When you try to figure out what are thrips, you can receive a lot of different answers because there are more than 6,000 species that have are already known. Most thrips species are pests of commercially grown plants. They mostly feed on plants by sucking their nutrients although some of them are known to be predators too. Thrips damage substantial swathes of agricultural land, and therefore, it is essential to keep them in control.
In a suitable environment, like in a greenhouse, thrips can multiply exponentially and create large swarms because they can reproduce asexually. They do not have any natural predator, and hence it also aids in their multiplication making them an inconvenience for humans. Identifying them by their characteristic morphology is not very easy, and one should go through thrips lifecycle for a better understanding.
Table of Contents
- What do Thrips Look Like?
- Where Do Thrips Come From?
- Thrips Lifecycle
- Different Types of Thrips
- Different Types of Thrip Infestation
- How to Get Rid of Thrips? 2 Steps to Follow
What do Thrips Look Like?
People often wonder – what do thrips look like? It is easy to answer this question if you can have some information related to their morphology. Thrips are small and thin insects that can be 1 mm long or even less. They have unique asymmetrical mouthparts and fringed wings. The wings are not suitable for authentic flight, and hence they use an unusual mechanism called the clip and fling to lift themselves by making an unsteady circulation pattern. It creates transient vortices very close to the wings and hence the flight is weak.
Thrips have a representative cigar-shaped body that has elongation with transverse constrictions. A sizeable predatory thrip can be up to 14 mm in length. Those of them that can fly have two identical, strap-like wing pairs with bristle borders. Their wings fold when the body is at rest.
It has compound eyes which are made up of many small ommatidia and three clear eyes on its head. The legs usually end in two tarsal divisions with a pocket-like arrangement that is called “arolium” at the pretarsus. It can backtrack this arrangement which is useful for it while walking on vertical surfaces.
It has asymmetrical mouthparts, and the right mandible is vestigial and limited. Usually, thrips bite takes place with its left mouth. It has two distinct suborders known as Terebrantia and Tubulifera, but overall, both look the same.
Where Do Thrips Come From?
A thrips damage can be extensive if you do not take proper measures. You must know the habitat that will be useful to counter them effectively. The insect is rampant all over North America, and you can find it everywhere. Its typical hiding places include flower blossoms, hiding of bark, under the leaves, etc.
All along the summer and spring season, thrips usually feed and infest flowers, fruit crops, vegetables, flowering plants, and trees. They can find their perfect habitat in a greenhouse, and you can see them here all through the year. In such an environment, thrips will multiply at a fast rate, and you can be left wondering – where do thrips come from?
However, during the winter, you may not find them because they generally conceal themselves to save from the harsh weather. During the season, they try to see some underground shelter or below plant debris which usually stays after cultivation. It is to ensure that they maintain proper body temperature during the period for survival. Hence, if you are left wondering ‘what do thrips look like,’ you can find them easily in the summer and spring season.
It is essential to understand thrips lifecycle to get better information on them. Female thrips lay tiny eggs which can be about 0.2 mm long, but there is some difference in egg deposition within the two suborders of this insect. Terebrantia females usually cut an aperture in plant tissue with its ovipositor and deposit its eggs in them, depositing one egg in each hole. Tubulifera females lay its eggs individually or in small groups on protruding plant surfaces.
In a thrips lifecycle, it undergoes incomplete metamorphosis to become an adult. Its initial two periods after birth is known as the nymph or larvae, and it resembles small wingless adults that do not have the genital parts. They get their food from plant tissues during this period. The third and fourth periods in Terebrantia and also the fifth period in Tubulifera consist of a resting and non-feeding stage which is very much identical to pupae. The genitalia and wings-buds form here and other body parts get their shape. It takes 8 to 15 days to develop into an adult, and a thrips lifecycle is of about 45 days. You can find both winged and wingless adults in thrips depending upon the climate. During the spring season, the winged form is more prevalent while wingless thrips constitute about 98% of the whole population during the summer season.
Different Types of Thrips
People who have been bewildered by the question ‘what are thrips’ can be in for some great learning in this section. It is because there are many types of thrips and identifying them is essential if you are into cultivation, irrigation or simple gardening. Therefore, we take a look at them one by one.
Western Flower Thrips
Western Flower thrips are year-round pests, and are a native of Southwestern United States but is also found in South America, Europe, and Australia. It feeds on more than 500 types of host plants including vegetables, ornamental crops, and different fruits.
The male of the species is nearly 1 mm long while the length of the female is about 1.4 mm. A female western flower thrip takes birth from fertilized eggs whereas males take delivery from unfertilized eggs. The females differ in color from yellow to dark brown to red while males are less spotted and can be pale yellow only. An adult western flower thrip has long wings of two pairs and is generally thin or elongated.
A female can lay 40 to 100 eggs in the flower, fruit, foliage or tissues of the plant. Its eggs are 0.2 mm long, white and oval-shaped. A nymph has red eyes and is yellowish. It feeds on its host plant for at least two life stages, and after that, it falls from its host plant to complete its remaining two life stages. The lifecycle of the nymph stage lasts from 5 to 20 days whereas an adult may live from 2 to 5 weeks. Its life depends a lot upon the ambient temperature. You can see thrips damage through areas of discoloration and holes at the places where it feeds on the plant.
Chilli thrips can have devastating effects and, it is an invasive species that has rapidly spread out from Asia. People found it in Texas in 2006, at St. Vincent in 2004, in Puerto Rico in 2007 and Florida in 2005. It predominantly targets new growth as host plants develop wrinkled leaves with typical brown scarring on the veins, the calyx of fruits and in flower buds. It can destroy many types of crops that include mango, strawberry, cotton, peanuts, roses, pepper, citrus, grapes, tea and blueberry. It may also transmit three types of tospoviruses.
Under best weather conditions, chili thrips can have a fast lifecycle. It can develop from an egg to an adult within two weeks, and that can have disastrous consequences for any crop. Female chili thrips lay their eggs inside plant tissues and can lay up to 40 eggs during their lifecycle. It undergoes two nymph and two pupal stages before becoming an adult. After completing the first two nymph stages, it drops from the plant and completes its remaining two pupal stages in leaf litter or loose soil near the base of its host plant. It can also pupate in the folds of flowers, barks or any deep crevice inside the plant. The pupal stage lasts from two to seven days.
Thrips on Roses
If you have thrips on roses, the effect can be devastating. You will not get the feel of fresh roses that you may be visualizing. They will cause visible damage to the petal edges. You can often notice thrips on roses in dry weather conditions. However, they can also occur throughout the year.
If there are thrips on roses, you will see some visible marks. When petals unfold, it will have an ugly appearance as scars and chew marks will be visible and bloom will not take place fully. The leaves will also look shriveled and deformed so that thrips damage to the young plant will be maximum.
To control this type of situation, it is essential that you use an effective insecticide in every spray cocktail. Also, you must ensure that while you spray, spread it out so that an insect or larvae come in contact with it and gets eliminated.
During the early stages of a cannabis plant, thrips cannabis may attack it and therefore, it is essential to have an eye on this intruder at all times. It is a fast moving insect that keeps itself going by sucking the plant sap. It is a common pest in marijuana cultivation, and you must take steps to prevent its rampant growth.
Thrips cannabis are about 1 to 1.5 mm in length and belong to the order of Thysanoptera. They are usually small yellowish-white insects which are from the types of Frankliniella occidentalis. When these are adult, they have an elongated shape like any other thrips and fly between plants. You can expect infection from them in most greenhouses and indoor cannabis cultivation.
However, if you take some precautions, you can limit their growth. Try to get rid of the remains of any previous crop and remove any weeds that grow around the plant. Try to introduce new substrate after each harvest and discard the old ones. You can also use predatory species like the Amblyseius swirskii or use a natural insecticide spray like potassium soap or neem oil. Employing these methods will help you to keep thrips at bay from your marijuana cultivation.
Different Types of Thrip Infestation
A thrips infestation is always an unpleasant sight, but at times, you may have to face it. Taking a corrective action will ensure that they get eliminated, and you can have a fulfilling stay. We look at some familiar places where thrips may be present and ways to counter them.
Thrips on Humans
Although not much but there have been some accounts of thrips on humans. However, no one will like to get a thrips bite as it can be quite irritating. There are two species of thrips which are known to bite people – Frankliniella tritici and Limothrips cerealium. Some people have also known a third species, Frankliniella bispinosa that can even bite humans. It is found throughout Florida and can be a type of serious nuisance during the spring season. A thrips bite may have many kinds of reactions that may range from slight irritation to a skin rash.
You can control thrips bite by using some mild lotion or cream for the purpose, but that will not be needed as the problem tends to die on its own. With a season change, thrips can also go away automatically, and you need not employ any particular process for it.
Thrips in House
Thrips in-house can always lead to an infestation so that you will find the intruder at all placed inside the house. It can be highly discomforting, and you must devise ways by which you can contain them and their unlimited growth.
You can always use a liquid spray to thrips them off, but it will only be effective if they are small in number because you will have to apply the spray at known places. Moreover, a house may have many untreated areas which can be their breeding place. In such a condition if you think they are abundantly there in a house, try using aerosols (bombs) that can take care of all adults. However, all adults that hatch after a few hours of a ‘bomb’ attack won’t die and the problem may repeat after 1 to 2 days once again.
The best way can be to use a space spray for the purpose which will ensure that you can eliminate all young and adults effectively. It will be active 24 hours a day and help in breaking their life cycle because with no adults there will be no eggs. You only need to install a small aerosol machine which works on a battery in each room. The device releases a blast of pyrethrin after each hour that is helpful for killing the pest. A can of pyrethrin usually lasts for about 30 to 40 days so that you will only have to look into this aspect. Rest, the machine can automatically take care. Within 2 to 3 months, you can expect to break the thrips lifecycle, and none of them will be present in your home. For each household, you may need 3 to 5 such machines because each of them will be required for a room if the infestation is massive.
You can ultimately eliminate thrips from your house in this way. You only need to take care of the refill cans and nothing else apart from it.
Thrips in Pool
As with everything else, thrips in a pool can be a real menace if you are planning for a pool session. Usually, this type of thrips stays near a lake that has plants around it so that they feed on the plant and flock towards the water body. You may not be able to see them with your naked eye but can only feel their prick. It is a type of “probing” that thrips do to find out whether it is a plant material or not. The ‘pinpricks’ may cause itching or in some cases, create a rash.
How to Get Rid of Thrips? 2 Steps to Follow
1) Use Shock Chlorination
A natural pool has 1.0 to 3.0 ppm of chlorine in it. If you desire shock chlorination, increase the level from 5.0 to 10.0 ppm. It can help in getting rid of all insects and thrips. The chlorine level in the pool will automatically return to normal within two days, and then you can enjoy again.
2) Follow-up with Algaecide
Once the chlorine level is back to 1.0 to 3.0 ppm, follow it up with an algaecide. Then, wait for 12 hours and remove any dead algae with vacuum and brush.
3) Vacuum and Brush – It is the final stage of ensuring that there are no thrips in your pool. You can clear any thrips in the pool or any other dead organic material in this way. Using a vacuum and brush, you can do regular pool maintenance for about 10-15 minutes in a day and ensure that there are no thrips around.
Thrips are highly potent pests and can destroy crops substantially. They also tend to multiply very fast due to which controlling them can be an issue. However, with proper understanding and best techniques, you can reduce thrips damage and hope to get them cleared from your farm or garden.