Plant Pests-Whitefly

Plant Pests-Whitefly

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Plant Pests-Whitefly

So these little past are the pests that haunts most plant growers, including myself. Of course whitefly come in many different variants. It is estimated that there are about 1500 different species of these little garden horrors.

However one variety is known as the glasshouse whitefly. This garden pest is a sap-sucking pest that attacks your plants. So, at the same time they give off a sticky substance better known as “honeydew” . This honeydew can be seen all over the infestation. Adult whitefly and the nymphs excrete this sticky honeydew on the foliage, which allows the growth of black sooty moulds. This black sooty mould can become a real problem making the plants look totally un-healthy. Ultimately, the leaves, fruit and stems are all targets for these little monsters.

Last year was a particular bad year for whitefly. These little garden enemies thrive in hot summers. Last year was a good year for growers of all types of plants! However I had a particular bad attack of whitefly. Especially on my pepper plants. My peppers were very bushy. So, the first whitefly outbreak was missed . Causing me a much bigger problem and not really catching up with problem. Eventually I had to attack them by removing my peppers outdoors. This gave me the room to attack the whiteflies from every angle. next year I will keep a closer eye on things.


So one of the favoured “biological” methods is to introduce the tiny parasitoid wasps, Encarsia formosa. Importantly, these enemies of the whitefly must be introduced in the first instance. Giving the wasps time to devour the whitefly nymphs emerging pests. After a successful attack of the nymphs by the parasitic wasps then the results will let you see the nymphs turning black. This turning black will help you monitor the situation of how the wasps are doing.

Importantly, the grower must be careful not to use an insecticide at the same time as introducing the parasitic wasps. Another point is not to use the yellow stick cards when introducing the wasps. Of course, the wasps will also land on the sticky cards. As a general rule then the following precautions will be a great help when battling against these little pests.

As I recommend for most flying insects then the sticky yellow cards must be used. There are other types of sticky cards and all are most useful. These cards help the grower to spot any type of insects at an early stage. After the pests are spotted then the attack against them can be mounted.

Newly introduced plants should be quarantined first before placing the plants in there final growing space. This gives time to allow any whitefly eggs or nymphs to develop and spotted so that action can be taken.

Watch for weeds

Growers should be aware that these insects will also thrive on weed. So good greenhouse housekeeping is imperative. Not allowing weeds to grow will eradicate this from happening.

Sooty moulds that develop in the later stages of a whitefly attack, thrive best in hot and humid environment! So good ventilation is very important.

Finally, good hygiene and cleaning your growing environment including the greenhouse should be carried out every winter. This should include using an “insect fumer” . Another product worth considering is the “Hot shots” vapour pads. These products give off an insecticide vapour that penetrates all the area where the growing takes place.

Plant Pests-Fungus Gnats

Plant Pests-Fungus Gnats

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Plant Pests-Fungus Gnats

So one good thing about “Fungus Gnats” is that the adults are visible to the naked eye. I must confess that I am not familiar with these little pests and so m on a learning kerb myself. Perhaps one of the reasons why is because the larvae actually feed on the plants roots including the feeder roots. Of course damage to these feeder roots causes slower growth of the effected plants.

Consequently, this opens up the way for the plants to be effected by bacterial infections. Adult gnats can over winter in cold weather. many other insect pests are destroyed by the old of winter but not these little guys.

Over watering could be problem

So the fungus gnats will invariably feed on plants that have the beginning of root rot. Often caused by the plant grower over watering. The gnats can often be found living in over saturated soil. However , a good watering regime would be the answer. In my experience then beginner gardeners will often over water their plants ! Thinking that more water is better than none. However, this is not so a like most things then practice and disappointments due to dying plants will all come with practice and tolerance.

My advice is always to use sticky yellow pads

Like most things insects the adult gnats will be flying around your greenhouse/conservatory or growing room. Catching the adults as they are flying about will help the grower to identify pests. Including the adult fungus gnats. However fungus gnats can also be seen walking about on your plants as they are not very good flyers. In my opinion we should all use the yellow sticky pads where ever space is available. I use them all the time and its unbelievable what little monsters that you can catch and identify.

Once identified you can take evasive action to get rid of the pests.

Natural organic measures can be used including the addition of parasitic nematodes Steinernema feltiae. Of course, these naturally occurring parasites which are soil born will naturally infect the fungus gnats larvae with bacteria and fortunately, kill them.


So like many things in life then “prevention is better than a cure”! here at Hydrostore we can offer any grower a preventative online. The product that we recommend is “Nilnat” . Commercial growers use this products before the crops are infected. Also you can use this if you spot the small black adult walking about close to your growing medium or on the yellow sticky cards.

Plant Pests-Starting With Aphids

Plant Pests-Starting With Aphids

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Plant Pests-Starting With Aphids

There is no doubt about it that whatever and wherever you grow your plants then sooner or later you will be confronted by these little pasty guys! The dreaded aphids. In fact I have just sprayed some early clusters appearing on my greenhouse on the citrus trees. So, this prompted me to start a series of blog posts about pests and some of the best ways to control them.

What are Aphids ?

Well these little guys are small insects of differing colours. They can be seen in green (the popular I think) grey, black, red, yellow and a few other colour. The bodies are mainly pear shaped and they hang out in clusters of differing sizes depending on how long they are aloud to live. Of course its always a bit disheartening when you spot your fist Aphid outbreak! Especially when you are new to growing plants.

These little horrors can be found on most type of plant both in doors and outside. I our part of the world here in West Yorkshire the aphids are generally know by there colour. So, the green ones are known as “green flies” and the black and grey ones as “black flies”. Importantly though they are all aphids and require controlling in the same way.

So, usually the first sign of an outbreak will be spotted on “new growth leaves”. Aphids will live on the underside of new leaves and suck at the juices of the plant. Both indoor and outdoor plants can be affected, so a close watch should be a part of your plants maintenance. At first the aphids dont seam to have much affect on your young plant leaves. However a bad infestation will lead to the plant leaves dropping off, usually turning yellow first.

Aphids can spread diseases

Aphids can be a huge problem on certain crops. Of course we have all seen the shiny sticky substance they the give off. This is known as “Honeydew”. This sweet excretion is a food of other insects such as ants. Ants will often farm the aphids for their honeydew Thus perhaps causing other problems for the discerning gardener. So, another problem that can manifest itself is that the honeydew is also a food source for moulds. These moulds can often be seen on plants that have not been treated for the aphid infestation. They look unsightly and should be treated as soo as possible. All these things should be part of the plant growers hygiene practises and not neglected. Once you spot aphids then action must be taken ASAP.

Aphids give live birth

Of course this is why these little pests can multiply so quickly. Female aphids give birth to live young. So, as soon they are born then the young aphids are able to start the assault on your plants. After four moulting’s of a white coloured skin then these little guys can start producing more offspring’s. Fundamentally, increasing the size of the infestation with an aphid population explosion. This is why early vigilance and intervention is required by the plant grower, indoors or outdoors. If you see an early outbreak then attack it.

So, the young aphids are known as “nymphs”. This is common in the insect world. The nymphs look very much like the adult insects and can cause the same amount of plant damage accordingly. Aphids can easily spread their colonies to other parts of the plant or garden. This is done by some of the adults having wings. These adults emerge when the local colony is getting too large to sustain.

Aphids natural predators

Like most of the world of natural history then there are natural balances to help eradicate these aphid pests and the powdery mildew that follows. . Of course the most people know of the most popular aphid eater , the “ladybird) or “ladybug ” as it is called in the USA. These predators are a member of the beetles family. In my opinion then the ladybird is a common and welcome site to the regular outdoor gardener. These bright coloured flying beetles are a welcome site and come in any forms and colours. The most common been bright red with black spots.

Ladybirds arrive on this planet in four stages, Firstly the eggs are laid on wild plants such as nettles. The eggs hatch into a larva and quickly develop into the pups and then the adult ladybird emerges into the bright red and yellow dotted beetle that we all recognise. Clusters of up to forty eggs can be seen on the leaves of nettles and other wild plants. Consequently these eggs hatch in about four to ten days.

Ladybirds can be seen hibernating around garden sheds and even in houses. Emerging in spring and soon starting their life cycle over again. These beetle are rampant feeders of aphids and can eat as many as 5,000 aphids in a year.

Here in the UK ladybirds are available to buy. Adults or larvae are available between the months of April to August. Another good organic way of aphid control is from “Neem Oil” . This treatment is derived from the seeds of the tropical “Neem Tree” and can be used as an insecticide and other things such as, aphids, spidermites, mealybugs, and scale. It also controls diseases, such as powdery mildew. This is a beneficial product to have handy for your plants and is available from Hydrostore online.