Ecological stoichiometry es is a general theoretical framework. The host plant appeared to change in attractiveness to other aphids after the host plant had been colonized. The indices of food plant vigour and body sizes of studied moths were found to be correlated strongly and positively figs 3 and 4, thereby supporting the plant vigour hypothesis price, 1991. Host plant quality and fecundity in herbivorous insects. Specialist versus generalist insect herbivores and plant. Microarray analysis has confirmed that many of the modifications of gene expression that occur in plants following attack by herbivorous insects can be accounted for by the effects of compounds elicitors released by chewing insects. More time spent eating, and less time spent wandering around looking for food, yields healthier, stronger insects. Starting with herbivory, plantinsect interactions date back to the devonian period. Low host specificity of herbivorous insects in a tropical forest.
Effect of hostplant manipulation by a gallinducing insect. Fabaceae, affects the performance of the bean weevil. Larval consumption and growth in hostshifted herbivorous insects. Host plantbased variation in fitness traits and major.
Variation in host plant quality may affect the body size of herbivorous insects, which in turn, can determine their lifehistory parameters such as survival, fecundity and fitness. Potential evolution of host range in herbivorous insects. Such hostplant association expansions would follow from nat. A small portion of the plant host should be placed into a bottle with a small amount of stream water, and air space should be maintained at the top of the bottle. Effects of high quality aromatic rice varieties on the. Components of host plant quality such as carbon, nitrogen, and defensive. We used drought to alter host plant quality of the ribwort plantain, plantago lanceolata, and. Most notably, chewing insects and necrotrophic pathogens e.
Cascading effects of variation in plant vigour on the. Brunissen et al suggested that the aphids could discriminate between previously infested and noninfested potato plants by the odour of the plant. A suggested mechanism for the success of introduced nonnative species is the enemy release hypothesis erh. Animals require energy and nutrients for growth and reproduction. In the glanville fritillary shortage of food during the postdiapause stage has also been shown to reduce fecundity or life span. Insects free fulltext larval host preference and suitability for. A key factor influencing these interactions is host plant quality. Although the number of adults and the sex ratio were unaffected by plant quality, female biomass was greater on higher quality plants and there was a plant quality x insect density interaction table 1. Host specialization by reproductive interference between. Changes in host plant quality induced by defoliation also have been suggested as a possible mechanism driving complex dynamics among insect herbivores benz, 1974. Temperature, food quality and life history traits of. Aphids, similar to other herbivorous insects, require sugars, nitrogenous compounds.
We investigated if plant quality of different wild common bean populations, phaseolus vulgaris l. Oct 12, 2016 the performance and population dynamics of insect herbivores depend on the nutritive and defensive traits of their host plants 1. Particularly specialist insect species have to find specific plant species on which they can feed and reproduce host plants among plant species that do not support feeding and or reproduction of the insects non host plants. Pdf host plant quality and fecundity in herbivorous insects. If it happens to be in a field of the same plant, it will quickly encounter another meal. Mortality of nymphs was unaffected by plant quality but negatively affected by insect density with no interaction present table 1. We introduce a new model of the evolution of host specialization in herbivorous insects. Low host specificity of herbivorous insects in a tropical. We attempted to verify the reasons behind this host change. Nine rwa resistance genes, dn1, dn2, dn3, dn4, dn5, dn6, dn7, dn8 and dn9, for wheat have.
It is divided into four sections, wherein the first two sections deal with neurophysiology and the diversity of behavioral induction cues. Host plant quality and fecundity in herbivorous insects by. Awmack cs, leather sr 2002 host plant quality and fecundity in herbivores insects. Plant quality, defined as a general term, includes all physical, chemical or biological traits of a plant relevant for its. Agronomy free fulltext wheat nitrogen fertilisation effects on. The impact of microbial symbionts on host plant utilization. Phytophagous insects range from those that are strictly monophagous, i. The average proportion of herbivorous species feeding on a particular host plant that was unique effectively specialized 17 to that plant was estimated as f. May 28, 20 awmack cs, leather sr 2002 host plant quality and fecundity in herbivores insects. Plants and insect herbivores are perpetually at battle in the evolutionary army race. Remote work advice from the largest allremote company. Introduction insects are the most diverse species of animals living on earth.
Effect of six host plant species on the life history and population growth parameters of rastrococcus iceryoides hemiptera. For more than 20 years insectplant relations have been a focus for studies in ecology and evolution. Here we analyse data for over 900 herbivorous species feeding on 51 plant species in new guinea and show that most herbivorous species feed on several closely related plant species. Apr 25, 2002 the average proportion of herbivorous species feeding on a particular host plant that was unique effectively specialized 17 to that plant was estimated as f t s t h t, that is, as the ratio. Food quality features such as the content of certain fatty acids, the absence of fibre e. N2 herbivory, defined as feeding on live plant tissues, is characteristic of highly successful and diverse groups of insects and represents an evolutionarily derived mode of feeding. The high variability in host plant quality induced strong cascading effects on performance of higher trophic levels herbivores and parasitoids. Understanding the mechanisms underlying the ecological interactions between insect herbivores and their host plants has been an important goal in ecology for a long time. Host plant quality is a key determinant of the fecundity of herbivorous insects. Complex effects of fertilization on plant and herbivore. Host plantbased variation in fitness traits and major detoxifying enzymes activity in scirtothrips dorsalis thysanoptera.
We would like to show you a description here but the site wont allow us. During the evolution, plants have evolved morphological barriers, including plant. Despite its ecological importance, no general explanatory framework for host specialization is currently available. The distribution of variation among hostplant attributes determines the optimal spatial resolution level for insect females to select the best resource patches for oviposition.
Effect of insect density and host plant quality on. Environmental education resources to commemorate earth days 50th anniversary. Host specificity and species richness of tropical insects are also key parameters in mapping global patterns of biodiversity. Plants evolve various ways to become less hospitable to insect herbivores, while insect herbivores develop sophisticated defense systems to cope with their host plants or to find novel ways to exploit new hosts 1.
Subsequently, the host can be removed from the bottle, wrung out, and discarded. A number of factors can influence the overall quality of a plant as a host for insects, and have been cited as possible causes of variation in herbivore population dynamics e. Host plant resistance, the allimportant rwa management strategy, is not effective in some instances due to the evolution of rwa biotypes 10,11,12. Some of the more polyphagous insects like grasshoppers and armyworms will consume every part of their host plant.
Plants do not offer homogeneous supplies of the resources required by herbivorous insects as many resource traits show considerable variation both within and between plants. Components of host plant quality such as carbon, nitrogen, and defensive metabolites directly affect potential and achieved herbivore fecundity. The distribution of variation among host plant attributes determines the optimal spatial resolution level for insect females to select the best resource patches for oviposition. Plant diversity effects on pollinating and herbivorous. These are variants of the pest that are able to overcome host plant resistance mechanisms, especially antibiosis and antixenosis. Many studies have tested the predictions of the erh using the community approach native and nonnative species studied in the same habitat or the biogeographical approach species studied in their native and nonnative range, but results are highly variable.
Thripidae, an emerging sucking pest of tea volume 36 issue 3 dhiraj saha. Abstracthost plant quality is a key determinant of the fecundity of herbivorous insects. Impact of variable host quality on herbivorous insects denno, r. As plant pathogens and herbivorous insects may share the same host plant, changes in plant traits caused by infection can act as a feeding deterrent to herbivorous insects, and can also alter their physiology and development, resulting in reduced growth rates, reduced adult size, and increased mortality rates 8,9.
Effects of crowding and host plant quality on morph determination in the soybean aphid, aphis glycines. Once the larva or nymph consumes the original host plant, it must go in search of a new food source. Plant quality, defined as a general term, includes all physical, chemical or biological traits of a plant relevant for its herbivores e. Recent experiments have revealed coordinated up and downregulation of transcripts encoding proteins with related functions, suggesting that largescale shifts. Leatherhost plant quality and fecundity in herbivorous insects.
Apart from the open ocean, insects can be found in all habitats. Components of host plant quality such as carbon, nitrogen, and defensive metabolites directly affect potential. Transcriptional responses of invasive and indigenous. Potential evolution of host range in herbivorous insects doug futuyma dept. The bottle should then be shaken vigorously to remove the epiphytes from the plant host. Host plant quality and fecundity in herbivorous insects annual. Scirtothrips dorsalis hood is a polyphagous species and an important sucking pest of tea camellia sinensis theaceae. Increased fecundity of aphis fabae on vicia faba plants. Plant quality bottomup and natural enemies topdown can influence the individual performance of herbivorous insects on their host plants, but few studies measured at the same time the influence on population densities in the field.
The importance of insects as crop pests, and the great potential of insects for the biological control of weeds, have provided further impetus for work in this area. Hostseeking behavior and mechanisms addresses mechanisms of searching behavior leading ultimately to host location of herbivorous insects. Effect of hostplant manipulation by a gallinducing. The role of selected plant metabolites in host plant choice.
The performance and population dynamics of insect herbivores depend on the nutritive and defensive traits of their host plants 1. Host specialization among closely related herbivores is common and is therefore a major theme in ecology. Leather sr 2002 host plant quality and fecundity in herbivorous insects. Larval consumption and growth in hostshifted herbivorous. Since indirect interactions are prevalent in terrestrial plantherbivore systems, we. Recently in poland, cases of host expansion have frequently been observed in the typically monophagous birdcherry ermine moth yponomeuta evonymella, which has moved from its native host plant, bird cherry prunus padus, to a new, widely distributed plant that is invasive in europe, black cherry p. Specialist versus generalist insect herbivores and plant defense. More and larger herbivore hosts on high quality plants can produce more.
Field experiments demonstrated that the proportion of larvae entering diapause differed among four host. Hosts already attacked by other insects may have defences induced and be lower quality. This chapter examines critically the role that reproductive load and host plant quality have on the reproductive patterns of herbivorous insects. There are many books on plantinsect interactions, for example those of elizabeth. Developmental stagedependent response and preference for host. Host seeking behavior and mechanisms addresses mechanisms of searching behavior leading ultimately to host location of herbivorous insects. Such host plant association expansions would follow from nat.
The life cycle of these insects is tightly synchronized with host plant phenology such that female herbivores. The literature on plantherbivore interactions focuses on plant. Exploring the relationship between phytophagous insects and host plants has been. Host plant quality also affects insect reproductive. Components of host plant quality such as carbon, nitrogen, and defensive metabolites directly affect. Factors affecting fecundity, fertility, oviposition, and larviposition in. Arthropods constitute the most diverse group of animals on earth, and a large fraction of arthropod species are phytophagous. N ratio of female grasshoppers and bees with increasing plant species richness grasshoppers or functional group richness bees see above.
Effect of insect density and host plant quality on wingform. Agrawal department of ecology and evolutionary biology, cornell university, e425 corson hall, ithaca, ny 148532701, usa there has been a longstanding hypothesis that specialist and generalist insects interact with plants in distinct ways. The striped stem borer ssb, chilo suppressalis walker lepidoptera. Shows that host plant quality is a determinant factor of insects fecundity and of insects reproductive strategies. Bottomup and topdown effects influence bruchid beetle. Jul 31, 2014 a key factor influencing these interactions is host plant quality. Effect of six host plant species on the life history and.
Although there is a vast empirical literature documenting such changes in any of a number of plantherbivore systems see karban and. For herbivorous insects, the primary and secondary metabolites, as well as specific. Components of host plant quality such as carbon, nitrogen, and defensive metabolites directly affect potential and. To assess whether a higher weight corresponded to a larger. The responses of insect herbivores to changes in host plant quality vary within and between feeding guilds. We attempted to verify the reasons behind this host change in the context of the. Abstract host plant quality is a key determinant of the fecundity of herbivorous insects. Plant diversity effects on pollinating and herbivorous insects can be linked to plant stoichiometry. The best studied of plant physiological responses specific to herbivores is the systemic release of volatile organic compounds. Theunissen 1994 found that host plant quality decreases with increasing plant species richness due to interspecific competition and thus the attractiveness for consumers decreases. Profiling the response of plants to herbivorous insects. T1 the impact of microbial symbionts on host plant utilization by herbivorous insects. Biological sciences insect populations distribution growth life history theory research mealy bugs mealybugs population population growth. Temperature, food quality and life history traits of herbivorous insects article in current opinion in insect science 11 november 2015 with 247 reads how we measure reads.