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Flickering and
Fluttering Fungus Gnats
Picture of adult fungus
gnat. Photo by Texas A&M
University:
http://hortipm.tamu.edu/pestprofiles/other/fungnatd/fungnatd.html
Adult
fungus gnats can be
found in almost all
plantings. They are
primarily a pest insect
in greenhouses, but they
can become a problem in
houses in the winter.
Houseplants may become
infested with fungus
gnats during warmer
weather and then are
brought indoors, which
allows them to continue
developing indoors.
Adult fungus gnats are
1/8 to 1/10 inches in
length, grayish black in
color, slender bodied
with long legs and
antennae. They also are
identified by the vein
pattern on their wings,
since they have a
Y-shaped wing vein.
Fungus gnats are
typically weak fliers,
so they usually remain
near the potted plant or
rest on foliage or
growing media.
Fungus gnats undergo
complete development:
egg, larva, pupa and
adult. Female fungus
gnats lay tiny, oval
semi-transparent eggs in
moist organic debris.
Fungus gnat larvae are
legless, elongate, white
to clear in color, with
shiny black heads. They
eat organic mulch,
compost, root hairs, and
fungi. The larvae can
damage roots of plants,
causing wilting, poor
growth and loss of
foliage. Pupation occurs
in the soil in silk-like
cocoons. The complete
lifecycle from egg to
adult usually occurs in
about 4 weeks, and they
continue to reproduce
throughout the year,
especially in controlled
environments such as
greenhouses or homes.
Some
Suggestions for Control
Measures:
Some Prevention Methods
-
Inspect plants
before purchasing
and use sterile
potting soil.
-
Allow
soil to dry for
several days to kill
some larvae, since
overwatering, poor
drainage and water
leaks can result in
a large population
of fungus gnats. If
the top layer of the
soil becomes dry the
larvae will die and
the females will not
lay eggs in the
soil.
-
Discard plant, if
heavily infested as
to avoid infesting
other plants.
Some Biological Controls
-
Some
larvae predators
include Steinernema
spp. nematodes,
Hypoaspis spp. mites
that can be applied
to the soil.
-
Bacillus
thuringiensis
israelensis (Bti)
can be applied to
the soil to control
larvae.
Some Chemical Controls
-
Larvae can be
controlled by many
chemical drenches,
including the
chemicals
azadirachtin,
fenoxycarb and
imidacloprid.
-
Adult
fungus gnats can be
controlled by foliar
treatments,
including the
chemicals bifenthrin,
permethrin,
resmethrin, and neem
oils.
Wet Weather
Could Mean
Springtail
Outbreaks
Photo of a springtail,
Order Collembola. Photo
by Dr. Bart Drees,
Professor and Extension
Entomologist, Texas A&M
University.
With all
the rain and snow, we
might see an outbreak of
springtails in all
areas. Large numbers of
springtails usually
occur together on water
surfaces such as in
puddles, ponds and
swimming pools,
especially the "water
springtail", Podura
aquatica (Linnaeus).
When these springtails
occur in large numbers
and search for a new
location, they can enter
homes and invade
kitchens and bathrooms.
They tend to crawl up
the sides of houses and
enter them through gaps
between bricks or around
doors and windows. They
usually die quickly
after entering a home,
due to low humidity and
lack of food. However,
springtails can live a
longer time in indoor
potted plants or in
buildings with a high
level of humidity.
Springtails are small,
about 0.04 to 0.2 inches
in length and they are
wingless. They vary in
color ranging from black
to gray to white,
yellow, lavender, red,
green or gold, depending
on species. Some
springtails are even
patterned and some are
iridescent or metallic.
Springtails get their
common name from a
forked structure called
a furcula on the end of
their abdomen, which
allows them to catapult
forward when they are
disturbed. This allows
them to be able to jump
3 to 4 inches in some
cases. Springtails
develop through
incomplete
metamorphosis, having an
egg, nymph and adult
stages. This means there
is little difference in
the appearance of the
nymph and adult forms,
except in size. They are
able to have multiple
generations a year.
Sometimes
springtails are
misidentified as fleas,
since they can occur in
homes and jump. However
springtails are round
and soft bodied, instead
of dark brown and
flattened like fleas.
Springtails also have
normal sized hind legs,
whereas fleas have
enlarged hind legs to
allow them to jump.
Springtails feed
bacteria, fungi,
lichens, algae and
decaying vegetation.
Some species feed on
carrion, and a few
carnivorous species eat
other springtails and
small invertebrates. In
addition, some species
feed on plant roots or
on tender young plants,
occasionally damaging
potted or greenhouse
plants. However, they
are harmless to man and
animals.
Populations of
springtails tend to rise
and fall depending on
temperature, moisture
and food availability.
They tend to flourish in
shady areas, that are
rich in decaying leaves
and humus, but they can
be found in urban lawns
Some
Control Options:
To reduce
the population of
springtails outdoors,
reduce watering
turfgrass or irrigate no
more than once a week.
Be sure to water the
soil deeply each time,
about 1 inch
penetration.
To reduce
springtail invasions
indoors, seal all cracks
and crevices with caulk
or expanding foam. Also
check weather stripping
around doors and windows
and replace when needed.
Also rake leaves and
mulches 1 foot away from
foundations, so
springtail populations
do not increase around
structures.
Insecticides can be
applied around the
perimeter of the
foundation, including
areas around windows or
doors, under siding and
in openings in brick or
wood walls. Insecticides
containing such
chemicals as permethrin,
bifenthrin or cyfluthrin
can be used.
If
springtail infestations
continue to occur
indoors, it may be due
to populations living in
potted plants or moist
areas in walls or
storage areas. They will
tend to infest areas
that are moist and have
fungal growth. This
includes areas such as
toilet bowl tanks, wet
insulation, drains,
moist basements and damp
walls. To control indoor
infestations, the damp,
organic matter must be
removed. Then the
springtails can be
vacuumed and
insecticides can be
applied as a spot
treatment.
Beware of
Booklice
Lurking in
Structures
Photo of adult
booklouse. Photo by Dr.
Bart Drees,
Professor and Extension
Entomologist, Texas A&M
University.
As more
homeowners are indoors
during the cold weather,
they might come across a
small crawling insect
called a booklouse (Liposcelis
spp.). Despite being
called 'lice', booklice
are not harmful to
people or pets. They get
their common name from
their association with
books or paper. Adult
booklice are 1/32 to ¼
inches in length,
wingless and
creamy-white in color.
They have soft bodies,
chewing mouthparts, and
long thread-like
antennae. Nymphs look
like adults, only
smaller in size. Their
lifecycle from egg to
adult occurs in about 3
to 4 weeks.
Most
booklice require a
relative humidity of at
least 50-60%, due to
loss of moisture through
their exoskeletons. High
humidity is also
necessary for the growth
of their primary food
source, mold.
They
invade by means of
stored goods, groceries,
cartons, or on paper.
Booklice feed most
commonly on molds as
well as fungi, grains,
and other starchy
material, including glue
from book bindings. When
found indoors, they are
found in such places as
moldy books and paper,
damp places, sweating
pipes, new plaster and
sheetrock, damp
spillage, or wooden
pallets. They can live
and reproduce in wall
voids, storage trunks,
groceries, rugs, paper,
cartons, rope fibers,
closets and cabinets.
They do
considerable damage in
museum collections,
libraries, stored
products and food
processing plants, when
they are found in large
numbers. The presence of
psocid bodies in house
dust is also believed to
contribute to asthma
attacks. Large
populations of psocids
does warrant control for
these insects.
Some
Options For Control:
Reduce
moisture, since psocids
usually do not survive
when humidity falls
below 50%. A
dehumidifier or fan is
effective in reducing
moisture. Also repair
any moisture problems
and store boxes, bags,
books, and papers off
the floor to reduce
contact with moisture.
Clean the infested areas
thoroughly, and dry
items with a cloth or in
the sun. Also open
windows and doors and
turn off any
humidifiers, in order to
reduce humidity indoors.
Sometimes faulty air
conditioner systems
promote damp, humid
conditions, so they
should be repaired.
Locate
breeding sites such as
upholstered furniture,
moldy wood, old
mattresses, damp papers
or books and then
remove, treat or discard
the items. Also discard
infested food or treat
it by heating (place in
oven at 180°F or for 30
minutes) or freezing
(placing in freezer at
0°F for 4 days).
Household insecticides
containing such
chemicals as pyrethrins,
rotenone, allethrin, are
labeled for crawling
insects or booklouse
control and can be used
for spot-treating areas
of infestations.
Mention
of commercial products
is for educational
purposes only and does
not represent
endorsement by Texas
Cooperative Extension or
The Texas A&M University
System. Insecticide
label registrations are
subject to change, and
changes may have
occurred since this
publication was printed.
The pesticide user is
always responsible for
applying products in
accordance with label
directions. Always read
and carefully follow the
instructions on the
container label.
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