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6027888 
Journal Article 
EFFICIENCY OF SUCROSE FLOTATION IN RECOVERING INSECT LARVAE FROM BENTHIC STREAM SAMPLES 
Costa, R; Pask, W 
1971 
DUPLICATE BENTHIC STREAM SAMPLES WERE COLLECTED FROM THREE SITES ON SANDY CREEK (LAKE ONTARIO WATERSHED) IN WESTERN NEW YORK, 8 AND 22 SEPT., 1970. SAMPLES TAKEN ON 8 SEPT. WERE PRESERVED IN 10% FORMALIN. SAMPLES TAKEN ON 22 SEPT. WERE NOT PRESERVED. INSECT SPECIMENS WERE REMOVED FROM BOTH SETS OF SAMPLES BY FLOTATION WITH A SUCROSE SOLUTION OF 1.12 SP. GR. PRESERVED AND UNPRESERVED SAMPLES WERE COMPARED FOR EFFICIENCY OF RECOVERY OF INSECT LARVAE. MEAN RECOVERY FOR PRESERVED SAMPLES WAS 90.78% COMPARED WITH 83.03% FOR UNPRESERVED SAMPLES. THE RANGE OF RECOVERY VALUES FOR UNPRESERVED SAMPLES (66.7%) WAS MORE THAN TWICE AS GREAT AS THAT OF PRESERVED SAMPLES (29.5%). A PAIRED T-TEST FOR MEANS OF ALL TAXA SHOWED NO SIGNIFICANT DIFFERENCE (P 0.001) BETWEEN RECOVERY VALUES FOR PRESERVED AND UNPRESERVED SAMPLES. IN FACT, PRESERVATION MAY ENHANCE THE RECOVERY OF CERTAIN GROUPS--ZYGOPTERA, HEMIPTERA, TRICHOPTERA, AND CHIRONOMIDAE. APPARENTLY SAMPLES MAY BE PRESERVED WITHOUT SACRIFICING RECOVERY OF ANY SPECIFIC GROUPS OF INSECT LARVAE.--COPYRIGHT 1972, BIOLOGICAL ABSTRACTS, INC. 
Water Resources Abstracts; BENTHIC STREAMS; CHIRONOMIDAE; HEMIPTERA; INSECT LARVAE; SAMPLES; SUCROSE FLOTATION; TRICHOPTERA; ZYGOPTERA; SANDY CREEK(NY)