Host plant volatiles

Carroll M. J. and Berenbaum M. R. (2002). Behavioral responses of the parsnip webworm to host plant volatiles. J Chem Ecol 28 2191-2201. 

The biological activity of the banana weevil pheromone and those of related palm weevil species is strongly enhanced by host plant volatiles [399,417-419]. 

Marion-Poll, F. and Thiery, D. (1996). Dynamics of EAG responses to host plant volatiles delivered by gas-chromatograph. Entomologia Experimentalis etApplicata 80 120-123. 

Ochieng S. A., Park K. C. and Baker T. C. (2002) Host plant volatiles synergize responses of sex pheromone-specific olfactory receptor neurons in male Helicoverpa zea. J. Comp. Physiol. A 188(4), 325-333. 

Ginzel, M. D. and Hanks, L. M. (2005). Role of host plant volatiles in mate location for three species of longhomed beetles. J. Chem. Ecol., 31, 213-217. 

Soroka, J. J., Bartelt, R. J., Zilkowski, B. W. and Cosse, A. A. (2005). Responses of flea beetle Phyllotreta cruciferae to synthetic aggregation pheromone components and host plant volatiles in field trials../. Chem. Ecol., 31,1829-1843. 

Some plant volatiles act synergistically with aggregation pheromones. Aggregation of the American palm weevil, Rhynchophorus palmarum, on host plants is mediated by host-plant volatiles and a male pheromone (rhynchophorol).60 Acetoin, one of the major volatile components of the host plants Cocos nucifera, Saccharum officinarum, Jacaratia spp., and Elaeis spp., plays an important role in the aggregation of weevils on these plants. Although the pheromone alone is weakly attractive, its attraction is enhanced by acetoin. 

Several reports have revealed that host-plant volatiles show synergistic attraction with host visual cues 61 cinnamyl alcohol and (/ /-anethole, common flower scent components, attract Epicometis hirta (which damages the reproductive parts of flowers of several orchard trees and many ornamental bushes62) and enhance the attractiveness of light blue color 63... 

SYNERGISM BETWEEN PHEROMONES AND HOST PLANT VOLATILES... 

OCHIENG, S.A., PARK, K.C., BAKER, T.C., Host plant volatiles synergize... 

BICHAO, H., BORG-KARLSON, A.-K., ARAUJO, J., MUSTAPARTA, H., Five Types of Olfactory Receptor Neurons in the Strawberry Blossom Weevil Anthonomus rubi Selective Responses to Inducible Host-plant Volatiles, Chem. Senses, 2005, 30, 153-170. 

JONSSON, M., ANDERS0N, P., Electrophysiological response to herbivore-induced host plant volatiles in the moth Spodoptera littoralis. Physiol. EntomoL, 1999, 24, 377-385. 

Fig. 1 GC-EAG response of the banana weevil, Cosmopoiltes sordidus. to host-plant volatiles...

Onagbola, E. O. et al., Gnava leaf volatUes and dimethyl disulfide inhibit response of Diaphorina citri Kuwayama to host plant volatiles. J. Appl. Entomol. 135 404-414, 2011. 

From the hair-pencils of butterflies in Danainae and Ithomiinae (Papilion-oidea Nymphalidae), a wider variety of pyrrolizines (la-d, and 6a-d) have been identified than from Arctiidae moths. These compounds are biosynthesized from pyrrolizidine alkaloids, which are included in host plants fed by the larvae and protect them from the attacks of other herbivores [122]. In addition to novel lactones (7, 8a, and 8b) derived from an acid part of the alkaloids, many volatiles of more than 100 compounds (aromatics, terpenoids, hydrocarbons, and others) constitute scent bouquets of the male butterflies [123]. For example, the hair-pencil of Idea leuconoe (Danainae) which is distributed in South-East Asia contained 16 compounds (6b, 8a, 8b, 9, and others), and a mixture of the major volatiles applied to a butterfly dummy elicited an abdomen-curling acceptance posture in the females as a crude extract of the male hair-pencils did [ 124]. A chiral GC analysis revealed the absolute config-... 

Unlike parasitoids of other insect orders that have host-seeking larvae, most parasitic hymenoptera lay their eggs on, in, or very close to a host individual [11]. This requires the adult female to find a suitable host, often with the aid of chemical cues from host frass, pheromones, plant volatiles emitted upon host feeding or egg-deposition, silk, honeydew and other secretions. She may then chemically mark the host following oviposition to reduce superparasitism by herself or intra- and inter-specific insects [11]. 

Tetratrophic interactions between a host plant, a phytophagous pest (primary host), a hymenopteran parasitoid or symbiont (secondary host) and a hymenopteran hyperparasitoid (which parasitizes the secondary host) are of considerable importance, because hyperparasitism can significantly reduce populations of economically beneficial parasitoids [11]. Hyperparasitoids use host-marking (=spacing) pheromones, sex pheromones [12], and host-detection cues [42], but they also show additional chemically mediated interactions with the other partners. These include detection of the primary host s secretions by the hyperparasitoid [43], detection of plant volatiles by the hyperparasitoid [44], and detection of the hyperparasitoid s secretions by the primary host [45] or by the secondary host. The latter causes the secondary host to avoid locations where the hyperparasitoid is foraging [46]. 

Parasitic hymenoptera often eavesdrop on the pheromone communication of their host species. The type of host pheromone recognized depends on the host stage parasitized. Phoretic egg parasitoids are often attracted by the host sex pheromone, while species that parasitize later stages (larval, pupal) often do not respond to host sex pheromone components [ 11,42]. Larval parasitoids often recognize volatiles from the damaged host plant and/or host larval frass volatiles. Parasitoids of forest beetles respond to the beetle aggregation pheromones [42]. 

An example of a larval parasitoid that responds to the host sex pheromone is seen with Cotesiaplutellae (Braconidae), also a parasitoid of the diamondback moth. These insects were attracted equally to the pheromone blend (31,32,33, see above), the acetate 32, or aldehyde 31 components [80]. This larval parasitoid, however, was also strongly attracted to host frass volatiles, in particular, dipropyl disulfide 34, dimethyl disulfide 35, allyl isothiocyanate 36, and dimethyl trisulfide 37. In contrast, the egg parasitoid Trichogramma chilonis was only weakly attracted to 36. In both, T. chilonis and C. plutellae, plant volatiles, in particular (3Z)-hex-3-en-l-yl acetate 38, significantly enhanced attraction by the pheromone [80]. 

Several other examples of host plant recognition by hymenopteran parasitoids have been described recently. Six species of aphid parasitoids, Aphidius ervi, Trioxys sp., Praon sp., Aphelinus flavus, Lysiphlebus fabarum, and Aphidius rophalosiphi were most strongly attracted to their host aphid in combination with the damaged host plant [62]. For A. rhopalosiphi, three wheat volatiles were... 

Egg-deposition also can induce the host plant to emit volatiles that attract egg parasitoids. For example, egg deposition by the elm leaf beetle (Xantho-galeruca luteola) causes its host plant, the field elm (Ulmus minor), to release a blend of mostly terpenoids that attract the egg parasitoid Oomyzus galleru-cae (Eulophidae) [ 86]. Although the specific compounds that initiate the volatile emission and that attract the egg parasitoid are unknown, the host plant response can be induced with jasmonic acid. 

One additional factor that comes into play in the overall chemistry of the communication system relates to chemical signals from host plants that can override the photoperiodic control of phermone production. With the com earworm, it was found that a volatile chemical signal from com silk, probably ethylene, was required by wild insects for stimulation of pheromone production (33). This signal probably interacts with controls on the photoperiodic release of PBAN. 

Dicke M, Vanbeek TA, Posthumus MA, Bendom N, Vanbokhoven H, Degroot AE (1990) Isolation and identification of volatile kairomone that affects acaiine predator-prey interactions -involvement of host plant in its production. J Chem Ecol 16 381-396... 

Examples of natural products that may have potential in augmenting host plant resistance against A. flavus infection are certain plant derived volatile compounds (78, 85) as described earlier. 

Volatile compounds originating from the aflatoxin susceptible crop, cotton, and other plant-derived compounds that inhibit aflatoxin production have been identified. The various compounds are being tested for their potential to enhance host plant resistance by inhibition of fungal growth/aflatoxin production. 

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