Citrus tree cultivation, such as orange, lemon, mandarin, and grapefruit trees, is one of the most widespread and valuable agricultural activities in many regions of the world. However, these fruit trees are exposed to a wide variety of plagues and diseases that can seriously affect your production, reduce the quality of the fruit and jeopardize the viability of the crop. Having a complete and updated guide on Identification of citrus pests and their effective treatments It is essential for any professional producer, amateur or person responsible for managing green spaces.
Importance of pest control in citrus
Success in citrus pest management depends on the early detection, the accurate identification of each harmful agent and the application of integrated best practices, which combine cultural, biological, and chemical methods in a sustainable and environmentally friendly manner. Crop losses due to pests can have very serious economic consequences and affect both the domestic market and exports, since many pests are considered quarantine control.
The increasing pressure from traditional pests and the emergence of new exotic threats makes it essential to update knowledge and adapt intervention protocols based on the evolution of phytosanitary problems.
Main citrus pests: Identification and symptoms
- White fly (Aleurothrixus floccosus and other species)
- Fruitfly (Ceratitis capitata)
- Tetranychid mites (Tetranychus urticae, Panonychus citri, Eutetranychus orientalis, E. Banski)
- Citrus miner (Phyllocnistis citrella)
- California red louse (Aonidiella aurantii)
- Cotton buds (Planococcus citri, Delottococcus aberiae and others)
- Aphids (Aphis gossypii, aphis spiraecola)
- Trips (Pezothrips kellyanus, Chaetanaphothrips orchidii, other species)
- Lemon moth (Prays citri)
- Florida pink carrion caterpillar (Anatrachyntis badia)
- green bug (Closterotomus trivialis)
Below, you'll find a comprehensive description of each of these pests, with details on their biology, life cycle, symptoms and damage, as well as the most effective techniques for their control and prevention.
Whitefly in citrus (Aleurothrixus floccosus and other species)
La cottony whitefly It is one of the most common and widespread pests of citrus fruits. Belonging to the order Hemiptera, group Homoptera, it is composed of several species, the most important being Aleurothrixus floccosus. Other species such as Bemisia afer, Dialeurodes citri, Parabemisia myricae y Paraleyrodes minei may also be present, complicating diagnosis.
- ID: Adults measure approximately 1,5 mm, have a yellowish body, and wings covered with a waxy secretion, giving them a whitish appearance. The eggs are arranged in circles or semicircles on the underside of leaves.
- Nymphs: There are four nymphal stages with color changes from yellowish to grayish, and the generation of a characteristic cottony mass.
Symptoms and damage: They look themselves chlorotic spots On the upper surface, there is a concentration of honeydew on the underside, and the presence of black mold (a dark, saprophytic fungus that settles on the honeydew). The weakening of the tree affects the size and quality of the fruit.
- Biological cycle: It produces several generations per year, accelerating its development in spring and summer. It can be active year-round in temperate climates.
Prevention and control:
- Keep a proper watering and avoid excess humidity.
- Favor the auxiliary fauna like the parasitoid Cales noacki, which effectively regulates populations.
- Apply phytosanitary treatments when the maximum number of newly hatched larvae is detected, preferably in active sprouting.
- Integrated control: It is recommended to alternate biological methods and, if necessary, use authorized selective insecticides to prevent the development of resistance and protect beneficial fauna.
Fruit fly (Ceratitis capitata)
La Mediterranean fly It is considered one of the most dangerous and widespread pests of citrus growing worldwide. It can cause significant fruit losses, affect exports, and cause direct and indirect damage, both through pulp consumption and the introduction of secondary microorganisms.
- ID: Adults up to 5 mm, yellow in color with spotted wings and pointed ovipositor apparatus.
- Biological cycle: The female lays eggs in the fruit, from which larvae emerge and feed on the interior, softening and rotting the flesh. The larvae then hatch, fall to the ground, and form buried pupae, from which new adults emerge.
- Symptoms and damage: Yellow or greenish spots on the skin with a tiny incision, softening and darkening of the area, and the presence of multiple larvae inside the affected fruit. In advanced stages, the fruit drops prematurely.
Management and treatment:
- Monitoring and Traps: Install food and sexual traps (with pheromones) for population monitoring and mass capture of adults.
- Preventive treatments: Apply bait as soon as the fruit changes color and maintain constant monitoring of population growth.
- Specific treatments: Use authorized insecticides during the critical period, always respecting safety limits.
- Waste management: Remove fallen or unharvested fruit as it is a continuous source of infection.
Tetranychid mites in citrus
Mites, especially Tetranychus urticae (red spider), Panonychus citri, Eutetranychus orientalis y E. Banski, are among the most damaging and resilient pests of citrus fruits. They cause discoloration, bruising, defoliation, and commercial depreciation of the fruit.
- ID: The adult mite is tiny (0,3–0,6 mm), with characteristic lateral spots. They form colonies, mainly on the undersides of leaves, and can produce dense webs on fruits and tender shoots.
- Symptoms: The leaves are dented, the undersides are depressed, and the upper surface is chlorotic; the fruit has bronze spots. Severe attacks in spring and summer can cause massive defoliation.
Prevention and treatment:
- Inspect the plantation from spring and protect it if mobile forms of mites appear.
- Integrated management: Use of selective acaricides that respect auxiliary fauna, alternating active ingredients, and promoting natural enemies such as phytoseiids (predatory mites).
- Keep a proper watering, avoid water stress and control weeds that can serve as reservoirs.
- In the presence of foci, carry out localized treatments rather than generalized ones.
Citrus leaf miner (Phyllocnistis citrella)
El leaf miner It is a tiny butterfly whose larvae dig winding galleries in young leaves, weakening seedlings and mainly affecting lemon trees and tender shoots of orange and mandarin trees.
- ID: Adults 3–5 mm, pearly white, rapid cycle and several generations per year.
- Symptoms: Leaves filled with serpentine galleries (mines), deformed and prone to premature drop. Vigorous canopy reduction.
Prevention and control:
- Monitoring of young shoots (1 to 5 cm) and application of authorized products upon detection of the first outbreaks.
- Alternation of active ingredients to avoid resistance.
- Promote auxiliary fauna: lacewings, predators and native parasitoids.
- Avoid excessive pruning, which increases the development of susceptible tender shoots.
California red louse (Aonidiella aurantii)
This tough, circular-scutelled, reddish-brown mealybug produces chlorotic spots, weakening and falling of leaves and fruits, commercially depreciating the fruit in both national and international markets because it is a quarantine pest.
- ID: Red scales about 2 mm in size on fruits and leaves. Nymphs hatch live from the female, and generations overlap throughout the cycle.
- Symptoms: Affected areas with red scales, chlorotic leaves, and reduced tender stems. Tree vigor and development are compromised.
Prevention and control:
- Perform aeration pruning.
- Control ant populations, the main allies of mealybugs and enemies of natural predators.
- Apply treatments at the time of greatest presence of mobile or newly established forms. Sampling must be accurate to determine critical moments.
Cotton wool (Planococcus citri y Delottococcus aberiae)
Mealybugs form large cottony colonies, secrete honeydew that promotes the development of sooty mold, and transmit various pathogens. Their direct damage is the deformation and commercial depreciation of the fruit, as well as the weakening of the tree.
- ID: Females are oval, covered with powdery white wax; males are small and winged. Delottococcus aberiae, known as South African cottony mildew, can cause complete deformation of young fruit, with significant losses.
- Symptoms: Chlorotic spots, honeydew, sooty mold, presence of cottony colonies on fruits and between areas where fruits and leaves meet.
Prevention and control:
- Encourage useful predators such as Cryptolaemus montrouzieri, although its effectiveness depends on the time of release and crop conditions.
- Perform treatments when petals fall, thoroughly wetting the lower part of the trunk and crown.
- Apply integrated and chemical control if the population exceeds 10% of affected fruits in the sampling.
Aphids on citrus fruits (Aphis gossypii, aphis spiraecola and others)
Aphids are sucking insects that reproduce rapidly and can cause pests on shoots, leaves, and fruits. They transmit viruses such as citrus tristeza virus and other important pathogens.
- ID: Wingless and winged forms, green to black in color; colonies on young shoots, curled leaves, and honeydew present.
- Biological cycle: In temperate zones, populations can remain active year-round without the need for alternative host plants.
- Symptoms: Curled leaves, deformed shoots, decreased photosynthetic capacity, and severely affected fruit. They cause sooty mold and can be virus vectors.
Prevention and control:
- Strengthen natural enemies: parasitoids (such as Lysiphlebus testaceipes), coccinellids (Scymnus), lacewings (Chrysoperla carnea), hoverflies and cecidomids.
- Installation of yellow chromotropic traps for early detection of infestations.
- Apply selective aphicides if treatment thresholds are exceeded, preferably when the first colonies are observed.
Thrips in citrus fruits
El Citrus thrips (Pezothrips kellyanus), along with other species such as Chaetanaphothrips orchidii, Heliothrips haemorrhoidalis y Scirtothrips inermis, are small insects that cause superficial damage and scarring on young fruits, depreciating their commercial value.
- ID: Adults are dark brown or black, with light-colored wings. The larvae are white to orange in color and thigmotaxic, making them difficult to detect. They are primarily visible on flowers and small fruits.
- Symptoms: Circular or annular scarifications, whitish spots and crusty areas that can be confused with abiotic damage or other pests.
Prevention and control:
- Conduct direct sampling of newly set fruit, using 5–10% of fruit with larvae as the treatment threshold.
- Install white sticky traps to monitor relative abundance of adults.
- Avoid prolonged flowering and excessive pruning that increases susceptibility.
- Alternate chemical treatments with different modes of action to delay the development of resistance.
Lemon moth (Prays citri)
The lemon moth primarily attacks lemon trees, although it can also infect other citrus species. Its larvae penetrate flowers and shoots, destroying reproductive organs and affecting fruit production.
- ID: Small adults, cycle of several generations per year, greatest activity from spring to autumn.
- Symptoms: Flowers with perforated stamens and ovaries, lesions on set fruits and young shoots, with significant crop losses.
Prevention and control:
- Apply selective treatments with Bacillus thuringiensis and other biological products when 5% of the flowers are found to be affected.
- Pay special attention at the beginning of flowering and in autumn in case of regrowth.
- Maintain biodiversity to favor natural enemies.
Other emerging pests: pink caterpillar, green stink bug and new threats
In recent years, emerging pests with significant impact have been detected:
- Florida pink carrion caterpillar (Anatrachyntis badia): Small lepidopteran that can cause annular scarifications and dark spots in the stem area.
- green bug (Closterotomus trivialis): Causes bud wilting and sap exudation at the beginning of flowering.
- In both cases, monitoring, removing plant residues, and applying authorized treatments are essential.
It is important to highlight the need to update phytosanitary protocols in the face of the possible introduction of new exotic pests, especially in areas of citrus expansion, importation of plant material or climate changes that favor their establishment.
Fungal and bacterial diseases associated with pests
Insect pests often promote the development of secondary fungal diseases, such as:
- Gum (caused by Phytophthora spp.): Bark lesions, gummy exudation and weakening of the tree.
- Black spot (Guignardia citricarpa), alternaria, and mottling: Spots on fruits and leaves, which may be caused by previous insect damage.
- Citrus sadness (virus): It is transmitted mainly by aphids and can be lethal to the tree.
Prevention and control:
- Use resistant rootstocks.
- Apply authorized fungicides at the time of maximum susceptibility.
- Maintain good drainage and avoid overwatering.
- Perform aeration pruning and eliminate sources of infection.
Integrated pest management in citrus: keys to success
El MIP (Integrated Pest Management) involves the combination of agricultural, biological and, where necessary, chemical methods, prioritizing prevention and environmental sustainability.
- regular monitoring: Inspect trees frequently for early symptoms and pest populations.
- Biologic control: Promote natural enemies of pests (predators, parasitoids, and beneficial microorganisms). For more information, visit biological control in crops.
- Cultural methods: Pruning, rational irrigation, removal of fallen fruit, and soil management to reduce the incidence of pests.
- Responsible use of phytosanitary products: Select selective products, alternate active ingredients, and adhere to the recommended dosages and timing.
- Rotation and diversity: Avoid strict monocultures and promote crop rotation and biodiversity to break the biological cycles of pests and diseases.
Modern techniques and developments in pest control
The citrus sector is increasingly incorporating more precision technology, from the use of drones for localized detection and application of treatments to digital monitoring systems that allow outbreaks to be anticipated and interventions to be adjusted to actual crop conditions. You can also learn more at Reasons why citrus plants don't bear fruit.
Furthermore, the development of bioinsecticides, pheromones, and beneficial microorganisms expands the range of available tools, allowing us to reduce the use of chemicals and minimize the development of resistance.
Indicative monitoring and treatment schedule
The monitoring and treatment schedule should be adapted to the region and climate change, but in general:
- Spring Season: Activity of Phyllocnistis citrella, aphids, thrips and reactivation of mites.
- Summer: Maximum pressure from whiteflies, mites, mealybugs, thrips, and fruit flies.
- Fall Season: Pest outbreaks following rain and temperature drops; possible need for preventative fungal treatments.
- Winter: Reduced surveillance, winter oil treatments, and preventive inspection of the plantation.
Common mistakes and key recommendations
- Failure to correctly identify the pest before applying treatments.
- Carrying out chemical treatments without respecting the intervention thresholds and without alternating active ingredients.
- Neglecting ant control and plant debris management, which encourages re-infestation.
- Ignoring the importance of auxiliary fauna and functional biodiversity in natural pest control.
Useful resources and links for citrus pest control
- Technical guides and manuals on integrated pest management are available on official websites and agricultural associations.
- Updated lists of authorized phytosanitary products and applicable health regulations.
- Phytosanitary alert centers by autonomous communities and phytopathological diagnostic laboratories.
- Remote sensing technologies and digital monitoring platforms.
