September 2009. Spots and bugs on lettuce leaves from Trinidad: the question is, are they associated? Could the spots, which are assumed to be caused by fungi or bacteria, be transmitted by the bug.

There was no response from members, but it is likely that the spots are caused by a primary pathogen. The most likely cause is Alternaria, Septoria, Cercospora, or others. Similar spots caused by Alternaria were reported on PestNet from Kenya in June 2009.

http://www.pestnet.org/Summaries/Crops/Vegetables/Lettuce/LeafspotslettuceKenya/tabid/4058/language/en-US/Default.