I found the most amazing article today about the Two Spotted Spider Mite, a new mite that is ravaging the Americas because the current high temperatures allow them to breed at super speed.
Mites are a completely different animal family to other insects that insecticides usually affect and so are naturally immune to a number of pesticiudes.
However in addition to that, they have a collection of 39 different genes that they can turn on or off to protect them from anything from pesticides to poisons found naturally in plants.
As a result, the mite can feed on over 1100 different species of plant, from human edible fruits such as strawberries to plants that are normally toxic to all life, such as Jimson Weed (Datura)
Once the mite's genome was examined, it was found to have the smallest genome ever found for an arthropod (i.e., spineless animal with an external skeleton, segmented body and jointed legs) at only 90 million base pairs, it is incredibly tiny, most arthropods have genomes with billions of base pairs.
The incredible capacity for destruction that this organism has, combined with it's incredibly tiny genome makes it possible that it was produced by genetic engineering. After all, it wouldn't normally infest temperate regions, because it is kept in check, but once temperatures get over 90 degrees Fahrenheit, the mite begins to breed uncontrollably, laying up to 300 eggs a day without even needing to mate.
Additionally, some of the mites genes are very similar to those seen in bacteria and fungi, leading to the possibility that the organism was 'assembled' out of a toolbox of pre-made genes. Perhaps it was designed to ravage the warmer climates of the Middle East and the Americans are suffering blowback from thier own weapon because of the unusually hot weather.
You can find the original article here:
In addition, there is a very detailed pdf file available from Kansas State University
here.
However, because of the extremely unusual nature of this creature, I am going to put a copy of the article here, incase the original gets taken down for any reason.
[begin article]
Two-Spotted Spider Mites Flourishing
MANHATTAN, Kan. – It’s smaller than a pinhead. Even so, the voracious two-spotted spider mite
could be the world’s poster pest for dry, hot weather.
“They’re doing real damage in Kansas -- even worse than we saw in summer 2011. Two-spotted
spider mites can attack an amazing number of plants. As often as not, today’s scorched-looking
arborvitae foliage and yellowing rose leaves are reflecting both heat-wave stress and spider mite
damage,” said Raymond Cloyd, K-State Research and Extension entomologist.
Two-spotted spider mites produce multiple generations per growing season, Cloyd added. But,
when the weather’s dry and the temperature’s high, they can multiply really fast. Between 70 F
and 85 degrees, for example, the time they need to progress from egg to adult shortens by half
-- from 14 to seven days.
Each adult female in every generation lays an average dozen eggs per day (100 to 300 total).
She doesn’t even have to mate first, the entomologist said.
As a result, infestations easily expand, yet include spider mites in all stages of development.
The mix of stages alone makes controlling the pest difficult.
Adding to the problem, the mites have repeatedly proved they are able to develop pesticide
(miticide) resistance. That has eliminated multiple tools for gardeners, farmers and pest control
pros, Cloyd said.
“Mites aren’t an insect. They’re in a whole different family, along with spiders, ticks and scorpions,”
he said. “Spraying an infested plant with an insecticide simply eliminates the mites’ natural enemies.
Applications of carbaryl (Sevin, Adios, and Slam) have paved the way for some notably severe spider
mite outbreaks.”
Some products labeled for spider mite control also can cause unwanted results. Such
organophosphates as Malathion, Orthene and Dursban may actually stimulate female spider mite
reproduction, [ in addition to being incredibly toxic to humans -ed ]
Fortunately, with enough rain, a naturally occurring fungus helps keep two-spotted spider mites
in check, Cloyd said. When temperatures are moderate, beneficial insects and predatory mites
also serve as a natural control. Their job outstrips their abilities, however, when the weather heats up.
“The classic test for spider mites is to shake a branch over a sheet of white paper and see what falls
onto it. Mites look sort of like a typed period – a half-millimeter dot -- that moves,” he said. “If they
move fairly slowly and leave a green stain when crushed, they’re the two-spotted kind. If they’re
fairly quick and leave a red stain, they’re the beneficial mites that eat other mites.”
Human control efforts are more effective if started when an infestation is small, he said.
Unfortunately, two-spotted spider mites can go unnoticed as the growing season warms up and they
become increasingly active – and numerous. The pests not only are small but also tend to congregate
on the undersides of leaves.
Besides, they seem to prefer older leaves, Cloyd said. For instance, they can cause extensive damage
in a dwarf Alberta spruce before they get around to attacking the external, more visible needles.
(Spruce spider mites also attack these popular evergreens during spring and fall.)
On deciduous plants – pear trees, tomatoes, geraniums and the like – two-spotted spider mites’
damage shows up as small silver-gray to yellow leaf speckles. The mites’ mouthparts are like a
blood-drawing needle. They puncture plant cells and suck out the green chlorophyll.
With enough of that damage, infested leaves yellow, turn bronze and drop. Plants can get weaker,
lose large sections, become deformed or even die.
What’s a Plant Owner to Do?
Curbing two-spotted spider mites in the landscape takes patience and multiple approaches.
“You have to remember this is about management. Total control is impossible. If nothing else, new
spider mites can blow in from a neighbor’s yard, ballooning on the webbing they spin,” the
entomologist said.
Cloyd listed the following as helpful tools in limiting attacks:
* With a magnifying glass or sheet of white paper, start scouting for spider mites in mid to late spring.
* Fertilize enough to keep plants strong and healthy. But, don’t overdo it, especially with soluble forms
Cloyd listed the following as helpful tools in limiting attacks:
* With a magnifying glass or sheet of white paper, start scouting for spider mites in mid to late spring.
* Fertilize enough to keep plants strong and healthy. But, don’t overdo it, especially with soluble forms
of nitrogen. Over-fertilizing promotes soft, juicy tissues that are easier for mites to drain.
* Remove weeds and old garden debris. Either can serve as a breeding ground or winter haven.
* Don’t let plants go without needed water. (Irrigate in the morning to avoid disease problems.)
* A forceful water spray can dislodge spider mites in all life stages – eggs included. So, hose down
* Remove weeds and old garden debris. Either can serve as a breeding ground or winter haven.
* Don’t let plants go without needed water. (Irrigate in the morning to avoid disease problems.)
* A forceful water spray can dislodge spider mites in all life stages – eggs included. So, hose down
infested plants two or more times a week, targeting the underside of leaves. That can be enough to
keep a light infestation in check.
* Both organic and inorganic sprays can help control heavy infestations. Read labels to see if products
* Both organic and inorganic sprays can help control heavy infestations. Read labels to see if products
target a certain life stage. Repeat spray applications, as your chosen label suggests. Be sure to cover
the underside of leaves thoroughly. Don’t use the same product season-long or year after year.
“All of that is important. If you carefully read the label on insecticidal soaps or horticultural oils, for
“All of that is important. If you carefully read the label on insecticidal soaps or horticultural oils, for
example, you may find that frequent applications could harm roses or other plants,” Cloyd said.
* Remember that plant injury can result if you apply any pest control material – miticide, insecticide
* Remember that plant injury can result if you apply any pest control material – miticide, insecticide
or fungicide – when the air temperature is above 85 degrees.
Among the contact sprays that still work on two-spotted spider mites are: bifenazate (Floramite),
Among the contact sprays that still work on two-spotted spider mites are: bifenazate (Floramite),
hexythiazox (Hexygon), fenpyroximate (Akari), acequinocyl (Shuttle), fenbutatin-oxide (Hexakis),
insecticidal soap and horticultural oil. The products that penetrate plant tissues, so work past their
application time include: abamectin (Avid), spiromesifen (Forbid) and etoxazole (TetraSan).
Brief: If It’s Green, Look for Spider Mites
MANHATTAN, Kan. – Two-spotted spider mites have few prejudices. They’re perfectly willing to
Brief: If It’s Green, Look for Spider Mites
feed on an estimated 1,100 different plant species.
“They’re also willing to feed from the time they hatch until they die – through every one of their
“They’re also willing to feed from the time they hatch until they die – through every one of their
developmental stages,” said Raymond Cloyd, K-State Research and Extension entomologist.
The two-spotted mites are houseplants’ No. 1 pest, sometimes enclosing whole leaves in their webbing.
The two-spotted mites are houseplants’ No. 1 pest, sometimes enclosing whole leaves in their webbing.
In fact, Cloyd said, the pests are so tiny that webbing can be the first clue of an indoor infestation.
(Wind and rain typically dispose of webbing spun outdoors.)
Two spotted spider mites also are major damage-causers from commercial greenhouse to farm field
Two spotted spider mites also are major damage-causers from commercial greenhouse to farm field
--where they attack corn, cotton and soybeans They like wild and weedy plants, too, ranging from
berry thickets, Jimson weed and violets to henbit, wild mustard and wood sorrel.
The weeds, in turn, can serve as undisturbed breeding grounds that help the mites spread.
Entomologists at central U.S. land-grant universities have come up with the following, however, as
The weeds, in turn, can serve as undisturbed breeding grounds that help the mites spread.
Entomologists at central U.S. land-grant universities have come up with the following, however, as
some of the landscape hosts that two-spotted spider mites seem to prefer:
Annuals, ornamental - dracaena spike, fuchsia, geranium, hollyhock, impatiens (New Guinea and
Annuals, ornamental - dracaena spike, fuchsia, geranium, hollyhock, impatiens (New Guinea and
garden), marigold, pepper (sweet and hot), petunia, snapdragon and viola.
Annuals, vegetable – beans (various), sweet corn, cucumber, eggplant, muskmelon, squash,
Annuals, vegetable – beans (various), sweet corn, cucumber, eggplant, muskmelon, squash,
tomato and watermelon.
Perennials, mixed - lemon balm, chrysanthemum, columbine, coral bells, daylily, Michaelmas daisy,
Perennials, mixed - lemon balm, chrysanthemum, columbine, coral bells, daylily, Michaelmas daisy,
grape vine, English ivy, rose mallow, mint, monarda, oregano, salvia, creeping phlox,
primula/primrose, scabiosa, speedwell/veronica, strawberry (ornamental and fruiting) and
vinca/periwinkle.
Shrubs - arborvitae, azalea, burning bush, butterfly bush, boxwood, cotoneaster, wall germander,
Shrubs - arborvitae, azalea, burning bush, butterfly bush, boxwood, cotoneaster, wall germander,
holly, hydrangea, juniper, maple (amur and Japanese), privet, pyracantha, rhododendron,
rose and viburnum.
Tree – ash, birch (white/gray/river), cherry, citrus, Kentucky coffeetree, elm, black locust,
Tree – ash, birch (white/gray/river), cherry, citrus, Kentucky coffeetree, elm, black locust,
silver maple, pear, persimmon, plum and poplar.
“The list is handy. But, I’d get a hand lens and take a closer look at any plant that starts losing leaves
“The list is handy. But, I’d get a hand lens and take a closer look at any plant that starts losing leaves
or looking scorched -- particularly during hot, dry weather,” Cloyd said.
Spider Mites: World-Class ‘Adapters’
MANHATTAN, Kan. -- An international team of 55 scientists recently found why the two-spotted
Spider Mites: World-Class ‘Adapters’
MANHATTAN, Kan. -- An international team of 55 scientists recently found why the two-spotted
spider mite is such a survivor. They decoded its genome – its sequence of genes.
The team reported their resulting “gene map” is rather simple for an arthropod (which includes the
The team reported their resulting “gene map” is rather simple for an arthropod (which includes the
insects, crustaceans, and families of centipedes and spiders). Yet, the genome includes more
“detoxification” genes than ever seen before -- genes the mite can turn on or off, as needed.
“The team chose the two-spotted spider mite because it’s a destructive, global pest. It can fairly
“The team chose the two-spotted spider mite because it’s a destructive, global pest. It can fairly
easily develop pesticide resistance. Plus, it can feed on an amazing number of host plants – which
the team put at more than 1,100 plant species,” said Raymond Cloyd, K-State Research and Extension
entomologist.
The mite prefers hot, dry weather, he added. But, it’s a persistent pest for houseplants and commercially
The mite prefers hot, dry weather, he added. But, it’s a persistent pest for houseplants and commercially
grown greenhouse plants, as well as for landscapes, vegetable gardens, market farms, orchards and
row-crops. The mite also thrives on and can spread from a number of weed species.
Cloyd said the team’s kind of research is vital to a world of limited resources and growing populations.
Cloyd said the team’s kind of research is vital to a world of limited resources and growing populations.
It allows scientists to target specific gene segments as they seek ways to limit a pest’s damage.
Among this study’s findings: The spider mite has 39 protein-encoding genes (some previously
Among this study’s findings: The spider mite has 39 protein-encoding genes (some previously
unknown) in one “resistance” family. That’s many times the nine to 14 “detox” genes currently
identified in both insects and vertebrate animals.
“As part of their study, the team switched the mites from one host to another to see what happened,”
“As part of their study, the team switched the mites from one host to another to see what happened,”
Cloyd said. “They found this mite can activate some of those genes and deactivates others, to adjust
to a new situation. Undoubtedly, that’s also a factor in how the mites can actually adapt to toxic plants,
as well as develop resistance to pesticides.”
Strange Facts. . .
* An international team of scientists found a mystery when they mapped the DNA of the two-spotted
Strange Facts. . .
* An international team of scientists found a mystery when they mapped the DNA of the two-spotted
spider mite: Some of the mite’s genes are similar to those found in bacteria and fungi.
* Spider mites got their name because, like spiders, they spin webby strands of silk. While strong,
* Spider mites got their name because, like spiders, they spin webby strands of silk. While strong,
however, the mites’ silk is 185 to 435 times thinner. Spider mites are vegetarians, so they use their
silk for protection and travel, not entrapping prey.
* Scientists are predicting two-spotted spider mites will be a growing concern in a warming climate
* Scientists are predicting two-spotted spider mites will be a growing concern in a warming climate
because the mites multiply extremely fast at high temperatures -- 90 degrees F or more.
* The spider mite genome contains about 90 million “base pairs” of DNA. So far, that’s the smallest
* The spider mite genome contains about 90 million “base pairs” of DNA. So far, that’s the smallest
gene sequence that scientists have “mapped” for any arthropod (i.e., spineless animal with an external
skeleton, segmented body and jointed legs). Other arthropods’ gene maps have included up to
7.1 billion base pairs.
[ In other words, the average arthropod has 79,000 times more base pairs than the Spider Mite - Ed ]
* When scientists switched two-spotted spider mites from one host plant to another, they discovered that
one-half of the mites’ cytochrome P450 family of genes responded by either turning on or turning off.
The mites had adapted with the biggest basic-level change ever seen in an animal.
[ In other words, half of the mites genes are designed to switch on or off depending on their immediate
environment. The significance of this cannot be overstated, this is not the kind of behaviour you find in
nature - Ed ]
There is another article with more technical details of the mite's genetic structure here.
Christopher Carrion.
