COMPARATIVE STUIDES BETWEEN INSECT PATHOGENIC NEMATODES AND OTHER METHODS IN CONTROLLING SOME SOiL INSECTS AND FRUIT TREE BORERS

Abstract

The effect of mixing the nematode strains Steinernema carpocapsae (All), Heterorl!abditids bacteriopl!ora (J-IP88) and Heteror!tabditids bacteriopl!oro (I-! t) with four nematicides (Nemacur, Rugby, Temik and Vydate) against the 6th instar larvae, prepupae and pupae of both Spodopetra /ittoralis and Agrotis ipsilon were investigated.

The nematicide Rugby alone or combined with S. caf1JOcapsae or H. bacteriopl!ora (I--!P88) gave 100 %mortality, whereas its combinations with H. bacteriophora (I-! t) gave 93.3%. These mortality percentages were similar to those resulted by the nematode alone against S. littoralis. The combination of Oxamyl (Vydate) and nematodes gave mortality rates more than the Vydate alone, but mixing Nemacur and HP88 or l-It strains gave mortality rates more than in case of S. carpocapsue (All). Mortalities of the three tested concentrations of Temik, evidently differed when they were combined with ncimtocles. All concentrations of Rugby, combined with I-1 t, S c and I-IP88, gave maximum standard of mortality (100%), that weno: more than either the pesticide or each species of nematodes alone against A. ipsilon.

Combinations of nematode strains and nematicides were more lethal against S. littoralis prepupae than nematicides, but their efficiency were less or equal to those of nematodes alone which gave 100 %mortality for each strain.