Question

Pear decline caused by Caudidatus Phytoplasma pyri is transmitted by

• A. Psyllids
• B. Aphids
• C. Mites
• D. Whiteflies

Hint:

Remember that psyllids are the primary vectors for Candidatus Phytoplasma pyri (causing pear decline) and Candidatus Liberibacter asiaticus (causing citrus greening or Huanglongbing).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Phytoplasmas are specialized, cell-wall-less bacteria that inhabit the phloem of plants.
They are transmitted between hosts by sap-sucking insects that feed on phloem sap, such as leafhoppers, planthoppers, and psyllids.
Detailed Explanation:
Pear decline is a destructive disease of pear trees (Pyrus species) caused by the phloem-limited bacterium Candidatus Phytoplasma pyri.
This phytoplasma is transmitted by jumping plant lice, which belong to the family Psyllidae (Psyllids).
The primary vectors are psyllid species in the genus Cacopsylla, such as Cacopsylla pyricola and Cacopsylla pyri.
The psyllids acquire the phytoplasma while feeding on the phloem of infected trees. The pathogen then circulates through the insect's body and is transmitted to healthy trees via salivary secretions during subsequent feeding.
Aphids, mites, and whiteflies are not vectors for this specific phytoplasma.

Step 2: Final Answer:
Pear decline phytoplasma is transmitted by psyllids.