Journal of Chemical Ecology

The push-pull approach using semiochemicals in pest control requires both an attractant and a repellent. Many previous studies have arbitrarily tested one or more known insect repellents or plant essential oils (EOs) hoping to find repellents of an insect pest. We used a comprehensive approach that synergistically tests in the field numerous natural volatiles from commercial EOs to identify repellents of the red palm weevil Rhynchophorus ferrugineus (Coleoptera: Curculionidae), a worldwide pest of palms and date palms...

Terpenes are a major class of secondary metabolites present in all plants, and long hypothesized to have diversified in response to specific plant-herbivore interactions. Herbivory is a major biotic interaction that plays out across broad temporal and spatial scales that vary dramatically in temperature regimes, both due to climatic variation across geographic locations as well as the effect of seasonality. In addition, there is an emerging understanding that global climate change will continue to alter the temperature regimes of nearly every habitat on Earth over the coming centuries...

No abstract text is available yet for this article.

Amphibians are one of the most remarkable sources of unique natural products. Biogenic amines, peptides, bufodienolides, alkaloids, and volatile organic compounds have been characterized in different species. The superfamily Dendrobatoidea represents one of the most enigmatic cases of study in chemical ecology because their skin secretome is composed by a complex mixture (i.e. cocktail) of highly lethal and noxious unique alkaloid structures. While chemical defences from dendrobatoids (families Dendrobatidae and Aromobatidae) have been investigated employing ecological, behavioral, phylogenetic and evolutionary perspectives, studies about the analytical techniques needed to perform the chemical characterization have been neglected for many years...

Stylotermitidae appear peculiar among all termites, feeding in trunks of living trees in South Asia only. The difficulty to collect them limits the ability to study them, and they thus still belong to critically unknown groups in respect to their biology. We used a combination of microscopic observations, chemical analysis and behavioural tests, to determine the source and chemical nature of the trail-following pheromone of Stylotermes faveolus from India and S. halumicus from Taiwan. The sternal gland located at the 5th abdominal segment was the exclusive source of the trail-following pheromone in both S...

Eucalyptus species are among the most planted trees in forestry production, an ever-increasing commercial activity worldwide. Forestry expansion demands a continuous search for preventive and sanitary measures against pests and diseases. Massive application of phytosanitary products is incompatible with the forestry sector, so forest health management must be based on other principles. In this context, studies on insect plant relationships mediated by plant metabolites may contribute information relevant to plant resistance and genotype selection...

The broom twig miner, Leucoptera spartifoliella (Hübner) is a highly specific biological control agent for the Scotch broom, Cytisus scoparius (L.). Cytisus scoparius has become a major invasive weed spreading in North America, South America, Australia and both the South and North Island of New Zealand, causing a major disturbance to the ecology of the area where it has been established. Currently, there is no tool available to monitor the population density, dispersal, and establishment of L. spartifoliella...

No abstract text is available yet for this article.

Plant-plant signalling via volatile organic compounds (VOCs) has been studied intensively, but its contingency on abiotic conditions (e.g., soil nutrients, drought, warming) is poorly understood. To address this gap, we carried out a greenhouse experiment testing whether soil nutrients influenced signalling between potato (Solanum tuberosum) plants in response to insect leaf herbivory by the generalist caterpillar Spodoptera exigua. We placed pairs of plants in plastic cages, where one plant acted as a VOC emitter and the other as a receiver...

Feeding-choice experiments were conducted under laboratory conditions with two dorid spongivorous nudibranchs, Goniobranchus aureomarginatus and Ceratosoma amoenum, collected from a sponge meadow off Tauranga, New Zealand with two sponge prey (Dysidea teawanui sp.nov. and an undescribed species from the Dictyodendrillidae family, possibly Dictyodendrilla tenella (Lendenfeld 1888). The first choice of prey, the total number of prey choices made, and the time spent on each prey target was recorded, results indicating that each nudibranch had strong preferences for specific prey species...

The cyclic depsipeptide FR900359 (FR) is derived from the soil bacterium Chromobacterium vaccinii and known to bind Gq proteins of mammals and insects, thereby abolishing the signal transduction of their Gq protein-coupled receptors, a process that leads to severe physiological consequences. Due to their highly conserved structure, Gq family of proteins are a superior ecological target for FR producing organisms, resulting in a defense towards a broad range of harmful organisms. Here, we focus on the question whether bacteria like C...

Caterpillar salivary glucose oxidase (GOX) can function as both an elicitor or as an effector of plant defense responses depending upon the system. Treatment with GOX reduces the stomatal aperture of tomato and soybean leaves, thereby reducing the emission of volatile organic compounds (VOCs), that are important indirect defense responses of plants by attracting natural enemies of the caterpillars. Here we examined the effect of fungal GOX (fungal glucose oxidases have been used to determine specificity in defense response elicitation) on stomatal closure of maize leaves and on the volatile emission pattern whole maize plants...

An electroantennogram (EAG) technique compared the antennal olfactory responses by both sexes of eight Japanese Papilio species with known host plants in laboratory experiments. Papilio species were collected from Honshû and Kyûshû (Japanese islands). The behavioral responses to volatile leaf substances from Citrus deliciosa, Zanthoxylum ailanthoides, Phellodendron amurense, Orixa japonica, and Foeniculum vulgare were examined in laboratory experiments. Individual EAG reactions were recorded...

Insects avoid predation in various ways, and some use multiple ways to avoid predation. However, the effects of comprehensive avoidance methods and the differences in avoidance methods among different life stages of insects have not been sufficiently discussed. The big head stick insect Megacrania tsudai uses background matching as its primary defense and chemical defense as its secondary defense. The aims of this study were to identify and isolate the chemical components of M. tsudai using repeatable methods, determine the amount of the main chemical compound, and reveal the effect of the main chemical compound on its predators...

Disease suppressive composts are known, yet little information on the potential role of specific microbial antagonist within are available. Arthrobacter humicola isolate M9-1A has been obtained from a compost prepared from marine residues and peat moss. The bacterium is a non-filamentous actinomycete with antagonistic activity against plant pathogenic fungi and oomycetes sharing its ecological niche in agri-food microecosystems. Our objective was to identify and characterize compounds with antifungal activity produced by A...

Air potato, Dioscorea bulbifera L., is an invasive vine found in the southeastern United States and is native to Asia and Africa. The air potato leaf beetle Lilioceris cheni (Coleoptera: Chrysomelidae), is a host specific biological control agent introduced for D. bulbifera control. In this study, odor cues that control the attraction of L. cheni to D. bulbifera were investigated. The first experiment investigated the response of L. cheni to D. bulbifera leaves versus no leaves in the presence or absence of air flow...

We found that vittatalactone, specifically (3R,4R)-3-methyl-4-[(1S,3S,5S)-1,3,5,7-tetramethyloctyl]oxetan-2-one, is the male-produced aggregation pheromone of the western striped cucumber beetle, Acalymma trivittatum (Mannerheim), as was previously shown for the striped cucumber beetle, Acalymma vittatum (F.) (Coleoptera: Chrysomelidae). A synthetic mixture containing 9% of the authentic natural pheromone, is attractive to both sexes of both species in the field, as demonstrated by trapping using baited and unbaited sticky panels in California and earlier in Maryland...

Hypogean petrels return to the same nest burrow to breed on remote islands during the summer months. Their nocturnal behavior at the colony, strong musky odor and olfactory anatomy suggest an important role of olfaction in homing behavior and nest recognition. Behavioral experiments showed that olfactory cues are sufficient to allow nest identification, suggesting a stabile chemical signature emanating from burrows and facilitating nest recognition. However, the chemical nature and sources of this odor remain unknown...

Plants are often attacked sequentially by multiple enemies. Pathogen sequential co-infections can lead to indirect interactions mediated by plant induced responses whose outcome is contingent on differences in the magnitude and type of plant induced defences elicited by different species or guilds. To date, however, most studies have tested unidirectional effects of one pathogen on another, not discerning between conspecific vs. heterospecific infections, and often not measuring plant induced responses underlying such outcomes...

Lepidopteran specialist herbivores of the Notodontidae family have adapted to thrive on poplar and willow species (Salicaceae). Previous research showed that Cerura vinula, a member of the Notodontidae family occurring throughout Europe and Asia, uses a unique mechanism to transform salicortinoids, the host plant's defense compounds, into quinic acid-salicylate conjugates. However, how the production of this conjugates relates to the detoxification of salicortinoids and how this transformation proceeds mechanistically have remained unknown...