Isolation and characterization of highly polymorphic microsatellite markers from the marine invasive species Crepidula fornicata (Gastropoda: Calyptraeidae)

Many marine organisms have pelagic larvae and these are often important agents of dispersal and establishment of exotic species. The larval phase and the hermaphroditic reproductive system of the invasive marine gastropod Crepidula fornicata are crucial in determining the success of this species along the European coasts. To analyse these factors, we developed seven microsatellite loci specific to C. fornicata. On the same set of individuals, the microsatellite loci exhibited a greater level of polymorphism than previously studied allozyme markers and, thus, will permit fine‐scale analysis and larval pool studies.     

Six weeks in the life of a reproducing army ant colony: male parentage and colony behaviour

The army ant Eciton burchellii is one of the most conspicuous ant species in New World tropical forests, but studies of colony life histories have been hampered by the nomadic lifestyle of these ants, which alternate between a nomadic phase when the colony relocates frequently, and a statary phase when the colony remains at a fixed site. Here we report on a colony from Venezuela that we studied continuously for six weeks, from the time that the queen produced a reproductive brood until the adult reproductives emerged and the colony entered the next cycle. Our findings support the contention that reproductive larvae develop faster than worker larvae, and that the nomadic phases of colonies with reproductive broods are significantly shorter than those of colonies with worker broods. This strongly suggests that the onset of pupation is linked to the onset of the statary phase. We used microsatellite genotyping to accurately identify male and queen larvae and we describe how they can be distinguished morphologically. Using the same genetic markers, we determined the parentage of 81 males produced by this colony. Only one of the males had a genotype that could not be directly derived from the observed queen genotype, but this mismatch is most probably due to a single mutation at one of the microsatellite loci, rather than this male being a worker son. We therefore conclude that this colony provides no evidence that workers lay eggs that develop into adult males in the presence of the queen, confirming the results of an earlier study on male parentage in an Old World army ant. Received 16 November 2006; revised 15 January 2007; accepted 16 January 2007.     

Inheritance of microsatellite DNA in bisexual gynogenesis complex of Fangzheng silver crucian carp,Carassius auratus gibelio (Bloch)

Five gynogenetic progeny groups of silver crucian carp Carassius auratus gibelio were produced and sex ratios (males:total progeny) of each of the progeny groups were analysed. About 110 males and 366 females were genotyped at 15 microsatellite loci for comparison with their parents to (1) verify the gynogenesis status of Fangzheng C. auratus gibelio, (2) detect the incorporation of paternal genetic material into the offspring and (3) study the possible association of genetic exchange at microsatellite loci with the existence of sex. The sex ratios in progenies of five groups were highly variable, but all had significant female bias. The sex ratio ranged from 0 to 0·37. Significant differences in the sex ratio within and between groups were also found. Microsatellite genotyping at 15 loci showed that 100 and 97% of the progeny shared the same genotype with the mother in four groups and in one group, respectively, confirming that gynogenesis is the general mechanism of reproduction in C. auratus gibelio. However, 0·63% of all offspring did show incorporation of paternal genetic material. No single loci tested were associated with the occurrence of male progeny, indicating unknown genetic mechanisms for sex determination in C. auratus gibelio.     

Sex determination in the androdioecious barnacle Scalpellum scalpellum (Crustacea: Cirripedia)

How androdioecy (coexistence of hermaphrodites and males) is maintained is still poorly understood. Therefore, sex determination was studied in the androdioecious barnacle Scalpellum scalpellum L. First, 247 cypris larvae from seven broods were investigated for sexual dimorphism in larval morphology and found to be all identical. Second, experiments with cyprids showed that males and hermaphrodites differ distinctly in morphology as soon as 4–5 days after settlement. Third, 14 252 cyprids were allowed to settle on the bottom of their culture cages, and all surviving larvae developed into hermaphrodites and none into dwarf males. Fourth, larvae settled in hermaphrodite receptacles (i.e. future males) were removed at increasing intervals after settlement to study if the male and hermaphrodite sexual expressions are fixed or plastic. All larvae became dwarf males if allowed to stay there for more than 8 h after settlement. But if removed within 3 h after settlement, half of them developed into hermaphrodites. We conclude that an environmental sex determination mechanism operates in S. scalpellum. Together with a 1:1 hermaphrodite/male ratio observed in previously reported experiments offering a free choice of settlement, we suggest that all larvae are potential hermaphrodites, but only 50% can settle in hermaphrodite receptacles and yield males.     

A field study of potential ecological costs of resistance by ‘stem ducking’ in tall goldenrod,Solidago altissima

Culex quinquefasciatus Say (Diptera: Culicidae) is an abundant urban mosquito that is the vector of filariasis. Breeding in septic tanks, where there are very high levels of bacterial food, it is likely to have a different reaction to crowding compared with other mosquitoes. To test for the presence and type of crowding effects, four larval densities of C. quinquefasciatus varying from 0.4 to 3.2 larvae ml^?1 of water were reared in tubes. Mortality was found to greatly increase at densities above 0.8 larvae, whereas larval duration increased even above 0.4 larvae ml^?1. Changing the water in the tubes daily gave a small (but significant) response in reducing mortality and larval duration. However, when larvae kept at a low density shared the same water with larvae at high density, there was no chemical influence on their growth rate and mortality. The effect of crowding was primarily due to physical disturbances between larvae. When larvae were kept at a high density in the same volume of water, but in shallow trays with a large surface area and therefore much less contact between them, mortality was the same as for the lowest density. There was still, however, a significant increase in larval duration from 8.6 days at 0.4 larvae ml^?1 to 12.1 days at 3.2 larvae ml^?1. It is therefore concluded that the larvae respond to physical rather than chemical factors by prolonging larval development and having some increase in mortality.     

A comparison of honeybee (Apis mellifera) queen,worker and drone larvae by RNA‐Seq

Honeybees (Apis mellifera) have haplodiploid sex determination: males develop from unfertilized eggs and females develop from fertilized ones. The differences in larval food also determine the development of females. Here we compared the total somatic gene expression profiles of 2-day and 4-day-old drone, queen and worker larvae by RNASeq. The results from a co-expression network analysis on all expressed genes showed that 2-day-old drone and worker larvae were closer in gene expression profiles than 2-day-old queen larvae. This indicated that for young larvae (2-day-old) environmental factors such as larval diet have a greater effect on gene expression profiles than ploidy or sex determination. Drones had the most distinct gene expression profiles at the 4-day larval stage, suggesting that haploidy, or sex dramatically affects the gene expression of honeybee larvae. Drone larvae showed fewer differences in gene expression profiles at the 2-day and 4-day time points than the worker and queen larval comparisons (598 against 1190 and 1181), suggesting a different pattern of gene expression regulation during the larval development of haploid males compared to diploid females. This study indicates that early in development the queen caste has the most distinct gene expression profile, perhaps reflecting the very rapid growth and morphological specialization of this caste compared to workers and drones. Later in development the haploid male drones have the most distinct gene expression profile, perhaps reflecting the influence of ploidy or sex determination on gene expression.     

Fine‐mapping of a locus on linkage group 23 for sex determination in Nile tilapia (Oreochromis niloticus)

Genetic markers in tilapia species associated with loci affecting sex determination (SD), sex‐specific mortality or both were mapped to linkage groups (LG) 1, 2, 3, 6 and 23. The objective of this study was to use these markers to fine‐map the locus with the greatest effect on SD in Oreochromis niloticus. Our parental stock, full‐sibs of Nile tilapia (Swansea origin), were divided into three groups: (i) untreated, (ii) feminized by diethylstilbestrol and (iii) masculinized by 17α‐methyltestosterone. We analysed the first group for association of microsatellite markers representing these five LGs. The strongest association with gender was found on LG23 for marker UNH898 (χ²; P = 8.6 × 10^?5). Allele 276 was found almost exclusively in males, and we hypothesized that this allele is a male‐associated allele (MAA). Sex‐reversed individuals were used for mating experiments with and without the segregating MAA. Mating of individuals lacking the MAA resulted in all‐female progeny. Mating of two heterozygotes for MAA gave rise to 81 males and 30 females. Analysis of association between gender and genotypes identified the MAA in 98.6% of males as opposed to 8.0% of females (χ²; P = 2.5 × 10^?18). Eight markers that flank UNH898 were genotyped to map the locus on LG23 within a confidence interval of 16–21 cM. Mating of homozygous individuals for MAA is underway for production of all‐male populations.     

Sexual reproduction of the brooding sponge <Emphasis Type="Italic">Rhopaloeides odorabile</Emphasis>

Sexual reproduction of Rhopaloeides odorabile, a common Great Barrier Reef sponge, was quantified using histological sections from samples collected over two reproductive seasons. Rhopaloeides odorabile is viviparous and gonochoristic with a male biased sex ratio (2.5:1). Commencement and cessation of gametogenesis coincides with rising and falling sea surface temperatures (≈24–29°C). Spermatogenesis occurs from October until January. Females initiate oogenesis in September with the asynchronous development of oocytes, embryos and larvae occurring within the brood chambers. A larval release period of 5–6 weeks occurs during January and February. The minimum size of reproductive individuals was 176 cm³ for females and 192 cm³ for males. The total reproductive output for both sexes shows a positive correlation with size. A relative reproductive output index quantified the maximum reproductive investment at approximately 1 and 3% of the total choanoderm for females and males, respectively, which represents a lower range of reproduction in comparison to other viviparous sponges. Low reproductive output in R. odorabile may be offset by an extended spawning period, alleviating the risk of releasing larvae in potentially adverse conditions via one synchronised spawning event and increasing overall larval survival.     

Gender Specific Brood Cells in the Solitary Bee Colletes halophilus (Hymenoptera; Colletidae)

We studied the reproductive behaviour of the solitary bee Colletes halophilus based on the variation in cell size, larval food amount and larval sex in relation to the sexual size dimorphism in this bee. Brood cells with female larvae are larger and contain more larval food than cells with males. Occasionally males are reared in female-sized cells. We conclude that a female C. halophilus in principal anticipates the sex of her offspring at the moment brood cell construction is started. Additionally a female is able to ‘change her mind’ about the sex of her offspring during a single brood cell cycle. We present a model that can predict the sex of the larvae in an early stage of development.     

Genetic sex assignment in wild populations using genotyping‐by‐sequencing data: A statistical threshold approach

Establishing the sex of individuals in wild systems can be challenging and often requires genetic testing. Genotyping‐by‐sequencing (GBS) and other reduced‐representation DNA sequencing (RRS) protocols (e.g., RADseq, ddRAD) have enabled the analysis of genetic data on an unprecedented scale. Here, we present a novel approach for the discovery and statistical validation of sex‐specific loci in GBS data sets. We used GBS to genotype 166 New Zealand fur seals (NZFS, Arctocephalus forsteri) of known sex. We retained monomorphic loci as potential sex‐specific markers in the locus discovery phase. We then used (i) a sex‐specific locus threshold (SSLT) to identify significantly male‐specific loci within our data set; and (ii) a significant sex‐assignment threshold (SSAT) to confidently assign sex in silico the presence or absence of significantly male‐specific loci to individuals in our data set treated as unknowns (98.9% accuracy for females; 95.8% for males, estimated via cross‐validation). Furthermore, we assigned sex to 86 individuals of true unknown sex using our SSAT and assessed the effect of SSLT adjustments on these assignments. From 90 verified sex‐specific loci, we developed a panel of three sex‐specific PCR primers that we used to ascertain sex independently of our GBS data, which we show amplify reliably in at least two other pinniped species. Using monomorphic loci normally discarded from large SNP data sets is an effective way to identify robust sex‐linked markers for nonmodel species. Our novel pipeline can be used to identify and statistically validate monomorphic and polymorphic sex‐specific markers across a range of species and RRS data sets.     

Female-biased sex ratio in a wild bruchid seed-predator, Kytorhinus sharpianus. I. Larval competition and other factors

Abstract.

• 1 A wild bruchid seed-predator, Kytorhinus sharpianus, has a complex life cycle consisting of bi- and trivoltinism on a wild leguminous plant, Sophola flavescens. Observations of adults showed significant female-biased sex ratios (from 1:2 to 1:6) for nine generations over 4 years.
• 2 To investigate the potential effects of larval competition on the sex ratio, we altered the number of hatched eggs per seed and counted emergent males and females under laboratory conditions. Although only one adult could emerge per seed, the ratio of the females that emerged increased with the number of hatched eggs per seed. However, the sex ratio was not significantly different from 1:1 in the case of one hatched egg per seed.
• 3 We dissected seeds bearing two hatched eggs at regular intervals, and classified the surviving and the dead larvae according to their developmental stage. Over time, one larva within each seed always survived, while the other larva died from the second to fourth instar before the seed resource became exhausted.
• 4 In order to study the effects of the difference in the stages of two larvae in a seed on the emergence sex ratio, we manipulated intervals between the first and second ovipositions in the laboratory. As the difference in developmental stages of the two larvae increased, the closer to 1:1 the emergence sex ratio became.
• 5 Field observations, however, showed that about 60% of infested seeds were bored by only one K.sharpianus larva. This suggests that female dominance in larval competition within a seed may be relatively unimportant in causing the female-biased sex ratio in the field.

     

Isolation and characterization of eight polymorphic microsatellite markers from pink conch (Strombus gigas)

Many marine organisms have pelagic larvae, and these are often important agents of dispersal. The larval phase and the multiple paternity that occur in marine gastropods such as Strombus gigas are crucial for the success of this species throughout the Caribbean Sea. To analyse these factors, we developed eight microsatellite loci specific to S. gigas. On the same set of individuals, the microsatellite loci exhibited a greater level of polymorphism than previously studied allozyme markers and thus, will permit fine‐scale analysis and larval pool studies.     

Inheritance of Microsatellite DNA Markers in the Pacific Abalone <Emphasis Type="Italic">Haliotis discus hannai</Emphasis>

Microsatellite markers have been developed for a variety of abalones, and locus-specific homozygote excesses at population level have been recorded for microsatellite loci. To ascertain whether null alleles exist at microsatellite loci in the Pacific abalone, we studied the mode of inheritance of 7 microsatellite loci in 4 families with a reciprocal cross of 2 females × 2 males. All loci segregated codominantly, but only 3 loci (Hdh1321, Hdh78, and Hdd108C) conformed to Mendelian segregation and can be used for parental analysis and population genetic studies. When null alleles were considered, 2 loci (Hdh1761 and Hdh1457) confirmed Mendelian expectations in all families, while the remaining 2 loci (Hdd114B and Hdd229) showed deviation from Mendelian segregation in at least one family even though null alleles were considered. These results indicated the need to test the inheritance pattern for microsatellite markers in abalones before using them for population genetic or parentage analysis.     

Veligers from the nudibranch <Emphasis Type="Italic">Dendronotus</Emphasis><Emphasis Type="Italic">frondosus</Emphasis> show shell growth and extended planktonic period in laboratory culture

The planktonic period of planktotrophic veliger larvae from the nudibranch Dendronotus frondosus was characterized by laboratory culture methods. Larvae in culture successfully metamorphosed at 73–86 days after hatching. These veligers have Type 2 (Thompson) larval shells that significantly increased in length over the first 7–14 days after hatching. Direct observations of the development of nudibranch larvae with Type 2 protoconchs are limited, and these data help clarify previous attempts to correlate shell type and growth with minimum planktonic periods. Although these are not absolute values for the planktonic period of D. frondosus larvae, these data show the potential for extended larval dispersal and may help explain reports of an extensive geographic range in north-temperate waters for this species.     

Age,growth and hatch dates of ingressing larvae and surviving juveniles of Atlantic menhaden Brevoortia tyrannus

Ages, growth and hatch dates of ingressing Brevoortia tyrannus larvae were determined in a 3 year sampling survey at the mouth of the Chesapeake Bay, U.S.A. To determine if otolith‐aged cohorts had variable relative survival, hatch dates of summer‐caught young‐of‐the‐year (YOY) juveniles collected throughout the Chesapeake Bay were compared with hatch dates of ingressing larvae. Modal total length of ingressing larvae was similar among years: 28 mm in 2005–2006 and 2007–2008, and 30 mm in 2006–2007. Ages of ingressing larvae ranged from 9 to 96 days post hatch (dph); mean ages were similar among years, but significantly older in 2006–2007 (50 dph) than in 2005–2006 (44 dph) and 2007–2008 (46 dph). Larval growth rates differed among years. Earliest growth, when larvae were offshore (0–20 dph), was faster in 2006–2007 (0·62 mm day^?1), than in 2005–2006 and 2007–2008 (0·55 mm day^?1 in these years). Subsequently, from 30 to 80 dph, growth was slowest in 2006–2007. Hatch dates of ingressing larvae occurred from September to March and 90% (2007–2008) to 98% (2006–2007) had hatched prior to 31 December. In contrast, most surviving YOY juvenile B. tyrannus had hatched in January to February, suggesting selective mortality of early‐hatched individuals, apparently during the overwinter, larval to juvenile transition period.     

Microsatellite markers developed using a next‐generation sequencing technique for Neotrogla spp. (Psocodea: Prionoglarididae), cave dwelling insects with sex‐reversed genitalia

The genus Neotrogla (Psocodea: Prinoglarididae) comprises four named species from Brazil. Females of this cave‐dwelling insect are characterized by a conspicuous penis‐like intromittent organ, termed a gynosome, which is inserted into the vagina‐like male genitalia during copulation. Another evolutionarily novel structure, the spermathecal plate, enables a female to simultaneously store two freshly deposited spermatophores (consisting of sperm and possibly nutritious substances) in her sperm storage organ (spermatheca). It is unknown whether the two spermatophores are derived from two different males. To investigate the mating ecology and population genetic structures of these insects with sex‐reversed genitalia, 16 novel highly polymorphic microsatellite loci were isolated and characterized based on ~2,275 Mbp genomic sequences from an undescribed Neotrogla species. Our first screening detected 99,888 candidate loci. Similar to other hemipteroid insects studied thus far, AAT motif microsatellites were conspicuously dominant. We further screened 99 sequences, for which 50 pairs of polymerase chain reaction primers were successfully designed. Sixteen of these primers successfully amplified products of the expected size in the 11 Neotrogla sp. individuals collected from two caves. The number of alleles per loci varied from two to nine, with no significant deviation from the Hardy–Weinberg equilibrium in either population. Although the caves sampled were only approximately 1 km apart, significant genetic differentiation was detected between the two populations. In total, 13, 12, 13 and 11 loci were cross‐amplified in N. aurora, N. brasiliensis, N. curvata and N. truncata, respectively, indicating the applicability of these microsatellite loci for metapopulation genetic studies in multiple Neotrogla species.     

Inter- and intra-specific differences in the number of larval instars in British populations of 24 species of stoneflies (Plecoptera)

1. Ontogenetic changes during the life cycle of aquatic insects are important not only in life‐history studies but also in evaluating food‐web structure. They require information on the growth and number of larval instars but such information is lacking for many species, including Plecoptera. Therefore, the chief objectives of the present study were to determine inter‐ and intra‐specific differences in the number of larval instars in British populations of 24 species of stoneflies, to test Dyar’s hypothesis that growth followed a geometric progression, and to synthesise this information with previously published values for four British species. 2. Larvae were reared at constant temperatures in the laboratory from eggs from 63 populations (one to six populations per species). First instars from each population were divided into three batches and each batch was reared at one of three constant temperatures. For each species, the rearing temperature and source population had no significant effect on the mean size of each larval instar. 3. The relationship between the geometric mean length of each instar and instar number was well described by an exponential equation (P < 0.001, r² > 0.9 for all species), thus supporting Dyar’s hypothesis. Only one species, Brachyptera risi, had the same number of instars for males and females (12–13). For the other 15 herbivorous species and the four smaller carnivorous ones, the number of instars was higher for females than males (range 11–16 for males, 12–17 for females). The larger size of the females was due to their additional instars, not a sex difference in growth rates. In contrast, there was a clear growth separation of the sexes after the 9th or 10th instar for the four largest carnivores. The number of larval instars was highest for these four species (range 16–19 for males, 18–23 for females), and females were much larger than males. 4. A multiple regression equation with data from the present and previous studies (n = 27) showed that variability in the mean length of the first instar and the maximum number of larval instars for each species accounted for 88% and 91% of the variability in the mean length of the final instar for males and females, respectively. 5. Values for Plecoptera in other countries were in general agreement with those in the present study, especially in the same families. Two old, but widely quoted, high values are doubtful. The present study and four previous ones provide a sound basis for ontogenetic studies on 28 species of Plecoptera and their role in aquatic ecosystems.     

Age,growth, and sex ratio among populations of least brook lamprey,Lampetra aepyptera,larvae: an argument for environmental sex determination

Synopsis Sex ratios of least brook lamprey,Lampetra aepyptera, larvae varied widely among 12 geographically-diverse streams of the eastern United States. The extremes were 29 and 71% male, and the proportion of males increased significantly with relative population density, which was estimated among the streams from the number of larvae collected per m2 of substrate. The skewed sex ratios were not likely due to differential mortality between the sexes or differential recruitment to the adult stock, since they were established at the time of gonadal differentiation (at ca. 2 years of age) and remained relatively constant over the subsequent 2–3 years of larval life. Furthermore, although females seemed to predominate in the oldest larval age class, thus appearing to metamorphose later than males, their numbers were small and were omitted from the overall sex ratio. Sex ratio did not vary significantly with water hardness, pH, annual thermal units, or latitude. The possible adaptive significance of density-dependent sex determination in lampreys, however, remains elusive. It has been proposed that growth-promoting conditions might yield female-biased sex ratios as a tactic for ensuring that relatively large individuals become females, thereby increasing their fecundity. As predicted, larval size at a given age was generally greater in low-density populations, but there was no relationship between sex ratio and larval size, and female larvae were not consistently larger than the males.     

Morphology and development of <Emphasis Type="Italic">Pteromalus cerealellae</Emphasis> (Ashmead) (Hymenoptera: Pteromalidae) on <Emphasis Type="Italic">Callosobruchus maculatus</Emphasis> (F.) (Coleoptera: Chrysomelidae)

Pteromalus cerealellae (Ashmead) (Hymenoptera: Pteromalidae) is an ectoparasitoid of several stored-product insect pests. Very little information has been published on its biology and development in host larvae, which typically are concealed within seeds. We documented the development of P. cerealellae within fourth instar larvae of its concealed host, Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) infesting cowpea seeds. The preimaginal life stages of the parasitoid were characterized for the first time using morphological structures revealed by microscopic techniques including scanning electron microscopy. Pteromalus cerealellae produces hymenopteriform eggs and larvae. Eggs hatch into 13-segmented first instar larvae with peripneustic condition of spiracles. The larvae have simple, tusk-like mandibles, whereas the mandibles of the pupae and the adults are of the conventional toothed types. Using statistical analyses of the sizes of the larval mandibles and head capsules in conjunction with reliable characters such as the number of exuviae on the body of parasitoid larvae, cuticular folding, and excretion of the meconium, we recorded four larval instars for P. cerealellae. The data showed significant positive correlations between larval mandible lengths and widths of larval head capsules, as well as between mandible lengths and larval instars, suggesting that mandible length is a good predictor of the number of instars in P. cerealellae. Developmental time from egg to adult emergence was ∼12 d for females and ∼11 days for males at 30 ± 1°C, 70 ± 5% r.h. and 12L:12D photoperiod.     

Influence of host plant,geography and pheromone strain on genomic differentiation in sympatric populations of Ostrinia nubilalis

Patterns of mating for the European corn borer (Ostrinia nubilalis) moth depend in part on variation in sex‐pheromone blend. The ratio of (E)‐11‐ and (Z)‐11‐tetradecenyl acetate (E11‐ and Z11‐14:OAc) in the pheromone blend that females produce and males respond to differs between strains of O. nubilalis. Populations also vary in female oviposition preference for and larval performance on maize (C4) and nonmaize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure of O. nubilalis remains unknown. Host‐plant use (¹³C/¹⁴C ratios) and genetic differentiation were estimated among sympatric E and Z pheromone strain O. nubilalis males collected in sex‐pheromone baited traps at 12 locations in Pennsylvania and New York between 2007 and 2010. Among genotypes at 65 single nucleotide polymorphism marker loci, variance at a position in the pheromone gland fatty acyl‐reductase (pgfar) gene at the locus responsible for determining female pheromone ratio (Pher) explained 64% of the total genetic differentiation between males attracted to different pheromones (male response, Resp), providing evidence of sexual inter‐selection at these unlinked loci. Principal coordinate, Bayesian clustering, and distance‐based redundancy analysis (dbRDA) demonstrate that host plant history or geography does not significantly contribute to population variation or differentiation among males. In contrast, these analyses indicate that pheromone response and pgfar‐defined strain contribute significantly to population genetic differentiation. This study suggests that behavioural divergence probably plays a larger role in driving genetic variation compared to host plant‐defined ecological adaptation.