From the picture it is hard to tell. Could be water issue. Mine did something simular this year and it is 7 years old
It was aphids- had to spray

I planted 20th century pear from bareroot this winter and the first leaves were curled just like that too. The newer leaves that have branched out later in the season aren't curled though, I reduced watering and stopped adding fertilizer.

Thanks Campv & Dan8,

I visually checked almost all of the leaves and couldn't find any bugs like aphids.

I went to local nursery calloways and the folks told me that leaves curled because of under watering. I live in Dallas and for the past one month we are getting quite a bit of rain and a friend of mine regularly watered all my plants, not sure whether leaf curl is because of under watering.

I'll keep an eye on the tree

Thanks Campv & Dan8,

I visually checked almost all of the leaves and couldn't find any bugs like aphids.

I went to local nursery calloways and the folks told me that leaves curled because of under watering. I live in Dallas and for the past one month we are getting quite a bit of rain and a friend of mine regularly watered all my plants, not sure whether leaf curl is because of under watering.

I'll keep an eye on the tree