Structure,biochemistry and ecology of entomogenous galls in Selaginella Pal. Beauv. (Selaginellaceae) from India

Abstract

We studied the structure of newly found entomogenous galls in three Indian species of Selaginella, and the biochemical changes during gall development as well as their seasonal abundances in 10 squares of 1.5 m² under two differing habitat conditions, open and covered. Adult wasps (Cynipidae) initiate two types of gall formation by oviposition, spherical galls on vegetative shoots and elongated, club-shaped strobilar galls on reproductive shoots. Galls are anatomically and biochemically different from the unaffected shoots. Vegetative shoot apices bear more galls (84.6%) than reproductive shoot apices (15.4%). Gall frequency is significantly higher in covered (94.8%) than in open habitat (5.2%), and its seasonal peak occurs earlier in the former (43.1% during the rainy season) than in latter habitat (52.8% in autumn). We discuss the relationship between relative species density and gall seasonality as well as the possible role of certain environmental factors that make covered habitats more favorable to the gall inducer.     

Transformation of forage legumes using Agrobacterium tumefaciens

Summary Galls were induced in six species of forage legumes following inoculation with wild-type strains of A. tumefaciens. The plant species was more influential than the bacterial strain in determining the type of tumour produced. Inoculation of Medicago sativa resulted in small, disorganised tumours. The three Trifolium species, T. repens, T. hybridum and T. pratense, formed galls which tended to produce roots and both Onobrychis viciifolia and Lotus corniculatus produced teratomatous galls. The shoots elongated in the latter species only. In L. corniculatus, tissues that were infected by five bacterial strains were capable of shoot regeneration when cultured on a hormone-free medium. The transformed nature of these shoots was confirmed by their failure to root, the production of callus from leaves cultured on hormone-free medium and the presence of opines.     

Structure of floral galls of Byrsonima sericea (Malpighiaceae) induced by Bruggmanniella byrsonimae (Cecidomyiidae,Diptera) and their effects on host plants

Galls are anomalies in plant development from parasitic origin, and affect cellular differentiation or growth of plants. This parasite–plant interaction occurs in many environments and typically in vegetative organs of plants. The existence of galls in reproductive organs and their effects on the host plant are seldom described in the literature. In this paper, we present a novel study of galls in plants of the neotropical region. Galls of Bruggmmaniella byrsonimae develop in the flower buds of Byrsonima sericea DC. (Malpighiaceae) and affect development of the reproductive organs and the reproductive effort of these plants. The sepals and petals show hypertrophy of parenchyma tissues after differentiation, and the stamens exhibit degeneration of the sporogenic tissue. The gynoecium is not entirely developed; ovary and ovules are often absent. Changes in vascular tissues are also frequent, which may indicate high demand for nutrient resources by the new tissues initiated by the larva. We compared the amount of inflorescences, galls and fruits to evaluate possible effects on host reproduction. The results suggest that the Cecidomyiidae galls in flower organs affect fruit set and the reproductive success of B. sericea.     

Detection of an invasive gall-inducing pest, Quadrastichus erythrinae (Hymenoptera: Eulophidae), causing damage to Erythrina variegata L. (Fabaceae) in Okinawa Prefecture, Japan

In 2005, Quadrastichus erythrinae Kim, 2004 (Hymenoptera: Eulophidae), which induces stem, petiole, and leaf galls on Erythrina variegata L. (Fabaceae), was found on the following six islands in Okinawa Prefecture, Japan: Okinawa, Kume, Miyako, Ishigaki, Iriomote, and Hateruma. Galls were also found in Vietnam. In Japan, no further infestation records have been reported from any of Japan's other south‐western prefectures where Erythrina species grow. Because no Erythrina galls were observed in Okinawa Prefecture before 2005, Q. erythrinae seems to have invaded quite recently.     

Resistenza di Pterocladia Capillacea (Gmel.) Born. Et Thur. A Variazione di Salinità

Abstract

Resistence of Pterocladia capillacea (Gmel.) Born, et Thur. to salinity variations. In the present paper the effects of salinity variations on P. capillacea are reported. Particularly, growth of apical segments, regenerations of intercalary segments, colour of thallus and, for some samples, respiration and photosynthesis are examined. The results obtained show that in sea water with reduced salinity (¾), there is a good adaptation. At salinity levels lower or higher the following phenomena are seen: a) the colour decreases; b) regeneration is inhibited; c) the growth of apical segments is abolished or reduced. Respiration and photosynthesis have been determined in the material cultured in distilled water and in high salinity medium (× 4). The results show that in the first condition the rate of O₂ consumption remains constant for 48 hours, while O₂ production decreases after an hour. In salinity × 4, O₂ production compensate consumption after an hour. When intercalary segments (cultured in salinity ×4) are transferred to sea water photosynthesis is restored. On the contrary, when they are kept in sea water with high salinity for 23 hours, respiration decreases and photosynthesis is inhibited and is not restored by transferring the material to sea water with normal salinity for additional 24 hours. Analysis of pigments, carried out after 48 hours, has shown that in distilled water liposoluble pigments disappear while 30% phycoerytrin is still present. In salinity ×4, carotenoids and chlorophyll decrease to much lower quantities than phycoerythrin.     

Fungal diversity in galls of baldcypress trees

The baldcypress midge (Taxodiomyia cupressi and Taxodiomyia cupressiananassa) forms a gall that originates from leaf tissue. Female insects may inoculate galls with fungi during oviposition, or endophytes from the leaf tissue may grow into the gall interior. We investigated fungal diversity inside of baldcypress galls, comparing the gall communities to leaves and comparing fungal communities in galls that had successful emergence versus no emergence of midges or parasitoids. Galls of midges that successfully emerged were associated with diverse gall fungal communities, some of which were the same as the fungi found in surrounding leaves. Galls with no insect emergence were characterized by relatively low fungal diversity.     

Spatio-temporal patterns of mortality in Pemphigus populicaulis and P. populitransversus on cottonwoods

Summary Galls of the aphid species Pemphigus populitransversus and P. populicaulis from a single cottonwood in Clinton, New York were censused for mortality approximately every ten days during the summer of 1978. P. populitransversus had significantly higher survival than P. populicaulis. Both species of aphid showed considerably elevated mortality later in the season. Mortality was not spatially random, but neighboring galls had a tendency to die at close to the same time. This tendency to spatially autocorrelated mortality varied from time to time, being more pronounced earlier in the season than later. Later in the season, galls on the outer portions of branches tended to have a higher mortality rate than galls closer to the main trunk of the tree. This effect was highly significant in P. populicaulis, but only suggestive in P. populitransversus.The proportion of dead galls in samples of the two species taken at other times and places was consistent with the data from the censuses. In addition, the potential of two common predators, Anthocoris sp. and Leucopis sp., for producing autocorrelated mortality in Pemphigus was assessed in these collections. There was some association of Leucopis with regions of higher mortality, but this was not the case in Anthocoris. Leucopis tended to be found in galls of P. populicaulis more frequently than in P. populitransversus unlike Anthocoris, suggesting that some of the differential mortality between P. populitransversus and P. populicaulis might be due to this dipteran predator.     

Factors affecting components of fitness in a gall-making wasp (Cynips divisa Hartig)

Summary The galls of the agamic generation of the cynipid gall-wasp Cynips divisa were studied; these galls are found only on the main veins of the leaf. Galls are concentrated on the middle veins of leaves, and generally occur closer to the midrib than to the edge of the leaf. Survival of the gall-maker and fecundity of the energing wasp depend on wasp size and position of the gall. There is a striking pattern in gall size according to the number of galls on the vein. The number of galls on a vein appears therefore to have a strong effect on potential fecundity.     

Why a gall former can be a good biocontrol agent: the gall wasp Trichilogaster acaciaelongifoliae and the weed Acacia longifolia

ABSTRACT.

• 1 The pteromalid Trichilogaster acaciaelongifoliae (Froggatt) causes galls to develop in the place of inflorescences during the reproductive phase of its host Acacia longifolia (Andr.) Willd. (Fabaceae). After being introduced to South Africa during 1982 and 1983, this wasp reduced the reproductive potential of A. longifolia by >89% when only 50% of the branches on a tree were galled. In addition, vegetative growth of galled branches was reduced by 53% when the vacated galls had desiccated.
• 2 The wasp is able to manipulate its host so effectively because: (a) the dry mass of developing galls was significantly greater than that of the corresponding reproductive organs, peaking in spring (September) when galls were 25 times the mass of unfertilized inflorescences. (b) The large biomass diverted to gall production is accounted for by a high proportion (66–73%) of multiple-chambered galls. The dry mass of multiple-chambered galls was significantly greater than that of both single-chambered galls and pods. (c) The extent of biomass diversion to gall production was relatively greater during the earlier part of the reproductive season, enhancing stress on the host. (d) The wasp sometimes forced the plant to produce up to 200% more galls per branch than the normal quota of inflorescences. This phenomenon, called forced commitment, further increases stress on the host plant. (e) Galls constituted up to 21% and 40% of the dry and wet biomass of above-ground parts of infested trees, respectively. This caused breakage and mortality of large branches and stems. (f) Reproduction in A. longifolia has been shown elsewhere to be so energy consuming that vegetative growth is strongly inversely related to pod production. Because the stress from galling by T. acaciaelongifoliae coincides with and replaces reproduction with a greater stress, successful reduction of both reproduction and vegetative growth are achieved.
• 3 This biological control programme is the first in which a gall-forming hymenopteran has been used to control a weed. Since the effects of gall-formers are indirect compared with those of insects attacking vegetative plant parts, their potential as biocontrol agents has been underrated. This research provides ecologically based guidelines for the future selection of such agents.

     

Histological study of galls induced by aphids on leaves of Ulmus minor: Tetraneura ulmi induces globose galls and Eriosoma ulmi induces pseudogalls

The histological study of galls may provide information on the evolution of the organisms that induce them. The walls of two aphid-induced galls on leaves of Ulmus minor were therefore studied histologically: a globose gall induced by Tetraneura ulmi and a pseudogall induced by Eriosoma ulmi. Galls are regarded as extended phenotypes of aphids, and therefore, they can be used as tools for phylogenetic studies. The walls of the galls induced by T. ulmi are not reminiscent of the ungalled leaf structure of U. minor in any area, showing both cellular hypertrophy and hyperplasia. Galls induced by E. ulmi resemble the leaf structure of U. minor in certain aspects, but in most aspects they do not, showing only cellular hypertrophy. Processes of growth and differentiation are observed in both galls. Based on the findings of this study and other recent publications, we propose to categorize the galls induced by aphids into four types: (1) pseudogalls; (2) closed galls with a “door”; (3) closed galls determined by active processes of growth and differentiation of the lamina of the leaf; and (4) closed galls determined by active processes of growth and differentiation of the midvein.     

Antioxidant,Cytotoxicity, Apoptotic Properties of Extracts of Andricus sternlichti galls and Their Phenolic Characterisation by HPLC

Quercus L. galls have been used in Western and Eastern cultures for various diseases in traditional medicine. Galls are also used in the East for many purposes, including consumption as food, commercial inks, leather tanning. In the current study, Andricus sternlichti Bellido, Pujade-Villar & Melika, 2003 galls were extracted in different solvents. The possible antioxidant effects of gall extracts were determined using 7 different methods (β-carotene-linoleic acid assay, Phosphomolybdenum assay, DPPH and ABTS radical scavenging activity, CUPRAC and FRAP assay, Metal Chelating activity) to support each other. Total phenolic, flavonoid and tannin amounts of extracts are calculated by using standard curves. In addition, HPLC method used to characterize the phenolic component with 15 different standards. The MIA PaCa-2 cell lines was preferred to identify possible cytotoxic activities of galls. Expression of some genes (Bax, Bcl-2, FAS, BID, caspase-3, caspase-8, caspase-9, caspase-10, FADD, TRADD) role in the apoptosis was determined to investigate apoptotic effects of extracts. According the results, the gall extracts of A. sternlichti may be considered as a potential source of biological agents for their antioxidant capacity and rich bioactive compounds. The gall extracts exhibit antiproliferative activity via regulating expressions of apoptotic genes.     

The distribution of risk and density-dependent mortality in the galls of Eurosta solidaginis, the goldenrod gall fly

ABSTRACT.

• 1 This paper explores the net effect of a suite of mortality factors on a sedentary prey, the larvae of the goldenrod gall fly, Eurosta solidaginis Fitch (Diptera: Tephritidae).
• 2 Mortality is caused by unknown factors early in larval development, two species of parasitoid wasp (Hymenoptera: Eurytomidae), an inquiline beetle larva (Coleoptera: Mordellidae), and during the winter months downy woodpeckers Picoides pubescens (L.).
• 3 Distribution of mortality among galls relative to prey (gall) distribution was measured and discussed with respect to the distribution of relative risk of predation.
• 4 Galls are by and large contagiously distributed among quadrats, and mortality is distributed in a comparable pattern to that of galls.
• 5 The pattern of mortality on Eurosta larvae is neither density-dependent nor aggregated independently of gall distribution. Persistence in the system is probably a result of a combination of other factors such as adult mortality and early larval death which may have intergenerational density-dependent effects, and the linkage of locally unstable sub-populations via migration.

     

Nipponaphis species (Aphididae: Hormaphidinae) that form green galls on Distylium racemosum in Japan

Some species of the aphid genus Nipponaphis (Nipponaphidini) form green, globular or fig‐shaped galls on the evergreen Distylium racemosum, their primary host. Molecular phylogenetic analyses of aphid samples collected from both their galls and secondary hosts indicated the occurrence of four species in Japan: N. distychii, N. distyliicola, N. loochooensis and N. machilicola. The four species could also be discriminated from one another in morphology. The name N. litseae turned out to be a junior synonym of N. distychii. Galls formed by N. machilicola are reported for the first time in this paper. The life cycles of the four species are briefly reviewed.     

Competition and niche relationships among Eriosoma aphids occurring on the Japanese elm

Summary Galls of more than one species of Eriosoma (Aphidoidea) are found sympatrically even on single trees. Incipient galls are frequently invaded by conspecific and/or allospecific fundatrices. Eriosoma yangi, a component of Eriosoma communities, does not form its own galls but obligatorily usurps those of other species. There were interspecific differences in the timing of gall formation and the spatial distribution of galls. Nevertheless E. yangi fundatrices randomly invaded galls of any Eriosoma species and occupied 33%–41% of galls of each species. When more than one E. yangi fundatrix invaded one gall, mortal fights sometimes occurred. Fundatrices of gall-forming species also seemed to take part in such fights. Fundatrices of gall-forming species had a significant tendency to invade galls of a particular species. However, taking account of niche differences among species, invaders apparently entered available galls at random. Apparently E. yangi fundatrices search an extensive range within a branch for galls, while invaders of gall-forming species search a restricted speciesspecific range. The niche relation of gall-forming species in a northern community containing E. yangi were compared with those in a southern community lacking E. yangi. No obvious difference was found between them, suggesting that parasitism by E. yangi has not influenced niche divergence within the Eriosoma community.     

Host plant effects on the development and survivorship of the galling insect Neopelma baccharidis (Homoptera: Psyllidae)

In this study, the mortality factors acting upon the galling psyllid Neopelma baccharidis Burckhardt (Homoptera) caused by its host plant, Baccharis dracunculifolia De Candole (Asteraceae) were analysed. In March 1999, 982 galls of the same cohort were randomly marked on 109 individuals of B. dracunculifolia in the field. Galls were censused each month during their development, from April to August, and dead galls were collected and analysed for mortality factors. Gall dehiscence rates were calculated for each month. The major mortality source of N. baccharidis was gall dropping (13.2% of the original cohort), which is probably a normal outcome of previous mortality caused by the other factors observed in this study. Unknown factors killed 11.7% of this gall population and were ascribed to plant resistance during gall development. Empty galls represented 7.7% of the observed mortality and may be a consequence of egg retention or egg mortality/abortion related to variations in plant quality. Shoot mortality was high during the dry season and killed 7.5% of the galls, but this impact was minimized after the third month from gall formation due to the ability of nymphs to accelerate development and emerge from galls on dying shoots. However, the size of dehisced galls on dead shoots tended to be smaller, possibly affecting adult performance. Mortality of N. baccharidis attributed to B. dracunculifolia strongly controlled the galling insect population, killing 40.7% of the original cohort of galls. Plant‐mediated mortality was caused by often neglected factors acting predominantly during the first 3 months of development, which are critical to gall survivorship. These results reinforce the importance of bottom‐up forces in plant‐insect systems.     

A new Asphondylia species (Diptera: Cecidomyiidae) and a eulophid wasp (Hymenoptera) inducing similar galls on leaf buds of Schoepfia jasminodora (Schoepfiaceae), with reference to their ecological traits and a description of the new gall midge

Different gall inducers belonging to distinct insect orders are rarely known to induce similarly shaped galls on the same host plant organs. We report that Asphondylia tojoi Elsayed & Tokuda sp. nov. (Diptera: Cecidomyiidae) and Ceratoneura sp. (Hymenoptera: Eulophidae) induce galls on leaf buds of Schoepfia jasminodora Sieb. et Zucc. (Schoepfiaceae). We describe the gall midge species as new to science and report a phylogenetic analysis for known Japanese Asphondylia species. We also describe life histories of the two species, based on monthly surveys during 2015–2017: although both species are multivoltine, A. tojoi overwinters as first instars in galls, whereas Ceratoneura sp. possibly does so as adults outside the galls. In addition, the internal structure of galls differed between the two species. Galls containing A. tojoi consist of a single chamber with inner walls clearly covered with whitish fungal mycelia after the gall midges develop into second instars. Those containing the Ceratoneura sp. have multiple chambers with hard black inner walls. Although some eulophids are known to be inquilines of galls induced by Asphondylia species, we consider that the Ceratoneura sp. is probably a true gall inducer because of the different gall structure and absence of fungal mycelia in their galls. This is the first report detailing the annual life history of a Ceratoneura species. Asphondylia tojoi represents the first example of monophagous Asphondylia species with a multivoltine life history on a deciduous tree.     

Hypersensitivity of Fagus sylvatica L. against leaf galling insects

Hypersensitivity is known as a localized resistance of plants against pathogens. It also can be detected in response to galling insects, i.e., in the area immediately adjacent to the site of oviposition and attempted penetration by the galling larva. This host response includes morphological and histological changes that cause the death of the attacked tissue. It is observed as a rounded dark brown halo around the gall induction site. We provide the first observation on the occurrence and possible relevance of this induced mechanism by which one of the most common tree species in Germany, Fagus sylvatica L., resists attack by two of its most common galling insects, Mikiola fagi and Hartigiola annulipes (Diptera: Cecidomyiidae). Galls induced by these cecidomyiids were extremely common in the studied area in beech forests around Darmstadt, Germany. The availability of resources (leaves on a stem) was a poor predictor of attack by the galling insects as well as for gall abundance (galls successfully formed). Hypersensitive reaction was the most important factor acting against the galling population studied. More than 77% of the attempts of the insects to induce galls on F. sylvatica resulted in failure and consequently the death of the galling larvae. Therefore, few live galls remained to be found and destroyed by natural enemies. This corroborates the view that in galling insect–host plant system interactions plant-driven factors may play a major role in determining herbivore failure and success, and perhaps the resulting community structure.     

Microscopic study of the walls of galls induced by Geoica utricularia and Baizongia pistaciae in Pistacia terebinthus: a contribution to the phylogeny of Fordini

In the west of the Province of Leon (Spain), five species of gall-dwelling aphids, or greenflies, trigger the formation of different galls in Pistacia terebinthus: Forda formicaria, F. marginata, Paracletus cimiciformis, Geoica utricularia and Baizongia pistaciae. In the research presented here, a microscopic study was carried out of the wall of galls induced by the latter two species, G. utricularia and B. pistaciae. Galls induced by the first three species had already been studied previously by the same author. All the species of aphids mentioned above are included in the Eriosomatinae, Fordini. Among these, some authors further claim that it is possible to distinguish two clades: Forda and Paracletus would be included in one of these, whilst Geoica and Baizongia would be included in the other. The results of this study show that the walls of galls induced by G. utricularia and B. pistaciae present collateral vascular bundles. Specifically, there are two such vascular bundles: one distant from the chamber and the other separated from it by only a very few cells. The phloem in the latter vascular bundle is oriented towards the chamber. Furthermore, in the two galls studied, the chamber is lined with a lattice-like structure with hollows. These microscopic observations have enabled the walls of the galls studied to be differentiated from those triggered by Forda and Paracletus. These latter present a single vascular bundle, with the xylem oriented towards the chamber, whilst the surface of the chamber lining has a quilted appearance and lacks openings. This research provides data from microscopy to support the existence of two clades among the Fordini.     

Non-random distribution among a guild of parasitoids: implications for community structure and host survival

Abstract 1. Immature stages of the gall midge, Asphondylia borrichiae, are attacked by four species of parasitoids, which vary in size and relative abundance within patches of the gall midge’s primary host plant, sea oxeye daisy (Borrichia frutescens). 2. In the current study, a bagging experiment found that the smallest wasp, Galeopsomyia haemon, was most abundant in galls exposed to natural enemies early in the experiment, when gall diameter is smallest, while the wasp with the longest ovipositor, Torymus umbilicatus, dominated the parasitoid community in galls that were not exposed until the 5th and 6th weeks when gall diameter is maximal. 3. Moreover, the mean number of parasitoids captured using large artificial galls were 70% and 150% higher compared with medium and small galls respectively, while stem height of artificial galls significantly affected parasitoid distribution. Galls that were level with the top of the sea oxeye canopy captured 60% more parasitoids compared with those below the canopy and 50% more than galls higher than the plant canopy. 4. These non‐random patterns were driven primarily by the differential distribution of the largest parasitoid, T. umbilicatus, which was found significantly more often than expected on large galls and the smallest parasitoid of the guild, G. haemon, which tended to be more common on stems level with the top of the plant canopy. 5. Large Asphondylia galls, especially those located near the top of the Borrichia canopy, were more likely to be discovered by searching parasitoids. Results using artificial galls were consistent with rates of parasitism of Asphondylia galls in native patches of sea oxeye daisy. Gall diameter was 19% greater and the rate of parasitism was reduced by almost 50% on short stems; as a result, gall abundance was 24% higher on short stems compared with ones located near the top of the plant canopy. 6. These results suggest that parasitoid community composition within galls is regulated by both interspecific differences in ovipositor length and preferences for specific gall size and/or stem length classes.     

New records of Vaucheria species (Xanthophyceae) with associated Proales werneckii (Rotifera) from North America

The presence of galls on species of Vaucheria was investigated both seasonally and in a number of locations in North America. These galls are induced by the rotifer, Proales werneckii. In an Ohio stream, Vaucheria bursata and V. geminata were found to have galls throughout their growing season; September to January. Galls were most abundant in October and ranged in size from 90–260 μm in width and 140–790 μm in length. New records of Vaucheria with galls from locations in Alabama, California, Georgia, Louisiana, North Carolina, Ohio and Tennessee are reported. Three of the five taxa collected were not previously known to contain galls. In addition, worldwide literature on the distribution of these associated taxa was reviewed.