Entomology, Department of


Document Type


Date of this Version



Journal of Economic Entomology 66:6 (1973), pp. 1267–1268.

doi: 10.1093/jee/66.6.1267


Copyright © 1973 Entomological Society of America; published by Oxford University Press. Used by permission.


Numbers of arthropods drifting in an irrigation canal were recorded at 30-min intervals during and after an upstream application of ULV malathion. Flower-visiting and parasitic Hymenoptera were the first insects to increase; a bimodal drift pattern resulted from an interruption in the spray application. Diptera exhibited a delayed response but the numbers collected, especially Paracantha culta (Wiedemann), suggest high susceptibility. Ants occurred in large numbers over a long period, but mortality was probably low. Miridae and Cicadellidae were probably more susceptible than Orthoptera and adult Odonata but had similar delayed drift patterns. Tetragnathidae were the most, and Thomiscidae the least, susceptible spiders.