The dynamics and the timeline of speciation in the gall-forming aphid Geoica spp. within and among Pistacia host tree species.

Trees of the genus Pistacia serve as obligate hosts for gall-forming aphids (Hemiptera, Aphididae, Fordini). Each aphid species induces a characteristic gall on a single Pistacia host species. The genus Geoica (Fordini) induce similar spherical closed galls on the lower side of the leaflet's midvein, on different Pistacia species. Two species of Pistacia trees that harbor Geoica galls grow naturally in Israel: P. palaestina and P. atlantica. We analyzed the phylogeny and the genetic structure of the Geoica species complex in Israel, and assessed the genetic differentiation and the level of host plant specificity of the aphids between P. atlantica and P. palaestina. We found that the splitting of the genus between P. atlantica and P. palaestina is estimated to have occurred 24-25 Ma (the Oligocene/Miocene boundary). Five different haplotypes suggesting five different species have been further speciating among Geoica spp., galling on P. atlantica, and an additional three species, on P. palaestina.

Developing a large-scale dataset of flood fatalities for territories in the Euro-Mediterranean region, FFEM-DB.

This data paper describes the multinational Database of Flood Fatalities from the Euro-Mediterranean region FFEM-DB that hosts data of 2,875 flood fatalities from 12 territories (nine of which represent entire countries) in Europe and the broader Mediterranean region from 1980 to 2020. The FFEM-DB database provides data on fatalities' profiles, location, and contributing circumstances, allowing researchers and flood risk managers to explore demographic, behavioral, and situational factors, as well as environmental features of flood-related mortality. The standardized data collection and classification methodology enable comparison between regions beyond administrative boundaries. The FFEM-DB is expandable, regularly updated, publicly available, and with anonymized data. The key advantages of the FFEM-DB compared to existing datasets containing flood fatalities are its high level of detail, data accuracy, record completeness, and the large sample size from an extended area.

Revealing cryptic interactions between large mammalian herbivores and plant-dwelling arthropods via DNA metabarcoding.

In the past decade, it has become clear that omnivory, feeding on more than one trophic level, is important in natural and agricultural systems. Large mammalian herbivores (LMH) frequently encounter plant-dwelling arthropods (PDA) on their food plants. Yet, ingestion of PDA by LMH is only rarely addressed and the extent of this direct trophic interaction, especially at the PDA community level, remains unknown. Using a DNA-metabarcoding analysis on feces of free-ranging cattle from a replicated field experiment of heavily and moderately grazed paddocks, we reveal that feeding cattle (incidentally) ingest an entire food chain of PDA including herbivores, predators and parasites. Overall, 25 families of insects and four families of arachnids were ingested, a pattern that varied over the season, but not with grazing intensity. We identified the functional groups of PDA vulnerable to ingestion, such as sessile species and immature life stages. Most of the fecal samples (76%) contained sequences belonging to PDA, indicating that direct interactions are frequent. This study highlights the complex trophic connections between LMH and PDA. It may even be appropriate to consider LMH as omnivorous enemies of PDA.

Transcriptional up-regulation of host-specific terpene metabolism in aphid-induced galls of Pistacia palaestina.

Galling insects gain food and shelter by inducing specialized anatomical structures in their plant hosts. Such galls often accumulate plant defensive metabolites protecting the inhabiting insects from predation. We previously found that, despite a marked natural chemopolymorphism in natural populations of Pistacia palaestina, the monoterpene content in Baizongia pistaciae-induced galls is substantially higher than in leaves of their hosts. Here we show a general up-regulation of key structural genes in both the plastidial and cytosolic terpene biosynthetic pathways in galls as compared with non-colonized leaves. Novel prenyltransferases and terpene synthases were functionally expressed in Escherichia coli to reveal their biochemical function. Individual Pistacia trees exhibiting chemopolymorphism in terpene compositions displayed differential up-regulation of selected terpene synthase genes, and the metabolites generated by their gene products in vitro corresponded to the monoterpenes accumulated by each tree. Our results delineate molecular mechanisms responsible for the formation of enhanced monoterpene in galls and the observed intraspecific monoterpene chemodiversity displayed in P. palaestina. We demonstrate that gall-inhabiting aphids transcriptionally reprogram their host terpene pathways by up-regulating tree-specific genes, boosting the accumulation of plant defensive compounds for the protection of colonizing insects.

Large herbivores facilitate an insect herbivore by modifying plant community composition in a temperate grassland.

Large herbivores often co-occur and share plant resources with herbivorous insects in grassland ecosystems; yet, how they interact with each other remains poorly understood. We conducted a series of field experiments to investigate whether and how large domestic herbivores (sheep; Ovis aries) may affect the abundance of a common herbivorous insect (aphid; Hyalopterus pruni) in a temperate grassland of northeast China. Our exclosure experiment showed that 3 years (2010-2012) of sheep grazing had led to 86% higher aphid abundance compared with ungrazed sites. Mechanistically, this facilitative effect was driven by grazing altering the plant community, rather than by changes in food availability and predator abundance for aphids. Sheep significantly altered plant community by reducing the abundance of unpalatable forbs for the aphids. Our small-scale forb removal experiment revealed an "associational plant defense" by forbs which protect the grass Phragmites australis from being attacked by the aphids. However, selective grazing on forbs by sheep indirectly disrupted such associational plant defense, making P. australis more susceptible to aphids, consequentially increasing the density of aphids. These findings provide a novel mechanistic explanation for the effects of large herbivores on herbivorous insects by linking selective grazing to plant community composition and the responses of insect populations in grassland ecosystems.

Gall-forming aphids are protected (and benefit) from defoliating caterpillars: the role of plant-mediated mechanisms.

BACKGROUND: Interspecific interactions among insect herbivores are common and important. Because they are surrounded by plant tissue (endophagy), the interactions between gall-formers and other herbivores are primarily plant-mediated. Gall-forming insects manipulate their host to gain a better nutrient supply, as well as physical and chemical protection form natural enemies and abiotic factors. Although often recognized, the protective role of the galls has rarely been tested. RESULTS: Using an experimental approach, we found that the aphid, Smynthurodes betae, that forms galls on Pistacia atlantica leaves, is fully protected from destruction by the folivorous processionary moth, Thaumetopoea solitaria. The moth can skeletonize entire leaves on the tree except for a narrow margin around the galls that remains intact ("trimmed galls"). The fitness of the aphids in trimmed galls is unharmed. Feeding trials revealed that the galls are unpalatable to the moth and reduce its growth. Surprisingly, S. betae benefits from the moth. The compensatory secondary leaf flush following moth defoliation provides new, young leaves suitable for further gall induction that increase overall gall density and reproduction of the aphid. CONCLUSIONS: We provide experimental support for the gall defense hypothesis. The aphids in the galls are protracted by plant-mediated mechanisms that shape the interactions between insect herbivores which feed simultaneously on the same host. The moth increase gall demsity on re-growing defoliated shoots.

Activity of Ajuga iva Extracts Against the African Cotton Leafworm Spodoptera littoralis.

Control of the crop pest African cotton leafworm, Spodoptera littoralis (Boisduval), by chemical insecticides has led to serious resistance problems. Ajuga plants contain phytoecdysteroids (arthropod steroid hormone analogs regulating metamorphosis) and clerodanes (diterpenoids exhibiting antifeedant activity). We analyzed these compounds in leaf extracts of the Israeli Ajuga iva L. by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and thin-layer chromatography (TLC), and their efficiency at reducing S.littoralis fitness. First and third instars of S. littoralis were fed castor bean leaves (Ricinus communis) smeared with an aqueous suspension of dried methanolic crude extract of A. iva phytoecdysteroids and clerodanes. Mortality, larval weight gain, relative growth rate and survival were compared to feeding on control leaves. We used '4',6-diamidino-2-phenylindole (DAPI, a fluorescent stain) and phalloidin staining to localize A. iva crude leaf extract activity in the insect gut. Ajuga iva crude leaf extract (50, 100 and 250 µg/µL) significantly increased mortality of first-instar S. littoralis (36%, 70%, and 87%, respectively) compared to controls (6%). Third-instar larval weight gain decreased significantly (by 52%, 44% and 30%, respectively), as did relative growth rate (-0.05 g/g per day compared to the relevant controls), ultimately resulting in few survivors. Crude leaf extract (250 µg/µL) reduced gut size, with relocation of nuclei and abnormal actin-filament organization. Ajug iva extract has potential for alternative, environmentally safe insect-pest control.

Alkaloid chemodiversity in Mandragora spp. is associated with loss-of-functionality of MoH6H, a hyoscyamine 6ß-hydroxylase gene.

Mandrakes (Mandragora spp., Solanaceae) are known to contain tropane alkaloids and have been used since antiquity in traditional medicine. Tropane alkaloids such as scopolamine and hyoscyamine are used in modern medicine to treat pain, motion sickness, as eye pupil dilators and antidotes against organo-phosphate poisoning. Hyoscyamine is converted to 6ß-hydroxyhyoscyamine (anisodamine) and scopolamine by hyoscyamine 6ß-hydroxylase (H6H), a 2-oxoglutarate dependent dioxygenase. We describe here a marked chemo-diversity in the tropane alkaloid content in Mandragora spp. M. officinarum and M. turcomanica lack anisodamine and scopolamine but display up to 10 fold higher hyoscyamine levels as compared with M. autumnalis. Transcriptomic analyses revealed that H6H is highly conserved among scopolamine-producing Solanaceae. MoH6H present in M. officinarum differs in several amino acid residues including a homozygotic mutation in the substrate binding region of the protein and its prevalence among accessions was confirmed by Cleaved-Amplified-Polymorphic-Sequence analyses. Functional expression revealed that MaH6H, a gene isolated from M. autumnalis encodes an active H6H enzyme while the MoH6H sequence isolated from M. officinarum was functionally inactive. A single G to T mutation in nucleotide 663 of MoH6H is associated with the lack of anisodamine and scopolamine in M. officinalis.

Innate ability of goats to sense and avoid ingestion of noxious insects while feeding.

Large mammalian herbivores regularly encounter noxious insects on their food plants. Recent evidence revealed that goats efficiently avoid insect ingestion while feeding, yet it is unknown whether this ability is innate. We experimentally examined the behavioural responses of naive goat kids to a common insect, the spring-webworm (Ocnogyna loewii). We filmed and analysed the kids' behaviour while feeding and compared it to the behaviour described in adults. Naive kids sorted the webworms apart from the food without ingesting them (all webworms survived). They exhibited behaviours similar to those displayed by adults, demonstrating an innate ability to avoid insect ingestion. The kids detected webworms using tactile stimulation, obtained by repeatedly touching the leaves with their muzzles. This enabled them to pick webworm-free leaves (leaving 93% of webworms behind). While adults frequently shook or discarded leaves with webworms or spat out webworms, these behaviours were rare in kids. The kids' mean feeding rates doubled over the trials, indicating that their feeding efficiency on plants with and without insects improved with experience. As ingesting noxious insects could be fatal, innate avoidance is critical. These findings highlight the importance of direct interactions between mammalian and insect herbivores.

The effects of a windborne pollen-provisioning cover crop on the phytoseiid community in citrus orchards in Israel.

BACKGROUND: Several phytoseiid species can potentially control the citrus rust mite (CRM). Their effectiveness varies, however, as do their intraguild interactions. Under laboratory conditions, Euseius stipulatus, E. scutalis and Iphiseius degenerans preyed effectively on CRM, whereas Amblyseius swirskii and Typhlodromus athiasae had no effect on CRM. In combination with A. swirskii, Euseius numbers were reduced due to intraguild predation, and consequently CRM suppression was less effective. In the field, predatory mite species can be variably provisioned by windborne pollen released from cover crops such as Rhodes grass (RG). We aimed to determine the effects of RG on the phytoseiid community in two field experiments, on different cultivars (pomelo and Shamouti orange). We also tested these communities for negative interspecific abundance relationships that are expected if their respective laboratory-observed intraguild interactions are manifested in the field. RESULTS: Overall, on pomelo, we observed a dominance of A. swirskii, relatively low E. stipulatus and high CRM abundances. Amblyseius swirskii and E. stipulatus abundances were both elevated near RG, despite apparent intraguild predation by A. swirskii. Conversely, T. athiasae abundances were lower near RG, likely due to predation by A. swirskii. On Shamouti, E. stipulatus abundances were much higher than on pomelo and were not negatively related to A. swirskii abundances. There, RG increased E. stipulatus abundance, and CRM was reduced. CONCLUSION: RG cover cropping can enhance CRM control, depending on variation in intraguild interactions among phytoseiids, particularly between A. swirskii and E. stipulatus. These may be modulated by climatic and/or cultivar effects. © 2018 Society of Chemical Industry.

Standing on the shoulders of giants: young aphids piggyback on adults when searching for a host plant.

BACKGROUND: Upon the detection of imminent peril, pea aphids (Acyrthosiphon pisum) often drop off their host plant. Dropping in response to insect enemies is intermittent in nature, but when a mammalian herbivore feeds on their host plant, a large mixed-age group of aphids usually drops off the plant at once. Aphids that reach the ground are confronted with new, hostile environmental conditions and must therefore quickly walk toward a suitable host plant. The longer it takes an aphid to reach a host plant, the more it is exposed to the risks of starvation, desiccation and predation. RESULTS: We found that young nymphs, which have limited mobility and high mortality on the ground, quickly climb on conspecific (not necessarily parental) adults and cling to them before the latter start walking in search of a plant. This "riding" behavior is likely to be adaptive for the nymphs, for it shortens their journey and the time they spend off a host plant. Adults however, seem to be irritated by the riding nymphs, as they often actively try to remove them. CONCLUSIONS: After dropping from the host plant, young aphid nymphs travel at least part of the way back to a plant on the backs of adults. For the riding behavior to take place, nymphs need to successfully find adults and withstand removal attempts.

The oak gall wasps of Israel (Hymenoptera, Cynipidae, Cynipini)-diversity, distribution and life history.

Oak-galling wasps (Hymenoptera: Cynipidae, Cynipini) have been studied in Israel only superficially so far, despite interest in the Israeli fauna given its location at the southern edge of distribution range of the wasps and their oak hosts. We provide the first comprehensive review of the Israeli fauna of oak cynipids based on an extensive survey of the five naturally occurring oak species in Israel. We report 53 cynipid species, 37 of which are reported from Israel for the first time, 10 are currently known only from this country, and 9 are undescribed. With 27 species, Andricus is by far the biggest genus in Israel, followed by Cerroneuroterus, Neuroterus Plagiotrochus, and Pseudoneuroterus with 4 species each. Andricus megalucidus is synonymized under A. cecconii and Cerroneuroterus cerrifloralis is synonymized under C. lanuginosus. The sexual generations of Andricus cecconii, A. coriariformis, A. coriarius, A. miriami, Cerroneuroterus lanuginosus and Pseudoneuroterus macropterus are reported here for the first time. We recorded 65 gall types, with bud galls being the most common and conspicuous, followed by leaf and catkin galls. We provide illustrated keys for all Israeli species based on their galls, as well as information on host associations, life history, phenology and distribution patterns where available. 21 cynipid species are associated with Quercus ithaburensis and 27 species are associated with Q. boissieri, whereas Q. libani, Q. calliprinos and Q. cerris host much fewer species. Most species are currently known from either their sexual or asexual generation while only 24% of them are known from both. Mount Hermon was found to be an important hotspot, hosting about half of the Israeli cynipid fauna, and species richness generally declines from the Golan Heights southwards to the Judean Mountains. Cynipid species that are associated with oaks of sections Cerris and Quercus in Europe are mostly associated with the same sections in Israel.

Cascading effects on bacterial communities: cattle grazing causes a shift in the microbiome of a herbivorous caterpillar.

Large mammalian herbivores greatly influence the functioning of grassland ecosystems. Through plant consumption, excreta, and trampling, they modify biodiversity, nutrient cycling, and soil properties. Grazing mammals can also alter soil and rhizosphere bacterial communities, but their effect on the microbiome of other animals in the habitat (i.e., insects) is unknown. Using an experimental field approach and Illumina MiSeq 16S rRNA gene sequencing, we analyzed the influence of cattle grazing on the microbial community of spring webworm caterpillars, Ocnogyna loewii. Our experimental setup included replicated grazed and non-grazed paddocks from which caterpillars were collected twice (first-second and fourth-fifth instar). The caterpillars' microbiome is composed mostly of Proteobacteria and Firmicutes, and contains a potential symbiont from the genus Carnobacterium (55% of reads). We found that grazing significantly altered the microbiome composition of late instar caterpillars, probably through changes in diet (plant) composition and availability. Furthermore, the microbiome composition of early instar caterpillars significantly differed from late instar caterpillars in 221 OTUs (58 genera). Pseudomonas and Acinetobacter were dominant in early instars, while Carnobacterium and Acinetobacter were dominant in late instars. This study provides new ecological perspectives on the cascading effects mammalian herbivores may have on the microbiome of other animals in their shared habitat.

Biomarker-Driven Therapy in Metastatic Gastric and Esophageal Cancer: Real-Life Clinical Experience.

BACKGROUND: Precision treatment of cancer uses biomarker-driven therapy to individualize and optimize patient care. OBJECTIVE: To evaluate real-life clinical experience with biomarker-driven therapy in metastatic gastric and esophageal cancer in Israel. PATIENTS AND METHODS: This multicenter retrospective cohort study included patients with metastatic gastric or esophageal cancer who were treated in the participating institutions and underwent biomarker-driven therapy. Treatment was considered to have a benefit if the ratio between the longest progression-free survival (PFS) post biomarker-driven therapy and the last PFS before the biomarker-driven therapy was ≥1.3. The null hypothesis was that ≤15% of patients gain such benefit. RESULTS: The analysis included 46 patients (61% men; median age, 58 years; 57% with poorly-differentiated tumors). At least one actionable (i.e., predictive of response to a specific therapy) biomarker was identified for each patient. Immunohistochemistry was performed on all samples and identified 1-8 (median: 3) biomarkers per patient (most commonly: low TS, high TOPO1, high TOP2A). Twenty-eight patients received therapy after the biomarker analysis (1-4 lines). In the 1st line after biomarker analysis, five patients (18%) achieved a partial response and five (18%) stable disease; the median (range) PFS was 129 (12-1155) days. Twenty-four patients were evaluable for PFS ratio analysis; in seven (29.2%), the ratio was ≥1.3. In a one-sided exact binomial test vs. the null hypothesis, p = 0.019; therefore, the null hypothesis was rejected. CONCLUSIONS: Our findings demonstrated that implementing biomarker-driven analysis is feasible and could provide clinical benefit for a considerable proportion (~30%) of patients with metastatic gastric or esophageal cancer.

How goats avoid ingesting noxious insects while feeding.

As mammalian herbivores feed, they often encounter noxious insects on plants. It is unknown how they handle such insects. We experimentally examined the behavioural responses of goats to the noxious spring-webworm (Ocnogyna loewii), and manipulated their sensory perception to reveal the process of insect detection. Goats did not avoid plants with webworms, demonstrating a remarkable ability to sort them apart from the plant (98% of webworms survived). Initial detection of webworms involved tactile stimulation, done by repeatedly touching the leaves with the muzzle. This enabled them to pick webworm-free leaves. If the goats picked up leaves with a webworm, they shook or discarded the leaf. They spat out webworms that entered their mouths, after detecting them by touch and taste. By using their keen senses and efficient behaviours, goats are able to feed while accurately excluding insects. These findings highlight the importance of direct interactions between mammalian herbivores and insects.

Regional Nodal Irradiation After Breast Conserving Surgery for Early HER2-Positive Breast Cancer: Results of a Subanalysis From the ALTTO Trial.

Background: Two randomized trials recently demonstrated that regional nodal irradiation (RNI) could reduce the risk of recurrence in early breast cancer; however, these trials were conducted in the pretrastuzumab era. Whether these results are applicable to human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients treated with anti-HER2-targeted therapy is unknown. Methods: This retrospective analysis was performed on patients with node-positive breast cancer who were enrolled in the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimization phase III adjuvant trial and subjected to BCS. The primary objective of the present study was to examine the effect of RNI on disease-free survival (DFS). A multivariable cox regression analysis adjusted for number of positive lymph nodes, tumor size, grade, age, hormone receptors status, presence of macrometastatis, treatment arm, and chemotherapy timing was carried out to investigate the relationship between RNI and DFS. Results: One thousand six hundred sixty-four HER2-positive breast cancer patients were included, of whom 878 (52.8%) had received RNI to the axillary, supraclavicular, and/or internal mammary lymph nodes. Patients in the RNI group had higher nodal burden and more frequently had tumors larger than 2 cm. At a median follow-up of 4.5 years, DFS was 84.3% in the RNI group and 88.3% in the non-RNI group. No differences in regional recurrence (0.9 % vs 0.6 %) or in overall survival (93.6% vs 95.3%) were observed between the two groups. After adjustment in multivariable analysis, there was no statistically significant association between RNI and DFS (hazard ratio = 0.96, 95% confidence interval = 0.71 to 1.29). Conclusions: Our analysis did not demonstrate a DFS benefit of RNI in HER2-positive, node-positive patients treated with adjuvant HER2-targeted therapy. The benefit of RNI in HER2-positive breast cancer needs further testing within randomized clinical trials.

Turning in mid-air allows aphids that flee the plant to avoid reaching the risky ground.

When forced to drop from the plant, flightless arboreal insects can avoid reaching the risky ground by maneuvering their body through the air. When wingless pea aphids (Acyrthosiphon pisum) are threatened by natural enemies, they often drop off their host plant while assuming a stereotypic posture that rotates them in mid-air, aligning them with their feet pointing downwards. This position may increase their chances of re-clinging onto lower plant parts and avoid facing the dangers on the ground, although its effectiveness in realistic field conditions has not been tested. We performed both laboratory and outdoor experiments, in which we dropped aphids upon host plants to quantify clinging success in plants with different characteristics such as height and leaf size. Live aphids had twofold higher clinging rates than dead ones, indicating that clinging success is indeed affected by the active aerial-righting of dropping aphids. The ability to cling was positively dependent on the plants' foliage cover as viewed in vertical direction from above. Therefore, we released aphids in commercial alfalfa (Medicago sativa) fields with varying plant heights and foliage cover and induced them to drop. Most (up to 75%) of the aphids avoided reaching the ground in taller plants (65 cm), and 17% in shorter plants (21 cm), demonstrating the efficiency of the aphids' response in averting risks: both those of an approaching enemy on the plant and the plethora of new risks on the ground. Evidently, even in complex field environment, the aerial-righting mechanism can substantially reduce the possible risks following escape from a predator.

Acupuncture and Reflexology for Chemotherapy-Induced Peripheral Neuropathy in Breast Cancer.

BACKGROUND: Treatment of chemotherapy-induced peripheral neuropathy (CIPN), which affects approximately 30% to 40% of patients treated with neuropathy-causing agents, is mainly symptomatic. Currently available interventions are of little benefit. STUDY DESIGN: This study was conducted as a retrospective analysis of the efficacy of acupuncture and reflexology in alleviating CIPN in breast cancer patients. METHODS: Medical records of 30 consecutive breast cancer patients who received both chemotherapy and treatment for CIPN according to our Acupuncture and Reflexology Treatment for Neuropathy (ART-N) protocol between 2011 and 2012 were reviewed. Symptom severity was rated at baseline, during, and after treatment. RESULTS: The records of 30 breast cancer patients who had been concomitantly treated with chemotherapy and ART-N for CIPN were retrieved. Two records were incomplete, leaving a total of 28 patients who were enrolled into the study. Twenty patients (71%) had sensory neuropathy, 7 (25%) had motor neuropathy, and 1 (4%) had both sensory and motor neuropathy. Only 2 (10%) of the 20 patients with grades 1 to 2 neuropathy still reported symptoms at 12 months since starting the ART-N protocol. All 8 patients who presented with grades 3 to 4 neuropathy were symptom-free at the 12-month evaluation. Overall, 26 patients (93%) had complete resolution of CIPN symptoms. CONCLUSION: The results of this study demonstrated that a joint protocol of acupuncture and reflexology has a potential to improve symptoms of CIPN in breast cancer patients. The protocol should be validated on a larger cohort with a control group. It also warrants testing as a preventive intervention.

Differences in Monoterpene Biosynthesis and Accumulation in Pistacia palaestina Leaves and Aphid-Induced Galls.

Certain insect species can induce gall formation on numerous plants species. Although the mechanism of gall development is largely unknown, it is clear that insects manipulate their hosts' anatomy, physiology, and chemistry for their own benefit. It is well known that insect-induced galls often contain vast amounts of plant defensive compounds as compared to non-colonized tissues, but it is not clear if defensive compounds can be produced in situ in the galled tissues. To answer this question, we analyzed terpene accumulation patterns and possible independent biosynthetic potential of galls induced by the aphid Baizongia pistaciae L. on the terminal buds of Pistacia palaestina Boiss. We compared monoterpene levels and monoterpene synthase enzyme activity in galls and healthy leaves from individual trees growing in a natural setting. At all developmental stages, monoterpene content and monoterpene synthase activity were consistently (up to 10 fold on a fresh weight basis) higher in galls than in intact non-colonized leaves. A remarkable tree to tree variation in the products produced in vitro from the substrate geranyl diphosphate by soluble protein extracts derived from individual trees was observed. Furthermore, galls and leaves from the same trees displayed enhanced and often distinct biosynthetic capabilities. Our results clearly indicate that galls possess independent metabolic capacities to produce and accumulate monoterpenes as compared to leaves. Our study indicates that galling aphids manipulate the enzymatic machinery of their host plant, intensifying their own defenses against natural enemies.

Direct consumptive interactions between mammalian herbivores and plant-dwelling invertebrates: prevalence, significance, and prospectus.

Mammalian herbivores induce changes in the chemical composition, phenology, distribution, and abundance of the plants they feed on. Consequently, invertebrate herbivores (predominantly insects) that depend on those plants, and the predators and parasitoids that are associated with them, may be affected. This plant-mediated indirect interaction between mammals and invertebrates has been extensively studied, but mammalian herbivores may also directly affect plant-dwelling invertebrates (PDI) by incidentally ingesting them while feeding. The ubiquity and small size of PDI render them highly susceptible to incidental ingestion, but as common as this interaction may intuitively seem, very little is known about its prevalence and ecological consequences. Nevertheless, cases of incidental ingestion of PDI and associated adaptations for avoiding it that have been sporadically documented in several invertebrate groups and life stages allow us to carefully extrapolate and conclude that it should be common in nature. Incidental ingestion may, therefore, bear significant consequences for PDI, but it may also affect the mammalian herbivores and the shared plants. Future research on incidental ingestion of PDI would have to overcome several technical difficulties to gain better insight into this understudied ecological interaction.