Otiorrinco or beetle of the olive tree ( otiorhynchus cribricollis gyllenhaal, 1834), It is a secondary pest with little impact on the traditional olive grove. However, in young olive groves and intensive plantations can cause damage of some consideration. Therefore, in these cases, control is necessary when there are important populations of the olive beetle.
This pest is also known by the names of olive weevil beetle, Black olive otiorrinco, Serreta…
The species is different than that of the Olive green otiorhynchus (Polydrusus xanthopus).
States of the Otiorhynchus cribricollis
Egg: color initially white, oval shape and size of 0.8x1mm. The color turns black before hatching.
Larva: whitish and curved shape, the larvae are similar to those of other curculionides.
Pupa: The status of pupa occurs underground in a earthy capsule.
Adult: the adult females of olive weevil are brown and have a size of 7-8 mm . They do not have wings, their diffusion capacity being scarce. They develop their activity at night and when they are discovered they usually make themselves dead. No males of the olive beetle have been found.
Generations or biological cycle of the olive weevil beetle
The olive weevil beetle only has an annual generation.
The egg laying occurs during the end of summer-early fall. The laying needs wet soil, so they depend on rainfall. Otiorrinco females lay eggs during September if conditions are conducive or delay laying in October-November.
The eggs are deposited less than 6 cm underground and near the trunk of the olive tree, less than 25 cm away. After birth, Otiorhynchus cribricollis larvae feed on olive rootlets and various herbaceous plants, usually found no more than 25cm from the ground. They spend the winter in larval form.
During the month of April you begin to observe the first pupae, made in earthy capsules at a depth of 10 to 40cm.
The adults leave mainly during the month of May and June. In this phase, the olive beetle takes advantage of the night to feed on the leaves of the pacifiers or in the absence of these from the buds of the Cup.
During the day the Otiorrinco takes refuge under stones, barks or cracks near the trunk of the olive tree.
With the high temperatures at the end of June and July adults take refuge in more depth. Being usually forming groups of between 20 and 200 individuals.
In August, the temperature is reduced and the humidity increases, allowing the olive beetle to leave their shelter again to feed.
During the end of summer the females of the weevil beetle of the olive tree already have eggs.
However, the setting is not carried out until the humidity conditions are favorable, completing the cycle.
Damage caused by Cribricollis Othiorrhynchus
The Black olive otiorrinco damages both its larval and adult stages.
The Cribricollis Othiorrhynchus larvae feed on the olive roots. However, it is difficult to assess these damages as being of poor consideration.
The adults feed on the tender leaves, although they can also cut buds and damage the buds. The olive beetle mainly affects new plantations that do not have the pacifiers they usually feed on.
Population control through traps for Otiorrinco
We can use as traps for the Otiorrinco bricks located near the trunk and above ground. Olive weevil adults like to take shelter during the day under them.
Otiorrinco del olivo control treatment
The cultural measures and the biological control usually make the application of chemical treatments unnecessary, except in specific cases.
The early elimination of pacifiers leads adults to go up to the glass causing certain damage to production.
Although the olive beetle does not have parasites, if it is predatory, being part of the diet of spiders, birds or mice like the Moorish mouse (Mus spetrus).
When populations of Otiorrinco del Olivo are important, it may be necessary to perform control treatments.
The times most suitable for treatment are in June, before taking refuge for the summer and in September, before placing.
The usual treatment consists of wetting the soil around the trunk of the olive tree (25cm) with a solution of pyrethroid insecticides at a rate of 7 liters per tree.
In case of applying a phytosanitary treatment, we must make sure that the phytosanitary product has been authorized by the ministry for that use.
Additional information on olive diseasesis available on our website:
Olive trees resistant to Bold
We have translated the information on our website from Spanish to English. Note that some words may have seen their meaning altered during their translation.