Gall Maker Research Articles

Interactions between invasive pests and pathogens in a native chestnut forest

The introduction in the same area of different invasive species can result in novel interactions, with unpredictable consequences. We carried out a study in Galicia (northwestern Iberian Peninsula) with the aim of clarifying the interactions between two invasive species Cryphonectria parasitica and Dryocosmus kuriphilus. In 2018, we selected five chestnut plots affected by both species. We compared trees affected only by the insect and trees affected by both the insect and the fungus with respect to attack level, gall characteristics, female size and fecundity, and concentrations of nitrogen, water and secondary metabolites. We also evaluated female preferences in a greenhouse assay. There were higher levels of attack in trees affected by both invaders. However, the greenhouse assay showed that ovipositing females do not preferentially choose trees attacked by the fungus. The presence of the fungus had no effect on the size, wall thickness, or hardness of D. kuriphilus galls, but larvae were smaller in trees also affected by the fungus. The fecundity of females was strongly related to the presence of chestnut blight; the number of eggs per female was almost double in trees affected by the fungus. There were no relations between blight and the nitrogen or water content in the galls, where the insects feed. There were also no effects of chestnut blight on the concentration of terpenes or phenols, but condensed tannins were higher in trees with chestnut blight. The higher tannins induced by chestnut blight may directly or indirectly benefit gall wasps. Positive relationships between condensed tannin concentration and reproductive performance of other gall makers were previously reported. Tannins can also improve the negative effects of environmental conditions inside the gall. Our results indicate that the presence of chestnut blight can increase the suitability of chestnut trees for the invasive insect, D. kuriphilus, through the increase in tannins due to the presence of the fungus.

A chromosome-level genome assembly of the gall maker pest inquiline, Diomorus aiolomorphi Kamijo (Hymenoptera: Torymidae)

Diomorus aiolomorphi Kamijo (Hymenoptera: Torymidae) is an inquiline of gall maker Aiolomorphus rhopaloides Walker (Hymenoptera: Eurytomidae). They are of significant economic significance and predominantly inhabit bamboo forest. So far, only four scaffold-level genomes have been published for the family Torymidae. In this study, we present a high-quality genome assembly of D. aiolomorphi at the chromosome level, achieved through the integration of Nanopore (ONT) long-read, Illumina pair-end DNA short-read, and High-through Chromosome Conformation Capture (Hi-C) sequencing methods. The final assembly was 1,084.56 Mb in genome size, with 1,083.41 Mb (99.89%) assigned to five pseudochromosomes. The scaffold N50 length reached 224.87 Mb, and the complete Benchmarking Universal Single-Copy Orthologs (BUSCO) score was 97.3%. The genome contained 762.12 Mb of repetitive elements, accounting for 70.27% of the total genome size. A total of 18,011 protein-coding genes were predicted, with 17,829 genes being functionally annotated. The high-quality genome assembly of D. aiolomorphi presented in this study will serve as a valuable genomic resource for future research on parasitoid wasps. The results of this study may also contribute to the development of biological control strategies for pest management in bamboo forests, enhancing ecological balance and economic sustainability.

New species of gall wasps (Hymenoptera: Cynipidae: Aulacideini and Phanacidini) inducing galls on plants of the genera Sonchus and Crepis (Asteraceae) in Romania (Dobrogea Province) and notes on their parasitoids

Two new species of herb gall wasps (Hym., Cynipidae) developing on plants in the genera Sonchus L. and Crepis L. (Asteraceae) are described from Southeastern Romania (Dobrogea Province): Aulacidea andriescui sp. n. gall inducer on Sonchus palustris L. and Phanacis dobrogicus sp. n. gall maker on Crepis foetida subsp. rhoeadifolia (M. Bieb.) Čelak. In addition to the diagnosis, identification, morphological description, life-cycle, geographical distribution, photos of gall and host plant, and SEM images, data on the associated fauna obtained from the galls of the two new species are also presented.

Defensive patterns of chestnut genotypes (Castanea spp.) against the gall wasp, Dryocosmus kuriphilus

Plants draw from various genetically controlled defenses to protect against herbivores and pathogens. The efficacy of alternative defenses can vary with the biology and phylogeny of the enemy.Dryocosmus kuriphilus, an invasive gall maker native to China, has become one of the main pests of chestnut trees around the world. We studied genetic variation in resistance and susceptibility toD. kuriphiluswithin a replicated blocked planting of 12 chestnut genotypes established in Galicia, Spain in 2004. We found very high genetic variation in susceptibility toD. kuriphilus. We evaluated if the variation was due to host selection by the wasp, differential efficacy of inducible defenses in the trees, or variability in susceptibility of the plant to manipulation by the gallmaker. We assessed host selection by counting number of eggs laid by females in tree buds and comparing preferences with phytochemistry. We also measured inducible changes in phytochemistry within and around galls, gall physical characteristics, parasitism, and insect fitness. The effective defense mechanisms in resistant genotypes involved (1) hypersensitive reactions to eggs or neonates within buds and (2) early precise abscission of nascent galls from expanding leaves. Surprisingly, the genetic resistance toD. kuriphilusof the chestnut genotypes we tested was not related to phenols, terpenes, and primary nutrition.

Phytohormones in galls on eucalypt trees and in the gall‐forming wasp Leptocybe invasa (Hymenoptera: Eulophidae)

Abstract The role played by phytohormones in insect galls and the mechanisms underlying plant manipulation by gall makers are still unclear. Galls made by Leptocybe invasa on two Eucalyptus species were sampled, the correlations between the levels of nine phytohormones in galls and gall size were analysed, and phytohormone levels in the interior and exterior tissues of galls and L. invasa were determined. During two larval stages, the levels of three forms of cytokinins (CKs) in the galls of the two plant species all showed significantly positive correlations with gall size. Brassinosteroids (BRs) and dihydrozeatin riboside (DHZR) occurred at significantly higher levels in the interior tissues of the galls compared to in the exterior tissues of galls. Isopentenyl adenosine (IPA) was significantly higher in L. invasa larvae themselves, compared to levels in the interior and exterior tissues of galls. However, the levels of DHZR and BR were significantly lower or similar in the L. invasa pupae compared to that in the interior and exterior tissues of the galls. These findings indicate that phytohormones, especially CKs, act as key regulators of L. invasa galls, and that the larvae of L. invasa may themselves be a source of CKs.

MANGO STEM BORER: A SERIOUS PEST AND MANAGEMENT STRATEGIES

Different insect infect mango like mango hopper, mango mealy bug, mango shoot gall maker, mango fruit fly, mango stone weevil etc. and minor insect like mango leaf webber, mango leaf-gall maker, red ant etc. Among the different pests in the mango, Mango Stem Borer(Batocera rufomaculata) is also one of the chief pest attacking mango in Terai region of Nepal. B. rufomacacuata, for example, has been causing concern in mango orchards. This paper delves into the detail review of information about the mango stem borer, it’s nature of damage, biological cycle and management strategies.

Species of sucking pests of ornamental crops in the conditions of the Southern Coast of the Crimea

The results of the analysis of the species composition of sucking pests species during the period from 2009 to 2019 are presented. Based on long-term phytosanitary monitoring, 37 species belonging to 12 families were identified, of which the most numerous are the families Diaspididae and Aphididae of the order Hemiptera. According to the nature of trophic connections, 59.9% are monophages, 32.4% are polyphages and 8.1% are oligophages. According to the nature of the damage caused, sucking species differ from each other. Some species lead to a change in the color of leaves and flowers (thrips, mites, coccids), others cause deformation of the leaf blade and inflorescences (coccids, worms, false coccids, herbivorous mites) and the third group includes species that form galls on the leaves (laurel psyllid, pistachio marginal gall aphid). According to ecological features, sucking pest species are divided into three main groups: open-living species, which include aphids, cicadae, psyllas, white flies, the second group includes species that have covers of various nature on the body, such as coccids, worms and false coccids, and the third group consists of gall makers. The dominant species, the degree of harmfulness, the frequency of occurrence and the range of forage plants were determined.

Assessing invertebrate herbivory in human-modified tropical forest canopies.

Studies on the effects of human‐driven forest disturbance usually focus on either biodiversity or carbon dynamics but much less is known about ecosystem processes that span different trophic levels. Herbivory is a fundamental ecological process for ecosystem functioning, but it remains poorly quantified in human‐modified tropical rainforests.Here, we present the results of the largest study to date on the impacts of human disturbances on herbivory. We quantified the incidence (percentage of leaves affected) and severity (the percentage of leaf area lost) of canopy insect herbivory caused by chewers, miners, and gall makers in leaves from 1,076 trees distributed across 20 undisturbed and human‐modified forest plots in the Amazon.We found that chewers dominated herbivory incidence, yet were not a good predictor of the other forms of herbivory at either the stem or plot level. Chewing severity was higher in both logged and logged‐and‐burned primary forests when compared to undisturbed forests. We found no difference in herbivory severity between undisturbed primary forests and secondary forests. Despite evidence at the stem level, neither plot‐level incidence nor severity of the three forms of herbivory responded to disturbance. Synthesis. Our large‐scale study of canopy herbivory confirms that chewers dominate the herbivory signal in tropical forests, but that their influence on leaf area lost cannot predict the incidence or severity of other forms. We found only limited evidence suggesting that human disturbance affects the severity of leaf herbivory, with higher values in logged and logged‐and‐burned forests than undisturbed and secondary forests. Additionally, we found no effect of human disturbance on the incidence of leaf herbivory.

Diversity of insect galls from Mato Grosso State, Brazil: North Pantanal

Abstract: The Pantanal Biome occupies 20% of the Brazilian territory extending its distribution over two Brazilian States, Mato Grosso and Mato Grosso do Sul. This Biome is one of Brazil's poorly known regions concerning insect gall and their interactions with host plants. In this study, we characterized for the first time the gall morphology, identified host plants and the gall makers from an area of Brazilian wetlands from Mato Grosso State, known as Pantanal Matogrossense. We sampled Pantanal Biome areas in Poconé municipality, along the Transpantaneira Road, Mato Grosso State, Brazil, in two expeditions, July 2012 and January 2013, with a total effort of 2 hours. We characterized 91 morphotypes of insect galls in 54 host plant species; 28 gall makers in 24 host plant species; the richest host plant families are Fabaceae, Myrtaceae, and Sapindaceae. Psidium guineense Sw. is the super host species. This area in Pantanal Matogrossense is the second in the richness of gall morphotypes (N=91) and average morphotypes/plant species (1.7), comparing phytophysiognomies. Additionally, 15 plant species are new record as host in galler-host plant interaction in the world. This number represents 30% of the total of host plant species sampled in Poconé. This inventory is new knowledge to the Pantanal Matogrossense and representing a unique testimony of insect-plant interactions consumed by the unprecedented fire that occurred in Pantanal Biome in the dry season of 2020.

Diversity of insect galls from Mato Grosso State, Brazil: Cerrado

Abstract: The Midwest region of Brazil possesses large areas dominated by the Cerrado that is poorly known concerning insect gall and their interactions. In this study, we inventory the gall morphology, host plants, and the gall makers from Parque Nacional da Chapada dos Guimarães, Mato Grosso State, in areas of natural vegetation from Cerrado, for the first time. Samplings occurred in two expeditions, July 2012 and January 2013. We characterized 295 morphotypes of insect galls in 140 host plant species, with 89 gall makers; the richest family in host plants was Fabaceae (16.7%), and the species was Protium heptaphyllum (Aubl.) Marchand (Burseraceae, 3.7%). Parque Nacional da Chapada dos Guimarães is the richest Brazilian cerrado area in gall morphotypes (295) and the second in average morphotypes/host plant species (2.1). Additionally, six genera and 38 species are new records as host plants; two of them, Bernardia similis Pax and K.Hoffm and Ormosia macrophylla Benth., are new occurrences for Mato Grosso State, and other two, Vochysia petraea Warm. and Talisia subalbens (Mart.) Radlk. are listed in the Red List of Threatened Species IUCN. This inventory data represents a testimony of insect-plant interactions in a Brazilian Cerrado area that was consumed by an unprecedented fire in the dry season of 2020.

Ecological rigidity and the hardness of selection in the wild.

Hutchinson's ecological theater and evolutionary play is a classical view of evolutionary ecology-ecology provides a template in which evolution occurs. An opposing view is that ecological and evolutionary changes are like two actors on a stage, intertwined by density and frequency dependence. These opposing views correspond to hard and soft selection, respectively. Although often presented as diametrically opposed, both types of selection can occur simultaneously, yet we largely lack knowledge of the relative importance of hard versus soft selection in the wild. I use a dataset of 3000 individual gall makers from 15 wild local populations over 5 years to investigate the hardness of selection. I show that enemy attack consistently favors some gall sizes over others (hard selection) but that these biases can be fine-tuned by density and frequency dependence (soft selection). As a result, selection is hard and soft in roughly equal measures, but the importance of each type varies as species interactions shift. I conclude that eco-evolutionary dynamics should occur when a mix of hard and soft selection acts on a population. This work contributes to the rapprochement of disparate views of evolutionary ecology-ecology is neither a rigid theater nor a flexible actor, but instead embodies components of both.

Ecological and Evolutionary Stochasticity Shape Natural Selection.

The distribution of biodiversity depends on the combined and interactive effects of ecological and evolutionary processes. The joint contribution of these processes has focused almost exclusively on deterministic effects, even though mechanisms that increase the importance of random ecological processes are expected to also increase the importance of random evolutionary processes. Here we manipulate the sizes of old field fragments to generate correlated sampling effects for a focal population (a gall maker) and its enemy community. Traits and communities were more variable in smaller patches. However, because of the preference of some enemies for some trait values (gall sizes), random variation in population mean trait values exacerbated differences in community composition. The random distribution of traits and interactions created predictable but highly variable patterns of natural selection. Our study highlights how stochastic processes can affect ecological and evolutionary processes structuring the strength and direction of selection locally and at larger scales.

Leaf trichomes in Metrosideros polymorpha can contribute to avoiding extra water stress by impeding gall formation.

Plants inhabiting arid environments tend to have leaf trichomes, but their adaptive significance remains unclear. Leaf trichomes are known to play a role in plant defence against herbivores, including gall makers. Because gall formation can increase water loss partly through increased surface area, we tested the novel hypothesis that leaf trichomes could contribute to avoiding extra water stress by impeding gall formation, which would have adaptive advantages in arid environments. We focused on Metrosideros polymorpha, an endemic tree species in the Hawaiian Islands, whose leaves often suffer from galls formed by specialist insects, Hawaiian psyllids (Pariaconus spp.). There is large variation in the amount of leaf trichomes (0-40 % of leaf mass) in M. polymorpha. Three gall types are found on the island of Hawaii: the largest is the 'cone' type, followed by 'flat' and 'pit' types. We conducted laboratory experiments to quantify the extent to which gall formation is associated with leaf water relations. We also conducted a field census of 1779 individuals from 48 populations across the entire range of habitats of M. polymorpha on the island of Hawaii to evaluate associations between gall formation (presence and abundance) and the amount of leaf trichomes. Our laboratory experiment showed that leaf minimum conductance was significantly higher in leaves with a greater number of cone- or flat-type galls but not pit-type galls. Our field census suggested that the amount of trichomes was negatively associated with probabilities of the presence of cone- or flat-type galls but not pit-type galls, irrespective of environmental factors. Our results suggest that leaf trichomes in M. polymorpha can contribute to the avoidance of extra water stress through interactions with some gall-making species, and potentially increase the fitness of plants under arid conditions.

Urban trees facilitate the establishment of non-native forest insects

Cities, due to the presence of ports and airports and the high diversity of trees in streets, parks, and gardens, may play an important role for the introduction of invasive forest pests. We hypothesize that areas of urban forest facilitate the establishment of non-native forest pests. Based on scientific literature and a pan-European database on non-native species feeding on woody plants, we analysed where the first detections occurred in European countries. We collected site data for 137 first detections in Europe and 508 first European country-specific records. We also estimated the percentage of tree cover and suitable habitat (green areas with trees) in buffers around detection points. The large majority of first records (89% for first record in Europe and 88% for first records in a European country) were found in cities or suburban areas. Only 7% of the cases were in forests far from cities. The probability of occurrence decreased sharply with distance from the city. The probability to be detected in urban areas was higher for sap feeders, gall makers, and seed or fruit feeders (>90%) than for bark and wood borers (81%). Detection sites in cities were highly diverse, including public parks, street trees, university campus, arboreta, zoos, and botanical gardens. The average proportion of suitable habitat was less than 10% in urban areas where the species were detected. Further, more than 72% of the cases occurred in sites with less than 20% of tree cover. Hotspots of first detection were identified along the coastal regions of the Mediterranean and Atlantic, and near industrial areas of central Europe. We conclude that urban trees are main facilitators for the establishment of non-native forest pests, and that cities should thus be intensely surveyed. Moreover, as urban areas are highly populated, the involvement of citizens is highly recommended.

Levels of Leaf Damage by Phyllophages in Invasive Acer negundo and Native Betula pendula and Salix caprea

The validity of some concepts underlying the enemy release hypothesis was tested using the example of Acer negundo, an invasive tree species in Eurasia. For this purpose, the frequency of leaf damage and the proportion of leaf area removed by phyllophagous invertebrates were compared between A. negundo and two native species, Betula pendula and Salix caprea. The leaves of these trees were collected in the city of Miass, the Southern Urals, where three rounds of sampling were carried out in the same habitats during the same growing season. A total of 10 000 leaves were examined to record damage by leaf chewers, miners, or gall makers, other kinds of damage, and the proportion of removed leaf area. By the end of the growing season, the proportion of damaged leaves in A. negundo was estimated at 37%, compared to 66% in B. pendula and 78% in S. caprea, with damage by specialized endophagous species (leaf miners and gall makers) in the first species being very low or absent; the proportion of removed leaf area (relative to the total) in A. negundo was less than 1%, compared to 5.8% in B. pendula and 7.5% in S. caprea. Thus, the level of leaf damage by phyllophagous invertebrates in A. negundo growing in the Southern Urals proved to be lower than in tree species native to this region. Therefore, the absence or low activity of natural enemies for A. negundo may be one of the factors accounting for the success of its invasion in Eurasia.

Characterization of insect galls from a vegetation area in Altinópolis, São Paulo State, Brazil

Herein, we studied the occurrence of insect galls from natural vegetation around the Itambé Cave, Altinópolis, SP, Brazil. A sampling effort of 7.5 hours resulted in 41 gall morphotypes on 21 host plant species from 14 families. The richest families of host plants in morphotypes were Fabaceae (N = 11), Euphorbiaceae (N = 7), and Malpighiaceae (N = 5). Copaifera langsdorffii Desf. (N = 8), Croton floribundus Spreng. (N = 7), Diplopterys pubipetala (A. Juss.) W.R. Anderson & C.C. Davis (N = 5), and Bauhinia holophylla (Bong.) Steud. (N = 4) were the super host plant species. Among the gall makers obtained, cecidomyiids were reared in 81% of cases and Hemiptera (Diaspididae), Hymenoptera (Eurytomidae), Coleoptera (Apion sp./Apionidae), and Lepidoptera in 4.5% of cases, each. The parasitoids belong to the Chalcidoidea superfamily (Hymenoptera). One new species of Camptoneuromyiia (Cecidomyiidae) was found in Smilax oblongifolia Pohl ex Griseb. (Smilacaceae) as inquiline and a new species of Lestodiplosis in Diplopterys pubipetala (Malpighiaceae) was a predator. We also present the first register of Bauhinia holophylla as host plants of Cecidomyiidae, and we expand the occurrence of Rochadiplosis tibouchinae Tavares and Couridiplosis vena to São Paulo State. The results of this paper are a continuation of the description of gall morphotypes from the vegetation in Northeastern São Paulo State, and they also increase knowledge about the diversity of host plant and gall-maker associations in the Neotropical region.

Biotic stress (insect) of aonla (Emblica officinalis)in arid region of India: a review

Indian gooseberry, Emblica officinalis popularly also known as Aonla, amla, amrit phal is found attacked various number of insect-pests causing considerable damage. In India, the major insect-pests reported from aonla are shoot gall maker Betousa stylophora; leaf roller, Caloptilia (Garcillaria) acidula; hairy caterpillar, Selepa celtis; bark eating caterpillar, Indarbela quardrionotata; leaf roller, Tonica (Psorosticha) ziziphy; bag worm, Zeuzera sp.; fruit borer, Meridarchis sp.; pomegranate butter fly, Deudorix isocrates; fruit sucking moth, Achaea janata; fruit midge, Clinodiplosis sp.; cow bug, Tricentrus congestus; plant hopper, Seliza truncate; spherical mealy bug, Nipaecoccus viridis; weevil, Myllocerus discolour; termite, Odontotermes obesus; leaf miner, Phyllocnistis citrella and hairy caterpillars, Euproctis fraterna.

HOW TO BE A GOOD NON-POLLINATING FIG WASP: GALLING WASPS (Idarnes group flavicollis) DO NOT INTERFERE WITH THE FLORAL RECEPTIVITY

Mutualistic relationships are open to exploitation by non-cooperative species that can reduce the fitness of one or both cooperating partners. In addition to their obligate agaonid pollinators, a diverse community of non-pollinating fig wasps (NPFW) also uses the figs as a resource for the development of their broods. Some species of NPFW are gall makers and compete with the pollinators for the same pool of pistillate flowers. We experimentally demonstrated that the oviposition of the galling wasp Idarnes sp. group flavicollis at the beginning of anthesis does not interfere with stigma receptivity or the fig attractiveness of Ficus citrifolia . However, in situations of high Idarnes sp. infestation, the time window during which pollinators can enter the figs is shortened approximately by half. The enlargement of the Idarnes gall compresses the ostiole bracts, leading to an early closing of the fig ostiole, although the figs are still attractive. This negative effect on fig pollination seems to be more important in severely fragmented habitats where heliophilous fig tree species such as F. citrifolia are more abundant, favoring population of NPFWs, making over-infestation more frequent.

Two new species of Dactylasioptera (Diptera: Cecidomyiidae) inducing stem galls on Maireana (Chenopodiaceae)

AbstractTwo new species of gall midges of the genus Dactylasioptera Kolesik & Veenstra‐Quah, (Lasiopteridi: Lasiopterini) are described from hairy stem tip galls on Maireana (Chenopodiaceae) in southern Australia. Dactylasioptera lebelae sp. nov. Veenstra & Kolesik, 2018 causes galls on Maireana pyramidata ranging from filamentous to spheroid. Dactylasioptera milnae sp. nov. Veenstra & Kolesik, 2018 causes rosette shaped, leafy galls on Maireana brevifolia. Descriptions of larvae, pupae, male and female adults, as well as geographical distributions of the new gall midges are given. The two species differ from each other in the larval, pupal and adult morphology as well as in mtDNA sequence data (COI). Galls of both species contained fungal mycelium and inquiline wasps Megastigmus sp. (Hymenoptera: Torymidae) and Aprostocetus sp. (Hymenoptera: Eulophidae: Tetrastichinae). The new species are the first confirmed gall makers from the Australian genus Dactylasioptera that contained previously two described species: Dactylasioptera adentata Kolesik & Veenstra‐Quah, and Dactylasioptera dentata Kolesik & Veenstra‐Quah, 2018, both of which are likely inquilines reared from galls induced by Asphondylia spp. (Diptera: Cecidomyiidae) on chenopod host plants. A matrix of morphological characters of Dactylasioptera species is given.

The Galling Truth: Limited Knowledge of Gall-Associated Volatiles in Multitrophic Interactions.

Galls are the product of enclosed internal herbivory where the gall maker induces a plant structure within which the herbivores complete their development. For successful sustained herbivory, gall makers must (1) suppress the induction of plant defenses in response to herbivory that is usually mediated through the jasmonic acid pathway and involves volatile organic compound (VOC) production, or (2) have mechanisms to cope with herbivory-induced VOCs, or (3) manipulate production of VOCs to their own advantage. Similarly, plants may have mechanisms (1) to avoid VOC suppression or (2) to attract galler enemies such as parasitoids. While research on VOCs involved in plant–herbivore–parasitoid/predator interactions is extensive, this has largely focussed on the impact of piercing, sucking, and chewing external herbivores or their eggs on VOC emissions. Despite the importance of gallers, owing to their damage to many economically valuable plants, the role of volatiles in gall-associated herbivory has been neglected; exceptions include studies on beneficial gallers and their enemies such as those that occur in brood-site pollination mutualisms. This is possibly the consequence of the difficulties inherent with studying internally occurring herbivory. This review examines the evidence for VOCs in galler attraction to host plants, potential VOC suppression by gallers, increased emission from galls and neighboring tissues, attraction of galler enemies, and the role of galler symbionts in VOC production. It suggests a research focus and ways in which studies on galler-associated VOCs can progress from a philatelic approach involving VOC listing toward a more predictive and evolutionary perspective.