General information
Prays citri is currently considered the most harmful pest to the lemon tree because it destroys the floral organs of the trees. In addition, it can damage buds and small fruits.
Since damage occurs during the flowering period, the plants that are prone to attacks are those that have a gradual flowering period such as the lemon tree. Within this species, the Verna variety is the most attacked because it
has several consecutive blooming periods a year. Damage has also been seen in oranges and occasionally in the Clemenules Mandarin which also has a long flowering period.
Morphology and biology
The adult is 10 mm wide and a grey colour, its wings have dark spots and frayed edges. The larvae are a whitish or greenish colour with a brown head.
The adults fly at night and twilight, laying eggs preferably on the petals of the flowers that are still closed. They also lay their eggs in the sepals, shoots or small fruits. They normally pupate inside the flower in which
they have already fed, then joined with silk threads. They usually hibernate as a chrysalis and can produce between 3 and 5 generations a year.
Adult of Prays citri
Egg of Prays citri on flower
Caterpillar of Prays citri
Pupa of Prays citri
The eggs can be seen individually on the rose-pink petals as a whitish speck. If the amount of eggs that are laid over the floral buds is high, the damage will be severe during the flowering period. The caterpillar, born from
this egg, bores into the chorion and enters directly inside the flower, between the egg and the petal.
Source: F. García Marí, J. Costa Comelles and F. Ferragut. // Photos: E. Llácer in http//gipcitricos.ivia.es
Damages
The most serious damage is produced in the Verna variety of lemon trees during the two main blooming periods: in spring, from April to May, it is known as Cosecha and in summer, in September, it is called Rodrejo. The “Sanjuanera”
blooming period that takes place in June is not as abundant and also, causes slight damage.
In the case of attacks on flowers, the larva feeds on the anthers and pistils inside of the flower. It then moves on to other flowers and binds the damaged area with silk threads, forming a mass on the inside in which dried
petals and lots of dark-coloured excrement can be found. This type of damage could be confused with that of the Cacoecia caterpillar, with the difference being that this last pest has a preference for newly ripened
fruit and not flowers. Besides, Cacoecia does not produce sawdust and excrement.
Damages caused by Prays citri in a floral shoot
The larva feeds on the epidermis of the leaves. It excavates a gallery along the shoot with resin secretions. Attacks on newly ripened fruit tend to create a gallery in the style and Cacoecia caterpillar end up by
eating all the fruit.
Damages to growing fruits appear as superficial spots, which are caused by the larva feeding on the peel. In the centre of these spots, the chorion of the egg can be found.
Damages to growing fruits appear as superficial spots, which are caused by the larva feeding on the peel. In the centre of these spots, the chorion of the egg can be found. Sometimes, the larva can cause damage to the scions
in all types of citrus fruits, by entering under the grafted scutum and feeding on the cambium. Therefore, the scion dries up. Once the damage is caused, the larva abandons the fruit to pupate in the ground, although it
can also pupate near the damaged bud. Some pylarid moths such as Ephestia sp. or Cryptoblabes can cause similar damage to the scion.
Mass trapping
The males of this species are specifically captured in order to reduce mating, meaning that the unfertilised females will lay unviable eggs. In this way, the pest population is reduced.
For mass trapping, the amount of traps per surface area must be increased, depending on the location and uniformity of the plots. One trap controls a surface area between 500 and 1.000 m2. This means a density of
10 to 20 traps per hectare. On the borders of the plots, it will be necessary to place a barrier of traps separated 10 to 15 metres from each other.
Period of use
To achieve good control of Prays citri,it is advisable to combine the two methods: detection and monitoring and mass trapping. In spring you can place 1 or 2 traps per hectare to detect the pest and observe its population
levels.
With tolerance thresholds established in each area, the moment to adopt control measures, in this case mass trapping, can later be defined.
The tolerance threshold for Prays citri is very low and varies depending on the area. In general, it is between 7 and 21 captures per trap and per week. For mass trapping, traps should be placed throughout the plots.
In addition, traps are also recommended to be placed between July and August in order to protect this blooming period.
Necessary material
A trap ECONEX POLILLERO, ECONEX FOLDING WHITE TRIANGULAR WITHOUT SHEETS or ECONEX DISPOSABLE WHITE TRIANGULAR or ECONEX DISPOSABLE BLUE TRIANGULAR and a pheromone diffuser ECONEX PRAYS CITRI 2 MG 60 DAYS,
product authorised for use in organic farming, that lasts for 60 days under normal field conditions.
The trap:ECONEX FOLDABLE WHITE TRIANGULAR WITHOUT SHEETS is activated by placing an ECONEX SHEET FOR TRIANGULAR 1 UNIT on its base. The sheet is coated with a pressure-sensitive adhesive, solvent
free, in which the insects are trapped.
ECONEX PRAYS CITRI 2 MG 60 DAYS
Sexual pheromone diffuser of the species Prays citri to attract males, with a duration of 90 days in normal field conditions.
Code: UIPHOVA446
OMDF register number (Ministry of Agriculture of Spain): 111/2016
ECONEX PRAYS CITRI 2 MG 60 DAYS 10 UNITS
Code: UIPHOVA447
OMDF register number (Ministry of Agriculture of Spain): 111/2016
ECONEX FOLDING WHITE TRIANGULAR WITHOUT SHEETS
28x20x11 cm, hanger included.
Code: UIPFETA273
OMDF register number (Ministry of Agriculture of Spain): 064/2014
ECONEX SHEET FOR TRIANGULAR 1 UNIT PACK
Sticky sheet of 20 x 19 cm.
Code: UIPFETA248
OMDF register number (Ministry of Agriculture of Spain): 048/2024
ECONEX POLILLERO
It is the most suitable trap for the majority of lepidopterans, especially large moths.
Code: UIPFETA001
OMDF register number (Ministry of Agriculture of Spain): 123/2015
ECONEX DISPOSABLE WHITE TRIANGULAR
Code: UIPFETA242
ECONEX DISPOSABLE BLUE TRIANGULAR
Code: UIPFETA269
Recommendations about the different types of traps suggested
As shown in the graph, the most effective traps are the ECONEX WHITE TRIANGULAR without sheets and the ECONEX DISPOSABLE WHITE TRIANGULAR. However, these adhesive traps may require periodic
monitoring, approximately twice a month. It is neccesary because once the adhesive surface is completely saturated with insects, the trap stops working. In this case, the trap or the sticky sheet must be changed it. And
if the 60 days of duration has not exceeded, you can continue using the same pheromone diffuser. In order to reduce the maintenance work, it can be used the ECONEX POLILLERO. This trap is less effective
than the other ones but it can incessantly extend the captures during the whole lifetime of the diffusers.
Factors that influence the number of traps needed
The pest population, the bordering crops, the level of control required, etc...
One important factor is the size of the crop. In small and irregular crops, a greater number of traps are required than in larger and more uniform plots.
Another important factor is the distance between plots that have the same pest. In cases like this, the borders of the plots must be reinforced, so it could be necessary to place up to 20 traps per hectare or even more for
mass trapping.
Storing the diffusers
The diffusers must be stored in their original packaging in a cool and dry place and separated from food and drinks.
To preserve the diffusers for long periods of time, it is recommended to keep them in the refrigerator at 4 o C in which case they will last for 2 years. Or they can be kept in the freezer at -20 o C for 4 years.
Packaging difussers
ECONEX PRAYS CITRI 2 MG 60 DAYS 1 U.
Corrugated cardboard box of 400 units (20 packs of 20 units)
Box size: 0,32 x 0,24 x 0, 22 m (length x width x height).
Box weight: 1,5 kg.
Pack of 20 units.
Box of 400 units.
(20 packs x 20 units each)
ECONEX PRAYS CITRI 2 MG 60 DAYS 10 U.
Corrugated cardboard box of 2.000 units (20 packs of 100 units)
Box size: 0,32 x 0,24 x 0,22 m (length x width x height).
Box weight:: 2,3 kg.
Pack of 20 units.
(10 packs x 10 units each)
Box of 2000 units.
(20 packs x 100 units each)
Packaging traps
ECONEX FOLDING WHITE TRIANGULAR WITHOUT SHEETS
Corrugated cardboard box of 150 units
Box size: 0.60 x 0.40 x 0.35 m (length x width x height)
Box weight: 10.60 kg.
Number of boxes per pallet: 20
Pallet size: 1.20 x 0.80 x 1.95 m (length x width x height)
Pallet weight: 222 kg
Box of 150 units.
ECONEX SHEET FOR TRIANGULAR 1 UNIT PACK
Corrugated cardboard box of 500 units
Box size: 0.42 0.29 x 0.21 m (length x width x height)
Box weight: 10.75 kg.
Number of boxes per pallet: 50
Pallet size: 1.10 x 1.00 x 1.25 m (length x width x height)
Pallet weight: 545 kg
Box of 500 units.
ECONEX POLILLERO
Corrugated cardboard box of 35 units
Box size: 0.60 x 0.40 x 0.35 m (length x width x height)
Box weight: 9.80 kg.
Number of boxes per pallet: 20
Pallet size: 1.20 x 0.80 x 1.95 m (length x width x height)
Pallet weight: 206 kg
Box of 35 units.
ECONEX DISPOSABLE WHITE TRIANGULAR
Corrugated cardboard box of 250 units
Box size: 0.42 x 0.29 x 0.21 m (length x width x height)
Box weight: 13.10 kg.
Number of boxes per pallet: 50
Pallet size: 1.10 x 1.00 x 1.25 m (length x width x height)
Pallet weight: 665 kg
Box of 250 units.
ECONEX DISPOSABLE BLUE TRIANGULAR
Corrugated cardboard box of 250 units
Box size: 0.42 x 0.29 x 0.21 m (length x width x height)
Box weight: 13.10 kg.
Number of boxes per pallet: 50
Pallet size: 1.10 x 1.00 x 1.25 m (length x width x height)
Pallet weight: 665 kg
Box of 250 units.
Recommended information:
ECONEX PRAYS CITRI 2 MG 60 DAYS LEAFLET
Leaflet in PDF format that can be downloaded by clicking on the image.
ECONEX LEARNING CENTER
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