Published online by Cambridge University Press: 08 April 2017
The persistence of 34 formulations in the green (G) and red (R) berries of C. arabica var. typica, infested with female adult H. hampei were assayed by a dip-technique. The 3-day LC50 values in G and R (figures in parentheses) berries for thiodan EC 35 were 0.00284 (0.00327), and the relative ratio of values for other formulations were: perfekthion 1.2 (2.1) > carbicron 1.6 (2.3) > basudin 3.5 (3.2) > actellic 4.0 (3.6) > decis 4.1 (3.7) > thiodan EC 3 4.2 (4.2) > bidrin 5.8 (5.0) > malathion 5.8 (5.1) > lindane 5.8 (5.6) > ciodrin 5.9 (5.6) > folimat 6.0 (6.0) > belmark 6.2 (6.3) > aldicarb 8.0 (9.7) > nexion 11.0 (12.0)>kelthane 13.5 (15.4) > tiovel 14.6 (16.3) > dursban 15.6 (22.0) > chlordane 17.8 (23.8) > methomyl 21.5 (24.3) > aldrin 25.1 (24.9) > supona 27.2 (26.5) > dimilin 29.0 (27.5) > methoxychlor 31.7 (92.2) > chlorfenvinphos 35.8 (92.5) > dieldrin 41.2 (93.8) > phosdrin 65.0 (94.7)>sevin 104.2 (118.0)> nexagan 106.4 (121.9) > bimarit 196.4 (301.7) > azodrin 271.2 (410.4) > fenitrothion 448.3 (417.0) > chlorpyrifos 448.8 (614.3) > gardona 514.6 (703.1), -fold more than the thiodan EC 35 values.
The 7-day LC50 values for 29 formulations were ca 10–82% less than those of the 3-day values; the decrease in the values for leading formulations being thiodan EC 35 13.4 (8.3), perfekthion 6.5 (39.9), carbicron 12.4 (10.6), thiodan EC 324.3 (16.4), malathion 35.2 (25.7), lindane 82.1 (76.9) and tiovel 59.6 (67). The values for the 17 least toxic formulations (except dimilin and bimarit) showed ca 27–88% decrease during the last 4 days of observations.