Beetles, leaf

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. 

There was proposed a detailed account of iridoid biosynthesis in rove beetles which resembles the biosynthesis in leaf beetle larvae but exhibits distinct stereochemical differences [134], see also the chapter by Laurent et al., this volume. 

Attractive Compounds. Despite the fact that defence chemistry and insect-plant interactions have been extensively investigated in many leaf beetle species, not too much is known about the chemical background of intraspecific communication. 

Another unusual structure was identified from cereal leaf beetles, Oulema melanopus ( )-8-hydroxy-6-methyl-6-octen-3-one 199 was found to be a male-specific volatile. Electrophysiological investigations showed a sensitive detection of 199 by both sexes which is consistent with a male-produced aggregation pheromone [367]. The behaviour mediating capacity of the compound needs to be proven. 

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... 

Pasteels JM, Rowell-Rahier M, Braekman JC, Daloze D (1994) Chemical defence of adult leaf beetles updated. In Jolivet PH, Cox ML, Petitpierre E (eds) Novel aspects of the biology of Chrysomelidae. Kluwer Academic Publishers, Dordrecht, p 289... 

Pasteels JM, Termonia A, Daloze D, Windsor DM (2000) Distribution of toxins in Chrysomeline leaf beetles possible taxonomic inferences. In Furth DG (ed) Special topics in leaf beetle biology. Proc 5th Symposium on the Chrysomelidae. Pensoft Publishers, Sofia Moscow, p 261... 

The aggregation pheromone of the leaf beetle Diorhabda elongata Brulle (Coleoptera Chrysomelidae) have been identified as two compounds namely, (2E , 42 )-2,4-heptadienal and (2E , 42 )-2,4-heptadien-l-ol produced exclusively by males. They were also detected in trace quantities from females but the levels in males were 8—40 times higher. ... 

Many Insects have become specialists on crucifers and a few related plant families. These Include flea beetles, leaf beetles, cabbage root fly, aphids, cabbage butterflies and the dlamondback moth. At the same time, several polyphagous Insects such as the cabbage looper, armyworms and aphids are major pests of crucifers. Comparative studies on these specialists and generalists have provided valuable Information on host recognition and possible resistance mechanisms. 

Dolch and Tscharntke (2000) studied the effects of artificial defoliation of alder trees on subsequent herbivory by alder leaf beetle (Agelastica alni). After defoliation, herbivory by A. alni was significantly lower in the defoliated trees and its neighbors compared with trees distant from the manipulated trees. Laboratory studies confirmed that resistance was induced not only in defoliated alders but also in their undamaged neighbors (Dolch and Tscharntke, 2000). Follow-up work showed that alder leaves respond to herbivory by A. alni with the release of ethylene and of a blend of volatile mono-, sesqui-, and homoterpenes. This herbivory also increased the activity of oxidative enzymes and proteinase inhibitors (Tscharntke et al., 2001). 

Dolch, R. and Tscharntke, T. (2000). Defoliation of alders (Aims glutinosa) affects herbivory by leaf beetles on undamaged neighbours. Oecologia 125 504-511. 

Meiners, T. and Hilker, M. (1997). Host location in Oomyzus gallerucae (Hymenoptera Eulophidae), an egg parasitoid of the elm leaf beetle Xanthogaleruca luteola (Coleoptera Chrysomelidae). Oecologia 112 87-93. 

Wegener, R., Schulz, S., Meiners, T., Hadwich, K. and Hilker, M. (2001). Analysis of volatiles induced by oviposition of elm leaf beetle Xanthogaleruca luteola on Ulmus minor. Journal of Chemical Ecology 27 499-515. 

Kunert, M S0e, A., Bartram, S Discher, S., Tolzin-Banasch, K., Nie, L., David, A., Pasteels, J. and Boland. W. (2008). De novo biosynthesis versus sequestration A network of transport systems supports in iridoid producing leaf beetle larvae both modes of defense. Insect. Biochem. Mol. Biol., 38, 895-904. 

Coleoptera. A recent work on chrysomelidae (Peterson et al., 2007) evaluated the evolution of sexual isolation between two leaf beetles, Chrysochus cobaltinus and C. auratus, in a hybrid zone in Washington state (USA). By painting beetle cadavers with various cuticular extracts, the authors demonstrated a strong male preference for conspecific females according to species and sexual chemical specificity of their respective cuticular hydrocarbon profiles. This male mate choice reinforced sexual isolation. 

Aliphatic ethers have been observed in cuticular lipids from a few insect species. The surface lipids of the locust, L. m. cinerascens contained 4-5% aliphatic ethers (Genin et al., 1987). The major ethers were C29, C31 and C33 compounds with the alkyl moieties ranging in size from 11 to 20 carbons. The locust showed dimorphism solitary locusts had a majority of the longer-carbon-chain ethers while the gregarious locusts had a majority of shorter-carbon-chain ethers. The surface lipids of the red-shouldered leaf beetle, Monolepta australis, contained a series of 7-octadecenyl alkyl ethers, the major constituent being 7-octadecenyl pentadecyl ether (Southwell and Stiff, 1989). 

NIELSEN, J.K., Host plant discrimination within Cruciferae Feeding responses of four leaf beetles (Coleoptera Chrysomelidae) to glucosinolates, cucurbitacins and cardenolides., Entomol. Exp. Appl., 1978, 24, 41-54. 

Oreina leaf beetles (Chrysomelidae, Coleoptera) synthesize cardenolides as part of their defensive secretions that are released from specialized exocrine glands.139,140 Some Oreina beetles sequester and secrete PAs, which are taken directly as N-oxides from their Asteraceae food plants.59 It is assumed that PA acquisition evolved in species that already possessed the ability to synthesize and store cardenolides for efficient defense.14 O. cacaliae is the only species in this family that lost the ability to synthesize cardenolides autogenously. Instead the plant-derived PA A-oxides are stored in the body (primarily in the hemolymph) and... 

HARTMANN, T., THEURING, C SCHMIDT, J., RAHIER, M PASTEELS, J.M., Biochemical strategy of sequestration of pyrrolizidine alkaloids by adults and larvae of chrysomelid leaf beetles. J. Insect Physiol., 1999,45, 1085-1095. 

HARTMANN, T WITTE, L., EHMKE, A., THEURING, C ROWELL-RAHIER, M., PASTEELS, J.M., Selective sequestration and metabolism of plant derived pyrrolizidine alkaloids by chrysomelid leaf beetles. Phytochemistry, 1997, 45, 489-497. 

DOBLER, S., MARDULYN, P., PASTEELS, J.M., ROWELL-RAHIER, M Host-plant switches and the evolution of chemical defense and life history in the leaf beetle genus Oreina. Evolution, 1996,50,2373-2386. 

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