Pseudococcidae
One minute you’ve received a contented, wholesome succulent and the following you discover a clump of white fluff or some small, odd wanting bugs wedged in a crevice of your treasured plant. They appear to seem from out of nowhere.
When a sudden infestation of mealybugs occurred on my mother’s houseplants, although, everybody knew the place to place the blame: on the cuttings I’d introduced house from my college’s tropical greenhouse.
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Gradual to unfold on their very own, when you introduce them into your area on new vegetation, instruments, or provides, these pests will be notoriously arduous to handle.
Fortunately, there are alternatives out there that can assist you lower their numbers and decrease the success of their invasion, and we’ve received all of it laid out for you beneath!
Right here’s what we’ll discuss:
What Are Mealybugs?
Mealybugs are bugs of the Pseudococcidae household, and there are about 275 species that inhabit america. They share their superfamily, Coccoidea, with smooth scales.
Lots of the frequent species are within the Pseudococcus and Planococcus genera, together with Planococcus citri, the citrus or greenhouse mealybug, and Pseudococcus longispinus, the long-tailed mealybug.
Pseudococcidae species like to congregate in protected areas between plant elements, resembling crevices, slender areas between touching fruits and leaves, on stems close to the soil, and within the case of root feeding species, nestled between the roots and the soil.
These bugs will feed on most decorative species, together with woody and herbaceous perennials, flowers, timber (particularly citrus timber), grapes, orchids, succulents and cacti, and even some grasses.
They’re frequent in greenhouses and indoor areas, as they love heat, moist climates.
These bugs suck plant juices straight from the phloem with their piercing-sucking mouthparts, that are mainly like sharp straws.
The phloem is the a part of the vascular system that transports the sugary merchandise of photosynthesis (photosynthates) across the plant.
Due to this fact, you possibly can usually discover them clustered on leaf veins and midribs, fortunately slurping up the plant’s hard-earned meals.
Like aphids, they secrete a sticky, candy liquid referred to as honeydew from their abdomens. Black sooty mildew grows on these excretions, which makes a plant look fairly ugly. Discover ways to cope with sooty mildew right here.
Ants love the honeydew treats a lot they’ll shield the mealybugs from pure enemies, and even carry them to contemporary vegetation.
Not solely are vegetation infested with mealybugs, lined in sooty mildew, and crawling with ants fairly ugly, however they may also have diminished vigor.
If flowers are attacked, there could also be poor fruit set. And fruits lined in feeding, fuzzy bugs and black mildew aren’t solely unappetizing, however the fruits could drop or shrivel on the tree as properly.
Whereas feeding, Pseudococcidae pests can function a vector for viruses that may trigger yellowing and necrosis (dying).
Grapevine leafroll virus, for instance, is vectored by each the lengthy tailed and citrus mealybugs. It causes leaves to show purple or yellow, thick, and brittle, and finally they roll up.
Identification
As a household, you possibly can consider mealybugs as small, typically one centimeter lengthy, oval formed, white to grey, segmented, wax lined, wingless bugs.
Typically serving to with identification between species, some develop filaments that appear to be lengthy white legs down the perimeters of their our bodies, or that resemble two to a few waxy tails on the top of their abdomens, whereas others don’t develop filaments in any respect.
This description covers older nymphs and grownup females from many species, although there are a number of coloration shades.
Male adults appear to be gnats, with two wings and 4 eyes.
Nymphs of each sexes are flat and are available in pale shades of yellow, orange, or pink. The early instars don’t have a waxy protecting.
Pink to yellow eggs are laid in white or cream cottony wax-covered sacs referred to as ovisacs.
P. citri, the citrus mealybug, is essentially the most widespread and damaging greenhouse species.
These have a grey stripe down the size of their our bodies and don’t develop lengthy filaments. Once they feed, they inject toxins which deform the plant.
P. longispinus, the long-tailed mealybug, grows lengthy filaments from the top of its physique, and as a substitute of laying eggs like most species do, provides start to reside younger.
Rhizoecus species are root feeders. These have sac-shaped our bodies, produce reside younger, and develop an extended filament from the top of their abdomens.
It’s simple to confuse them with cottony cushion scales (Icerya purchasi) or woolly aphids (subfamily Erosomatinae).
Cottony cushion scale females have a red-brown physique coloration and a plume of white fluff extending from their our bodies.
Aphids, together with woolly aphids, are usually extra energetic, and can generally have wings, feed on leaf undersides and on stems, and aren’t as anxious usually about discovering a crevice to cover in.
If you happen to see one thing in your plant that appears like a fungal or mildew an infection, take a more in-depth look to ensure it’s not a Pseudococcidae infestation, as the 2 can look fairly related!
Biology and Life Cycle
The life cycle varies by species, however usually, females will lay as much as 600 eggs in ovisacs in protected areas on plant crowns, leaves, bark, or fruit.
Alternatively, some species give start to reside younger, as talked about above.
Eggs take six to 14 days to hatch, rising as tiny nymphs. For many species, the females undergo 4 instars, that are the levels between every time they molt because the insect develops. Males have 5 instars.
Through the nymph stage, they’re referred to as crawlers and are very cell. Adults have legs as properly however are usually gradual transferring. They don’t sometimes transfer far, and like to settle in a single spot to feed.
Early on of their lives as crawlers, nymphs lack that protecting waxy protecting, and that is the perfect time to implement natural and chemical pesticide management strategies.
As soon as they mature into adults, the waxy coating repels moisture – in addition to any chemical compounds which may be carried together with it.
Males are not often seen, as they’re tiny, solely reside for a couple of days, and don’t feed. They aren’t at all times even wanted, as many species have females that may reproduce asexually.
This is called parthenogenesis, the place the embryos develop with out fertilization.
Relying on the species, they will full two to 6 generations per yr. These braving the nice outside normally end two and can overwinter as eggs or early instars below bark.
Indoors, and outside in heat climates, you’ll be capable of discover all levels at one time.
Monitoring
As they’re small and love to cover in protected locations, it’s simple to overlook a couple of mealybugs which might be sucking in your plant. That’s, till they’ve fully taken over.
Commonly examine all crevices in addition to leaf and flower whorls, inspecting for egg plenty, nymph or grownup aggregations, or particular person crawlers.
Use a hand lens that can assist you see the distinction between these bugs or different bugs and fungal infections.
Verify any outside vegetation earlier than bringing them inside for the winter.
Favourite hosts embody most of the numerous smooth and juicy vegetation that we wish to spruce up our houses with, resembling orchids, and numerous kinds of cacti and succulents.
Sure outside ornamentals and fruiting vegetation are generally affected as properly, resembling hibiscus, citrus timber, and grapes.
If you happen to discover yellow or wilted foliage, examine the roots for underground infestation by eradicating the pot and gently knocking soil away from a piece of root if the roots aren’t seen.
Natural Management Strategies
These bugs are notoriously arduous to manage.
They disguise in protected areas, develop a waxy coating which shields them and repels chemical compounds, unfold simply on new vegetation in addition to instruments and pots, and may survive with out feeding on reside materials for as much as two weeks.
Fortunately, there are a number of choices for owners, together with some environment friendly and hungry pure volunteers.
Utilizing an built-in pest administration (IPM) method is the best choice, as this can optimize and shield the pure enemies of those pests whereas offering efficient management.
Yow will discover out extra about IPM and learn how to design a great program in your backyard right here.
Organic Management
There are a lot of pure enemies within the panorama that wish to make a meal out of mealybugs. Outside, and when launched into greenhouses, these beneficials can preserve populations at tolerable ranges.
Parasitic wasps, ladybugs, inexperienced and brown lacewings, spiders, minute pirate bugs, and predaceous midge larvae can launch a powerful assault on Pseudococcidae species.
The mealybug destroyer (Cryptolaemus montrouzieri) is a shiny, rotund girl beetle with a red-orange head and thorax, black wing covers, and an urge for food for Pseudococcidae.
You should buy these predators at Arbico Organics and introduce them to your greenhouse!
Leptomastix dactylopii are small amber coloured wasps which parasitize older instar nymphs or adults by laying their eggs within the our bodies of those pests. The ensuing larvae eat the host’s physique from the within out, turning it into a tough yellow mummy.
L. dactylopii is especially efficient towards the citrus mealybug and is commercially out there for greenhouse growers.
P. longispinus is focused by none aside from the long-tailed mealybug parasitoid, Anagyrus fusciventris.
Anagyrus fusciventris
This tiny wasp not solely parasitizes pests within the older life levels, however the grownup wasps additionally puncture and feed on these within the younger levels.
Yow will discover these predators out there at Arbico Organics.
Cultural Management
For the reason that females can’t fly and don’t transfer shortly once they do resolve to make use of their quick legs, these bugs don’t quickly disperse on their very own.
In the event that they unfold, it’s most likely the fault of the plant proprietor. (Or in my mother’s case, a well-meaning daughter bearing slicing presents…)
So, it is sensible that one of the simplest ways to guard your plant infants is to rigorously examine any new introductions earlier than you carry them house. Verify your instruments and pots too, particularly below rims and in grooves.
Clear up particles and take away any free bits of bark, as these make good overwintering websites.
Destroy closely infested vegetation.
Keep away from pointless fertilizer purposes, as extra nitrogen could cause vegetation to develop too shortly, leading to weak, smooth development that’s extra prone to damaging bugs.
Plus, it might probably trigger a rise in mealybug egg manufacturing as properly.
Bodily Management
In case you have the time and good eyes, you possibly can handpick mealybugs off your vegetation to bodily take away aggregations or people, particularly if there aren’t many but.
Alternatively, spray vegetation with a tough jet of water to dislodge egg sacs, crawlers, and adults.
Natural Pesticides
You could must resort to utilizing spot remedies if there aren’t any pure enemies current in your greenhouse or house.
Use a cotton swab soaked in isopropyl alcohol to kill aggregations and egg plenty.
Sprays will be ineffective, as their protected areas make them arduous to succeed in. Plus, because of the moisture-repelling waxy coating, eggs and adults are protected from most contact sprays.
With a number of purposes and good protection, insecticidal soaps will be efficient towards these within the crawler stage.
Bonide Insecticidal Cleaning soap
Discover insecticidal cleaning soap merchandise resembling Bonide Insecticidal Cleaning soap at Arbico Organics, or Backyard Secure Insecticidal Cleaning soap at Dwelling Depot.
Monterey Horticultural Oil
Apply horticultural oil, resembling this product from Monterey, out there from Arbico Organics, or neem oil to knock down pest populations earlier than introducing a useful insect species like Cryptolaemus montrouzieri or lacewings.
Enable these merchandise to dry on the vegetation and begin taking impact earlier than releasing beneficials. Bear in mind that neem oil will be poisonous for pollinators resembling bees, so use early within the morning or later at evening once they aren’t current.
Chemical Pesticide Management
Pyrethroids resembling bifenthrin, out there at Dwelling Depot, will kill mealybugs.
However remember that pyrethroids can hurt useful bugs, so scout for the presence of pure enemies earlier than utilizing, and use with warning!
Indoor Out of doors Insecticide with Bifenthrin
Systemic pesticides are more practical than contact pesticides, as they course by way of the plant itself and will probably be sucked up by any bugs which might be feeding on it.
Be sure you observe all bundle directions for protected use in case you select to use these merchandise.
Neonicotinoids resembling imidacloprid and dinotefuran are generally utilized by industrial growers to manage outbreaks, since they don’t require a number of purposes. And, being systemic, attain locations on the plant that contact pesticides wouldn’t.
Pestered Vegetation
Whether or not you notice you’ve received them or not, mealybugs aren’t welcomed by plant house owners or vegetation.
These tiny, smooth, alien wanting bugs suck sugary life blood, excrete sticky honeydew which grows ugly sooty mildew, and may vector illness.
Sometime, after I’m positive my mother’s forgotten who launched mealybugs to her plant assortment within the first place, I’ll rigorously method the topic of how she handled them.
Till then, have you ever ever handled a mealybug infestation? Inform us about the place you imagine it originated and what methods you had success with within the feedback part beneath!
And whilst you’re at it, discover ways to shield your backyard and houseplants from different sucking bugs starting with these articles on frequent backyard pests subsequent:
© Ask the Specialists, LLC. ALL RIGHTS RESERVED. See our TOS for extra particulars. Initially printed June fifteenth, 2021. Final up to date April twenty sixth, 2025. Product images by way of Arbico Organics and Dwelling Depot. Uncredited images: Shutterstock.
