Frankliniella occidentalis
Encyclopedia
The western flower thrips (Frankliniella occidentalis (Pergande)) is an important pest insect in agriculture. This species of thrips
is native to North America but has spread to other continents including Europe, Australia, and South America via transport of infested plant material. It has been documented to feed upon over 500 different species of host plants, including a large number of fruit, vegetable, and ornamental crops. The adult male is about 1 millimeter long; the female is slightly larger, about 1.4 millimeters in length. Most western flower thrips are female and reproduce by arrhenotokous parthenogenesis
. Males are rare. They are variable in color, with some color types more abundant in certain seasons. Colors vary from red to yellow to brown. Each adult is elongated and thin, with two pairs of long wings. The eggs are oval or kidney-shaped, white, and about 0.2 millimeters long. The nymph is yellowish in color with red eyes.
The life cycle of the western flower thrips varies in length due to temperature, with the adult may living from two to five or more weeks, and the nymph stage lasting from five to 20 days. Each female may lay 40 to over 100 eggs in the tissues of the plant, often in the flower, but also in the fruit or foliage. The newly hatched nymph feeds on the plant for two of its instars, then falls off the plant to complete its other two instar stages. The insect damages the plant in several ways. The major damage is caused by the adult ovipositing in the plant tissue. The plant is also injured by feeding, which leaves holes and areas of silvery discoloration when the plant reacts to the insect's saliva. Nymphs feed heavily on new fruit just beginning to develop from the flower. The western flower thrips is also the major vector of tomato spotted wilt virus, a serious plant disease.
Western flower thrips is a year-round pest, but is less destructive during wet weather. Damage can be reduced by growing barriers of non-host plants around crops and by eliminating reservoir plants, plants that the thrips are especially attracted to, such as jimson weed
. The thrips' natural enemies include bugs of genus Orius
. Other agents show promise as biological pest control
, including the fungus Metarhizium anisopliae.
Flower-feeding thrips are routinely attracted to bright floral colors, especially white, blue, and yellow, and will land and attempt to feed. Some flower thrips will "bite" humans wearing clothing with such bright colors, though no species feed on blood; such biting does not result in any known disease transmission but skin irritations are known to occur.
Thrips
Thrips are tiny, slender insects with fringed wings . Other common names for thrips include thunderflies, thunderbugs, storm flies, thunderblights, and corn lice...
is native to North America but has spread to other continents including Europe, Australia, and South America via transport of infested plant material. It has been documented to feed upon over 500 different species of host plants, including a large number of fruit, vegetable, and ornamental crops. The adult male is about 1 millimeter long; the female is slightly larger, about 1.4 millimeters in length. Most western flower thrips are female and reproduce by arrhenotokous parthenogenesis
Arrhenotoky
Arrhenotoky or arrhenotokous parthenogenesis is a form of parthenogenesis in which unfertilized eggs develop into haploid males.This form is observed in some marine invertebrates, beetles, scorpions, mites, bees, etc....
. Males are rare. They are variable in color, with some color types more abundant in certain seasons. Colors vary from red to yellow to brown. Each adult is elongated and thin, with two pairs of long wings. The eggs are oval or kidney-shaped, white, and about 0.2 millimeters long. The nymph is yellowish in color with red eyes.
The life cycle of the western flower thrips varies in length due to temperature, with the adult may living from two to five or more weeks, and the nymph stage lasting from five to 20 days. Each female may lay 40 to over 100 eggs in the tissues of the plant, often in the flower, but also in the fruit or foliage. The newly hatched nymph feeds on the plant for two of its instars, then falls off the plant to complete its other two instar stages. The insect damages the plant in several ways. The major damage is caused by the adult ovipositing in the plant tissue. The plant is also injured by feeding, which leaves holes and areas of silvery discoloration when the plant reacts to the insect's saliva. Nymphs feed heavily on new fruit just beginning to develop from the flower. The western flower thrips is also the major vector of tomato spotted wilt virus, a serious plant disease.
Western flower thrips is a year-round pest, but is less destructive during wet weather. Damage can be reduced by growing barriers of non-host plants around crops and by eliminating reservoir plants, plants that the thrips are especially attracted to, such as jimson weed
Datura stramonium
Datura stramonium, known by the common names Jimson weed, devil's trumpet, devil's weed, thorn apple, tolguacha, Jamestown weed, stinkweed, locoweed, datura, pricklyburr, devil's cucumber, Hell's Bells, moonflower and, in South Africa, malpitte and mad seeds, is a common weed in the...
. The thrips' natural enemies include bugs of genus Orius
Orius
The genus Orius consists of omnivorous bugs in the family Anthocoridae . Adults are 2–5 mm long and feed mostly on spider mites, thrips, and their eggs, but will also feed on pollen and vascular sap .These predators are common in gardens and landscapes...
. Other agents show promise as biological pest control
Biological pest control
Biological control of pests in agriculture is a method of controlling pests that relies on predation, parasitism, herbivory, or other natural mechanisms...
, including the fungus Metarhizium anisopliae.
Flower-feeding thrips are routinely attracted to bright floral colors, especially white, blue, and yellow, and will land and attempt to feed. Some flower thrips will "bite" humans wearing clothing with such bright colors, though no species feed on blood; such biting does not result in any known disease transmission but skin irritations are known to occur.