Lichtensia viburni
Lichtensia viburni
The Viburnum Scale (Lichtensia viburni Signoret, 1873) is an insect belonging to the Coccidae family.
Systematics –
Domain Eukaryota,
Kingdom Animalia,
Suborder Eumetazoa,
Branch Bilateria,
Phylum Arthropoda,
Subphylum Hexapoda,
Class Insecta,
Subclass Pterygota,
Cohort Exopterygota,
Subcohort Neoptera,
Superorder Paraneoptera,
Section Rhynchotoidea,
Order Rhynchota,
Suborder Homoptera,
Section Sternorrhyncha,
Superfamily Coccoidea,
Family Coccidae,
Genus Lichtensia,
Species L. viburni.
The following terms are synonymous:
– Philippia oleae Gómez-Menor Ortega, 1958;
– Filippia viburni Balachowsky, 1935;
– Filippia rosmarini Goux, 1934;
– Lichtensia rifana Balachowsky, 1931;
– Philippia oleae Leonardi, 1920;
– Filippia oleae Lindinger, 1912;
– Coccus lentiscicola Salem, 1908;
– Lichtensia eatoni Newstead, 1895;
– Coccus lentiscicola Mina Palumbo, 1882;
– Philippia viburni Lichtenstein, 1881;
– Philippia hederae Lichtenstein, 1881.
Geographic Distribution and Habitat –
Lichtensia viburni is a scale insect belonging to the superfamily Coccoidea, present in all major olive-growing areas of Italy and the Mediterranean basin, including countries such as France, Spain, Portugal, the Czech Republic, and North Africa (e.g., Tunisia). It is frequently associated with olive trees (Olea europaea) and other plant species such as viburnum, ivy, myrtle, and mastic.
It is a well-represented species in the Mediterranean region, although it rarely reaches densities sufficient to cause serious economic damage.
Its habitat is typically olive groves, where it concentrates mainly on the undersides of leaves and shoots, preferring the densest and innermost areas of the canopy where humidity and the microclimate favor its growth.
This species has also been recorded in other European countries and North Africa on olive trees and ornamental plants, confirming its widespread Mediterranean distribution.
Morphology –
Lichtensia viburni exhibits strong sexual dimorphism and several characteristics typical of soft scale insects.
The adult female has an oval, slightly convex body, approximately 4–6 mm long. It is yellowish in color with light darker spots.
During oviposition, it is covered with a white, waxy ovisac that contains the eggs and can be very visible in infestations.
The nymphs (young stages) are yellowish-green, oval in shape, mobile in the early stages, then sessile when they begin feeding.
The male is small, winged, and has a more elongated body than the female; adult males emerge from a single waxy follicle.
These characteristics allow macroscopic identification of the insect in the field and distinguish its different developmental stages.
Suitability and Life Cycle –
Lichtensia viburni has a life cycle closely linked to seasonal trends, with heterometabolic development (without complete metamorphosis).
The insect overwinters as a nymph, immobile and often clustered in bark crevices or under leaves.
The first generation occurs in late spring (May-June); mature females lay eggs in their waxy ovisac.
After about 2–3 weeks, the nymphs emerge, disperse, and begin feeding.
The second-generation nymphs appear between August and September and subsequently overwinter.
In particularly favorable climatic conditions, the number of generations (1–2) can vary depending on temperature and latitude. In warmer Mediterranean climates, some populations report only one significant generation per year on the olive tree, while in more temperate zones, the second generation can be observed.
Growth is closely influenced by canopy microclimate, leaf density, and nutrient availability.
The accumulation of protective wax and oviposition delay the effectiveness of some chemical pesticide treatments, making management based on natural adversaries often more effective.
Ecological Role –
Lichtensia viburnum feeds by sucking sap with piercing-sucking mouthparts, thus depriving the plant of nutrients.
Direct damage involves plant impoverishment due to sap removal and trophic punctures, resulting in slowed leaf and shoot development.
The sugary secretion of these insects (honeydew) promotes the growth of sooty mold and can reduce the photosynthetic capacity of leaves, making them asphyxiated and sticky.
Honeydew also attracts ants and can intensify the establishment of saprophytic fungi on the vegetation.
Severe infestations are rare or localized, generally not widespread in well-managed olive groves.
In orchards with excessively dense canopies or favorable microclimatic conditions (e.g., low internal light), the infestation may be more persistent.
Numerous entomophagous insects contribute to the natural regulation of populations:
– Coccinellid beetles, predators of scale insects.
– Hymenoptera Chalcididae parasitoids, such as Coccophagus howardii and other genera that attack juvenile stages.
– Specific Lepidoptera, such as Coccidiphaga scitula, are among the reported natural attacks.
The presence of these pests can keep populations below economic damage thresholds, often making intensive chemical treatments unnecessary.
Correct cultural practices, such as thinning pruning and good canopy aeration, reduce favorable habitat for scale insects.
A diverse nearby flora can favor the establishment of natural enemies.
An agroecological approach is important in rebalancing populations, offering effective tools to sustainably contain Lichtensia viburnum, reducing dependence on chemical pesticides, such as:
– Functional biodiversity: introducing diverse plant species to the edges and under the olive grove can favor the presence of natural predators and parasitoids, improving biological control.
– Rotation and companion planting: Growing plants that attract beneficial insects helps stabilize natural enemy populations.
– Microclimate management: Strategic pruning, the use of cover crops, and maintaining semi-shaded areas help reduce favorable conditions for scale insect proliferation.
– Reduction of chemical inputs: Reduced use of insecticides preserves natural enemies, enhancing the self-regulation of Lichtensia viburnum populations.
– Soil and plant health: Practices such as composting and mulching improve plant vitality, making them less susceptible to stress caused by trophic punctures.
In summary, agroecology not only limits direct and indirect damage from Lichtensia viburnum, but also strengthens the overall resilience of the olive grove by integrating biological controls, microclimate management, and sustainable cultivation practices.
Guido Bissanti
Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– Russo G., 1976. Agricultural Entomology. Special Section. Liguori Editore, Naples.
– Pollini A., 2002. Handbook of Applied Entomology. Edagricole, Bologna.
– Tremblay E., 1997. Applied Entomology. Liguori Editore, Naples.
Photo source:
– https://inaturalist-open-data.s3.amazonaws.com/photos/120427138/original.jpeg