Melon aphid performance on chrysanthemum as mediated by cultivar, and differential levels of fertilization and irrigation

Abstract

Population parameters of the melon aphid, Aphis gossypii Glover, were compared for insects grown on six cultivars of chrysanthemum, Dendranthema grandiflora Tzvelev ('Fontana', 'Iridon', 'Pink Lady', 'Splendor', 'White Diamond', and 'White View Time') fertilized with 3 different levels of nitrogen (80, 160 and 240 mg N/l) and 2 levels of irrigation (high 300 ml and low 210 ml every other day). Fecundity, longevity, and survivorship of aphids were significantly affected by the cultivar treatment, but were not affected by irrigation or fertilizer treatments or by any combination of interactions among cultivar, fertilizer and irrigation. Significantly fewer aphids survived on the cultivar 'Pink Lady' (populations reduced by 20.8%) than any other cultivar examined. Intrinsic rates of increase (r m ), finite rates of increase (R 0 ), and population doubling times (DT) for aphids were different among fertilizer levels and cultivars, but were not different among irrigation levels. There were no significant fertilizer by irrigation interaction effects upon r m , R 0 , or DT. The highest rate of fertilizer applied (240 mg N/liter) adversely affected the intrinsic rate of increase of melon aphids; however, aphid intrinsic rate of increase was weakly correlated with foliar soluble protein levels (r = 0.989, P= 0.0954). Foliar soluble protein levels were not associated with fertilization treatment. Melon aphids perform consistently better on the cultivars 'White Diamond', 'Fontana', and 'Splendor', relative to those aphids growing on 'Iridon', 'Pink Lady', or 'White View Time'. In general, melon aphids performed best on 'White Diamond' and poorest on 'Pink Lady'.

Influence of Nitrogen Fertilization on Biology of Aphis Gossypii (Hemiptera: Aphididae) Reared on Chrysanthemum Iindicum (Asteraceae)

“…Additionally, our obtained data showed a significant reduction in aphid age specific fecundity on the nutrient deficient plants. That was not in agreement with Bethke et al (1998), who demonstrated that the fecundity of A. gossypii is affected by plant cultivar, not fertilizer level. According to figure 1, the age specific fecundity of A. gossypii declined slowly after the 10th day, for all tested treatments.…”

Performance of cotton aphidAphis gossypii(Hemiptera: Aphididae) lineages on cotton varieties

“…The knowledge of aphid performance on a plant species is important in evaluating its resistance level sensu lato. Reliable measures of aphid performance are demographic variables including fecundity and the intrinsic rate of natural increase (r m ) (Dixon 1987;Zeng et al 1993;Sandströ m 1994;Ruggle and Gutierrez 1995;Bethke et al 1998). Plants supporting aphid populations displaying lower values of r m and fecundity are considered more resistant than plants where aphid populations show higher values of these traits.…”

Desenvolvimento e parasitismo de Lysiphlebus testaceipes (Cresson) e Aphidius colemani Viereck (Hymenoptera: Braconidae) em Aphis gossypii Glover (Hemiptera: Aphididae) em duas cultivares de crisântemo

“…A condição fisiológica, como presença de componentes químicos, e a morfológica da planta hospedeira podem determinar a sua resistência inerente, bem como as condições para o crescimento da população de afídeos. Plantas hospedeiras resistentes podem influenciar a atividade e a biologia dos inimigos naturais (Painter 1951, Bethke et al 1998. Como resultado da interação controle biológico e plantas resistentes podem surgir efeitos negativos, como alta mortalidade e período de desenvolvimento mais longo dos inimigos naturais (Obrycki & Tauber 1984, Gamarra et al 1997, ou positivos, com a maior redução da praga (Obrycki et al 1983, Farid et al 1998, Messina & Souresan 2001.…”