Almond bark beetle 

Almond bark beetle - the world of plants
  • The scientific name : Ruguloscolytus amygdali Guerin
  • the family : coleoptera 
  • Symptoms of the disease
  • Note a large number of small round holes on the branches and stems of infected trees.
  • The presence of a resinous substance above the entry and exit hole of adult insects. 
  • Complete drying of branches and small trees (when the infestation is severe) 

Almond bark beetle - the world of plants

Almond bark beetle - the world of plants
Almond bark beetle - the world of plants

  • Description of the insect: 

The adult insect is small, 3 mm long, and has a cylindrical shape. The color of its head and chest is black, while the antennae are brown. There are numerous pits on the chest. 

  • The larva is 4 mm long, white in colour, and has no legs. 

Almond bark beetle - the world of plants
Almond bark beetle - the world of plants

  • The causes of disease
  • Climate change affects the distribution and population dynamics of many insect pests. 
  • Weak trees or infected with fungal diseases. 
  • Poor soil conditions such as high humidity. 
  • Conditions suitable for the spread of the disease
  • The temperature rises in summer and decreases in winter. 
  • Neglecting pruning.  
  • Disease development cycle
  • They emerge at temperatures above 18°C to form the winter generation. After a period of cold weather, the air temperature begins to rise, and all the adult beetles that have accumulated in the bark to wait for suitable flight conditions will suddenly emerge and produce the spring generation during the months of March and April. The spring generation is followed by the summer generation, which begins in May to June. 
  •  The insect has three generations annually. 
  • The female digs a primary groove in which she lays eggs. The eggs hatch into worm larvae that dig secondary tunnels under the bark, vertical or inclined to the mother’s tunnel. The tunnels do not intersect, as is the case in the apple bark weevil.
  • Losses from the spread of the disease: 
  • It can affect neighboring economic crops.
  • It weakens the trees and attracts other borer pests, the most important of which are capnoids
  • Control strategy 
  • Preventive measures to prevent the occurrence of the disease 
  • Locate trees containing overwintering larvae and destroy them before the first generation begins to emerge. 
  • Branches after cutting should be burned immediately, because if left on the plot, adults can get out and attack the nearest trees. If these branches are saved for firewood or other uses, they must be placed in plastic bags and in closed places. In areas with problems of adjacent abandoned plots, extreme caution must be taken against the attack of this pest.
  • Good service for an apricot orchard is regular irrigation
  • Pruning infected branches, cutting down weak and dead trees and burning them.
  • Chemical and organic control recommendations 
  •  Organic control: Coating tree branches with a solution consisting of the pesticide cyclose benzene and spent olive oil (after using it for various purposes) in a ratio of 6:1 during the bud dormancy season. 
  • Chemical control: Spraying the stem and branches with dieldrin or lindane during the active season of the insect.
  • References 
  • ZEIRI, Asma; BRAHAM, Mohamad; BRAHAM, Mohamad. The effects of Climatic Variability and Change on the activity of the Almond bark beetle Scolytus amygdali in the coastal zone of Mahdia. Revue des Regions Arides, 2014, 35: 1833-1837. 
  • Zeiri, A., Ayberk, H., Buhroo, A. A., Braham, M., & Braham, M. (2015). Observations on the overwintering forms of Scolytus Amygdali (Coleoptera: Curculionidae) in Tunisia. Munis Entomology and Zoology,(10), 209-214 
  • Blachowsky 1962. Traite d´Entomologie (t, I, vol. 2) Talhouk AS1968. Contribución al conocimiento de las plagas almendro en los países del mediterraneo.  


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