High-fat and high-sugar diets induce rapid adaptations of fat storage in the house fly Musca domestica L.

Dietary change can be a strong evolutionary force and lead to rapid adaptation in organisms. High-fat and high-sugar diets can challenge key metabolic pathways, negatively affecting other life-history traits and inducing pathologies such as obesity and diabetes. In this study we use experimental evolution to investigate the plastic and evolutionary responses to nutritionally unbalanced diets. We reared replicated lines of larvae of the housefly Musca domestica on a fat-enriched (FAT), a sugar-enriched (SUG), and a control (CTRL) diet for thirteen generations. We measured development time in each generation, and larval growth and fat accumulation in generation 1, 7, and 13. Subsequently all lines were reared for one generation on the control diet to detect any plastic and evolutionary changes. In the first generation, time to pupation decreased on a fat-rich diet and increased on a sugar-rich diet. The fat-rich diet increased fat accumulation and, to a lesser extent, dry weight of the larvae. Multigenerational exposure to the unbalanced diets caused compensatory changes in development time, dry weight, as well as absolute and relative fat content, although pattern and timing depended on diet and trait. When put back on a control diet, many of the changes induced by the unbalanced diets disappeared, indicating that diet has large plastic effects. Nevertheless, fat-evolved lines still grew significantly larger than the sugar-evolved lines, and sugar-evolved lines had consistently lower fat content. This can be an effect of parental diet or an evolutionary change in nutrient metabolism as a consequence of multigenerational exposure to unbalanced diets.

Live yeasts accelerate Drosophila melanogaster larval development.

Insect guts house a complex community of microbes that affect host physiology, performance and behavior. Gut microbiome research has largely focused on bacteria-host symbioses and paid less attention to other taxa, such as yeasts. We found that axenic Drosophila melanogaster (reared free of microbes) develops from egg to adult more slowly (ca. 13 days) than those with a natural microbiota (ca. 11.5 days). Here, we showed that live yeasts are present and reproducing in the guts of flies and that the fast development time can be restored by inoculating larvae with a single yeast species (either Saccharomyces cerevisiae or Lachancea kluyveri). Nutritional supplements (either heat-killed yeasts, or a mix of essential vitamins and amino acids) slightly sped the development of axenic flies (to ca. 12.5 days), but not to the same extent as live yeasts. During the first two instars, this acceleration appears to result from additional macronutrient availability, but during the third instar, when most growth occurs, live yeasts increased feeding rate, implying an effect mediated by the gut-brain axis. Thus, the fly-yeast interaction extends beyond yeasts-as-food to yeasts as beneficial interactive symbionts.

Interindividual variation among Culex pipiens larvae in terms of thermal response.

This study aims to determine the phenological characteristics of thermal responses in the larvae of a Culex pipiens complex field population at the individual level under the influence of thermal regime of its habitat. The analysis is based on a structured population model quantifying the thermal responses of development time and survival under variable conditions and characterising the variety between the larvae (interindividual variety). During the study performed in Turkish Thrace on a monthly basis between May 2021 and June 2022, a total of 3744 larvae were reared as peer larval cohorts and 2330 larvae as siblings in artificial containers to be fully exposed to the natural thermal condition that was recorded hourly. The development process of larvae was monitored daily from egg to adult. As a result, a total of 4788 adult mosquitoes emerged, with a development period ranging from 8 to 52 days in the females and 7 to 50 days in the males, and the survival rate was found to range from 0% to 100%. Both parameters varied by month and individuals, and the variations manifested itself, particularly in the colder periods. The results indicate that the variation between the individuals in terms of thermal response in the larvae of C. pipiens, along with the thermal acclimation ability, appears to be fate determinant in resisting fluctuating thermal regimes, surviving in concurrent climate change and adapting to new conditions with modifications in the seasonal phenology, such as maintaining reproductive dynamics throughout the winter thanks to global warming.

Size rather than complexity of sexual ornaments prolongs male metamorphosis and explains sexual size dimorphism in sepsid flies.

Male sexual ornaments often evolve rapidly and are thought to be costly, thus contributing to sexual size dimorphism. However, little is known about their developmental costs, and even less about costs associated with structural complexity. Here, we quantified the size and complexity of three morphologically elaborate sexually dimorphic male ornaments that starkly differ across sepsid fly species (Diptera: Sepsidae): (i) male forelegs range from being unmodified, like in most females, to being adorned with spines and large cuticular protrusions; (ii) the fourth abdominal sternites are either unmodified or are converted into complex de novo appendages; and (iii) male genital claspers range from small and simple to large and complex (e.g. bifurcated). We tracked the development of 18 sepsid species from egg to adult to determine larval feeding and pupal metamorphosis times of both sexes. We then statistically explored whether pupal and adult body size, ornament size and/or ornament complexity are correlated with sex-specific development times. Larval growth and foraging periods of male and female larvae did not differ, but the time spent in the pupal stage was ca 5% longer for sepsid males despite emerging 9% smaller than females on average. Surprisingly, we found no evidence that sexual trait complexity prolongs pupal development beyond some effects of trait size. Evolving more complex traits thus does not incur developmental costs at least in this system.

Within-population variation in body size plasticity in response to combined nutritional and thermal stress is partially independent from variation in development time.

Ongoing climate change has forced animals to face changing thermal and nutritional environments. Animals can adjust to such combinations of stressors via plasticity. Body size is a key trait influencing organismal fitness, and plasticity in this trait in response to nutritional and thermal conditions varies among genetically diverse, locally adapted populations. The standing genetic variation within a population can also influence the extent of body size plasticity. We generated near-isogenic lines from a newly collected population of Drosophila melanogaster at the mid-point of east coast Australia and assayed body size for all lines in combinations of thermal and nutritional stress. We found that isogenic lines showed distinct underlying patterns of body size plasticity in response to temperature and nutrition that were often different from the overall population response. We then tested whether plasticity in development time could explain, and therefore regulate, variation in body size to these combinations of environmental conditions. We selected five genotypes that showed the greatest variation in response to combined thermal and nutritional stress and assessed the correlation between response of developmental time and body size. While we found significant genetic variation in development time plasticity, it was a poor predictor of body size among genotypes. Our results therefore suggest that multiple developmental pathways could generate genetic variation in body size plasticity. Our study emphasizes the need to better understand genetic variation in plasticity within a population, which will help determine the potential for populations to adapt to ongoing environmental change.

Correlated responses in basal immune function in response to selection for fast development in Drosophila melanogaster.

Often, immunity is invoked in the context of infection, disease and injury. However, an ever alert and robust immune system is essential for maintaining good health, but resource investment into immunity needs to be traded off against allocation to other functions. In this study, we study the consequences of such a trade-off with growth by ascertaining various components of baseline innate immunity in two types of Drosophila melanogaster populations selected for fast development, in combination with either a long effective lifespan (FLJs) or a short effective lifespan (FEJs). We found that distinct immunological parameters were constitutively elevated in both, FLJs and FEJs compared to their ancestral control (JB) populations, and these constitutive elevated immunological parameters were associated with reduced insulin signalling and comparable total gut microbiota. Our results bring into focus the inter-relationship between egg to adult development time, ecdysone levels, larval gut microbiota, insulin signalling, adult reproductive longevity and immune function. We discuss how changes in selection pressures operating on life-history traits can modulate different components of immune system.

Life history responses of the small brown planthopper Laodelphax striatellus to temperature change.

Temperature is a key environmental factor in ectotherms and influences many life history traits. In the present study, the nymphal development time, sex ratio and wing dimorphism of the small brown planthopper Laodelphax striatellus were examined under the conditions of constant temperatures, naturally varying temperatures (or different generations), and different temperatures combined with different photoperiod. The results showed that from 18 to 28 °C, the developmental time of nymphs was gradually shortened with the increase of temperature, whereas the high temperatures of 30 and 32 °C in the third to fifth instar nymphal stages and high summer temperature of 28.8 and 29.7 °C significantly delayed developmental time and resulted in higher mortality of nymphs. In all treatments, the developmental time was longer in females than males. The nymphs took significantly longer time to develop in the short daylength of 12 h than in longer daylengths of 13, 14, 15 and 16. Differences in developmental time were also found between wing morph, with long-winged individuals being significantly longer than the short-winged individuals at lower temperatures and significantly shorter than the short-winged individuals at higher temperatures. In all treatments, the sex ratio was stable, approaching 1:1, without being affected by temperature, generations and photoperiod. Photoperiod and temperature had significantly influence on the wing dimorphism. Long daylength combined with different temperatures resulted in significantly higher proportions of long-winged morph, whereas the low temperatures combined with the short daylengths in autumn and winter resulted in significantly high proportion of short-winged morph. This study broadens our understanding of the life-history traits of this planthopper and provides basic data for analyzing the effects of climate change on the planthopper reproduction.

Premarket Development Times for Innovative Vaccines--To What Extent Are the Coronavirus Disease 2019 (COVID-19) Vaccines Outliers?

One reason expressed in surveys of people reporting coronavirus disease 2019 (COVID-19) vaccine hesitancy is how rapidly these vaccines have reached the market. To estimate the length of time the COVID-19 vaccine spent in research and development as compared to other novel vaccines, we apply previously established methods for estimating medical product development times, using the key associated patent filings cited by the manufacturer as the marker of when commercial development activity began. Applying these methods to a cohort of recently approved innovative vaccines and comparing them to the first-approved COVID-19 vaccine (BioNTech/Pfizer), we found key patent filings for the technology in this COVID-19 vaccine occurred 10.0 years prior to regulatory authorization. By this metric, the development timelines for innovative vaccines have been shortening since the 1980s, and the COVID-19 vaccine comfortably fits within this pattern. Vaccine development timelines have now even drawn to parity with many of the most commonly used drugs.

Propagule size and seed development duration: high photosynthate allocation and growth allometry.

MAIN CONCLUSION: The divergences in propagule mass have been more consistently associated with divergences in seed development duration or fruit pedicel cross-sectional area than with divergences in any other biotic factors. Allometry and Corner's rule became an important theme in evolutionary biology of plant trait structure and function. Being one of the most widely noticed plant traits, propagule (seed and fruit) mass variation mechanism across species is still controversial. Here we examined correlations between propagule mass and seed development duration as well as other traits, such as cross-sectional area of fruit pedicel, life form, fruit type and leaf area over four census years, to test an important life history strategy for propagule biomass allocation. We investigated 491 species, belonging to 91 families and 320 genera, representing 95% of native wild species in Beijing Botanical Garden. The scaling correlations between propagule mass and seed development duration and the other traits were determined using phylogenetic generalized linear models. Results show a significant positive relationship among propagule mass and seed development duration, leaf area and pedicel cross-sectional area for all species and for each life form (except vines) regardless of phylogeny. The variation in seed mass has been more consistently associated with variation in seed development duration than with divergences in any other variable, such as growth form, fruit type, pedicel cross-sectional area and leaf area, whereas variation in fruit weight was found to be more associated with variation in pedicel cross-sectional area than the other. Biotic factors, such as seed development duration, pedicel cross-sectional area, growth form and leaf area, mediate propagule size variation, of which seed development duration or pedicel cross-sectional area is the most important. The results further supported a hypothesis that large-seeded species evolved owing to high photosynthate availability and growth allometry in plant body. A mechanistic mathematical model involving seed development duration was provided to expound propagule mass variations across species.

Causes and consequences of variation in development time in a field cricket.

Variation in development time can affect life-history traits that contribute to fitness. In Gryllus vocalis, a non-diapausing cricket with variable development time, we used a path analysis approach to determine the causative relationships between parental age, offspring development time and offspring life-history traits. Our best-supported path model included both the effects of parental age and offspring development time on offspring morphological traits. This result suggests that offspring traits are influenced by both variation in acquisition of resources and trade-offs between traits. We found that crickets with longer development times became larger adults with better phenoloxidase-based immunity. This is consistent with the hypothesis that crickets must make a trade-off between developing quickly to avoid predation before reproduction and attaining better immunity and a larger adult body size that provides advantages in male-male competition, mate choice and female fecundity. Slower-developing crickets were also more likely to be short-winged (unable to disperse by flight). Parental age has opposing direct and indirect effects on the body size of daughters, but when both the direct and indirect effects of parental age are taken into account, younger parents had smaller sons and daughters. This pattern may be attributable to a parental trade-off between the number and size of eggs produced with younger parents producing more eggs with fewer resources per egg. The relationships between variables in the life-history traits of sons and daughters were similar, suggesting that parental age and development time had similar causative effects on male and female life-history traits.

Effects of elevated temperatures on the development of immature stages of Anopheles gambiae (s.l.) mosquitoes.

OBJECTIVE: This study investigated the effects of temperature on the development of the immature stages of Anopheles gambiae (s.l.) mosquitoes. METHODS: Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24 h, and data were analysed using Kaplan-Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal-Wallis test where data were not normally distributed. Larval and pupal measurements were log-transformed and analysed using ordinary least square regression with robust standard errors. RESULTS: Increasing the temperature from 25 to 36°C decreased the development time by 10.57 days. Larval survival (X2 (6) = 5353.12, p < 0.001) and the number of adults produced (X2 (5) = 28.16, p < 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p < 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced. CONCLUSIONS: Increased temperature affected different developmental stages in the life cycle of An. gambiae (s.l.) mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature and Anopheles mosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.

Effects of the short- and long-term accumulation of detritus in larval habitats on life history traits of Aedes aegypti in temperate Argentina.

Aedes aegypti larvae that develop in containers largely depend on plant detritus as a source of nutritional resources. However, few studies have evaluated the performance of immature individuals under natural amounts and quality of this food source. Here, we aimed to assess the effect of the variation in the accumulation time and amount of detritus on life history traits of Ae. aegypti under semi-field conditions. Ae. aegypti larvae were raised with detritus collected in different sites to represent natural variability in its amount, simulating short (28 days) and long (70 days) accumulation. A control with optimal food conditions (yeast) was included. Survival, development time and wing length of adults were compared among treatments. Survival was relatively high in all treatments. Development time was similar among treatments but significantly longer and more variable in containers with the lowest detritus amounts. Wing lengths were smaller in the treatments with detritus than in the control, especially in females. The results support the hypothesis that, in a temperate region, Ae. aegypti larvae may have a nutritional limitation, at least in some containers, and emphasize the importance of performing experiments that simulate the environmental conditions to which individuals are exposed in nature.

Host Plant-Based Artificial Diets Enhance Development, Survival and Fecundity of the Edible Long-Horned Grasshopper Ruspolia differens (Orthoptera: Tettigoniidae).

Wild swarms of the long-horned grasshoppers Ruspolia differens (Serville) which are widely harvested for consumption and sale in Africa are seasonal and unsustainable, hence the need for innovative ways of artificially producing the insects. We investigated the development, survival, and reproduction of R. differens in the laboratory on diets mixed with host plants [Digitaria gayana Kunth, Cynodon dactylon (L.) and Megathyrsus maximus Jacq (Poales: Poaceae); Ageratum conyzoides L. (Asterales: Asteraceae)] identified from guts of their wild conspecifics with a view to developing a suitable diet for artificial mass rearing of the edible insect. A standard diet comprising ground black soldier fly, Hermetia illucens L. (Diptera: Startiomyidae) larvae, soybean flour, maize flour, vitamin premix, and ground bones was tested for rearing R. differens as a control against the same ingredients incorporated with individual powders of the different host plants. Whereas R. differens developed more slowly in the diet mixed with D. gayana than in the control diet; its development was faster in the diet mixed with C. dactylon. Mortalities of R. differens in host plant-based diets were 42.5-52.5%, far lower than in the control diet with 71% mortality. The insects raised on the diet mixed with M. maximus laid approximately twice more eggs compared to R. differens fecundities from the rest of the diets. However, inclusion of host plants in the diets had no detectable influence on R. differens adult weight and longevity. These findings support inclusion of specific host plants in artificial diets used for mass rearing of R. differens to enhance its survival, development, and fecundity.

Sex-specific associations between life-history traits and a novel reproductive polymorphism in the Pacific field cricket.

Associations between heritable polymorphisms and life-history traits, such as development time or reproductive investment, may play an underappreciated role in maintaining polymorphic systems. This is because selection acting on a particular morph could be bolstered or disrupted by correlated changes in life history or vice versa. In a Hawaiian population of the Pacific field cricket (Teleogryllus oceanicus), a novel mutation (flatwing) on the X-chromosome is responsible for a heritable polymorphism in male wing structure. We used laboratory cricket colonies fixed for male wing morph to investigate whether males and females bearing the flatwing or normal-wing (wild-type) allele differed in their life-history traits. We found that flatwing males developed faster and had heavier testes than normal-wings, whereas flatwing homozygous females developed slower and had lighter reproductive tissues than normal-wing homozygous females. Our results advance our understanding of the evolution of polymorphisms by demonstrating that the genetic change responsible for a reproductive polymorphism can also have consequences for fundamental life-history traits in both males and females.

Responses of Manduca sexta larvae to heat waves.

Climate change is increasing the frequency of heat waves and other extreme weather events experienced by organisms. How does the number and developmental timing of heat waves affect survival, growth and development of insects? Do heat waves early in development alter performance later in development? We addressed these questions using experimental heat waves with larvae of the tobacco hornworm, Manduca sexta. The experiments used diurnally fluctuating temperature treatments differing in the number (0-3) and developmental timing (early, middle and/or late in larval development) of heat waves, in which a single heat wave involved three consecutive days with a daily maximum temperature of 42°C. Survival to pupation declined with increasing number of heat waves. Multiple (but not single) heat waves significantly reduced development time and pupal mass; the best models for the data indicated that both the number and developmental timing of heat waves affected performance. In addition, heat waves earlier in development significantly reduced growth and development rates later in larval development. Our results illustrate how the frequency and developmental timing of sublethal heat waves can have important consequences for life history traits in insects.

Responses of Manduca sexta larvae to heat waves.

Climate change is increasing the frequency of heat waves and other extreme weather events experienced by organisms. How does the number and developmental timing of heat waves affect survival, growth and development of insects? Do heat waves early in development alter performance later in development? We addressed these questions using experimental heat waves with larvae of the tobacco hornworm, Manduca sexta. The experiments used diurnally fluctuating temperature treatments differing in the number (0-3) and developmental timing (early, middle and/or late in larval development) of heat waves, in which a single heat wave involved three consecutive days with a daily maximum temperature of 42°C. Survival to pupation declined with increasing number of heat waves. Multiple (but not single) heat waves significantly reduced development time and pupal mass; the best models for the data indicated that both the number and developmental timing of heat waves affected performance. In addition, heat waves earlier in development significantly reduced growth and development rates later in larval development. Our results illustrate how the frequency and developmental timing of sublethal heat waves can have important consequences for life history traits in insects.

The seesaw of diet restriction and lifespan: lessons from Drosophila studies.

Diet restriction (DR) studies undergo the implementation of reduced single or multiple component/s of the fly food without causing malnutrition. The question of how and why DR modifies the fate of lifespan in fruit flies Drosophila melanogaster has prompted us to emphasize by attending the control food composition first. Certain concentrations of DR food do not always confer an extended lifespan, rather it enables the flies to achieve their normal lifespan, which was probably reduced by the control food per se (having toxic effect caused due to the excess levels of dietary components). However, the current paradigm of DR studies has elicited its benefits and losses via trade-offs in the organismal traits and have highlighted the need for a common diet, but have not claimed the tested diets as balanced. So, the DR effect on lifespan and other fitness traits cannot be justified only based on varying control food across labs and hence, the approach of DR studies has to be revisited and a balanced diet has to be formulated. The current article discusses the need for a balanced diet, the traits to be considered before designing a diet, and certain problems in the existing synthetic medium. Therefore, based on the control food composition, the validity of lifespan extension conferred by these nutrient restricted diets need to be accounted for.

Lacking Advanced Degrees are not a Barrier to Entry into Academic Surgery Leadership.

BACKGROUND: Undergraduate and graduate medical education offerings continue to create opportunities for medical students to pursue MD+ degree education. These educational endeavors provide formal education in fields related to surgery, which gives trainees and surgeons diverse perspectives on surgical care. This study sought to assess current prevalence of additional advanced degrees among leaders in academic surgery to assess the relationship between dual degree attainment and holding various leadership positions within surgical departments. METHODS: The Association for Program Directors in Surgery database was used to identify academic surgical programs, which comprised our study population. Each department of surgery website in the APDS database was interrogated for departmental leaders and their reported academic degrees. RESULTS: Among 3223 identified surgeon leaders, 14.6% (470/3223) were found to possess MD+ degrees. Most common degrees possessed included MBA, MPH, and PhD. In comparing different types of surgeon leaders such as chairs, program directors, and division chiefs, no group was found to have a significantly higher prevalence of MD+ degrees than others. CONCLUSION: Prevalence of MD+ degrees among current academic surgery leaders is low, and the lack of an advanced degree should not be considered a barrier to entry into leadership positions. We hypothesize that these findings are likely to evolve as larger proportions of trainees obtain MD+ degrees during medical school and academic development time throughout residency.

Inheritance of key life-history traits in crosses between northern and southern populations of the cabbage beetle Colaphellus bowringi (Coleoptera: Chrysomelidae).

A southern population (S) from Xiushui County (29°1'N, 114°4'E) and a northern population (N) from Shenyang city (41°48'N, 123°23'E) of the cabbage beetle, Colaphellus bowringi vary greatly in their life-history traits, and may serve as an excellent model with which to study the inheritance of life-history traits. In the present study, we performed intraspecific hybridization using the two populations, comparing the key life-history traits (fecundity, development time, body weight, growth rate, and sexual size dimorphism (SDD)) between the two populations (S♀ × S♂ and N♀ × N♂) and their two hybrid populations (S♀ × N♂ and N♀ × S♂ populations) at 19, 22, 25, and 28°C. Our results showed that there were significant differences in life-history traits between the two parental populations, with the S population having a significantly higher fecundity, shorter larval development time, larger body weight, higher growth rate, and greater weight loss during metamorphosis than the N population at almost all temperatures. However, these life-history traits in the two hybrid populations were intermediate between those of their parents. The life-history traits in the S × N and N × S populations more closely resembled those of the maternal S population and N population, respectively, showing maternal effects. Weight loss for both sexes was highest in the S population, followed by the S × N, N × S, and N populations at all temperatures, suggesting that larger pupae lost more weight during metamorphosis. The changes in SSD with temperature were similar between the S and the S × N populations and between the N and the N × S populations, also suggesting a maternal effect. Overall, our results showed no drastic effect of hybridization on C. bowringi, being neither negative (hybrid inferiority) nor positive (heterosis). Rather, the phenotypes of hybrids were intermediate between the phenotypes of their parents.

Gut bacterial communities and their contribution to performance of specialist Altica flea beetles.

Host plant shifts are a common mode of speciation in herbivorous insects. Although insects can evolve adaptations to successfully incorporate a new host plant, it is becoming increasingly recognized that the gut bacterial community may play a significant role in allowing insects to detoxify novel plant chemical defenses. Here, we examined differences in gut bacterial communities between Altica flea beetle species that feed on phylogenetically unrelated host plants in sympatry. We surveyed the gut bacterial communities of three closely related flea beetles from multiple locations using 16S rRNA amplicon sequencing. The results showed that the beetle species shared a high proportion (80.7%) of operational taxonomic units. Alpha-diversity indicators suggested that gut bacterial diversity did not differ among host species, whereas geography had a significant effect on bacterial diversity. In contrast, analyses of beta-diversity showed significant differences in gut bacterial composition among beetle species when we used species composition and relative abundance metrics, but there was no difference in composition when species presence/absence and phylogenetic distance indices were used. Within host beetle species, gut bacterial composition varied significantly among sites. A metagenomic functionality analysis predicted that the gut microbes had functions involved in xenobiotic biodegradation and metabolism as well as metabolism of terpenoids and polyketides. These predictions, however, did not differ among beetle host species. Antibiotic curing experiments showed that development time was significantly prolonged, and there was a significant decline in body weight of newly emerged adults in beetles lacking gut bacteria, suggesting the beetles may receive a potential benefit from the gut microbe-insect interaction. On the whole, our results suggest that although the gut bacterial community did not show clear host-specific patterns among Altica species, spatiotemporal variability is an important determinant of gut bacterial communities. Furthermore, the similarity of communities among these beetle species suggests that microbial facilitation may not be a determinant of host plant shifts in Altica.