|Chu, Chang Chi|
Submitted to: Sweetpotato Whitefly Progress Review Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 4/1/2002
Publication Date: 6/1/2002
Technical Abstract: Leaf samples were taken from field grown cotton and cantaloupe in Phoenix, AZ in 2000 and 2001. Measurements from eggs to nymphs and exuvia for the morphological development of whitefly stages were made at Fargo, ND. The 4th instars on cotton leaves were longer and wider compared with that on cantaloupe leaves. From cotton, the length of the four nymph stages were 250, 355, 434 and 724 mm, respectively, and widths 135, 214, 270 and 498 um, respectively. For cantaloupe nymphs, the lengths were 244, 350, 456, and 603 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 compared with nymphs on cotton leaves. The values for nymphs from cotton and cantaloupe leaves were 57 vs. 66 um, 76 vs. 98 um, 71 vs. 123 um and 214 vs. 258 um for the first, second, third and fourth instars, respectively. As nymphs developed from first to fourth instars, the ventral half of the body increased more compared with the dorsal half of the body. The ratios of the ventral and dorsal halves of the bodies were 0.53, 0.57, 0.61 and 0.70 for first, second, third and fourth instars, respectively. On average, adult body length from head to tail were 807 and 884 um and body weights were 17 and 39 ug for males and females, respectively. Eggs weighed 0.8 ug per egg. Exuvia weighed 1.2 and 3.6 ug for non-parasitized and parasitized exuvia, respectively. The significances of the differences for each stage of development on the two plant species are being analyzed.