Am. Mayoral et al., PROBING BEHAVIOR OF DIURAPHIS-NOXIA ON 5 CEREAL SPECIES WITH DIFFERENT HYDROXAMIC ACID LEVELS, Entomologia experimentalis et applicata, 78(3), 1996, pp. 341-348
The feeding behaviour of Diuraphis noxia (Kurdjumov) (Homoptera: Aphid
idae) was electronically monitored on five cereal species (Triticum ae
stivum L., T. turgidum L., Secale cereale L. and x Triticosecale Wittm
ack) containing different hydroxamic acids levels and on Hordeum vulga
re L., lacking these compounds, by means of a DC-System. With increasi
ng DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) levels D. nox
ia showed less probing particularly before reaching the phloem phase a
nd a lower percentage of aphids achieved sustained phloem ingestion. H
owever, no significant correlation was found between DIMBOA levels and
the total time of phloem feeding. These findings indicate that factor
s from the mesophyll and vascular tissues appear to be involved in the
effects of resistance. The underlying mechanism, however, remains unc
lear. Thus, DIMBOA seems to be only part of the chemical defenses of t
he cereal plants that might be implicated in D. noxia resistance.