July 19 clear most of day except towards late evening. Air temperature went up to 69.4°F at Britten Mann. This afternoon went out to central marsh area. Chironomids were much in evidence and 1st swarms of mosquitoes (Aedes) were encountered. As the afternoon wore on they became much more pestiferous. Many of the Arctophtila ponds now dried up or almost so—only the larger & deeper ones have water. On all of them the adult caddis flies are in evidence. The marsh crane fly was actively noted in sustained flights of several hundred yards. The midge activity was at the highest thus far noted. One caribn fly was noted + captured. On the shores of Walschley Slough great numbers of muscid flies probably 15-20 per sq. meter were noted. The Chironomids continued to fly on until I went to bed at 2 a.m. They were in flight even over the edge of the ocean.