Effect of Temperature On the Rate of Development of Nacobbus Serendipiticus in Excised Tomato Roots

How temperature affects the rate of development of Nacobbus serendipiticus was studied in excised tomato roots in aseptic nutrient agar. Second stage larvae entered the roots and small galls bearing lateral rootlets were associated with third stage females. Males occurred in the galls and entangled in the egg sacs of females. The life-cycle from egg to egg was completed in 36 days at 25° C, and 43 days at 20° or 30°. At 20° and 25°, some individual galls contained more than one female but not at 30° where there were sometimes as many as four males per gall. The sex-ratio (males to females) was 2.33, 0.14, 1.00 and 7.33 at 15°, 20°, 25° and 30° respectively.