Citrus thrips are small insects belonging to the order Thysanoptera. These organisms generally measure less than a millimeter. Thrips can cause damage to citrus trees by feeding on the tissues, particularly young shoots and leaves. They have been reported as new pests in several countries since 1990 because of the scarring they cause on fruit. In this article we presented the morphological description of thrips, development conditions, development cycle, symptoms and methods of control.
Morphorogical description
Thrips have a distinctive body adapted to their lifestyle:
1 Size: They have a body generally measuring less than a millimeter in length. their small straw sometimes and difficult to detect with the naked eye.
2 Body: Shape: They have an elongated and cylindrical body like tube shape. this morphology and distinguishes the family Thysanoptera.
3 Wings: Citrus thrips have two pairs of fringed wings. the forewings are thicker than the hindwings. These wings are folded along their backs when not in flight.
4 antennae: these are relatively long and thin antennae. have several segments. Their role is to detect pheromones, odors and several environmental signals.
5 Piercing: sting mouth: thrips have a mouth adapted to pierce plant tissues and feed on cell sap.
6 color: the color of thrips is variable, it is yellow to light brown. some have patterns or spots on their bodies.
Development condition
Citrus thrips thrive in conditions favorable for reproduction and survival, such as hot and dry climate. However, relatively high humidity is unfavorable for the development of thrips. The presence of natural predators, such as certain types of penis bugs and ladybug larvae, can influence the development of thrips populations by regulating them.
Thrips have a specific mouth for perforating cells and sucking out cell juices. They use their sharp mouthparts to create small punctures in the tissues of leaves, buds; etc.
Citrus thrips are mainly spread in two ways:
Active movement: Citrus thrips are capable of actively moving from one plant to another. They use their wings to fly short distances and their legs to walk or jump between leaves and plant stems. This mode of travel allows them to colonize new areas within a culture or between different cultures.
Development cycle
The development cycle of citrus thrips includes several distinct stages, from egg to adult. Here is a general description of the life cycle of these insects:
Egg: The life cycle of citrus thrips begins with the laying of eggs. Females lay their eggs in tender plant tissues, such as young leaves, buds or flowers of citrus fruits. The eggs are generally elongated and translucent.
Symptoms
Citrus
thrips can cause a variety of symptoms on host plants, primarily affecting the
vegetative parts of the tree. Here are some common symptoms associated with a
citrus thrips infestation:
Leaf discoloration: Thrips feed by puncturing plant cells to suck out cell juices. This can cause the leaves to discolor, turning them yellowish, silver, or tan.
Deformed leaves: Young growing leaves can be particularly susceptible to thrips attack. Their feeding can cause leaves to distort, making them appear twisted or curled.
Tissue necrosis: Citrus thrips can cause damage to plant cells, leading to areas of necrosis on leaves and other parts of the plant. These necrotic areas can appear as brown or black spots.
Deformed buds: Thrips have a preference for young shoots and buds. Their feeding on these parts can cause deformations, delay in bud opening and growth abnormalities.
Presence of silver spots: Citrus thrips can leave silver or silver spots on leaves as a result of their feeding. These spots may be a hallmark of thrips activity.
Stunted growth: Severe thrips infestation can cause overall stunted growth of the plant, affecting the production of new leaves, flowers and fruit.
Control methode
Control of
citrus thrips can be achieved by a combination of methods, favoring sustainable
and environmentally friendly approaches. Here are some methods of controlling
citrus thrips: