Basically, lilies are very delicate plants and, hence, vulnerable to onslaughts of many insect and animal predators that may vary from microscopic mites to elk and deer. To a great extent the climatic zone and region where the plants are cultivated are responsible for the existence or non-existence of a specific predator. However, you can be rest assured that predators are not as harmful as some diseases like Botrytis blight, Fusarium or even those caused by viruses. They have the potential to obliterate all the crops or even the entire plantings in a garden.
Aphids are the most important pests in a lily garden and you need to do everything possible to check them. There are very few pests that breed as fast as aphids and, hence, you need to ensure that you take all measures to get rid of them as soon as you notice them. This is especially essential if you are growing lily species or varieties that are known to be vulnerable to virus. Apart from spreading virus diseases, the various aphid species that form colonies in lilies also make the plants physically weak, by making the leaves twisted and distorting the flower buds.
Aphids are known to multiply very rapidly producing a large number of progenies. If you closely scrutinize a plant infected by aphids, you will notice a solitary female aphid along with multitude of tiny progenies. Generally, these insects move by crawling, but occasionally they also produce winged nomad offsprings that are capable of flying long distances and form new colonies in other plantings.
You may use systemic insecticides to control aphids. When you mix the insecticide with water and water the plants with the solution, the chemical is absorbed by the roots and supplied upwards to the plant’s tissues. Since aphids are sucking insects, they ingest the poison while sucking the plant’s sap and are eliminated in the process. This type of control is especially very effective in container plantings, as the chemical remains intense for a longer period of time. If you want to get rid of the aphid problem, it is essential to spray the plants with systemic insecticides on a regular basis. You can also use these insecticides in combination with fungicides. It has been seen that many lily growers have used the insecticide acephate (for instance, Orthene) very successfully to control aphids. Similarly, malathion, an insecticide that is showered over the soil and watered in has the competence to protect plants from aphid invasions all through their growing season.
There are various products available in the market for fumigating greenhouses and these need to be always used carefully. It is essential to use them in controlled conditions. Aphids are especially bothersome in greenhouses, where the atmosphere is most favourable for their rapid increase. What is worse is that their natural predators are usually not present in conditions prevailing inside a greenhouse.
You should know that the insecticides that are sold in the market keep changing continually. Therefore, you need to check their content before purchase and also use them very cautiously. It is advisable that you use rubber gloves as well as protective clothing every time you use these insecticides. In fact, there are many insecticides that can be taken up by the body via the skin and they may result in neurological problems.
Using mineral oils or petroleum oil sprays is often effective in reducing the spread of viruses in a variety of crops, including lilies and potatoes. The film created by these oils does not eliminate the aphids, but it stops them from spreading the disease via their stylets by blocking them. In fact, it has been found that oil sprays are about 60 percent effectual in checking viruses in commercial cultivations. However, the weekly sprays used by the commercial growers are seldom feasible for home gardeners. Nevertheless, it may be worthwhile for gardeners having large lily plantings. Gardeners and commercial cultivators using oil sprays should not use them when it is hot during the day, or else it may cause the leaves to scorch and even be distorted. Ideally, oil sprays should be used just before sunset. Usually, using light summer oil diluted to 1 percent is effective. Generally, it is safe to use mineral oils and petroleum oils and they can even be used in combination with nearly all fungicides and insecticides.
Gardeners should know that using any type of spray on soft young seedlings may prove to be dangerous. Therefore, it is advisable that you control aphids, which are usually attracted to seedlings, using granular systemic insecticides like malathion. This type of insecticides are not sprayed on the plants, but sprinkled on the soil before watering. Even home gardeners can use similar products – for instance, branded products like Cole’s systemic granules or Dexol.
In case you find that your plants in your garden are continually being invaded by aphids coming from any external source, the above mentioned efforts to check them may not prove to be effective. Hybridizers as well as other lily aficionados may grow their lilies in screen houses that provide protection from aphids, but aphids can be transported even into these via tools or clothing. Therefore, you should ensure that you maintain a spray program even in aphid-proof screen houses. It is possible to inhibit migrant aphids from moving from one plant to another by creating barriers using gauze or other vegetation. Ensure that these barriers are higher than the lilies.
Last, but not the least important, aphids survive the cold winter months by laying eggs. These eggs are produced by migrant stage. Therefore, it is very important to destroy all dead plants or parts that may shelter the over wintering eggs of aphids.
Lily bulbs have a loose structure and this makes them easy prey of the pests that survive between the bulbs’ scales. Bulb mites (scientific name Rhizognyphus echinopus) are bothering, but generally they are secondary pests, as they invade bulbs of several other plants alongside those of lilies.
Usually, the adult bulb mites measure as much as a pinhead. They are rounded having yellowish white color that has hints of pink. When the climatic conditions are warm bulb mites are generally found in large numbers, especially a little higher than the basal plate as well as between the bulb’s scales. Therefore, it is understandable that these pests attack the basal plate and the roots, entering the bulb’s center sooner or later.
You may use a number of methods to control bulb mites. You may treat the bulbs using hot water for about an hour. The water should be at 44°C (111°F). Alternatively, you may fumigate the dry bulbs with Para dichlorobenzene – the active compound in mothballs, in a sealed container. This method involves spreading the fumigant over the container’s base – using 4 grams for every litre of air space. Subsequently expose the bulbs to the atmosphere for about 12 hours.
You may also control bulb mites by dusting the lily bulbs with sulfur flowers. Perhaps, this is the most effective as well as most suitable means for the home gardener. If there are any bulbs that have been severely affected by mites, destroy them right away.
Deer, hares, and rabbits
Deer, rabbits and hares are all herbivorous animals that frequently nibble on young plants, flowers, buds, seedpods as well as other parts of a plant. On the other hand, these herbivorous animals rarely cause severe damage to plantings. In rural areas, you can set up and properly maintain fences that will keep off deer, rabbits and hares. You may also have a dog as your pet, because dogs usually prevent deer invasions, while keeping several cats will help to keep off rabbits.
There are various other means that will help you to keep these herbivores away from your garden. For instance, you may use chemical controls as well as repellents, trapping and shooting. However, even if they prove to be effective, all these methods will only solve the problem temporarily. It is interesting to know that sometimes concoctions having foul odours, which can be bought or made at home, are effective in keeping deer at bay. These concoctions are packed in sacks made from muslin and dangled around the plants.
Leatherjackets, wireworms, and millipedes
These are underground pests that can be responsible for considerable damage of lilies and various other crops, thereby causing losses to the growers. All these insects can be found in grasslands.
Leatherjackets are basically larvae of daddy-long-legs (Tipulidae) or crane fly. These insects are without legs and move very sluggishly. They have a dull brownish color and may grow up to a length of about 3.75 cm (1.5 inches).
On the other hand, wireworms are actually larvae of click beetles. These insects are slender, downy, tough as well as wiry and grow up to a length of 2.5 cm (1 inch). These creatures have a golden yellow hue and possess six minute legs. These creatures make holes into the lily bulbs.
Millipedes are creatures with several tiny legs. These dull-colored pests are also very sluggish. When disturbed, they curl up to protect themselves.
Nevertheless, it is possible to control all these pests by dusting the soil with Bromophos or benzene hexachloride (BHC). You may also use non-chemical controls, such as baiting using slices of carrot, potato, and other root vegetables that can be placed beneath the soil surface. You may skewer these traps on a stick with a view to mark the place where they are positioned and removed after a few days when pests are attached to them. Destroy the pests right away.
For long lily beetle (Lilioceris lilii) has been a major source of headache for lily growers in Europe and now they are also reported in the lily plantings in eastern regions of North America. Both the larvae as well as adult lily beetle feed on lily leaves and other lilaceous plants, such as Fritillaria and Convallaria (commonly known as lily of the valley). These pests have an insatiable appetite in both life stages and can eat up entire plants in a short time.
The larva of lily beetle is a humpbacked, dirty yellowish creature having a dark head. It covers itself in nauseatingly dark, slippery excrement. The adult lily beetle usually grows up to 8 mm (0.25 inch) in length and possesses a bright scarlet along with an antennae and tiny black legs. The females lay their eggs on the foliage’s underside.
There are a number of ways you can control lily beetles effectively. One way to control these pests is to soak the soil with a potent insecticide like acephate (for instance, Orthene), as this will kill the mature larvae that subsist just beneath the surface of the soil during the winter months. At the same time, never transport the soil infested with lily beetles or for that matter any other pest to another site. If you find any adult lily beetle, catch it between your fingers and destroy it.
Adult Liothrips vaneeckii or lily thrips are extremely small and have a black hue. On the other hand, their larvae are minute and salmon pink. Both the adult as well as larvae spend their entire life cycle inside the lily bulbs. They feed locally at the bottom of the scales, weakening the bulbs severely and rendering them flaccid. When the bulbs become flabby, it facilitates the entry of bacteria and fungi, often causing the bulbs to rot.
You can control these harmful creatures employing a number of methods. You may treat the lily bulbs with hot water ideally at 44°C (111°F) for an hour to get rid of these pests. Alternatively, you may also sprinkle benzene hexachloride (BHC) on the ground. Another way to prevent lily thrips from harming your plants is to wash or immerse the bulbs in an insecticide solution.
Agasphaerops nigra, commonly known as lily weevil, is indigenous to the western regions of North America extending from the north of California to the Vancouver Island in Canada. This pest has reportedly been found in lilies native to this region as well as the cultivated forms of Easter lily (Lilium longiflorum).
The larvae of lily weevil are minute, legless grubs having a whitish body and chestnut-brown heads. These pests make holes into the stem as well as bulbs of lilies. Adult weevils appear during March and April and they feed on the plants’ leaves.
Using systemic insecticides can be very effective in checking weevils from invading the lilies.
Several eelworm or nematode species are found in soils everywhere. While some of them are harmless or maybe even useful to the plants, most of them are disparaging. In fact, meadow nematode or root lesion and the leaf-lesion nematode are the most destructive for lilies. Although these pests are microscopic, in some regions they are capable of causing severe damage to lily plants, provided measures are not undertaken to keep them under control.
Nematodes can break through root tissues, thereby killing cells while they advance. Once they penetrate the root tissues, these pests move towards the center, feeding on the tissue, laying their eggs and obliterating the cells in the region. Gradually, the roots turn out to be soft and flaccid and sooner or later succumb to infections that enter upon the basal plate of the bulb, changing it into a sort of mush.
It has often been found that river water transports nematodes, which then enter the agricultural fields via irrigation. In addition to playing host to bacteria, some nematode species also carry viral diseases. When a plant is infested by nematodes, its growth is stunted. Moreover, nematodes can even decrease the commercial production considerably. In fact, crops infested by nematodes are usually not affected uniformly.
Foliar nematodes are present in the soil. When they find a favourable host, these pests climb through the stem in an outside film of moisture and eventually assault the leaves and flowers.
You can effectively control nematodes in several different ways. First and foremost, you need to keep the foliage dry to the best of your abilities as this will prevent the movement of foliar nematodes. At the same time, you may also use systemic insecticides to eliminate these organisms. Another way of controlling nematodes is treating the lily bulbs with hot water for about an hour. The water should be hot at 44°C (111°F).
Alternatively, you may fumigate the soil using methyl bromide, metamsodium (for instance, Vapam) and chloropicrin. In fact, this is a very successful method of controlling nematodes, especially in commercial plantings. If you are growing lilies in a greenhouse, it is important to undertake steam sterilization.
You may also apply any effective nematicide like fenamiphos, for instance, Nemacur, while planting the lily bulbs. If possible, add carnivorous nematodes to the soil, as they will serve as natural predators for these organisms.
It is advisable that you don’t plant the lilies in the same site over and over again, as this will put off the destructive nematodes from increasing their population in your home garden.
Pheasant and quail
It has been often found that pheasants and quails have a tendency to peck shoots as they emerge in the beginning of spring. These birds may also destroy the bulbs with their beaks when the climatic conditions are cold for provisions when other foods are rarely available, thereby destroying the bulbs. When they cause severe damage you can check these birds by trapping or shooting. You cannot kill these birds and use of poison grains is strictly banned in many regions. Hence, you should never use them to check quails and pheasants.
It has been found that often mice and voles greedily consume the bulbs of lily plants, particularly when they are present in large numbers and are not properly checked by bird and animal predators. In case you find moles very active in your area, you can be sure that there are mice and voles too, as the latter two use the tunnels made by moles to get to the lily bulbs. While traps and poison are both effective means to control their menace, in home gardens, your dog or cat may also help you to get rid of this problem.
Sometimes even chipmunks and squirrels prey of bulbs of various plants in gardens. The best means to control them is to plant the bulbs at a distance from trees, because these two pests actually loathe to go too far from the shelter of their homes in the trees.
In the western regions of North America, many gopher species pose a serious threat to lily plantings. These pests have a liking for lily bulbs and have the capacity to consume large number of bulbs just in one season. Trapping is a successful means to control these pests, but on a smaller scale.
Slugs and snails
Slugs and snails are hermaphroditic molluscs that lay huddles of rounded, whitish, glutinous eggs in small spots in the soil. These jelly-like eggs can be obliterated by farming the top few inches of the soil frequently, which brings the eggs to the surface and expose them to birds and frosts.
Especially, slugs can cause problems above the soil surface as well as beneath the ground, subject to the prevailing species. These molluscs thrive in moist conditions, shaded places beneath dead leaves as well as plant debris or among plants that usually have low growth. Slugs and snails are usually widespread in the rainy season.
It has been found that slugs and snails are at their destructive best when new lily shoots emerge. They feed on them voraciously. If not controlled, they climb the stems afterward in the season and strip the plants completely of their leaves.
Snails and slugs can be effectively controlled by restricting the habitat in the region of the lilies. This can be achieved by checking the weeds and employing mulch rather than any ground cover planting. At the same time, you can place a bait enclosing metaldehyde among the plants just before the evening hours. The baits are very effective when placed at a time the lily shoots start emerging and also when the weather is damp. You should remove the old baits and place new ones following a heavy rain. It is important to note that liquid bait like Deadline may not be as attractive as the pelletized bait for pets. Some lily enthusiasts have also successfully used beer traps. This method involves pouring some beer into a low dish and placing it close to the lily plantings during the early evening hours.
Symphylids are very small insects that are present in some soils and it may be very difficult to get rid of them. When their population multiplies rapidly and go beyond control, these tiny insects possess the ability to severely damage lily crops. You can hardly see these tiny creatures with naked eyes and their presence can be ascertained by testing the soil in any agricultural laboratory. Normally, fumigation is the best means to eradicate symphylids.