Agricultural entomology: Green aphid of citrus fruits

Agricultural entomology: Green aphid of citrus fruits

Classification and host plants

Class: Insects
Order: Rincoti
Suborder: Homoptera
Family: Aphidids
Genus: Aphis
Species: A. citricola van der Goot

Bibliographic reference:
Phytopathology, agricultural entomology and applied biology” – M.Ferrari, E.Marcon, A.Menta; School edagricole - RCS Libri spa

Host plants: Citrus fruits (especially Mandarin, Clementines and Orange), various arboreal and shrubby Rosaceae, Vine, herbaceous (Composite, Umbrelliferous, etc.).

Identification and damage

LAphis citricola is the most harmful of the citrus fruit among the aphids and in particular of the mandarin, clementine and orange.
The adults (about 1.5-2 mm long, depending on whether they are wingless or winged) are greenish in color; they have siphons and a brownish color codicle. The damage occurs on the shoots and on the leaves; but the aphid can also attack flowers and fruits. On the leaves, on the lower page, and on the shoots it causes, with the bites of nutrition, showy crumplings that hinder the development of the plant, when it attacks flowers and fruits, it can cause sagging and drop.
In addition, the Aphis citricola produces abundant honeydew that smears the vegetation and allows the development of fumaggini.
Finally, like other aphids, it is responsible for the spread of virosis.
It should also be remembered the brown aphid of citrus fruits (Toxoptera aurantìì) which, like the Aphis citricola and the Aphis gossypii, colonizes the leaves and shoots of the citrus fruits. The damage and type of struggle are similar to those described for green aphid.

Biological cycle

In the citrus areas, LAphis citricola generally performs an anolocycle, wintering as an adult female; from the spring there are multiple generations (even up to 40) that all take place on citrus fruits or on shrubby plants (Crataegus sp., Spiraea sp.). In addition, Aphid can perform a dioecious holocycle that takes place between shrubby Rosaceae (primary hosts) on which it winters as a durable egg, and on Citrus or other arboreal and / or herbaceous (secondary hosts).

Green aphid of citrus fruits - Aphis citricola van der Goot (photo http://whatcom.wsu.edu)

Green aphid of citrus fruits - Aphis citricola van der Goot (photo Kenpei)

Fight

The fight against Aphis citricola is chemical and follows the criteria of guided and integrated struggle.
In consideration of the danger for citrus fruits, the treatments are also carried out when the first infestations appear.
The intervention threshold was estimated at around 10% of attacked shoots (for brown aphid it is 30% while for aphis gossypii it is 20%).
The products to be used are specific aficides and medium-wide spectrum products.
In nature, Aphid is controlled by numerous natural enemies such as Chrysopid Neuroptera, Coccinellid Beetles and Sirphid Diptera which, however, are not always able to contain populations within the limits of damage.


Video: How to Easily Get Rid of Aphids on Plants