Insect pests on Azolla pinnata at Bangkhen, Thailand.
Five species of insect pests were collected on Azolla pinnata in ponds at Bangkhen, Thailand, during studies in September-November 1977. These were a species of Cryptoblabes near C. gnidiella (Mill.) Nymphula enixalis (Swinh.), Polypedilum johannseni Sublette & Sublette, a species of Bagous near B. nodieri Hust. and a species of Criotettix. Feeding damage was severe in some ponds. The most destructive species was Criotettix but Cryptoblabes was also important, despite the fact it was preyed on by ants and parasitised by an unidentified braconid. N. enixalis caused significant damage and P. johannseni may be important because of the very large numbers present, though it appears to feed only facultatively on Azolla. Bagous was a minor pest.