Wednesday, December 3, 2008
Tillandsia - by Paul T. Isley III
These rather bizarre looking plants come from the family of flora, Bromeliacee (bro-meh-lee-AH-say-eye), more commonly referred to as BROMELIADS. The bromeliad family includes a wide range of plants, such as the pineapple, Ananus comosus, and the famous "Spanish Moss," Tillandsia usneoides Linnaeus. A plant family name is used to describe a broad variety of related plants. Cactus (actaceae) and Orchid (orchidaceae) are the common names for plant families which you are probably familiar. More closely related plants in these families are separated into GENERA. Examples of two orchid genera would be Cattleya and Cimbidium. Each individual type of plant is then given a species name that separates it from all other plants.
The bromeliad genus, Tillandsia, is named for a Finnish physician, Elias Tillands (d. 1693). It is an epiphytic (able to grow without soil) genus comprising over 400 recognized species, largest in the family. Even today, more species are being discovered in the remote corners of Latin America as dedicated enthusiasts seek them out. Some Tillandsia species are ubiquitous, growing over thousands of square miles. Many numbers in the millions in their native habitats. There are also a few exotic species that are confined to a single valley or mountain range. Because of their specialized growth requirements, they are difficult to cultivate and generally are not available.
With the exception of some of the southern parts of the United States, all tillandsias come from Latin America. Although the majority of species flourish in MESIC (wet) habitats, most popular species of Tillandsia proliferate in XERIC (subject to drought and/or aridity) environments. They are often found growing exposed to sunlight, perched singly or in clumps on various types of cacti, thorny scrub bushes, or trees, rock outcroppings, cliffs, or even directly on the gravelly or sandy ground.
Tillandsias are true air plants, unlike the popular "air fern," which is actually a green-dyed seaweed from Great Britain. Xerophytic tillandsias are able to exploit what we would consider to be harsh habitats-that is, droughty and hot-by the development of very interesting mechanisms that are discussed in some detail in the sections on Foliar Trichomes and Trichome Variations. Suffice it to say here that among the tillandsioid modifications are: the development of a thick layer of water storage tissue, which increases the number and shield completely of the absorbing trichome (white fuzz on the leaves), a decrease in leaf number, a decrease in root development, a decrease in overall plant size and impoundment capacity, a reduction in the number of flowers and fruits per shoot (plant), and an increasing tendency for self-fertilization.
Xeric-growing tillandsias have evolved to be stress tolerant because extreme epiphytism is possible only under certain very rigid criteria. Because of these adaptations, tillandsias are poorly designed to grow large quickly.
Tillandsias are tremendously adaptable, tolerating a wider range of conditions than most other plants. After being place in a good location and having made the adjustments to their new surroundings, they are capable of surviving for long periods of time without attention. Take care of them, but do not be a slave to them. They will manage just fine.
Tillandsias vary greatly in size, shape, and texture. A strand of Tillandsia usneoides is very small indeed, with 3 cm. or 4 cm. constituting a healthy and viable plant. Yet a mesic species, e.g. Tillandsia grandis Schlechtendal sometimes grows to be five meters tall when in bloom! Mesic tillandsias such as T. flabellata Baker originate in rainforests and are soft-leaved, while xerophytes like T. jucunda Castellanos have stiff leaves. Tillandsia ponderosa L. B. Smith and T. yunkeri L. B. Smith are rosette-shaped like the well-known Aechmea fasciata Baker. These plants have leaves emanating from a single point in the center of the plant, forming a well in which the plant impounds water amonth the leaf axils.
Species such as T. caput-medusae, T. bulbosa and T. butzii appear to be from another galaxy, let alone another planet. One beautiful species, T. plumosa, appears to be a snow-covered sea urchin.
This fuzzy-leaf covering consists of foliar hairs called TRICHOMES or PELTATE SCALES. Although the trichomes are present in many forms of plant life, they are very highly developed in xeric species of Tillandsia. When it rains or there is dew in the air, these scales rapidly transfer water from the leaf surface to elongated storage celles inside it. As discussed in the section, Foliar Trichomes, the scales aid the plants n a number of other important functions. In some species that receive moisture at frequent intervals, the trichome wings are vertical to the leaf surface in order to facilitate epidermal drying. In others, the wings parallel the epidermis to help insulate the leaf from extreme heat. Another valuable function performed by the trichomes is to reflect the excess sunlight that might damage the leaf.
Tillandsias that live under mesic conditions have smaller, widely dispersed trichomes. Often, they cannot be seen with the naked eye. Tillandsia tectorum has perhaps the largest trichomes, and these are easily visible. The reflection of the light off these trichomes is what gives the plant its bright white countenance.
One of the most remarkable characteristics of this genus is the incredible diversity of species within it. Probably no other genus, and few families, are so vastly different in MORPHOLOGY (appearance). Why are so many species so different from each other? This intriguing question is answered in more detail in the section on Evolution.
BLOOMS AND REPRODUCTIONS
Beautiful flowers are another remarkable feature of these plants. The intensity and richness of the purples, reds, pinks, yellows, and greens is truly something to behold! When you notice the plants beginning to send out its inflorescence, more light may intensify the colors. The blooming cycle for the some rapidly growing species may be only two or three weeks. For most, it is a month or two, and for some of the most xeric, slow growing species, it may last as long as a year. A number of species, such as Tillandsia xiphioides, T. duratii, T. purpurea, and T. straminea, have wonderfully fragrant, long lasting blooms. The flowering season for tillandsias usually begins in late fall or early winter and runs through early spring. In the United States, however, there always seems to be something blooming in a fair size collection.
During or after blooming, tillandsias produce anywhere from one to a dozen baby plants called offsets, offshoots, or pups. Many produce pups from the base of the plant, while other grow offshoots from the base of the inflorescence. The former offset are termed BASITONAL, while the later are ACROTONAL. Some produce numbers of pups from among the leaf axils along the stem in CAULESCENT (stem-growing) species. Some species, such as Tillandsia latifolia, produce pups from the inflorescence itself, and a few, such as T. tricolor, grow pups at the end of short runners called STOLONS.
Pups gradually grow to adult size in one to four years, while the parent plant gradually dies over the space of a generation or two. In this way, along with seed production, the species is perpetuated, increasing in numbers through the generations. Although the parent plant eventually dies, in most species, it keeps up its appearance until the pups are fully grown. Since each parent usually produces more than a single offset, the plant will increase in numbers over the years forming beautiful multiblooming clump.
A few Tillandsia species produce very large blooming spikes with thousands of seeds. The total energy of the plants is devoted to this effort, so they produce no offsets. These MONOCARPIC species are some of the larger, mesic TAXA (taxonomic unit, e.g. genus or species), such as T. prodigiosa Baker.
Many people find their plant will not bloom if kept in the house. This is usually because a person's indoor environment does not duplicate closely enough the natural environment. Most often, the plant does not receive enough light and/or moisture to sustain a concerted blooming effort. In other words, the plant is not strong enough. Or maybe the length of time the plant receives sufficient light is not long enough to trigger the blooming cycle.
If your plant is mature, keep it outside and eventually it will bloom if given the right conditions of sufficient light, air circulation, temperature, and moisture. Once the inflorescence has developed, bring the plant indoors to enjoy it if you desire. Interestingly, a number or experienced collectors sometimes do not want a particular Tillandsia to bloom. For once begun, the cycle is irreversible, and that particular plant will not grow any larger. It will reproduce, but the shoot will have seen its day, and if the specimen has taken a number of years to grow to magnificent, unheard-of-proportions, one can understand someone's desire in wishing not to lose an old friend.
For those who really want to see their plant(s) bloom, it can be done artificially. The plant should be strong and healthy before flowering is induce. There are two basic methods, both of which work well. One is to buy a product called Florel at your local nursery. A little solutuin is mixed with water and sprayed onto the plant. The other way is to place the plant in a plastic bag with a piece of ripe apple for a couple of days. The ethylene gas from the apple will do the trick in 6-14 weeks, depending on the species. Many people get more satisfaction if the plant is allowed to complete its life cycle naturally. In addition, the bloom tends to be longer lasting.
Tillandsia pups can be left attached to the parent plant, eventually forming an attractive clump, or they can be separated and attached to something else to grow singly. If you choose to separate the plants, wait until the pups are half the parent size before removing them. Use a sharp knife or pair of clippers and cut them off cleanly at the point of attachment. Keep the wound clean and let it dry for a day or two. If you want the Tillandsia to root to the surface of the mounting material, it should be rough or filled with crevices to give the roots something to grab hold of. The plant can be glued, wired, pinned or tied with a fishing line or strips of nylon stocking material.
As previously mentioned, tillandsias reproduce by seed and offset. In their native habitats, they have adapted to conditions of often brisk air movement and intense sunlight. If tillandsias produce seeds like most other plants, most of them would fall to the ground, and the species gradually would become extinc. But the plants have evovled a fuzzy, cottony attachment on the seed coat called a COMA. This parachite like apparatus allows the seed to float on air currents for long distances, thereby allowing them to maintain their habitats high on trees, on cliffs, etc. It also allows them to rapidly colonize new habitat sites and establish these FOUNDER POPULATIONS is one of the important factors involved in the great MORPHOLOGICAL (physical) diversity within the genus. The coma hair, like the trichome, indicates a high degree of specialization.*
One of the most compelling aspects of tillandsias is the ease which they are maintained in an outdoor patio or under a tree. In coastal or humid environs, many will flourish in full sun.
As a general rule of thumb, the greener, softer-leaved plants require less sun and more moisture, and they tend to thrive in cool environments. The grayer, stiffer-leaved species prefer more light and less moisture and are usually from warmer areas. One should acquire tillandsias that will take advantage of the locations in which they are to be grown.
Most xeric species come from climates that are often humid so they do not TRANSPIRE (lose water) as quickly as they would in a dry environment. The rate at which a plant will lose its internal water supply ( the soft tissues of a bromeliad are 80-90% water) is a function of temperature and humidity. The higher the temperature and the lower the humidity, the faster the plant will lose water.
During periods of low humidity, intense sunlight can burn the leaves or even the most xerophytic Tillandsia unless the plant has been gradually acclimated to long periods of direct light. In much of the eastern, midwestern, and southern United States where it is quite humid, the problem of too much light is not as critical as it is in other, drier areas.
The ability of tillandsias to survive long periods of drought (owner neglect?) qualifies them to be among the world's hardiest plants-especially when combined with their ability to withstand near-freezing temperatures, extreme heat, high wind, etc. In combination with the fact that there is no soil to contend with, they also qualify as one of the world's most carefree plants for growers-if one has basic understanding of how the plants function.
Tillandsia love fresh air breezes (particularly in hot, humid conditions). Of course, with more exposure to actual wind, they dehydrate and should receive more water. Temperature is not much of a factor unless it either approaches freezing or gets quite hot. The mesic species are more susceptible to extremes of cold and heat. If the environment is hot and dry, overwatering the plants is amost impossible. In fact, under these conditions, the more tillandsias are watered and fertilized (asssuming they are receiving strong light), the faster they will grow.
At Rainforest Flora, Inc., we water the plants, except Tillandsia tectorum, from one to three tiimes a day in the hot, dry summer, and the plants grow rapidly. Xeric tillandsias cannot be overwatered unless the epidermal surfaces remain wet for longer than a couple days. In this case, the leaves will not be able to exchange vital gases and may suffocate, as a human who drowns from lack of oxygen. This is explained in more detail in the section on Water and Moisture Aspects.
If growing conditions include low humidity, tillandsias can be grouped close to other soil-bound plants. The moisture of the overall group of plants will help humidify the surrounding air, creating a livable microclimate. Another way to accomplish this is to fill a large flat pan with gravel and water and place the mountings on it.
As a rule, tillandsias are not bothered by insect pests. Scale and mealy bugs are the most common, and they are easily eradicated. The plants can be dippled in a pesticide solution of malathion or cygon(prefarable) and a tad of liquid dishwater detergent (the detergent acts as a surfactant that allows the water to spread across the leaf surface instead of beading on it). Usually a tablespoon per gallon of pesticide will do the trick. The plants are then soaked for a few minutes and subsequently allowed to dry; they should not be rinsed.
If a tillandsia should begin to rot-that is, the center leaves fall out-it should not be discarded unless there is nothing left alive. This may be checked by taking the plant and pulling gently on the centermost leaves. If they come out easily and the tips are black, the process should be continued in circular fashion from the center outward. If a point is reached where resistance is felt and there is a substantial portion of the plant left, it can be saved.
The specimen should be dried completely and then treated as any other Tillandsia because it will often produce numerous pups. However, if the pulled leaf tips are white, the plant was healthy and the leaves were pulled too hard.
Sometimes part of a Tillandsia base may become soft and mushy like a bruised apple. A clean knife is used to excise the bruise. All of the brown area must be removed or the rot will spread. The base should be kept dry until it callouses over, and then the plant should be treated as before. If the rot has not spread too far, the plant will soon root and produce new growth.
Tillandsias kept in the house longer than a month need to be watched closely until they establish themselves in an environment. They love fresh air, good light, and humidity-conditions often absent in the home. However, since tillandsias possess the ability to adapt to a wide range of climatic conditions, they often will grow (or at least not decline) indoors if they are given as much of their natural surroundings as possible.
Tillandsias kept in the house should receive plenty of strong light from a nearby window (preferably facing east, west, or south). If this is not practical, broad spectrum flourescent lights are available that provide 92% of actual sunlight when placed 15-30 cm. above the plants.
Watering is critical indoors since there is usually a lack of humidity, especially in homes or offices with air conditioning and/or central heating. A successful way to water the plants is to totally submerge them every week or two in a sink, bathtub, or bucket in room temperature water containing a small amount of fertilizer. They should remain submerged overnight, or at least for a few hours.
Soaking the plants in this manner will allow access to enough water to overcome any deficit. Although the plants cannot respire while under water, it will not be critical unless extended for more than a day or so. At this point the plants may suffocate from a lack of carbon dioxide and oxygen respiration.
Misting also helps in dry conditions, but this should be done in addition to thorough soaking, not in lieu of it. In dry conditions, water misted onta a plant often evaporates before the plant has had the opportunity to absorb it. Even if it does absorb water misted on the epidermis, it may not be enough to overcome a water deficit. The plants will gradually dehydrate and may eventually die from a lack of moisture.
In a light airy house, most tillandsias will adapt. In a stuffy, closed-in environment, they may not. Success varies from person to person, household to household, species to species, even plant to plant. If the plants thrive, terrific. If they begin to look poorly, they should be moved outdoors.
One foolproof method for enjoying the plants indoors is to rotate them every month with plants that are growing in better, outdoor conditions or under wide spectrum fluorescent light.
FERTILIZATION AND WATER QUALITY
Xeric tillandsias are supreme OLIGOTROPHS-nutrient scavengers. In nature, they receive little in the way of nutrients, however, they make maximum use of those nutrients that are available. This does not mean a generous fertilization program is useless. To the contrary, a consistent fertilization program during the warm months will produce much larger, more robust plants when combined with strong light and frequent thorough watering.
The most important nutrient in terms of plant vigor and foliar growth is nitrogen. Most commercial fertilizers contain a high percentage of urea-based nitrogen. However, the nitrogen must be broken down by bacteria in soil before it becomes available to the plant. This is fine for potted plants, but not for epiphytes that have no soil-bound roots. Amoniacal or nitrate nitrogen is immediately usable, but many fertilizers have little in their mix.
Potassium and phosphorus are critical to plant health. Among other things, they enhance flowering and seed setting, help the plant resist disease, promote root growth, and strengthen cell walls.
A highly recommended fertilizer is EPIPHYTES DELIGHT. It contains the two useful forms of nitrogen and little that is urea-based. Besides the necessary phosphorus and potash, this well balanced source of nutrients also contains eight essential chelated trace elements so the plants can grow to their full potential.
Epiphyte's Delight is designed to provide a plant ratio of 2:1:3, which is believed to be the optimum ratio for balanced growth. The plants will grow faster, larger, and produce more vibrant, impressive blooms and more offsets when fertilized in combination with a program of bright light and the supply of sufficient water.
The plants should be fertilized on a consistent schedule. A very dilute amount every time the plants are watered would be ideal. But fertilization every week or two with a stronger solution is fine. If fertilization is performed on a bi-weekly basis, up to a 1/2 tablespoon per gallon ratio may be used. The plants are misted or submerged in the solution of fertilizer and water.
Water does make a difference in the appearance of the plants. Many city dwellers have alkaline water in their public system. Over time this can cause a white salt and mineral buildup on the leaves that is unsightly. Bromeliads in general, and tillandsias in particular, prefer slightly acid (pH 6.0) water. A pH of 7.0 is neutral. City water often has a pH of 8.0 or more, which is quite alkaline.
Epiphyte's Delight contains sufficient quantities of an acid-forming compound (phosphoric acid) to counteract most alkaline water conditions. If your water is alkaline, mix 1/2 tablespoon of Epiphyte's Delight in one gallon of water and let it stand overnight. This will give the fertilizer time to precipitate much of the dissolved minerals and salts in the water. A fine dustlike material collect in the bottom of the container. Do not apply this to the tillandsias but use it on your garden plants instead.
For plants that are submerged in water and not fertilized as part of their regular care, a little vinegar, sulfuric, or phosphoric acid added to the water will drop the pH. A pH test kit can be purchased from a swimming pool supply store or an aquarium shop.
Tillandsias are most often marketed on pieces of sandblasted or tumbled grapewood, which is relatively light and easy to work with. Pieces of driftwood, bark manzanita, etc., also serve the purpose of providing an attractive background and mounting for tillandsias.
Mounting most tillandsia is simple. Smaller pieces may be glued directly onto the surface of the wood. A natural depression in an appropriate mounting spot may be used for the root base. If one wishes, a drill can sculpt a small hole or depression to better anchor the plant. However, care should be taken to avoid attaching the plant deep into a hole that will cover up much of the base.
There are advantages and disadvantages to every type of glue, but generally, any adhesive will accomplish the task. We use hot glue because it dries in a minute. When hot glue is used, care must be taken with small species such as Tillandsia argentea and T. ionantha. The glue comes out of the gun at 380 F. If this heat reaches the meristematic (growing tip) tissue, the plant may die. If the plant has a good root base on which to put the glue, the process should not be a problem if one is careful. One tip is to wait 10-30 seconds before attaching the plant. This gives the glue on the mounting medium a chance to cool a little.
Many species are AGEOTROPIC, that is, they grow irrespective of graviity and can therefore be mounted in any position-even upside down. The plants can be creatively mounted on hanging pieces of wood, using all its dimensions. Some species, such as Tillandsia incarnata are CAULESCENT (grow along a stem) and can be mounted in a hanging position. The apex of the plant grow upward toward the light source. Species like T. magnusiana and T. atrovirdipetala should be mounted in a horizontal position so water cannot accumulate among the leaf axils, which could cause the plant to rot.
Larger species, such as Tillandsia xerographica, T. fasiculata, and T. rodrigueziana Mez cam be glued when mounted in a sitting position. But when the plants are meant to be hung, they are normally too large to be mounted effectively with glue. Wire or fishing line is often used. The wire or line should be made as unobtrusivel as possible. This is accomplished by threading it behind the outer leaf sheaths (bases). Then the wire or line can be threaded through the wood, the material is twisted or tied tightly at the back, and, if not performed too low on the plant, the specimen should be stationary.
A word of caution! Plants are stuck into holes often rot when the base becomes wet and does not have an opportunity to dry. This mistake occurs often when people stick the plants down into the opening of a seashell. Another problem is sometimes encountered when a giant swath of sphagnum moss is wrapped around the plant base. This is usually done to make the whole mounting look more attractive. But again, it blocks air circulation, and will often hasten the demise of a plant if kept moist. Tillandsia punctulata and T. cyanea are about the only widely available tillandsias that prefer the moist arrangement, and that is because they are mesic species.
Sphagnum moss, or any other such medium, is normally used as a cosmetic device to hide the glue or wire used to mount the plant. As long as only a small amount is used, this is fine. The knowledgeable grower knows the purpose of the moss and will not keep it excessively wet.
Many mesic species of Tillandsia are terrestrial and prefer to be potted in soil. A good soil mix is fast-draining, porous, and slightly acidic.
DECORATING AND LANDSCAPING WITH TILLANDSIA
Tillandsias can be used with great effect in decorating or landscaping. They are so varied in morphology and so versatile as to care conditions that virtually the onlu real limits involved are one's imagination.
Tillandsias can be attached to tree branches and grown as in nature. They can be suspended in midair on fishing line or wire. They can be mounted on tree stumps, rocks, patio posts, or anything else one has lying around.
Certainly tillandsias can be grouped together and grown as a collection-it is the way most people grow them. But they can also be used create great depth in an overall garden situation. Appropriately placed, tillandsias can show off areas not available to other plants.
When attaching plants to a tree or shrub, certain facets of plant care should be kept in mind. One should remember that most Tillandsia species will grow larger and faster with higher light levels. Therefore, most of the species should not be attached deep in a tree canopy where they will be afforded little light-at least if they are to be watered frequently.
The plants can be mounted on tree branches at all angles, as this is the way they grow naturally. One never sees the branch of a tree with all the tillandsias lined up like so many sentinels along the top of a branch. Experimentation and imagination are the keys. Some species can be grown well upside down. Most will thrive if mounted horizontally. Of course tank-type species should be attached vertically so the tanks can fulfill their water-impounding purpose.
By grouping three or four plants of the same species together, the grower can save a year or two in the time it takes to develop a clump. This is often a good way to go with smaller and/or slow growing species.
Species such as Tillandsia incarnata, T. sphaerocephala, T. bergeri, and T. tectorum, along with many others, grow saxicolouslu on rocks or cliff faces. This natural way of growing the plants can be used with great success in one's garden, and virtually all ther xerophytic species can be grown in this manner.
In the patio, a wall is often the logical place to start decorating with the plants. If the patio is well lit, it provides the perfect environment. One or two large specimens strategically placed with normally set the pattern for how and where future plants will be positioned. Patio posts make ideal settings because they are usually open, airy, and receive bright light. If the posts are wooden, barefoot plants eventually will root to the posts and, after a few years, form an attractive clump.
Tillandsias can be attractively mounted on pieces of wood, stones, sea shells, bric-a-brac, or prized ceramic pieces. One enterprising UCLA student marketed tillandsias mounted on old tennis shoes that had been preserved with special resin coating! It makes no difference what the mounting material is, as long as it is not something toxic. Much more important are the condition in which the plant is cultivated.
TILLANDSIAS AS ANIMAL HOSTS IN NATURE
As a rule, tank-type bromeliads, including mesic tillandsias, play hosts to a great variety of animals. Entire ecosystems or worms, arthopods, reptiles, amphibians, and insects live out their entire lives in just one or a few plants. For some creatures, water impounding bromeliads provide the only source of water for part of the year. Most of these creatures are not considered pests.
The pests most commonly found on xeric tillandsias are the armored scales (family Diaspidae) and the soft scales (family Coccidae). These insects are not often encountered, but when they are, an entire population of plants may be infested. Another insect pest is the mealybug (family Pseudococcidae). Mealybugs most often flourish at the base of a plant amonth the leaf axils.
PESTS ON TILLANDSIAS IN CULTIVATION
As in the wild, the two most commonly encountered pests in gardens, at least in Southern California, are mealybugs and scales. Both may be eliminated by submerging the plant for a few minutes in a pesticide bath. Although malathion is often prescribed, some consider it to be too weak to always achieve 100% per control. Cygon (dimethoate) does provide control, and it is not considered a strong or dangerous pesticide. Once mixed, the solution should always be used within 24 hours. After this time the water will have broken down the active ingredients into harmless byproducts. Both of these pests are a food source for the ladybug (family Coccinellidae), which can provide a certain amount of control.
Female scales are mobile only as newly hatched nymphs, or "crawlers." The crawlers of both sexes disperse and find a suitable spot on which to settle. Scales then grow and molt, producing a second nymphal stage in which the sexes are only slightly differentiated. After the next molt, males begin to develop wings and copulatory organs. Interestingly, adult males lack the stylet (stiff, tubelike mouth part used for feeding) of true bugs, so they cannot feed. Female adult scales develop a waxy shell. Then they insert their mouth parts into the leaf and feed.
As can be seen in the accompanying photo, mealybugs are fluffy and white. They are mobile and often introduced to the plant by ants who use their sugary exudate as food source. Mealybugs are covered with a white or yellowish, powdery wax. Waxy filaments often are found around the body. They develop in colonies and excrete large amounts of honeydew. Mealybug eggs, which are yellowish or orange, are laid in the masses of white cottony sacs. The ground mealybug, Rhizoecus falcifer, is smaller, with a body covered evenly with white wax. Living in the soil exclusively, it attacks the roots of terrestrial plants.
Both scales and mealybugs belong to the order of insect, Homoptera. Homopterous insects are PHYTOPHAGUS (plant eating) and puncture the sieve tubes with their PROBOSCIS. They suck the plant juices from the vascular tissues. The internal turgor pressure on the fluid pushes it out and saves the insect the work of having to suck. The juice of the tillandsias, however, contains more carbohydrate than the insect need. Scales and mealybugs cope with this surplus in two ways. First, the sugar can be passed out of the body as liquid excrement, dropping onto the leaves or ground, or it may be sucked from the CORNICLES (growths on the backs of the insects) by hungry ants. The second method used by scales and mealybugs is to convert the excess carbohydrates into wax within the body; this is then secreted by the glands on the body surface as threads, or as an overall covering.
Snales are rarely a problem, with the exception of mesic species such as Tillandsia fraseri Baker. In a garden setting, however, they do have a tendency to take advantage of the protection offered by thorny specimens of Aechmea, Neoregelia, Bromelia, etc. In California the common garden snail, Helix aspersa, is sometimes a real problem, and clusters of snails can be encountered buried among the leaf axils. To a lesser degree, this applies to slugs (family Arionidae) as well.
(Reference Material: Drummond, W.C. 1954. Pests on Bromeliads, Los Angeles, California. The Bromeliad Society Bulletin. Vol. IV, pp3-5.)
(Grzimek. 1975. Grzimek's Animal Life Encyclopedia. New YOrk, N.Y. Von Nostrand Reinhold Co. Vol. II Insects. Vol. III Mollusks.)
(*All text and photo of this particular blog is taken from - "Tillandsia" book by Paul T. Isley III)