Olive leaf fly
- The scientific name : Dasineura oleae
- the family :Diptera
- Symptoms of the disease :
- The infestation causes symptoms of cracking and swelling on the bark of limbs, accompanied by extensive internal necrosis of the bark, causing drying of limbs or even death of entire trees.
- Infestation occurs on leaves, causing oblong masses and deformities, while defoliation has been reported in severely infested trees.
- . When galls form on the leaves, the plant's ability to photosynthesize is reduced, and the quantity and quality of the crop may be affected
- Description of the insect: Its length is (2.5 mm). The male’s abdomen and head are yellow, while the female’s abdomen is light brown. The antennae are knobby. The larva is (3 mm) long, legless, and yellowish white in color.
- The causes of disease :
- The availability of appropriate conditions, such as temperature and humidity, has a relationship with the development of this insect, especially as it goes through a stage of cessation of development that extends from the middle of the summer until the beginning of the spring.
- The use of agricultural chemicals causes the elimination of many creatures and insects that maintain the natural balance.
- Conditions suitable for the spread of the disease :
- Lack of care for olive trees in general (pruning, balanced fertilization, irrigation) before harvesting them.
- Not taking good care of the land and plowing (excessive plowing, not removing weeds).
- The tree itself is weak as a result of lack of attention to potassium and nitrogen phosphorous fertilization.
- Disease development cycle :
D. oleae eggs are laid on the lower surface of the leaf, and the hatched larvae penetrate the underlying tissue and form galls in which they live and develop until adults emerge.
D. oleae develops one generation per year in mountainous areas and two generations in coastal areas
- Losses of disease spread
- Serious wounds on the leaves, causing them to fall and thus losing the ability to produce flower buds and fruits the following year
- Larval feeding activity may lead to the release of plant volatiles such as linalool
- Control strategy
- Preventive measures to prevent the occurrence of the disease:
Pruning the insect-infected olive parts and then burning them, and irrigating the trees properly during the hot months of summer and fall
- Chemical and organic control recommendations
- Using parasites such as
P. oleae and Q. Dasineurae
– Use yellow sticky traps
– Spraying systemic pesticides (dimethoate) during the insect’s active season (the first of March).
- References
- Doğanlar, M., Sertkaya, E., & Skuhravá, M. (2011). Pest status of olive leaf gall midge Dasineura oleae (Angelini, 1831), description of Lasioptera oleicola Skuhravá sp. new (Diptera: Cecidomyiidae) and effectiveness of parasitoids on their populations in Hatay Turkey. Turkish Journal of Entomology, 35(2), 265-284. Batta, Yacoub A. “New findings on infestation and phenology of Dasineura oleae Angelini (Diptera, Cecidomyiidae): an emerging pest on olive trees in the Palestinian Territories. “ Journal of Plant Diseases and Protection 126.1 (2019): 55-66
- Caselli, Alice, et al. Infestation of the gall midge Dasineura oleae provides first evidence of induced plant volatiles in olive leaves. Bulletin of entomological research, 2022, 112.4: 481-493. Simoglou, KB, et al. “Euzophera bigella (Zeller)(Lepidoptera: Pyralidae) and Dasineura oleae (F. Low)(Diptera: Cecidomyiidae): emerging olive crop pests in the Mediterranean?.” Journal of Pest Science 85 (2012): 169-177
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