Comparative Biology of a Novel Strain of Russian Wheat Aphid (Homoptera: Aphididae) on Three Wheat Cultivars

Abstract

In spring 2003, several outbreaks of the Russian wheat aphid, Diuraphis noxia (Mordvilko), were reported in fields of supposedly resistant wheat cultivars ('Stanton', 'Halt', and 'Prairie Red') in eastern Colorado. We conducted two laboratory experiments to compare the biological performance of this new biotype 2 (B2) to that of two D. noxia collections of biotype 1 (B1) from western Kansas by using three wheat cultivars as host plants: 'Trego', a susceptible cultivar, and Stanton and Halt, two cultivars with different genetic sources of resistance. Survival of solitary nymphs from first instar to adult for the two clones of B1 on Trego was 96 and 90%, respectively, compared with 67 and 43% on Stanton, and 65 and 57% on Halt. In contrast, B2 had 60% survival on Trego, 43% survival on Halt, and 85% survival on Stanton. One clone of B1 required longer to mature on Halt compared with Trego or Stanton, but no other differences in developmental time among cultivars were significant. The standardized fecundity of solitary foundresses of the B1 clones was 19.6 and 20.1 nymphs on Trego, compared with 4.6 and 0.9 on Stanton, and 2.8 and 1.1 on Halt, respectively, over the same period. In contrast, fecundity of B2 was 21.1, 20.8, and 19.7 on Trego, Stanton, and Halt, respectively. When larger colonies developed on individual plants over longer periods, Trego supported the largest number of B1 aphids by experiment's end, whereas Stanton and Halt yielded the largest numbers of B2. The order of overall plant damage was Trego > Stanton > Halt when infested with B1, with no significant differences for B2. Trego had more pronounced leaf rolling than other cultivars, independent of biotype. Collectively, the results suggest that D. noxia B2 from Colorado has evolved cross-virulence to both Dn4- and Dny-based resistance sources.

Differential invasion success among biotypes: case of Bemisia tabaci

“…Biotypic variations within species have been extensively described in whiteflies and aphids. Biotypic variation has been related to insecticide resistance (Horowitz et al 2005), host range (Dolatti et al 2005;Hebert et al 2006), plant physiological disorders induced by the insect (Yokomi et al 1990) or differential fitness (Jyoti and Michaud 2005). These differences tend to persist when several biotypes are brought in sympatry, suggesting at least partial reproductive isolation among them; however the exact degree of isolation is usually unknown (Diehl and Bush 1984).…”

Comparative population structure of Chinese sumac aphid Schlechtendalia chinensis and its primary host-plant Rhus chinensis

“…Aphids (Homoptera: Aphididae), the insect group for which the most frequent formation of host-adapted races or biotypes has been reported, are particularly interesting models in the study of genetic and demographic components of plant adaptation (Blackman et al 1990;Wool et al 1995;Margartopoulos et al 2000;Lushai et al 2002;Haack et al 2000;Faten et al 2002;Haley et al 2004;Jyoti and Michaud 2005). Most aphids parasitizing their host-plant form gallnuts, which are abnormal growths produced by aphids parasitizing the midribs of leaves and other tissues.…”

Nitric oxide is an upstream signal involved in the multisignalling network during the Russian wheat aphid resistance response and its application enhances resistance

“…In addition, alternative host suitability can be quantified using growth rate parameters, such as the r m (Pucherelli et al 2011). For instance, Jyoti and Michaud (2005) compared the performance of two RWA biotypes (RWA1 and RWA2) on three wheat cultivars using r m . They noted that RWA1 performed better on the susceptible Trego than on either of the two resistant cultivars, Stanton and Halt, whereas RWA2 performed well on all three cultivars and formed larger colonies.…”