|Chu, Chang Chi|
|Freeman, Thomas - NDSU, FARGO, ND|
Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Proceedings
Publication Acceptance Date: April 1, 2002
Publication Date: June 1, 2002
Technical Abstract: Leaf samples were taken from field grown cotton and cantaloupe in Phoenix, AZ in 2000. The morphological development of silverleaf whitefly stages were determined at Fargo, ND. Nymphs on cotton leaves were longer and wider compared with nymphs on cantaloupe leaves. From cotton, the length of the 4 nymph stages were 257, 355, 589 and 724 um, respectively, and widths 140, 217, 395 and 498 um, respectively. For cantaloupe nymphs, the lengths were 244, 350, 456, and 601 um and widths were 129, 192, 267 and 411 um, respectively. With nymphs placed on their sides, dorso-ventral measurements for nymphs on cantaloupe leaves were greater except for the 3rd instars compared with dorso-ventral measurements for nymphs on cotton leaves. The values for nymphs from cotton and cantaloupe leaves were 63 vs. 66 um, 78 vs. 98 um, 139 vs. 124 um and 214 vs. 259 um for the 1st, 2nd, 3rd and 4th instars, respectively. As nymphs developed from 1st to 4th instars, the ventral half of the body increased more compared with the dorsal half of the body. The ratios of ventral and dorsal halves of bodies were 0.53, 0.57, 0.63 and 0.70 for 1st, 2nd, 3rd and 4th instars, respectively. On the average, adult body length from body lengths from head to tail were 953 and 1127 um and body weights were 17 and 39 ug for males and females, respectively. Egg weight was 0.8 ug per egg. Exuvia weighed 0.8 and 5.4 ug for non-parasitized and parasitized from 4th instar nymph's exuvia, respectively. The significances of the differences for each stage of development on the two plant species are being analyzed.