Sexual differences in flower defense and correlated male‐biased florivory in a plant–florivore system

Male‐biased florivory is a prominent phenomenon in the interaction between plants and florivores, and is potentially related to the evolution of flower traits and sex expression; however, its adaptive significance is not well understood. We studied florivory in the geometrid moth Chloroclystis excisa utilizing flower buds of a sexually polymorphic shrub, Eurya japonica, to reveal relationships between flower sex and moth oviposition preference, moth larval performance, and plant phenolics composition. In the field, C. excisa exploited flower buds on male and hermaphrodite trees but never those on female trees. In the laboratory, moths showed a strong oviposition preference for male over female flower buds, and larvae did not survive on female buds. Mortality was caused solely by feeding on the calyx covering the female bud. Female calyces contained higher concentrations of total phenolics and condensed tannins than did male calyces. These results suggest that substantial sexual differences in defense against florivory may have evolved in association with the differentiation of flower sexes and that a strong preference for the weakly defended flower sex may have evolved in florivores as a counter‐adaptation.     

Preference induction and the benefits of floral resources for a facultative florivore

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Florivory indirectly decreases the plant reproductive output through changes in pollinator attraction

Species often interact indirectly with each other via their traits. There is increasing appreciation of trait‐mediated indirect effects linking multiple interactions. Flowers interact with both pollinators and floral herbivores, and the flower‐pollinator interaction may be modified by indirect effects of floral herbivores (i.e., florivores) on flower traits such as flower size attracting pollinators. To explore whether flower size affects the flower‐pollinator interaction, we used Eurya japonica flowers. We examined whether artificial florivory decreased fruit and seed production, and also whether flower size affected florivory and the number of floral visitors. The petal removal treatment (i.e., artificial florivory) showed approximately 50% reduction in both fruit and seed set in natural pollination but not in artificial pollination. Furthermore, flower size increased the number of floral visitors, although it did not affect the frequency of florivory. Our results demonstrate that petal removal indirectly decreased 75% of female reproductive output via decreased flower visits by pollinators and that flower size mediated indirect interactions between florivory and floral visitors.     

Geographic variation in oviposition preference for male and female host plants in a geometrid moth: implications for evolution of host choice

Several dioecious plant species exhibit sexual dimorphisms in defensive traits. However, the effects of sexual dimorphism on defense against herbivores remain poorly understood. Eurya japonica (Thunb.) (Theaceae) is a dioecious shrub that shows sexual dimorphism in the chemical defense of flower buds. Female calyces contain higher concentrations of total phenolics and condensed tannins than do male calyces. Male flower buds are edible for a florivore moth, Chloroclystis excisa (Butler) (Lepidoptera: Geometridae), whereas the female flower buds are lethal to the moth larvae. The moths prefer to oviposit on male over female E. japonica flower buds. As the moths also occur in areas lacking E. japonica, we tested whether the oviposition preference for E. japonica flower sex differed between moths sympatric and allopatric with E. japonica. The moths sympatric with E. japonica showed a stronger preference for male E. japonica than the moths allopatric with E. japonica. Our phylogeographic study using mitochondrial cytochrome oxidase subunit I gene sequences revealed little genetic differentiation between moth populations sympatric and allopatric with E. japonica. These results suggest that the adaptive oviposition preference for flower sex of E. japonica has evolved rapidly in C. excisa.     

Uncovering different parameters influencing florivory in a specialist herbivore

1. It has become increasingly recognised that several herbivores switch from folivory (leaf‐feeding) to florivory (flower‐feeding) during larval development. Yet, it remains poorly understood which cues influence this behaviour, whether a switch to florivory is consistently shown on different hosts, and to what extent florivory could be hindered by plant traits. 2. Using the sawfly Athalia rosae and two Brassicaceae differing in architecture and surface structure, the cues that influence larval movement to the flowers were investigated. A broad set of behavioural assays was employed and physical and chemical plant traits potentially affecting the larvae were analysed. Furthermore, the consequences of folivory versus florivory on insect performance were studied. 3. The larvae preferred flowers over leaves. Consumption of particular flower parts correlated partly with measured plant traits such as glucosinolate distribution. Visual cues were of higher importance than volatile cues. The initial position of newly hatched larvae on plants influenced the probability of the larvae reaching the flowers during development. Trichomes and surface waxes hindered the larvae from moving upwards to the flowers. Larvae developed slower and gained less body mass when feeding on inflorescences of Brassica nigra than when feeding on leaves, in contrast to the patterns observed before on Sinapis alba, where florivory led to an improved performance. 4. This study demonstrates that florivory depends on various host plant traits. It reveals new insights into different parameters influencing this multifaceted phenomenon and into the expected impact on the ecology and fitness of both the attacking herbivores and the plants.     

Florivory: the intersection of pollination and herbivory

Plants interact with many visitors who consume a variety of plant tissues. While the consequences of herbivory to leaves and shoots are well known, the implications of florivory, the consumption of flowers prior to seed coat formation, have received less attention. Herbivory and florivory can yield different plant, population and community outcomes; thus, it is critical to distinguish between these two types of consumption. Here, we consider the ecological and evolutionary consequences of florivory. A growing number of studies recognize that florivory is common in natural systems and in some cases surpasses leaf herbivory in magnitude and impact. Florivores can affect male and female plant fitness via direct trophic effects and through altered pathways of species interactions. In particular, florivory can affect pollination and have consequences for plant mating and floral sexual system evolution. Plants are not defenceless against florivore damage. Concepts of resistance and tolerance can be applied to plant–florivore interactions. Moreover, extant theories of plant chemical defence, including optimal defence theory, growth rate hypothesis and growth differentiation–balance hypothesis, can be used to make testable predictions about when and how plants should defend flowers against florivores. The majority of the predictions remain untested, but they provide a theoretical foundation on which to base future experiments. The approaches to studying florivory that we outline may yield novel insights into floral and defence traits not illuminated by studies of pollination or herbivory alone.     

The selective florivory of Erioscelis emarginata matches its role as a pollinator of Philodendron

Flowers commonly face the dilemma of needing to be attractive to pollinators but unattractive to nectar robbers or florivores. When the pollinator has chewing mouthparts, there is also a considerable risk of the pollinator consuming the flowers. Scant field records indicate that the florivorous beetle Erioscelis emarginata (Mannerheim) (Coleoptera: Scarabaeidae: Cyclocephalini), which pollinates Philodendron spp., feeds selectively on the sterile staminate flowers. Here, the hypothesis was tested that E. emarginata prefers sterile staminate flowers of Philodendron bipinnatifidum Schott and Philodendron melinonii Brongn. ex Regel (Araceae) over fertile flowers. This study also examined whether such a preference exists regardless of the proportion of fertile vs. sterile flowers in each Philodendron species. Analysis of nutritional and defensive compounds plus scanning electron microscopy on each flower type were performed. The feeding preference of florivores for either P. bipinnatifidum or P. melinonii was also examined. In both species, sterile flowers were significantly more consumed than fertile ones. The sterile zone of P. bipinnatifidum was significantly larger than that of P. melinonii, and sterile staminate flowers of both plants were consumed at similar rates. Calcium oxalate was markedly low in sterile flowers, which also presented smaller papillae than the other flowers. This study presents evidence that the balance between pollination and florivory has most likely evolved through a strong feeding preference for less‐defended sterile flowers regardless of the size of the sterile zone.     

Effects of florivory on floral volatile emissions and pollination success in the wild parsnip

In addition to reducing fitness by consuming reproductive structures, florivores may also reduce plant fitness by altering interactions with pollinators. To date, the effects of florivore activity on the volatile profile of flowers and subsequent attractiveness to pollinators have not been extensively investigated. In this study, we had three specific objectives: to determine the impact of florivory by the parsnip webworm Depressaria pastinacella on the floral volatile profile of the wild parsnip Pastinaca sativa, to ascertain the mechanisms by which florivory changes the volatile profile, and to estimate the consequences of florivory on visitation by pollinators and eventual seed set. An overall indirect effect of webworms on seed set, that is, the effect of infestation on pollination success, was not detected. However, this overall lack of indirect effect masks the heterogeneity among individual plants. For seven of 14 plants examined, pollination success was altered by webworms, and in four of these plants the alteration in pollination success was consistent with webworm-altered visitation. Webworms significantly altered floral fragrance, in particular causing disproportionate increases in the emissions of octyl esters. Additionally, volatiles from webworm frass, which contains large amounts of the octyl ester metabolite n-octanol, may alter the floral fragrance in ways that change attractiveness of flowers to pollinators. This study suggests that the effects of florivores on plant fitness are not limited to the removal of floral units but may also involve alterations in floral volatile composition, through damage-induced release and detoxification of particular constituents, that affect visitation and pollination success. Handling Editor: Steve Johnson. An erratum to this article can be found at     

Pollinators shift to nectar robbers when florivory occurs,with effects on reproductive success in Iris bulleyana (Iridaceae)

• Studies have indicated that florivory and nectar robbing may reduce reproductive success of host plants. However, whether and how these effects might interact when plants are simultaneously attacked by both florivores and nectar robbers still needs further investigation.
• We used Iris bulleyana to detect the interactions among florivory, nectar robbing and pollination, and moreover, their effects on plant reproductive success. Field investigations and hand‐pollination treatments were conducted on two experimental plots from a natural population, in which Experimental plot was protected from florivores and Control plot was not manipulated.
• The flower calyx was bitten by sawflies to consume the nectary, and three bumblebee species were pollinators. In addition, the short‐tongued pollinator, Bombus friseanus, was the only robber when there was a hole made by a sawfly. The bumblebee had significantly shortened flower handling time when robbing, as compared to legitimate visits. Pollinator visitation and seed production decreased significantly in damaged flowers. However, seed production per flower after supplementary hand‐pollination did not differ significantly between damaged and undamaged flowers. Compared to the Experimental plot, bumblebees visited fewer flowers per plant in a foraging bout in the Control plot.
• The flowers damaged by florivory allowed B. friseanus to shift to a nectar robber. Florivory and nectar robbing collectively decreased plant reproductive success by consuming nectar resources, which may reduce attractiveness to pollinators of the damaged flowers. However, the changes in pollinator behaviour might be beneficial to the plant by reducing the risk of geitonogamous mating.

     

Florivory by a floriphilic katydid,Phaneroptera brevis,induces changes in a leaf trait in Lantana camara

1. Plants can induce a response when they are attacked by herbivores. Although the induction of responses by herbivory in both flowers and leaves is relatively well studied, whether florivory (feeding of flowers) can also induce responses in flowers and leaves is less well explored and there are still unanswered questions. These include whether plants exhibit different levels of induced responses depending on the length of exposure to the florivores. 2. To address this knowledge gap, this study used a tropical floriphilic katydid, Phaneroptera brevis, and its non‐native food plant, Lantana camara. Nursery experiments were performed in which dry matter content and anthocyanin concentration of the flower (corolla and stamens), leaf dry matter content, and leaf blade punch resistance were measured at three time phases before and after exposing the plant to the katydid individuals for 0–7 days. 3. It was demonstrated that increasing the length (days) of exposure to the katydid individual leads to higher levels of induced plant response (leaf blade punch resistance), but only in the leaves. It was also shown that higher levels of induced plant response owing to the increase in the length of exposure to the katydid individual was not observed beyond the first set of leaves developed after the exposure. 4. These results address the knowledge gap and show that plants can exhibit different levels of induced responses depending on the length of exposure to florivores. This study thus highlights the far‐reaching importance of florivory on plants.     

Edaphic factors and plant–insect interactions: direct and indirect effects of serpentine soil on florivores and pollinators

Edaphic factors can lead to differences in plant morphology and tissue chemistry. However, whether these differences result in altered plant–insect interactions for soil-generalist plants is less understood. We present evidence that soil chemistry can alter plant–insect interactions both directly, through chemical composition of plant tissue, and indirectly, through plant morphology, for serpentine-tolerant Mimulus guttatus (Phrymaceae). First, we scored floral display (corolla width, number of open flowers per inflorescence, and inflorescence height), flower chemistry, pollinator visitation and florivory of M. guttatus growing on natural serpentine and non-serpentine soil over 2 years. Second, we conducted a common garden reciprocal soil transplant experiment to isolate the effect of serpentine soil on floral display traits and flower chemistry. And last, we observed arrays of field-collected inflorescences and potted plants to determine the effect of soil environment in the field on pollinator visitation and florivore damage, respectively. For both natural and experimental plants, serpentine soil caused reductions in floral display and directly altered flower tissue chemistry. Plants in natural serpentine populations received fewer pollinator visits and less damage by florivores relative to non-serpentine plants. In experimental arrays, soil environment did not influence pollinator visitation (though larger flowers were visited more frequently), but did alter florivore damage, with serpentine-grown plants receiving less damage. Our results demonstrate that the soil environment can directly and indirectly affect plant–mutualist and plant–antagonist interactions of serpentine-tolerant plants by altering flower chemistry and floral display.     

Florivory by the occupants of phytotelmata in flower parts can decrease host plant fecundity

Some types of plant accumulate liquid in their inflorescences creating phytotelmata. These environments protect the flowers against florivory, although they may be colonized by aquatic or semi-aquatic florivorous insect larvae, whose effects on the fitness of the plants remain unclear. We tested the hypothesis of floral antagonism by the occupants of phytotelmata, which predicts that florivory by the occupants of the phytotelmata represents a cost to the female fitness of the plant, reducing its fecundity. We manipulated experimentally the infestation by 3 florivores larvae species occupants of phytotelmata in inflorescences of Heliconia spathocircinata (Heliconiaceae) to test for negative direct trophic effects on the fecundity of the flowering and fruiting bracts. We found that the foraging of the hoverfly (Syrphidae) and moth (Lepidoptera) larvae in the inflorescences contributed to a decline in the fecundity of the plant. While the lepidopteran impacted fecundity when foraging in both flowering and fruiting bracts, the syrphid only affected the fruiting bracts, which indicates that the nectar and floral tissue are the principal resource exploited by the hoverfly. By contrast, soldier fly (Stratiomyidae) had a neutral effect on fecundity, while foraging in flowering or fruiting bracts. These findings corroborate our hypothesis, that herbivory by the larval occupants represents cost to the host plant having phytotelmata. The negative influence of this foraging on plant fecundity will nevertheless depend on the consequences of the exploitation of resources, which vary considerably in ephemeral habitats such as the phytotalmanta of flower parts.     

Evolution of tolerance in an invasive weed after reassociation with its specialist herbivore

The interaction between the European wild parsnip Pastinaca sativa and its coevolved florivore the parsnip webworm Depressaria pastinacella, established in North America for over 150 years, has resulted in evolution of local chemical phenotype matching. The recent invasion of New Zealand by webworms, exposing parsnips there to florivore selection for the first time, provided an opportunity to assess rates of adaptive response in a real‐time experiment. We planted reciprocal common gardens in the USA and NZ with seeds from (1) US populations with a long history of webworm association; (2) NZ populations that had never been infested and (3) NZ populations infested for 3 years (since 2007) or 6 years (since 2004). We measured impacts of florivory on realized fitness, reproductive effort and pollination success and measured phenotypic changes in infested NZ populations relative to uninfested NZ populations to determine whether rapid adaptive evolution in response to florivory occurred. Irrespective of country of origin or location, webworms significantly reduced plant fitness. Webworms reduced pollination success in small plants but not in larger plants. Although defence chemistry remained unchanged, plants in infested populations were larger after 3–6 years of webworm florivory. As plant size is a strong predictor of realized fitness, evolution of large size as a component of florivore tolerance may occur more rapidly than evolution of enhanced chemical defence.     

Wasp florivory decreases reproductive success in an epiphytic bromeliad

Flower predation or florivory may alter the sexual expression, floral display, and reduce the reproductive success in plants. In this article, we estimated the effect of florivory on the reproductive success of the epiphytic bromeliad Werauhia gladioliflora during 2001–2003 in a premontane area in Costa Rica. Floral buds of W. gladioliflora are attacked by the wasp Eurytoma werauhia (Eurytomidae), which inhibits flower anthesis. Nearly, a quarter of the sampled population flowers were lost due to wasp infection and it accounted for nearly 70% of the reduction in fruit set. Flowers located on the inflorescence upper segment had a higher attack incidence. In the studied population, florivory has a major role in the reproductive success of W. gladioliflora. Florivory on epiphytic plants is scarcely reported in the literature, but evidence suggests that this phenomenon is more spread in the epiphytic community. Whether florivory in W. gladioliflora is a selective pressure influencing the reproductive success or a localized factor operating at the studied population is a subject requiring additional data.     

Selection of plant parts by Depressaria multifidae (Lep., Oecophoridae) on its seasonally-restricted hostplant, Lomatium grayi (Umbelliferae)

ABSTRACT.

• 1 Depressaria multifidae Clarke feeds on a broader variety of Umbelliferae plant parts than other Depressaria species.
• 2 Early instar larvae feed in the sheaths surrounding floral buds and leaves. Later instar larvae feed in the sheaths and floral stems and on flowers and leaves.
• 3 Floral stems bored by larvae had significantly larger basal stem diameters than floral stems that were not bored. Smaller stems usually have umbels with only male flowers, and wither after flowering, too soon for larvae to complete development. In contrast, larger stems often have umbels with some hermaphroditic flowers, which remain green and erect long enough for larvae to complete development. Hence, selection may favour larvae that bore only in relatively large stems.
• 4 In the laboratory, larvae fed sheaths with enclosed floral buds, flowers, or leaves all pupated at the same weight, but larvae fed floral stems pupated at a significantly lower weight. Larval and pupal development time was the same on all plant parts.
• 5 In the field, larvae restricted to a single umbel throughout development pupated at the same weight as those restricted to a single leaf.
• 6 Unlike in other Depressaria species, nitrogen levels only partly correspond to the pattern of use of plant parts in D.multifidae. Nitrogen values varied as follows: floral buds > immature leaves ≥ flowers > floral stalks > sheaths excluding floral buds or leaves.
• 7 The broad variety of plant parts used by D.multifidae may result partly from the problem of feeding on a small, seasonally restricted hostplant; the greater use of sheaths and floral stems than in other Depressaria species may result from selection for safety from parasites or predators.
• 8 The results for D.multifidae indicate that the way in which an insect feeds on a plant species can vary broadly even at a single site.

     

Floral affinity and benefits of dietary mixing with flowers for a polyphagous scarab, <Emphasis Type="Italic">Popillia japonica</Emphasis> Newman

Many generalist herbivores, especially adult beetles, are facultative florivores, feeding on leaves but readily accepting floral tissues when available. We speculated that day-flying beetles with high energetic requirements would benefit from dietary mixing with nutrient-rich flower tissues and favor them during foraging. We tested that Floral Affinity Hypothesis with Popillia japonica, a day-active ruteline scarab that feeds intermittently throughout its adult life on multiple plant species. In field tests with six species of flowering hosts, far more landings occurred on flowers than on foliage for all plants except Hibiscus syriacus which bears flowers along the main stem rather than terminally. Trials with elevated plants showed that height of the floral display contributes to beetles landing on flowers. Flower petals generally were preferred over leaves in laboratory choice tests. Nitrogen and water content were comparable or higher in foliage than in petals, but plant sugars were much higher in petals. Longevity and fecundity of beetles provided single-plant diets of Hibiscus, Rosa × hybrida, or Trifolium flowers for 3 weeks were as high, or higher, than for beetles fed foliage of Tilia cordata, a highly suitable resource. As expected, rotating flowers or Tilia foliage with marginally suitable Quercus palustris foliage enhanced those parameters relative to a diet of Quercus alone, but beetles provided high-quality Tilia foliage also benefitted from dietary mixing with flowers. Nearly all past dietary mixing studies concerned immature insects, for which growth rate is paramount. Opportunistic florivory by adult beetles represents a type of dietary mixing wherein the premium may be calorie-rich food for fueling flight muscles, with ensuing reproductive benefits.     

Between florivory and herbivory: inefficacy of decision‐making by generalist floriphilic katydids

1. Florivory, which is less studied but as equally widespread as herbivory, can have effects on plant and floral trait adaptations, individual fitness, and community interactions. However, there are still knowledge gaps in our understanding of florivory, including the role of neural constraints and diet specialisation of florivores in floral resource utilisation. 2. According to the neural constraint hypothesis, a generalist flower‐visiting katydid is expected to have lower decision‐making efficacy in feeding when subjected to the presence of both capitula and leaves, compared to the presence of either one of the two resources. 3. In the present study, experiments using the katydid, Phaneroptera brevis, and the plant, whiteweed, Ageratum conyzoides, were carried out to examine the foraging behaviour of the katydid to test our hypothesis. The results confirmed the prediction of the neural constraint hypothesis. 4. The decision‐making efficacy was generally lowered when the katydid was presented with the choice for both the resource that is preferred (capitula) and less preferred (leaves). It was also shown that Phaneroptera brevis is floriphilic, as it prefers capitula to leaves. 5. In conclusion, the first evidence of neural constraint in florivory is provided and suggests that more can be explored into the effects of neural constraints and diet specialisation in floral resource utilisation.     

Flower visitation patterns of the coexisting honey bees Apis cerana japonica and Apis mellifera (Hymenoptera: Apidae)

We compared flower visitation patterns of two coexisting honey bees, Apis mellifera Linnaeus and Apis cerana japonica Radoszkowski, on 20 plant species, including three exotics, under natural conditions in Nara, Japan, from April to August 2012. We also measured flower color based on bee color vision (15 flower species), nectar volume (nine species) and nectar concentration (eight species). Flowers colored white, pink, red, purple and cream were classified as bee‐blue‐green, and yellow was classified as bee‐green. Apis cerana visited 14 plant species and A. mellifera visited 11. Although the two Apis species are similar in morphology, they visited different plants: in particular, A. cerana visited native plant species more often than did A. mellifera. Both A. mellifera and A. cerana visited not only nectariferous flowers but also those with no nectar. We also found different visitation patterns between A. cerana and A. mellifera: Apis cerana more often visited flowers with smaller color angle (bee‐blue‐green), lower chroma and higher brightness, and flowers secreting nectars of higher concentration and smaller volume than did A. mellifera.     

Diapause dynamics, seasonal phenology, and pupal color dimorphism of Papilio polyxenes in southern Florida, USA

In the European grapevine moth, Lobesia botrana (Denis and Schiffermüller) (Lepidoptera: Tortricidae), it has recently been shown that volatiles emitted from the main host plant, grapevine, are attractive to adult females. Here, using wind tunnel experiments, we tested the attractiveness of various grapevine, Vitis vinifera L. (Vitaceae), plant parts at different phenological stages, including ripe berries infested with the pathogenic fungus Botrytis cinerea (Persoon: Fries) (Sclerotiniaceae) to laboratory‐reared virgin and mated male and female moths. We also tested the attractiveness of the non‐host plant, tansy [Tanacetum vulgare (L.) (Asteraceae)], as flowers and flower volatiles were previously shown to be attractive to L. botrana females in the field. Mated female moths were the only adults to exhibit upwind orientation to grape plant parts in the flight tunnel. The most attractive parts of the grapevine plants were leaves, flower buds, and ripe berries. No attraction was observed to flowers. This corresponds to the phenological stages available when females of the 2–3 generations during a year are present in the field. No attraction was observed to leaves and flowers of tansy.     

Variation in pollen limitation and floral parasitism across a mating system transition in a Pacific coastal dune plant: evolutionary causes or ecological consequences?

Background and Aims Evolutionary transitions from outcrossing to self-fertilization are thought to occur because selfing provides reproductive assurance when pollinators or mates are scarce, but they could also occur via selection to reduce floral vulnerability to herbivores. This study investigated geographic covariation between floral morphology, fruit set, pollen limitation and florivory across the geographic range of Camissoniopsis cheiranthifolia, a Pacific coastal dune endemic that varies strikingly in flower size and mating system.Methods Fruit set was quantified in 75 populations, and in 41 of these floral herbivory by larvae of a specialized moth (Mompha sp.) that consumes anthers in developing buds was also quantified. Experimental pollen supplementation was performed to quantify pollen limitation in three large-flowered, outcrossing and two small-flowered, selfing populations. These parameters were also compared between large- and small-flowered phenotypes within three mixed populations.Key Results Fruit set was much lower in large-flowered populations, and also much lower among large- than small-flowered plants within populations. Pollen supplementation increased per flower seed production in large-flowered but not small-flowered populations, but fruit set was not pollen limited. Hence inadequate pollination cannot account for the low fruit set of large-flowered plants. Floral herbivory was much more frequent in large-flowered populations and correlated negatively with fruit set. However, florivores did not preferentially attack large-flowered plants in three large-flowered populations or in two of three mixed populations.Conclusions Selfing alleviated pollen limitation of seeds per fruit, but florivory better explains the marked variation in fruit set. Although florivory was more frequent in large-flowered populations, large-flowered individuals were not generally more vulnerable within populations. Rather than a causative selective factor, reduced florivory in small-flowered, selfing populations is probably an ecological consequence of mating system differentiation, with potentially significant effects on population demography and biotic interactions.