Monophagous Insect Research Articles

Complex habitat changes along elevational gradients interact with resource requirements of insect specialist herbivores

Stenothermal habitat specialists such as monophagous insects may be threatened by climate-change induced range shifts, if resource requirements along migration routes or future habitats are not met. Little is known about altitudinal shifts of inconspicuous, less mobile species relative to latitudinal range shifts in prominent, mobile organisms such as butterflies. Here, we address three questions: What are the resource requirements—habitat area, quality and fragmentation—for two specialist herbivores? How do habitat characteristics change with altitude? Do species resource requirements suggest an increased vulnerability towards temporal or spatial bottlenecks under climate change? We mapped the spatial distribution of a riparian shrub, Veronica stricta (Plantaginaceae), at local (300 m elevational gradient, n = 252 patches) and regional scales (600 m gradient; n = 102) in the Tongariro National Park, New Zealand. Patch occupancy and patch-level population dynamics of Trioza obscura (Hemiptera: Triozidae) and an undescribed gall midge (Diptera: Cecidomyiidae) were recorded in 2010 and 2011. Habitat suitability and population dynamics were predicted with generalized linear models, applying information theoretic model averaging. Habitat area had the largest positive influence on insect presence and survivorship, the latter benefitting from larger insect populations. Habitat quality showed a species-dependent effect on occurrence (T. obscura: negative effect of plant shade; cecidomyiid: positive effect of host inflorescences) and survival (T. obscura: positive response to leaf-nitrogen and host size; cecidomyiid: positive response to inflorescence abundance). Only cecidomyiid colonization had a weak negative response to habitat fragmentation. Altitude contributed positively to patch suitability and survivorship of the cecidomyiid, but decreased survivorship of T. obscura. Altitude-related changes in the landscape matrix, such as the transition from forested to subalpine vegetation, positively affected habitat area and fragmentation, which in turn offset a steady decrease in host plant size (i.e., patch quality). Our study revealed that habitat area, quality and fragmentation do not always follow simple linear trends along elevational gradients. We recommend that species distribution models should consider these complex patterns when predicting range shifts. We suggest that species vulnerability to climate change depends on whether resource requirements allow for upward migration and suitable habitats are available in future distribution ranges.

Small-scale resource tracking in a population of a long-lived insect

How plant-feeding insects distribute themselves and utilize their host plant resources is still poorly understood. Several processes may be involved, and their relative roles may vary with the spatial scale considered. Herein, we investigate small-scale patterns, namely how population density of a gall midge is affected by individual growth form, phenology, and microsite characteristics of its herb host. The long-lived plant individuals vary much with regard to number of shoots, flower abundance, and flowering phenology. This variation is connected to site characteristics, primarily the degree of sun exposure. The monophagous insect galls the flowers of the host plant – an easily defined food resource. It is a poor disperser, but very long-lived; diapausing larvae can stay in the soil for many years. Galls were censused on individual plants during 5 years; from a peak to a low in gall population density. Only a very small fraction of the flowers produced (<0.5%) were galled even in the peak year. Nevertheless, most plant individuals had galls at least 1 year. In a stepwise multiple regression, plant size (number of shoots) was found to be the most important predictor of gall density (galls/flower). However, gall density decreased more than one order of magnitude over the plant size range observed. There was also a weak effect of plant phenology. Early flowering plants had lower gall densities than those starting later. Sun exposure had no direct effect on gall density, but a path analysis revealed indirect effects via the timing of flowering. Gall population change was highly synchronous in different parts of the study area with no significant decrease in synchrony with distance.

Effect of Bio-inoculants Applied to M&lt;sub&gt;5&lt;/sub&gt; Mulberry Under Rain-fed Condition on Growth and Cocoon Traits Performance of Silkworm, &lt;em&gt;Bombyxmori&lt;/em&gt; L.

Nutrition plays a pivotal role in sericulture. It improves the growth, development, health, feed consumption and conversion of silkworm thereby improving the commercial traits. Silkworm, Bombyx Mori L., is a monophagous insect that drives almost all required nutrients for its growth and development from mulberry leaf. Application of the required nutrient in the required amount to mulberry plant is, therefore, very essential for the successful silkworm growth and cocoon production. The present investigation was carried out at the department of sericulture, GKVK, UAS, Bangalore, India in 2007 with an objective to determine the effect of three bio-inoculants application to M 5 mulberry plant on silkworm (PM x CSR 2 ) growth, development and coocoon traits. The feeding experiment was laid-out in Completely Randomized Design (CRD)with eight treatments replicated three times. The result revealed that the larval growth variables and cocoon traits were significantly better when developing worms were fed on mulberry leaves raised by applying the recommended doses of nutrients. However, the recommended rate of chemical fertilizers application was found either the same or on par with 25 per cent reduced Nitrogen and Phospherous (NP) application when supplemented with bio-inoculants ( Azotobactersp., Aspergillus awamori and Trichodermaharzianum ). This indicate that 25 per cent reduction of NP application does not adversely affect larval growth and cocoon traits when supplemented with the above three microbes. Keywords : Bio-inoculants, Cocoon traits, Growth variables, M 5 mulberry, Rain-fed

Grape phylloxera (Daktulosphaira vitifoliae) – a review of potential detection and alternative management options

AbstractThe management options for grape phylloxera, Daktulosphaira vitifoliae, a monophagous insect pest of Vitis species are reviewed. Although in a worldwide context, grape phylloxera is managed predominantly by the use of resistant rootstocks developed through conventional breeding of hybrid crosses of American Vitis species, this management aspect is largely excluded from the review so that emerging technologies in the field of detection, quarantine and alternative management are discussed. In some viticulture regions of the world, where grape phylloxera's geographic distribution is limited (e.g. Australia), the pest is managed through a combination of surveillance, detection and quarantine. Although some alternative management options for grape phylloxera exist they have received relatively limited research attention because of the relative success of resistant rootstocks. The resilience of resistant rootstocks as the primary management option could also be challenged in the future by host‐plant interactions with diverse grape phylloxera clonal lineages and by potential impacts of climate change on both grapevine and grape phylloxera distribution. A range of control options exist which could be integrated into an improved management system for grape phylloxera. Priority areas for future evaluation and further development include early detection techniques, investigation into the use of biological control agents and development of an integrated approach to grapevine phylloxera management.

Climate oscillations and species interactions: large‐scale congruence but regional differences in the phylogeographic structures of an alpine plant and its monophagous insect

AbstractAim To predict the fate of alpine interactions involving specialized species, using a monophagous beetle and its host plant as a case study.Location The Alps.Methods We investigated genetic structuring of the herbivorous beetle Oreina gloriosa and its specific host‐plant Peucedanum ostruthium. We used genome fingerprinting (in the insect and the plant) and sequence data (in the insect) to compare the distribution of the main gene pools in the two associated species and to estimate divergence time in the insect, a proxy for the temporal origin of the interaction. We quantified the similarity in spatial genetic structures by performing a Procrustes analysis, a tool from shape theory. Finally, we simulated recolonization of an empty space analogous to the deglaciated Alps just after ice retreat by two lineages from two species showing unbalanced dependence, to examine how timing of the recolonization process, as well as dispersal capacities of associated species, could explain the observed pattern.Results Contrasting with expectations based on their asymmetrical dependence, patterns in the beetle and plant were congruent at a large scale. Exceptions occurred at a regional scale in areas of admixture, matching known suture zones in Alpine plants. Simulations using a lattice‐based model suggested these empirical patterns arose during or soon after recolonization, long after the estimated origin of the interaction c. 0.5 million years ago.Main conclusions Species‐specific interactions are scarce in alpine habitats because glacial cycles have limited the opportunities for co‐evolution. Their fate, however, remains uncertain under climate change. Here we show that whereas most dispersal routes are paralleled at a large scale, regional incongruence implies that the destinies of the species might differ under changing climate. This may be a consequence of the host dependence of the beetle, which locally limits the establishment of dispersing insects.

History and active pharmacokinetic principles of mulberry: a review

Mulberry, Morus spp. of the family Moraceae being the primary food plant for the monophagous insect Bombyx which has special significance in sericulture industry. Due to its chemical composition and pharmacological functions it is being utilized as a medicinal plant. Many active compounds isolated from the mulberry plants which used as medicines. Biochemical compounds such as Moranolin (DNJ), Moran (glycopeptides), hydrophobic flavonoids (flavones and flavonone), 2- Arylbenzofuran, and Ethanolic extract, Flavonoids, Polyphenols, Carotenoids, Vitamins A, C, E, Ethyl acetate, γ -aminobutyric acid, Flavanics are isolated from different parts of mulberry plants which play a vital role in Hypoglycemic activity, Anti-obesity action, Lipid-lowering action, Antioxidants action, Anti- inflammatory actions, Antiallergic action, Vasoactive action, Neuroprotective action, Anticancer action. Mulberry plants are identified for their profitable health consequences and therefore attracted the attention of the pharmaceutical industry. The main objective of presentreviewis to provide the active principlesof Mulberry plants.

No Evidence for Enemy Release During Range Expansion of an Evergreen Tree in Northern Europe

Plant distributions are dynamic but the role of plant-insect interactions in controlling range dynamics is not well understood. Enemy release, for example could facilitate plant range expansion under climate change. We conducted a transplant experiment with the evergreen tree Ilex aquifolium L. in both the historical and the expanding range in Denmark to study possible effects of geographical position, small-scale distance, and plant types on presence and performance of the monophagous insect leaf-miner Phytomyza ilicis Curtis. The leaf miner was present in the entire range of I. aquifolium in Denmark, and there were no differences in emergence success depending on geographical position. Small-scale distance to existing adult plants influenced the activity of the insect on the transplants, and oviposition density was negatively correlated with distance to adult plants. Plant type had an effect on leaf miner feeding, oviposition and mining, and the native provenance of I. aquifolium supported higher densities than two cultivars. There was no evidence that enemy release facilitates the current range expansion of I. aquifolium.

Increased reproductive capacity and physical defense but decreased tannin content in an invasive plant

Abstract Plant invasions create novel plant–insect interactions. The EICA (evolution of increased competitive ability) hypothesis proposes that invasive plants will reallocate resources from defense to growth and/or reproduction because they have escaped from their co‐evolved insect natural enemies. Testing multiple herbivory by monophagous and oligophagous herbivores and simultaneous measurement of various plant traits will provide new insights into the evolutionary change of invasive plants. In this context, we conducted a common garden experiment to compare plant growth and reproduction, chemical and physical defense, and plant responses to herbivory by different types of herbivores between invasive North American populations and native East Asian populations of mile‐a‐minute weed, Persicaria perfoliata. We found that invasive mile‐a‐minute exhibited lower biomass, flowered earlier and had greater reproductive output than plants from the native range. Compared with native populations, plants from invasive populations had lower tannin content, but exhibited higher prickle density on nodes and leaves. Thus our results partially support the EICA hypothesis. When exposed to the monophagous insect, Rhinoncomimus latipes and the oligophagous insects, Gallerucida grisescens and Smaragdina nigrifrons, more damage by herbivory was found on invasive plants than on natives. R. latipes, G. grisescens and S. nigrifrons had strong, moderate and weak impacts on the growth and reproduction of mile‐a‐minute, respectively. The results indicate that mile‐a‐minute may have evolved a higher reproductive capacity in the introduced range, and this along with a lack of oligophagous and monophagous herbivores in the new range may have contributed to its invasiveness in North America.

Spatial trade-offs in the digestive and reproductive systems of grape phylloxera

Trade-offs between reproduction and other energy-requiring activities are present in insects. However, feeding and reproduction are not often thought to be trade-offs, although in small insects space may be limiting for both ingestion of food and egg development. This study characterised the structure of the digestive system of radicicolae Daktulosphaira vitifoliae (Hemiptera: Phylloxeridae) to investigate how feeding and egg development occur in this species. Using light and electron microscopy, the midgut of D. vitifoliae was observed to be composed of anterior and posterior regions, separated by a hindgut connection. The midgut is compressed during the development of parthenogenetically produced eggs in adults; individual eggs are ~30% of the adult length and in volume internally occupy 3–5% of the body cavity. The midgut posterior chamber is suggested to be essential for the continual supply of energy during periods of reduced food intake. The presence of the hindgut and an anal opening indicated that waste excretion through the anus was physiologically possible, although honeydew excretion was not observed. The structure of the digestive system of radicicolae D. vitifoliae is atypical, containing adaptations that may assist the survival of the monophagous insect during dispersal events to a new Vitis food source.

How many hosts? Modelling host breadth from field samples

Summary 1. Host‐specificity is important in fundamental and applied studies of biodiversity, but it is difficult to generate definitive data for many species. 2. Here, we present a model framework for estimating the realized host breadth of dependent fauna from samples collected from replicate host individuals. We use Bayesian, Zero‐inflated Poisson regression to model the abundance conditional upon host use – our focal parameter. We illustrate the model using a data set of insects on threatened and non‐threatened plant species from eastern Australia. Estimating co‐extinction risk through threats to host organisms is a key application for the model, requiring assessment of the host‐specificity of biota, whilst incorporating uncertainty. 3. The host breadth model indicated that several insect species had high probability of narrow host breadth, including several species that appeared to only have one host. Furthermore, the model distinguished polyphagous, oligophagous and monophagous insect species. Modification of the model to account for false positives also identified tourist occurrences. 4. The host breadth model can be utilized not only towards focusing conservation actions on the most co‐threatened dependent invertebrate species, but also for other projects involving host‐specificity, such as estimating the number of insects globally, and selecting the most likely candidates for biological control of invasive species. Further uses are likely in various data sets of associations between species.

The Silent Mass Extinction of Insect Herbivores in Biodiversity Hotspots

Habitat loss is silently leading numerous insects to extinction. Conservation efforts, however, have not been designed specifically to protect these organisms, despite their ecological and evolutionary significance. On the basis of species-host area equations, parameterized with data from the literature and interviews with botanical experts, I estimated the number of specialized plant-feeding insects (i.e., monophages) that live in 34 biodiversity hotspots and the number committed to extinction because of habitat loss. I estimated that 795,971-1,602,423 monophagous insect species live in biodiversity hotspots on 150,371 endemic plant species, which is 5.3-10.6 monophages per plant species. I calculated that 213,830-547,500 monophagous species are committed to extinction in biodiversity hotspots because of reduction of the geographic range size of their endemic hosts. I provided rankings of biodiversity hotspots on the basis of estimated richness of monophagous insects and on estimated number of extinctions of monophagous species. Extinction rates were predicted to be higher in biodiversity hotspots located along strong environmental gradients and on archipelagos, where high spatial turnover of monophagous species along the geographic distribution of their endemic plants is likely. The results strongly support the overall strategy of selecting priority conservation areas worldwide primarily on the basis of richness of endemic plants. To face the global decline of insect herbivores, one must expand the coverage of the network of protected areas and improve the richness of native plants on private lands.

The olive fly endosymbiont, "Candidatus Erwinia dacicola," switches from an intracellular existence to an extracellular existence during host insect development.

As polyphagous, holometabolous insects, tephritid fruit flies (Diptera: Tephritidae) provide a unique habitat for endosymbiotic bacteria, especially those microbes associated with the digestive system. Here we examine the endosymbiont of the olive fly [Bactrocera oleae (Rossi) (Diptera: Tephritidae)], a tephritid of great economic importance. "Candidatus Erwinia dacicola" was found in the digestive systems of all life stages of wild olive flies from the southwestern United States. PCR and microscopy demonstrated that "Ca. Erwinia dacicola" resided intracellularly in the gastric ceca of the larval midgut but extracellularly in the lumen of the foregut and ovipositor diverticulum of adult flies. "Ca. Erwinia dacicola" is one of the few nonpathogenic endosymbionts that transitions between intracellular and extracellular lifestyles during specific stages of the host's life cycle. Another unique feature of the olive fly endosymbiont is that unlike obligate endosymbionts of monophagous insects, "Ca. Erwinia dacicola" has a G+C nucleotide composition similar to those of closely related plant-pathogenic and free-living bacteria. These two characteristics of "Ca. Erwinia dacicola," the ability to transition between intracellular and extracellular lifestyles and a G+C nucleotide composition similar to those of free-living relatives, may facilitate survival in a changing environment during the development of a polyphagous, holometabolous host. We propose that insect-bacterial symbioses should be classified based on the environment that the host provides to the endosymbiont (the endosymbiont environment).

Genetic population structure and hybridization in two sibling species, Tomoplagia reticulata and Tomoplagia pallens (Diptera: Tephritidae)

Tomoplagia reticulata and T. pallens are sibling species that are specialists on Eremanthus glomerulatus. Besides adult terminalia, they show slight morphological differences and distinct geographic distributions. Once, however, they were found sympatrically. Using data from allozyme and mtDNA, we examined patterns of intra- and interspecific genetic structure, and investigated the possible occurrence of gene flow between them. Both species showed low diversity and high genetic structure, which can be linked to their high degree of specialization. Larval development occurs within flower heads, tissues that are available only during a short period of the year. Afterward, as they do not hibernate, they probably suffer a great reduction in population size, which leads to low genetic diversity. As monophagous insects, their population structure may correspond to the fragmented distribution of E. glomerulatus, which could isolate fly populations and increase inbreeding within them. One population exhibited a mixed genetic composition, compatible with one hybridization season when species were sympatric. This hybridization seems to be a rare event, due to T. pallens unusual range expansion.

Effects of associational resistance and host density on woodland insect herbivores

1. Specialist herbivores often become less abundant per unit of host tissue as host density increases (resource dilution). They usually become less abundant when non-host species are mixed with their host plants (associational resistance). Most studies of these trends have involved herbaceous host plants and have not examined both trends for the same herbivores. 2. Three hypotheses were tested for the response of insect specialists to host plant density: resource concentration, plant apparency and resource dilution. Two hypotheses were tested for the response of herbivores to non-host plants: associational resistance and plant apparency. 3. From 1992 to 2007, I examined the responses of three monophagous insect herbivores to the densities of their host, Pinus edulis, and of two non-hosts, Pinus ponderosa and Juniperus spp. 4. Herbivore loads increased with host density, though the correlations were weak and often variable between generations. These results were consistent with the resource concentration and plant apparency hypotheses, but not with resource dilution. 5. Herbivore loads decreased as non-host density increased, consistent with the associational resistance hypothesis. This and other studies have shown that associational resistance is important in many types of plant communities. 6. The absence of resource dilution on woodland trees contrasted with studies of herbaceous host plants. Further comparisons of woody and herbaceous host plants are needed to elucidate the reasons for this difference.

Dispersal ability and host‐plant characteristics influence spatial population structure of monophagous beetles

Abstract. 1. Dispersal plays an integral role in determining spatial population structure and, consequently, the long‐term survival of many species. Theoretical studies indicate that dispersal increases with population density and decreasing habitat stability. In the case of monophagous insect herbivores, the stability of host‐plant populations may influence their spatial population structure.2. The tallgrass prairie in Iowa, U.S.A. is highly fragmented and most prairie insects face a landscape with fewer habitat patches and smaller host‐plant populations than 150 years ago, potentially making dispersal between patches difficult. Some herbivores, however, use native plant species with weedy characteristics that have increased in abundance because of disturbances.3. Mark–recapture data and presence–absence surveys were used to examine dispersal and spatial population structure of two monophagous beetles with host plants that exhibit different population stability and have responded differently to fragmentation of tallgrass prairie.4. Chrysochus auratus Fabricius exhibits a patchy population structure and has relatively large dispersal distances and frequencies. Its host plant is variable locally in time and space, but is more abundant than 150 years ago. The other species, Anomoea laticlavia Forster, exhibits a metapopulation or non‐equilibrium population structure and has relatively small dispersal distances and frequencies. Its host‐plant populations are stable in time and space.5. The results indicate that dispersal ability of monophagous beetles reflects the life‐history dynamics of their host plants, but the spatial population structure exhibited today is strongly influenced by how the host plants have responded to the fragmentation process over both time and space.

Are associational refuges species‐specific?

Summary Associational refuges – reduced herbivory on plants in presence of other plant species – may be caused by general and species‐specific plant characteristics. However, the species specificity of associational refuges has rarely been evaluated. This study examined the species specificity of one known example of associational refuges, the forb Lythrum salicaria and the monophagous insect herbivores Galerucella calmariensis, G. pusilla and Nanophyes marmoratus. The underlying mechanism was examined in order to evaluate connections between mechanisms and species specificity. Laboratory studies showed that N. marmoratus but not Galerucella individuals were attracted by odour from undamaged host plants, and that neither species was distracted by odour from Myrica gale. Field experiments showed that three non‐host plant neighbours with an appearance similar to M. gale, and artificial shrubs, reduced the abundance and egg‐laying of Galerucella species by 70–90%. The abundance of N. marmoratus was increased 18‐fold on plants in thickets compared with outside. . The different responses by N. marmoratus and the Galerucella species to plant neighbours appear to be because N. marmoratus, but not Galerucella, uses olfactory information in the initial host‐finding process.

Phylogenetic indices for measuring the diet breadths of phytophagous insects.

Prevailing methods of measuring diet breadth of phytophagous insects are not consistent between studies and generally rely on counts of a variety of higher plant taxa (e.g. genera, families, orders). Results derived from them can be inconsistent if different taxonomic levels are used between studies. In any case, such indices do not include information from the whole branching structure of the host plant phylogeny, and do not address the fact that higher taxa are not necessarily phylogenetically equivalent. Here we present novel phylogeny-based methods which address these shortcomings. Although a previously proposed index (the Phylogenetic Diversity index) may be employed, it cannot be used to measure diets of strictly monophagous insects (i.e. those which utilise a single host species). We therefore introduce a modification of this index (the Root Phylogenetic Diversity index) which may be applied to all diets. In addition, we propose a Clade Dispersion index as a branch-length-independent measure of the degree to which hosts are scattered across the host phylogeny. We describe how these indices could be employed in studies of insect diet breadth and discuss potential problems which may be encountered in their use.

An Integrative Paradigm for the Dynamics of Monophagous Parasitoid-Host Interactions

Although much research on exploiter-victim interactions has concerned predators and their prey, over the past 25 years there has been a flurry of theoretical work involving monophagous insect parasitoids and their herbivorous insect hosts. This is, in part, because such tightly coupled systems are apt to be the most likely to exhibit strong top-down control from the third to the second trophic level. This theory is approaching a crossroad. It is becoming increasingly clear that the community surrounding tightly coupled host-parasitoid interactions cannot be neglected in determining the dynamics of these systems. It is also apparent that spatial scale may be pivotal in the persistence and dynamics of such species couples. In this paper I propose that a general paradigm of the population dynamics of monophagous parasitoid-host associations is emerging, and we are now, more than ever, in a position to investigate it theoretically and experimentally.

ASYNCHRONY OF INFECTION TIMING, HABITAT PREFERENCE, AND SYMPATRIC SPECIATION OF SCHISTOSOME PARASITES.

Sympatric speciation, which has been the subject of many theoretical studies based on principally genetic models, requires at least two fundamental conditions; (1) the establishment, through disruptive selection, of a stable polymorphism in a heterogeneous environment; and (2) the of reproductive isolation between the morphs (Maynard Smith 1966; Rice 1984, 1987). Studies of natural biological systems, however, remained restricted to a few taxonomically different groups, predominantly insects. Divergent host races in monophagous insects (Bush 1969; Tauber and Tauber 1989), where habitat diversification and asynchrony in seasonal timing of reproduction was implicated in the restriction of gene flow, have provided the best evidence for nonallopatric speciation. Considering that sympatric speciation was closely linked with a process of habitat (-host) shifts, Price (1980, p. 41) and others emphasized the potential applicability of this process to populations of parasites and stated that if host race formation can lead to speciation of phytophagous insects, it can also be important among animal parasites. It is now well accepted that coevolution of lineages of hosts and parasites (phylogenetic or parallel speciation), where host speciation has been accompanied by divergence of their parasites, is not the only pattern for the of hostparasite associations. Parasites, particularly those whose life cycle involves active dispersion (Combes 1991a), have the opportunity of lateral transfer to unrelated host species, a major feature of parasite evolution (Futuyma and Kim 1987, p. 441). Natural metazoan parasite populations, independently and sympatrically maintained by two or more different hosts, diverging to host-adapted populations have been little studied. Such a situation exists for the trematode Schistosoma mansoni on the Caribbean island of Guadeloupe (1528 kM2), where two species of vertebrate hosts (human and rat) are involved in the transmission dynamics of the parasite.

Responses of maxillary sensilla styloconica inBombyx mori to glucosides fromOsmunda japonica, a nonhost plant

We isolated glucosides from the royal fern,Osmunda japonica, which elicit a deterrent response in larvae ofBombyx mori. These compounds were absent in taro (Colocasia antiquorum) and castor-oil plant (Ricinus communis) leaves and did not evoke responses of sensory cells in the lateral and medial sensilla styloconica ofSpodoptera litura. This glucoside extract of the royal fern leaves stimulates receptors generally associated with deterrent. It is also possible that this compound may act as a behavioral deterrent, and from actual feeding tests, it is suggested that this compound may prevent feeding in some monophagous insects, such asBombyx mori. The deterrent glucoside possesses a noncyclic aglycon.