutworms that selectively targets males only and is inheritable across generations. What makes this extra exciting is this discovery was found by chance due to curious minds and the pure desire to explore.

During campus greenhouse maintenance, tobacco cutworm caterpillars (Spodoptera litura) were found and brought to an insect physiologist on campus, who decided to use them as feeder insects. Because this was not typical routine, the researcher forgot about the caterpillars and several days later found a container of adult moths. Typical, except they were all female. On a hunch, the females were bred with males collected from another location. Once again, all the offspring were female. This happened consecutively over 13 generations. Of all the descendants produced over that time, only three had males.

Microbial symbionts that hitchhike inside the cytoplasm of insect cells are not unknown or uncommon. However, in most cases the hitchhiker is a bacterium that is somehow inheritable from parent to offspring and can affect host reproduction, usually by killing underdeveloped males or preventing male birth. Researchers at Minami Kyushu U. determined they were not dealing with a male-killing bacteria after they introduced antibiotics to infected cutworms with no success. Genetic analysis revealed that not only was there a virus present instead of a bacterium, but it was a virus that had not been seen before. To further support data that suggested SIMKV was infectious and inheritable, a slurry of smashed up infected pupae and adults was injected into noninfected specimens. Each generation born following this procedure produced more females and fewer males, until eventually no generation were born with males.

Upon further investigation, the SIMKV virus was found to be vulnerable to heat. High temperatures cause the virus’s effects to diminish or become neutralized. Since tobacco cutworms prefer subtropical climates, researchers suspect balmy temperatures keep the virus suspended. It was just another example of chance that the cutworms were collected during a mild summer, whose lower temperatures allowed the virus to ‘activate,’ which allowed researchers to observe the sexual imbalance.

Researchers believe that male-killer viruses in insects are likely more common than was once anticipated. Advancements in areas like these are foundational keys to advances in invasive species mitigation and pest control. Better understanding of male killing bacteria and viruses can also help with the development of a potential ‘female-killer.’

Read the article: Nagamine et al., 2023.



 Merle Shepard Gerald R.Carner and P.A.C Ooi. Insects and their Natural Enemies Associated with Vegetables and Soybean in Southeast Asia. 2Tobacco cutworm (Spodoptera litura). Credit: Merle Shepard, Gerald R.Carner, and P.A.C Ooi, Insects and their Natural Enemies Associated with Vegetables and Soybean in Southeast Asia.

tobacco cutworm caterpillar. K. Kiritani 2Tobacco cutworm caterpillar. Credit: K. Kiritani,

Male killing virus by KK copyFemale tobacco cutworms infected with SIMKV male-killing virus were mated with uninfected males. All offspring of each generation were female. After 13 generations, few to zero males were produced according to Nagamine et al., 2023 . Credit: KNKleiner, TRIES.


C[Ant] Love No More

A quote from ‘Little Creatures Who Run the World’ by E. O. Wilson, says, “Not all ants use violence to dominate their world, some use more subtle methods.” This is one of my favorite insect related quotes, not only because it is cheeky, but because there is so much truth in such a simple statement. Social insects, such as ants, bees, termites, etc., have gained the reputation of being efficient team players. However, this teamwork efficiency is not restricted to the colony. Ants often form mutualistic relationships with plants, fungi, bacteria, and other insects. Butterflies and ants are known to form myrmecophilous relationships (literally meaning ‘ant love’). Butterfly larvae benefit from the presence of ants because they provide protection against predation and/or parasitism. This results in an increase in butterfly survival rate. In exchange the tending ants are provided with resources (examples of myrmecophily). This dynamic seems to shift when invasive ants are introduced to the ecosystem, especially when ant becomes predator and butterfly becomes prey. In these situations, mutualism is set aside and the violent side of ants comes out to play.

After a two-year research survey, evidence suggested that butterfly abundance may be reduced due to the presence of red imported fire ants (Solenopsis invicta, RIFA). The survey area included three Texas ranches. Researchers treated adjacent quadrants of land with heady-duty ant bait that was administered by helicopter. Sections of land between quadrants were left untreated. Pollinator traps of different colors were set at different intervals across all sites. Accumulated results revealed that butterfly abundance was over 26% higher in treated areas compared to untreated areas. This suggests the presence of RIFA negatively affects butterfly abundance. Researchers believe this is because of fire ant predation. Researchers found 1.3x as many overwintering butterflies in the treated areas compared to untreated areas. Butterflies that overwintered in untreated areas during immature life stages (eggs, larvae, or chrysalis) were more vulnerable to RIFA predation. Researchers determined further evaluation and research is needed in order to better understand the effects of RIFA on butterfly abundance and to better evaluate the suggested evidence that some species may be affected differently than others.

Read the research: Geest et al., 2023

‘An ant is a wise creature for itself, but it is a shrewd thing, in an orchard or garden.’ - Francis Bacon.

ant-butterfly friends
Crematogaster hodgsoni ants attending to a lilac silverline caterpillar. Credit: Ashok Sengupta and G.S. Girish Kumar.

Fire-ants-butterflies-pic of traps
Example of blue, white, and yellow colored traps set out by researchers to collect pollinators. Credit: David Berman

fire ants on butterfly
Caption Fire Ants (Solenopsis invicta) eating Palamedes swallowtail in Tiger Bay Forest, FL. Credit: John Serrao, Science Photo Library

Citrus In Your Backyard!

The Asian citrus psyllid (Diaphorina citri) and the Citrus Greening pathogen (Candidatus liberibacter asiaticus) are threatening citrus in multiple Texas counties, and we need your help to collect samples to monitor the spread to ensure that you and your neighbors are not affected. This pest and pathogen are extremely detrimental to Texas citrus, both economically and agriculturally. The presence of either can greatly affect citrus yield.

TISI is offering FREE diagnostic services! If you suspect your citrus has either the psyllid pest or the Citrus Greening pathogen, or you would like your citrus plants to be part of our screening survey, contact

We will send you all the instructions you will need. If you are located within 200 miles of our headquarters, we can collect samples, and/or provide traps and monitoring services ourselves. Not only will we share the results and management strategies (where applicable), but you will become part of a multi-county monitoring survey that is striving to improve the health of Texas citrus!

Also Available: TISI offers educational workshops that highlight information about the Asian citrus psyllid, the pathogen Citrus Greening, and what you need to look out for in your own backyard. If you are interested in this, TISI will provide trapping materials, assist with management strategies, and more. Don’t waste another second. Help us stop the spread!

symptoms of citrus greening. Jeffrey W. Lotz. Florida Department of Agriculture and Consumer Services.
Symptoms of citrus greening bacterium. Credit: Jeffrey W. Lotz, Florida Department of Agriculture and Consumer Services,

citrus greening
Leaf mottle on grapefruit, a characteristic symptom caused by citrus greening bacterium but also seen on trees infected by Spiroplasma citri. Credit: J.M. Bove.

Student Art Contest

The Washington Invasive Species Council (WISC) and the Washington Department of Fish and Wildlife (WDFW) invite school-age students to participate in an art contest to help spread the word about not spreading invasive species. You do not have to be a Washington resident to enter the contest.

The goal of this contest is to capture the creativity of young people to help spread the word about invasive species related damage and how we are all affected.

The contest is divided into three divisions of students:

Grade school (kindergarten through fifth grade)
Middle school (six through eighth grade)
High school (9th-12th grade)

The submissions window is now open. All submissions must be entered by May 31, 2024. Additional general information, prizes, etc. can be found HERE. A list of ‘species of most concern’ and the contest rules can be found HERE.


student art contest
Student Art Contest. Credit: Washington Invasive Species Council.

Horizon Scanning How To

Horizon scanning is an evidence-based process with combined risk screening and consensus-building to identify threats. This has become a valuable tool for prioritizing invasive species management and prevention. Click HERE to watch a presentation that will explain how to conduct a horizon scan for invasive species threats using Florida as an example. Provided by the Invasive Species Centre.

Invasive Species Centre  copy

North American Invasive Species Management Association Training Webinars

This program is designed to provide the education needed for professionals and students who are managing or learning to manage invasive species. The courses include the most current invasive species identification, control, and management techniques, and how to comply with local and federal regulations.

Participants may register and enroll at any time, and will receive a certificate of invasive species management from NAISMA upon completion of the program.

All live webinars are open to the public. Recorded webinars are available to members of NAISMA.

NAISMA 2020 Webinar Schedule:

  • December 20, 1pm CDT- The Dilemma for Control of Invasive Species: Incorrect Terms Limit Our Capacity to Respond. REGISTER.
  • January 17, 1pm CDT- Protecting Threatened and Endangered Species from Pesticides. REGISTER.



NAISMA Weed Biological Control 101 Course

NAISMA is offering a short course that guides participants through the fundamentals of classical weed biocontrol. The Classical Weed Biological Control 101 Short Course is separated into multiple chapters, each of which is covered by a different biocontrol professional. Each chapter will review the science and regulations that guide the practice, covering all the steps from pre-release studies to post-release monitoring. Students will leave the course with a foundational knowledge of background principles that guide classical biological control (CBC) and learn how to distinguish CBC from other forms of biocontrol.

This course is intended for anyone interested in learning more about classical weed biological control. No previous experience is necessary, but knowledge of general ecology and invasive species concepts is helpful. A certificate from NAISMA will be issued upon successful completion of the course.

To register for this course or for more information: click here.

For additional invasive species management courses, see the NAISMA online learning library.



NAISMA bio 101NAISMA Weed Biocontrol 101 Course. Credit: NAISMA.

Invasive Spotlight:

Tropical Soda Apple
(Solanum viarum)

Tropical soda apple (Solanum viarum), a native to Argentina and Brazil, is an upright, thorny perennial subshrub or shrub that grows from 3 to 6 feet (1 to 2 m) in height, with prickly stems and leaves. It produces clusters of tiny white flowers, and green-and-white mottled young fruit that mature to yellow golf-ball sized fruit. Its fruit is sweet smelling and attractive to livestock and wildlife, which eat it and spread the seeds. Tropical soda apple remains green over winter in most southern locations. It is typically found in open semi-shaded areas such as pastures, ditch banks, roadsides, recreational areas, citrus groves, sugar cane fields, and wet areas of rangeland. It is usually found in poorly drained and sandy soils, but cannot survive in extremely wet soils.

Tropical soda apple causes several problems as it has the ability to grow and spread quickly. Each plant can produce approximately 50,000 seeds. Ecologically, it reduces biological diversity in natural areas by displacing native plants and disrupting ecological integrity. Its prickles can restrict wildlife grazing and create a physical barrier to animals, preventing movement through infested areas. Agriculturally, tropical apple soda infests crop fields and reduces usable pastureland and can prevent cattle from reaching shade. Tropical soda apple can play host to several viruses and insect pests that attack important vegetable crops. The fruit contains solasodine, which is poisonous to humans. Because of these threats, tropical soda apple is on the Texas Department of Agriculture and Federal Noxious Weed Lists. This species has been reported in East Texas.

If you believe you have found tropical soda apple, please REPORT IT! here. For more general or management information, see the species page.

tropical soda apple. James Rollins. 
Tropical soda apple ( Solanum viarum) vegetation. Credit: James Rollins,
tropical soda apple flower and fruit. Charles T. Bryson. USDA Agricultural Research Service.
Tropical soda apple flower and fruit. Credit: Charles T. Bryson, USDA Agricultural Research Service,

soda apple eddmap
U.S. distribution of tropical soda apple. Credit: EddMaps

Get Involved Today!!

The Texas Invasive Species Institute (TISI) and The Texas Research Institute for Environmental Studies (TRIES) have many surveys and projects underway. These facilities strive to provide yearly invasive species presence and absence data to the authorities. Pre-screening is one of the first lines of defense in the war against invasives. However, sometimes it is hard to do it alone.

With the aid of the public and citizen scientists, we could cover a much wider area, and gather a more substantial amount of data. When it comes to protecting our environment, there is an opportunity for everyone! Together we can make a difference, one research project at a time.

See how you can get involved by reading the projects listed below or see all the available projects on the Texas Invasives website HERE.

Aquarium Watch: Looking for Prohibited Invasive Aquatic Species

Please help and natural habitats by looking for 14 prohibited or invasive aquatic species that might be for sale in your local aquarium store(s). With just one photo you can assist us in finding and documenting which stores are selling prohibited or invasive species. will use this information to contact the appropriate Texas institutions to ensure the appropriate steps are taken for each case.

If you would like more information please email, and mention you want to assist with our Aquarium Watch.

Air Potato Survey

Help Texas Research Institute for Environmental Studies conduct an air potato survey by actively reporting any infestations seen in your area. The air potato (Dioscorea bulbifera) is a fast growing, high climbing vine. Potato-like tubers are the primary means of reproduction for this vine. They can be as small as a marble or as large as a softball. Native yams are often confused for air potatoes. To avoid this confusion, please refer to the key below:

- Plants rhizomatous; bulbils never produced in leaf axils; petiole base never clasping the stem; Native D. villosa
- Plants tuberous; bulbils produced in leaf axils; petiole base sometimes clasping the stem; Invasive D. bulbifera

For additional information, please refer to the TexasInvasives information page.

If you believe you have identified an air potato vine, please email and include the following information: an image, an approximate number of vines present, the location (including whether it is on public or private land), and if bulbils are present (the potato-like tubers that emerge from the stem).

Participation opportunities
Participation Opportunities. Credit: KNKleiner, TRIES.

Armorded catfish. Photographer United States Geological Survey
Armored catfish (Hypostomus plecostomus). Credit: United States Geological Survey.

air-potato (Dioscorea bulbifera)2 bulbil. credit Karen Brown
Air-potato (Dioscorea bulbifera), bulbil emerging from leaf axil. Credit: Karen Brown.

Video Invasion

Monthly video picks about invasive species or the people that want to tell us more about them. There are some amazing citizens and professionals around the world that poke, prod, chase, dive, and investigate everything they can about these alien invaders. Jump into this cinematic rabbit hole. You never know what you may learn.

Spot on Science: Invasive Species. NewsDepth

Many of the plants, animals, and insects you see each day are not native to the U.S. The European starling (Sturnus vulgaris) was introduced on purpose, zebra mussels (Dreissena polymorpha) were accidentally introduced via ships, and commonly garlic mustard (Alliaria petiolate), knotweed (Polygonum sp.), or purple loosestrife (Lythrum salicaria) many have great names, but their impact on ecosystems is not so great.

6 Invasive Species That Are Actually Saving the Planet. SciShow

Even though the word "invasive" comes with negative connotations, not all non-native species are invasive and not all invasives are terrible! Here are six “invasive species” that can do more good than harm.

3 Invasive Species That Prey on Other Invasive Species. Tsuki

Invasive species can threaten native wildlife and cause an imbalance in the ecosystem. In areas effected by multiple invaders, it is not uncommon for various invasive species to find themselves not only in competition with each other but preying on each other. This video will explore 3 invasive species that prey on other invasive species.

More News

Climate Catastrophe Produced Instantaneous Evolutionary Change
A form of evolution called ‘spatial sorting’ is used to describe what many invasive and native insects do after climate catastrophes, such as Hurricane Harvey.

Bumble Bees Drop to Shake Off Asian Hornets
Bufftailed bumble bees (Bombus terrestris) display a remarkable behavior to shake off attacking Asian hornets (aka. yellow-legged hornets, Vespa velutina). With Asian hornets reported in the U.S. for the first time, is this behavior enough for bees to stave off hornets, and at what cost?

In Search of Butterflies, I Learned to Battle Invasive Species
A single homeowner’s journey to remove invasive species from her yard in the hopes to encourage butterflies to return.

Genomics Detective Work Reveals Pest Moth Travels
The fall army worm moth (Spodoptera frugiperda) is an invasive pest to agricultural crops. Analyzing the genetic markers and gene flow could provide vital information about pesticide resistance or how to slow/stop spread.

Soil Carried on Sea Freight Loaded with Dangerous Pests and Diseases
Live microorganisms, worms, seeds, insects, and various regulated biosecurity organisms were found in soil collected from the external surfaces of sea freight.

Invasive Species Aren’t Always the Bad Guys
The disappearance of native seed dispersers has led to a 60% decline in some plants struggling to keep up with climate change. In some cases, invasive species may be the lifeline native plants need to adapt.

Navy Works With Local Partners to Eradicate Invasive Species
Military and contractual divers are working together to protect the marine ecosystem in and around Pearl Harbor to stop the spread on aquatic invasive species.

Study Combines Drones with GPS Tracking to Survey Feral Pig Abundance and Density
Aerial drone surveying was combined with GPS tracking to account for variations between data collection and environmental factors that would influence detection and population estimates of feral pigs (Sus scrofa).

Missing Shipwreck Found After 128 Years Thanks to Invasive Species of Mussels
In the process of producing a documentary about mussel species, including zebra mussels (Dreissena polymorpha), two filmmakers accidently stumbled upon a missing shipwreck.

Operation Launched to Halt Introduction of Invasive Species
China General Administration of Customs launched a special operation to combat the illegal introduction of invasive species after an international report highlighted the threat of spread through trade and travel.

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, teach identification of local invasive plants, and 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:

Dallas County Master Gardeners Workshop
November 16th
Time: 11am
Contact: Sue Smith (

CITRUS WORKSHOPS: Stay tuned for upcoming 2023 virtual weekend presentations about Citrus diseases and FREE testing we offer at Texas Invasive Species Institute.