Thrips, mango, India

March 2017. We have a 12-acre mango orchard. This year we have observed a problem on newly emerged leaves. No sprays have been applied. Can somebody help me diagnose the problem?

There were several suggestions:

• nutrient deficiency, possibly zinc; see: http://agritech.tnau.ac.in/horticulture/horti_min_nutri_fruits_mango.html
• thrips
• powdery mildew or mango malformation.
• mites

A member wrote that he had a similar problem on grafted mangoes, and on seedling root stocks. It was caused by the citrus thrips, Scirtothrips aurantii, which was controlled by imidacloprid (Confidor 70WG). If the problem is thrips, you will be able to spot the yellowish nymphs or greyish adults on the underside of the leaves. Use imidocloprid or biological insecticides.

Later, thrips were confirmed.