Common Interior Pests

8/14/2019 Common Interior Pests

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Common Pests

Interior Plantscaping


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Background info on Pests

Often more common than diseases on indoor plants

More often plants bring in insect problems fromwhere they were grown (even if insects do not appearto be present, eggs can pass through insecticidal

control Early detection and control is key preferably before

a plant is installed permanently in an indoorlandscape.

Quarantine new plants as problems may notmaterialize for a few weeks as latent eggs hatch.

Use 10x power hand lens for initial search andbinocular microscope for detailed viewing


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Mites

Most common indoor pest problem

Although there are several mite species thatcan attack indoor plants the two-spotted

spider mite (Tetranychus uricae) is mostcommon (Broad and Cyclamen are theothers)

Size: 1/16th 1/80th (average around 1/50th) of

an inch (about the size of a period on aprinted page with eight legs. Color can begreen, yellow or red with two spots near thehead.


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Mites

Dry, warm conditions promote the growth ofspider mites. Cool, humid conditionsdiscourage them.

In lower level infestations mites will be onunderside of leaves in larger infestationsthey can also be found on the tops of theleaves and walking on the web like structuresthey form between leaves and stems.

At 75 degrees mites will develop from eggs toadults in 2 weeks


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Mites

Mites are sucking/piercing insects causing damage throughremoval of sap. It looks like yellow stippling on the leaf andthen eventually leaves will turn bronze or grey.

Control by rinsing under faucet (if possible) weekly,increase humidly, use a cleaning spray (rubbingalcohol/soap in water) or with neem oil or soap (test plantsfor phytotoxicity) horticultural oil spray or systemic miticide

biological control includes predatory mites.

Plants most prone to attack are Dracaena marginata,palms, and Ivy (Hedera spp.)


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2-spotted Spider mite and eggs


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Electron Microscope 130X


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Mite damage and webbing


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Mealybugs

Several species including a root feeding form

Name comes from the powdery wax coating they

excrete to protect themselves from drying.

Insects are usually pinkish under the coating and areabout to 1/8th of an inch in length averaging 3/16 .

Easier to spot with the naked eye.

Closely related to scale insects

They like to hide in leaf axils and other protectedparts of the plant making them difficult to contact with

an insecticidal spray. Larger infestations will also be

on leaves and along succulent stem growth.


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Mealybugs

Mealy bug are sucking/piercing insects. Damage isseen as yellow foliage that also may be distorted orstunted if feeding starts during the leafs development.Leaves may drop off and plant may die.

Side effect is the excretion of honeydew which issticky and can be a food source for sooty mold

It takes 6-8 weeks eggs to develop to adults. Control with cotton swaps dipped in rubbing alcohol,

mechanical control (crushing / scraping) insecticidalsoap, neem. Biological control: Mealy Bug Destroyer(Cryptolaemus montrouzieri)

Most susceptible plants include Aglonema andAlocasia


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Mealy bug sans Meal


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Mealybugs


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Mealybug Destroyer


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Scale Insects

There are several species of scale on indoor plants the most common beingsoft brown scale (Coccus hesperidium) less common is armored scale ()

Adult females are 1/16" to 1/8" in diameter including the outer protectiveshell.

The shell can be flattened, rounded, or oyster shell in shape. Female and its eggs are protected from sprays under the shell.

Eggs hatch out into tiny crawlers (grey-brown) which is the most susceptiblestage for the insect and can be controlled with simple soap spray. Handlens or better needed to detect them.

Crawlers find a new location to hunker down and do not move. Maleseventually develop into winged adults and seek out females. Onegeneration takes about 60 days.

Piercing sucking insects - produce honeydew and damage is like other

piercing/sucking insects. Control by physical removal (scraping) or regular spraying with soap to

catch crawlers. Neem oil, Horticulture oil Most susceptible plants are palms and Ficus benjamina.


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Scale Female and juveniles


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Armored Scale


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Whiteflies

Most commonly the greenhouse whitefly(Trialeurodes vaporariorum) a 1/10" or less white,moth-like insect

Usually found on flowering plants like poinsettia,fuchsia, and hibiscus.

Usually found on the underside of the leaf but mayfeed on the top as well. Adults fly when disturbed.

Sucking/piercing insect. Honeydew excreted Life cycle 21-36 days.

The flightless larvae are the easiest to control sopersistence pays. Control with soap, neem, pyrethrin or my favorite the

vacuum cleaner.


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Whitefly generations


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Aphids

Sucking piercing insect (1/16" to 1/8") with soft-bodies species vary in color (red, yellow, black, green, greyand wooly. Produce Honeydew the most commonindoors is Green Peach Aphids (Myzus persicae)

Sexual generation can be skipped or delayed throughfemale oogenesis. Females can start producing viableeggs 7-10 days after hatching

Adults usually have wings but often indoors allfemales without wings.

Found on underside of leaves and on new succulent

growth. Control with strong stream of water to knock off or

insecticidal soap


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Aphids


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Thrips

Thrips are tiny (1/20" or less), elongate, yellowish to

dark insects. Most commonly Wester flower thrips

(Frankliniella occidentalis)

Rasping/sucking insects feed on flower buds and

blossoms. Leaves appear silvery grey from damage

and black excrement dots may be visible

Life Cycle takes 18-21 days.

Difficult to control without more and few indoor

pesticides available. Usually best to discard plants

when found.


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Thrips


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Fungus gnats

Adults tiny, dark, slender flies about 1/8 that swarmfrom plants when disturbed. Mature larvae are about1/4 long with a shiny black head and white, almosttransparent body.

They prefer wet organic soil to lay their eggs in.Larvae of some species can feed on roots in the toplayer of the pot and can transfer diseases. Othersfeed only on non-living organic matter

Large infestation causes yellowing and wilting ofleaves

Control through water management in soil, neemdrench or applying diatomaceous earth on thesurface of the pot (like tiny razor blades)


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Fungus Gnats

Documents

Common Interior Pests