Information

Agricultural entomology: Cecidomy of pear fruit, Contarina pyrivora

Agricultural entomology: Cecidomy of pear fruit, Contarina pyrivora

Classification and host plants

Class: Insects
Order: Diptera
Suborder: nematocers
Family: Cecidomidi
Genus: Contarina
Species: C. pyrivora Riley

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

Host plants: Pear tree

Identification and damage

Cecidomia is a small fly (about 2-2.5 mm in size), ocher-grayish in color with a dark strip in the abdominal region.
The larvae are whitish, apod and lead endophytic life within the fruit.
The damage is evident on the fruits and is determined by the larvae that colonize the central part of the young fruits; the oviposition takes place, at the level of the anthers, in the phase of the outcropping bunches with the evident flower button.
The affected fruit trees deform in a characteristic way, stop their development and necrotize.

The fruits remain attached to the plant, like small blackish mummies to fall to the ground in later times.

Biological cycle

Cecidomia overwinters as a mature larva or as a pupa, in a rough bed of the soil.
In spring, adults flicker very early, on average from late March; the females oviposition, by means of their robust ovipositor, among the floral organs on the still half-closed bunches.
The larvae begin their activity at the end of the flowering-fruit setting phase, causing the damage described.
The larvae, when ripe, come out of the fruits and take shelter in the ground for wintering.

Cecidomia therefore performs one generation a year.


Pear fruit Cecidomia adult (photo http://croqueurs-idf.com)


Cecidomy of pear fruit (photo http://croqueurs-idf.com)

Fight

The chemical fight against cecidomy is justified only if there have been repeated infestations in the orchard over the years. In these cases, the treatment must be carried out at the phenological phase of the outcropping bunches, with evident petals but with a closed flower.
The agronomic preventive struggle, which consists in the working, even superficial, of the soil to reduce wintering forms, certainly helps to keep the weed potential low.


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