Resistance among accessions of the genera lycopersicon and solanum to four of the main insect pests of tomato in Israel

Laboratory, greenhouse and field experiments were conducted to identify plant accessions of the genus Lycopersicon and of Solarium pennellii resistant to Spodoptera littoralis (Boisd.), Plusia chalcites (Esp.), Heliothis armigera (Hbn.), and Phthorimaea operculella (Zeu.), four insect pests of the cultivated tomato. Percent survival, larval weight, duration of development, damage scores, etc., were the criteria used to determine the relative resistance of the examined accessions. The L. hirsutum accession LA 1777 and the L. hirsutum f. glabratum accession LA 407 were found to be highly resistant to all four insect pests. The S. pennellii accession LA 716 was found to be resistant to the first three insects, but only partially resistant to P. operculella. The possible mechanisms of resistance, i.e., the physical entrapment of larvae and the toxic action of phytochemicals in the various accessions, are discussed.