Host plant location

Mustard oils which are found in some essential oils and are probably the hydrolysis or breakdown products of glucosinolates, are involved in host plant location of a number of groups of insects (9) . . Pieris braccicae and rapae on plants in the Brass caceae (CruciferaeXT... 

Feeny P (1976) Plant apparency and chemical defense. In Wallace JW, Mansell RL (eds) Biochemical Interaction Between Plants and Insects. Recent Advances in Phytochemistry, Vol 10. Plenum Press New York 1 0 Fernandez P, Hilker M (2007) Host plant location by Chrysomelidae. Basic and Applied Ecology 8 97-116... 

Modem board and interface SW a bidirectional modem is used to connect the host system, located in the plant, with a remote PC. It is asynchronous, with a throughput of 28000 b/s. The remote PC must match the characteristics of the in-plant PC of the AEBIL system. 

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]. 

In the family Chrysomelidae (leaf beetles), the presence of defensive glands located on the elytra and on the pronotum has been reported for adults of 4 of the 19 subfamilies. As these beetles are phytophagous, it is not surprising that their host plant chemistry frequently plays a prominent role in their defensive... 

Parasitic plants often use chemicals released by their host plant to stimulate seed germination, to locate the host, or for haustorial development. Many different compounds are involved, including strigolactones, quinones, coumarins, flavonoids, and other phenolics. Flavonoids contribute to signaling in some species but not others. Haustorial development in Triphysaria versicolor can be induced in vitro by the anthocyanidins petunidin, cyanidin, pelargonidin, delphinidin, as well as their glycosides obtained from the host plant.Anthocyanins are not usually found in root exudates, however, and thus the mechanism by which they affect natural signals for parasitic plants in the soil is not clear. 

An insect host s exposure to parasites and predators may be increased by variable plant defenses in three ways. First, by restricting feeding activity to certain tissue types or portions of the host plant, the position of insect hosts becomes more predictable. Parasites (24,46,42) or predators (48) able to recognize physical plant traits such as tissue color or form, or those capable of employing the unique chemistry of the preferred tissues as cues (47,49) would be able to locate their hosts more readily by focusing their search on these traits. 

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. 

Lu, W Wang, Q., Tian, M. Y., He, X.Z., Zeng, X. L. and Zhong, Y. X. (2007). Mate location and recognition in Glenea cantor (Fabr.) (Coleoptera Cerambycidae Lamiinae) Roles of host plant health, female sex pheromone, and vision. Environ. Entomol., 36, 864-870. 

The ability of fungal pathogens to tolerate, or in some way detoxify, the defensive chemicals of their host plants, is undoubtedly a major co-evolutionary mechanism closely linked with the phenomenon of plant-pathogen specificity. Other factors may, however, also be involved in determining specificity, including the ability of soil-borne pathogens to successfully locate their normal host. 

Allelochemicals are most notable in examples of host-plant and nonhost-plant selection, a process that is vital for phytophagous pest insects to locate food plants and avoid unsuitable or toxic hosts. Aphids have taxonomi-cally unrelated summer and winter hosts. The bird-cherry-oat aphid, Rhopalosiphum yadi. is able to detect species-specific odors from each of its hosts, the bird-cherry tree. Prunus padus, in winter and summer cereal crops. One such allelochemical from the winter host is methyl... 

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