Gall Infestation Research Articles

Molecular Confirmation for Gall Midge (Biotype 3) Resistance in Phenotypically Resistant Rice Genotypes Using Functional Markers

This study performed molecular screening of rice genotypes, which showed no gall infestation in field conditions at the Regional Agricultural Research Station (RARS), Jagtial, during rabi, 2021-22. using functional markers such as “gm3del3” for the gm3 gene, “LRR del” for the Gm4 gene, and “PRP” for the Gm8 gene, six genotypes were analyzed. WGL-1145 contained all three resistance genes (gm3, Gm4, and Gm8). Additionally, three genotypes namely WGL-1147, WGL-1127, and Kakai had the Gm4 and Gm8 genes, while RP-5332-54-11-8-2-13 had only Gm8 and IR72476-B-P-9-3-1-1 possessed only gm3. These findings contribute to developing new rice varieties with resistance to gall midge, which can improve crop yields and food security in affected regions. Some promising rice varieties may be used as donors in breeding programs aimed at creating pyramided lines with durable gall midge resistance.

Ecological Impact of American Chestnut Hybrid Restoration on Invertebrate Communities Above- and Belowground

The cross-hybridization of American chestnut (Castanea dentata (Marsh.) Borkh.) with Chinese chestnut (Castanea mollissima Bl.) is a promising strategy for restoring a blight-resistant strain of this keystone species to the Appalachian mountains. To assess the ecological impacts of hybridization on invertebrate communities, we conducted a study across chestnut plots with varying degrees of hybridization (75%, 94%, or 100% American chestnut). Our findings indicate American chestnut hybridization impacted invertebrate communities above- and belowground. Aboveground insect community composition, insect herbivory, gall infestation, and belowground invertebrate diversity were all altered. While some of these differences could be explained by different growth habits or environmental differences, stark differences in Asian chestnut gall wasp infestation (Dryocosmus kuriphilus Yasumatsu.) suggest a genetic component. These results suggest that chestnut hybridization, and particularly expanded restoration efforts using chestnut hybrids, could impact invertebrate communities above- and belowground in addition to pest dynamics. Understanding these effects is crucial for successful chestnut restoration and ecosystem management.

Host Reaction of Some Local Tomato Varieties against Root Knot Nematode, Meloidogyne incognita (Kofoid and White) Chitwood

An experiment was conducted for the investigations on screening on different local tomato varieties against RKN, Meloidogyne incognita under net house conditions during the year 2021-22. Out of thirty-five varieties only four (Abhimanyu, HY- Rocky, HY- 1276 and HY-Red Boar) were found to be moderately resistant to the nematode having root gall index between 2.1 to 3.0. Twenty-one varieties were found to be susceptible having root gall index between 3.1 to 4.0, but the remaining varieties were quite vulnerable to the nematode having root gall index between 4.1 to 5.0. Additionally, it was discovered that, in comparison to the other tomato types, Amlan and HY-3682 (Special) had the most gall infestation. All the varieties showed significant differences in their responses or reactions to root-knot nematodes from moderately resistant to vulnerable.

Studies on the Efficacy of Heterogeneously Produced Pasteuria Penetrans (PP3) Isolate over Individual Pasteuria Isolates in the Spore Attachment, and Pathogenic Potential on Three Meloidogyne Species

The aim of the present test was to develop a Pasteuria penetrans isolate (Pp3) on a Meloidogyne blend and compare the attachment and pathogenic potential of this heterogeneously produced isolate with other Pp3 isolates produced on individual Meloidogyne species (Meloidogyne javanica, M. incognita and M. arenaria). Number of spores attached varied among Meloidogyne spp. Pp3 isolate originally multiplied on M. javanica showed greater attachment level with second stage juveniles (J2s) of M. javanica (13.8) than other Meloidogyne spp. tested and lesser attachment was observed on J2s of a M. arenaria. The Pp3 isolate showed variable influence on the Meloidogyne spp. in suppressing root-knot disease. There was a significant difference in numbers of eggmasses produced by females of Meloidogyne spp. Higher numbers of eggmasses were recorded with females of M. arenaria (370) while fewer numbers of eggmasses were observed in treatment where M. javanica (245) was present. Root galling differed significantly among treatments (P0.01) and higher gall infestation was recorded in M. arenaria treatment (6.2) while lesser galling was observed in M. javanica treatment (4.4). Final female population also varied among treatments (P0.05) showing higher numbers of females in M. arenaria treatment (456) and fewer with M. javanica (398). Parasitism of females of Meloidogyne spp. by Pp3 differed significantly among treatments. Higher numbers of females infected with Pp3 spores were recorded among females of M. javanica (14.4) while lesser numbers of parasitized females were observed in M. arenaria treatment (9.8). There were significant variations in numbers of endospores/female produced by females of Meloidogyne spp. however egg set data did not differ in the treatments. The results showed that the Pp3 isolate was more pathogenic on M. javanica compared with other Meloidogyne spp. (M. incognita, M. arenaria and M blend). The Pp3 isolate was found compatible with different Meloidogyne spp. while M. arenaria proved the least good host to bacterial parasite

Sun and shade galls of Clinodiplosis profusa (Cecidomyiidae) on Eugenia uniflora (Myrtaceae): Are there differences in their establishment and growth?

Gall-inducing insects stimulate their host plants, leading to the formation of distinct structures, such as the fusiform galls induced by Clinodiplosis profusa Maia, 2001 (Cecidomyiidae) on leaves of Eugenia uniflora L. (Myrtaceae). The influence of different light conditions on infestation rates, establishment, and morphogenesis of galls is little known. We tested if gall infestation is higher in E. uniflora sun plants compared to shade plants, and if the size, anatomical, and histometrical features of the mesophyll and epidermis are distinct between sun and shade leaves and galls. Gall infestation rates are similar in sun and shade plants, although the results indicate a possible difference in life cycle duration between the light conditions. Anatomical data revealed the leaves and galls respond similarly to sun and shade for number of cell layers. In the galls the hyperplasia provoked by C. profusa is influenced by distinct sunlight exposure. Cell hypertrophy and a reduced stomatal index in the galls is remarkable when compared to non-galled leaves. The cell sizes in the mesophyll and epidermis and stomatal densities are similar between the sun and shade galls, but these factors are distinct between the sun and shade leaves. Cell hypertrophy and epidermal differentiation patterns are more influenced by the gall inducer, which inhibits the influence of light on these patterns. In conclusion, gall morphogenesis is strongly influenced by galling stimuli for some developmental processes, but other processes are influenced by abiotic conditions, such as light exposure. This opens a field in gall ecological anatomy and development.

Study of anatomical alterations in mango leaf due to gall infestation

Study of anatomical alterations in mango leaf due to gall infestation

Survey on the incidence of Asian rice gall midge, Orseolia oryzae (Cecidomyiidae: Diptera) in Cauvery command area

A survey was conducted on the incidence of gall midge in paddy ecosystem in Cuavery and Kabini command area, Karnataka. In Cauvery and Kabini command area mainly Jaya, Jyothi, MTU 1001, BR 2655, Tanu, Gangavathi sona are cultivated in which about 50 % area is covered by Jaya. The crop is infested by gall midge which plays a significant role in limiting the rice production. During the survey along with gall midge other pests like yellow stem borer, hispa case worm, Leaf folder were noticed. Among the three districts surveyed Mandya districts has recorded higher gall midge infestation with per cent silver shoot of 9.03, which was followed by Chamarajanagar (8.70% SS). The lower gall midge infestation was noticed in the Mysore district with per cent silver shoot of 6.95. Due to the gall midge infestation the tiller become sterile and leads to yield loss. Early gall infestation in nursery results in the stunted growth and bushy appearance. Since gall midge being endoparasitic in nature, cultivation of resistant varieties is the most economical and feasible for its control.

Urbanisation and forest size affect the infestation rates of plant-galling arthropods and damage by herbivorous insects

Urbanisation is increasing globally and is considered to be a main driver of environmental change. Urbanisation-related factors include reduced habitat size and increased spatial isolation of the remaining habitats. As a consequence, the dynamics of plant and animal populations may change, which in turn might influence the quality and quantity of plant resources. Thus, urbanisation has the potential to disturb plant-animal interactions such as herbivory or galling. In the urban-rural setting of Basel (Switzerland), we aimed to assess whether the degree of urbanisation and forest size influence plant-galling infestation rates and leaf damage by mining and chewing arthropods on three tree species (sycamore, beech, and ash). We recorded species-specific responses to the degree of urbanisation and forest size. Gall infestation rate on sycamore leaves was affected by urbanisation but not by forest size. In contrast, gall infestation rates of beech gall midges responded sensitively to increasing urbanisation and decreasing forest size. The total leaf area damage caused by mining and chewing arthropods on sycamore was influenced by urbanisation and increased with increasing forest size. Leaf area damage by miners in beech tended to be affected by the degree of urbanisation, but not in ash. Urbanisation and forest size have the potential to alter herbivorous insect abundances. However, the effects depend on tree species and herbivore guild.

Petiole gall aphid (Pemphigus spyrothecae) infestation of Populus × petrovskiana leaves alters foliage photosynthetic characteristics and leads to enhanced emissions of both constitutive and stress-induced volatiles.

Poplar spiral gall aphid (Pemphigus spyrothecae) forms galls on the petiole in poplars (Populus) and mass infestations are frequent in poplar stands, but how these parasite gall infestations can affect the leaf lamina structure, photosynthetic rate and constitutive and stress volatile emissions is unknown. We investigated how the infestation by the petiole gall aphids affects lamina photosynthetic characteristics (net assimilation rate, stomatal conductance), C and N contents, and constitutive isoprene and induced volatile emissions in Populus × petrovskiana. The dry gall mass per leaf dry mass (M g/M l) was used as a quantitative measure of the severity of gall infestation. Very high fraction of leaf biomass was invested in gall formation with M g/M l varying between 0.5-2. Over the whole range of the infestation severities, net assimilation rate per area, leaf dry mass per unit area and N content decreased with increasing the severity of infestation. In contrast, stomatal conductance, leaf dry mass per fresh mass, constitutive isoprene emissions, and induced green leaf volatile (GLV), monoterpene, sesquiterpene and benzenoid emissions increased with increasing the severity of gall infestation. The rates of induced emissions were low and these emissions were associated with methyl jasmonate release from leaf laminas. The data demonstrate that petiole gall infestations lead to major changes in leaf lamina sink-source relationships and leaf water relations, thereby significantly altering lamina photosynthesis. Modifications in stress-induced emissions likely indicated systemic signaling triggered by jasmonate transported from the petiole galls to the lamina where jasmonate elicited a cascade of volatile emission responses. Enhance isoprene emissions and induced volatile emissions can play a major role in indirect defense against other herbivores, securing the food source for the gall aphids. In conclusion, a massive infestation by petiole gall aphids can profoundly modify the foliage photosynthetic performance and volatile emission profiles in poplars.

Does foliage metal accumulation influence plant–insect interactions? A field study of two sympatric tree metallophytes

Gossia (Myrtaceae) is a highly restricted tree genus most speciose in New Caledonia and eastern Australia. The latter group accumulates above-normal foliar manganese (Mn) concentrations, with some individuals exhibiting the rare Mn-hyperaccumulative trait. Whether foliar metals contribute to chemical defence has been addressed via numerous feeding experiments and very few field studies. This investigation exploited specifically different insect activities on the foliage of sympatric Gossia grayi (N.Snow & Guymer) and Gossia shepherdii (F.Muell.) N.Snow & Guymer, endemic to north-eastern Australia, to test for direct and indirect effects of foliar Mn enrichment on plant-insect interactions. Leaf organic and inorganic chemistries, specific weight, surface damage, gall infestation and occupancy were quantified. Discovery that both species are Mn hyperaccumulators augments the world listing by 5-7%. Highly elevated gall-Mn concentrations coupled with negligible gall parasitisation suggested chemical fortification and adaptation by the host insect - a Cecidomyiidae fly. Linear mixed modelling (LMM) showed differences in leaf Mn, phenolics, toughness and surface damage across tree species and leaf age. There was no direct relationship between leaf Mn and insect impact. However, LMM did resolve indirect effects, i.e. between insect impact and certain foliar elements, consistent with nutritional dynamics in a physiologically novel plant system where Mn is vastly overaccumulated.

Patterns of gall infestation in Heteropterys byrsonimifolia A. Juss. in a forest-savannah ecotone

ABSTRACT Galls are the result of a specific interaction between an inducer and a host plant. The species Heteropterys byrsonimifolia A. Juss. occurs in abundance in semideciduous seasonal forest ecotones and adjacent open formations. In the ecological reserve Quedas do Rio Bonito, located in the state of Minas Gerais, Brazil, this species is affected by a single gall morphotype. The present study aimed to evaluate whether the structural complexity of the host (test of the structural complexity hypothesis) and the distance between hosts (test of the resource concentration hypothesis) affect gall density in H. byrsonimifolia and to characterize the spatial distribution of the infestation. The results corroborate the two hypotheses tested, suggesting a metapopulation pattern of gall infestation in H. byrsonimifolia. Gallers were more successful in abrupt forest-savannah transition environments, which may be associated with greater stress-induced host vulnerability that plants usually experience in ecotones.

Galls in Schinus polygamus (Anacardiaceae): effects of forest structure on infestation intensity

Diverse ecological factors (top-down and bottom-up) act on the richness and abundance patterns of insect galls. Host plant density is a kind of bottom-up factor and is related to “resource concentration hypothesis.” In this study, we analyzed forest patches that differ in vegetational structure and host plant abundance: homogeneous forest patches (Schinus-dominated) and more complex forest patches, to determine whether there are differences in the intensity of gall infestation among individual trees. Insect galls were sampled from 15 Schinus polygamus trees along five transects in each forest (150 trees in total). Two galler species, a psyllid leaf galler and cecidomyiid shoot galler, were recorded. We found that Psyllidae gall infestation in S. polygamus presents higher values of galls per individual tree in Schinus-dominated forest patches than forest patches that are more diverse in plant species. Cecidomyiidae galls did not differ between areas and were not related to host plant abundance. We did not observe any variation in gall infestation within individual. Our study demonstrated that density-dependence effect could be more important for some galls species than others. The results suggest that biological attributes of galling insects’ infestation could be associated with susceptibility to host plant density.

Reaction of some selected soybean varieties (<i>Glycine max</i> (L) Merril) to root - knot nematode infection

Two-year screen-house studies to evaluate the reaction of five soybean varieties (TGX – 1987 – 34F, TGX -1987 – 38F, TGX – 1987 – 95F, TGX – 1986 -3F, TGX – 1985 – 8F) to root – knot nematode, Meloidogyne incognita , were conducted in the Faculty of Agriculture, University of Ilorin. Forty experimental pots containing pasteurized soil were used. Twenty pots were inoculated each with approximately 3,000 eggs of M. incognita while the other twenty which did not receive any treatment served as control. The experimental set up was a completely randomized design having each treatment replicated four times. Results showed that all the varieties were susceptible to M. incognita at varying degrees. While plant height of nematode inoculated varieties were significantly (P=0.05) lower than the un-inoculated plants, among the same varieties, there were significant differences in the number of branches of inoculated and non inoculated plants between different and among the same varieties. There were varietal differences in terms of seed weight which represented actual yield. Generally, the un-innoculated plants gave significantly higher yield than inoculated ones. Root gall infestation rated the same level for all the five varieties. However, variety TGX-1985 – 8F exhibited superior characteristics over the other four varieties because it showed higher level of tolerance to nematode infestation judging from its performance and yield. From the study, it can be deduced that the use of nematode resistant/tolerant Soybean varieties be adopted in the management of root- knot nematode infestation. It is one of the cheapest and safest control methods that pose no form of hazard to man and the environment. In nematode endemic ecological zones, TGX-1985 – 8F is therefore recommended as it proved to contain some specialized genes that conferred a higher level of tolerance against root- knot nematode, Meloidogyne incognita . Key Words : Glycine max, root – knot nematode, Dominant loci, Mi – 1.2, leucine zipper and R genes.

Gall Wasp <i>Leptocybe invasa</i> (Hymenoptera: Eulophidae) Management in Eucalypts

The invasive gall wasp Leptocybe invasa (Hymenoptera: Eulophidae) induces galls on the shoots of Eucalyptus camaldulensis Dehnh. and E. tereticornis Sm. and damage nursery seedlings young plantations and coppice shoots. The magnitude of the damage in nurseries and young plantations necessitates increased efforts to reduce the incidence and impacts of the pest. Identification of feasible and appropriate management methods will help in reducing the high cost of containing the pest in outbreak situations and avoid loss of planting material by state Forest Departments, Corporations and farmers while raising commercial Eucalyptus plantations. Deployment of gall tolerant clones and biological control agents has been attempted in the present study. Results show that eucalyptus gall wasp in nurseries can be managed by deploying identified gall tolerant, productive clones. Release of natural enemies like Quadrastichus mendeli and Megastigmus sp and regular monitoring of its population level in nurseries can further bring down the gall infestation.

Biology, Damage and Parasitoids of Eucalyptus Gall Wasp, Leptocybe invasa Infesting

Leptocybe invasa has been recorded few years back in Sri Lanka from Eucalyptuscamaldulensis plantation in Maragamuwa, where no natural enemies were reported. Recentobservations revealed a decreased gall infestation and hence, the present study was conductedto investigate the biology of L. invasa, its damage to E. camaldulensis and the presence ofany natural enemies to control the infestation.Leptocybe invasa has been recorded few years back in Sri Lanka from Eucalyptuscamaldulensis plantation in Maragamuwa, where no natural enemies were reported. Recentobservations revealed a decreased gall infestation and hence, the present study was conductedto investigate the biology of L. invasa, its damage to E. camaldulensis and the presence ofany natural enemies to control the infestation.L. invasa was found to be the only eucalyptus gall wasp attacking Maragamuwa eucalyptusplantation during the present study period. Life cycle duration of L. invasa was 132 days onaverage. Five stages of gall development on midribs and petioles of E. camaldulensis leaveswere observed. Adult L. invasa was more active in the morning. There was no significantdifference in the abundance of L. invasa between the two seasons although they were moreabundant in the wet season. Damage index was low throughout the study period. A clearpattern in colour change from red to green in young leaves of E. camaldulensis coppices wasobserved from the initial stage. L. invasa attacked the coppices of E. camaldulensis after theyreach their typical green colour and damage increased with the development of coppices.However, damage did not further increase after coppice maturity. A total of four differentparasitoid wasps, of which only Megastigmus could be identified, were reared from leaf andshoot galls of E. camaldulensis. Megastigmus was the most abundant and mean percentparasitization was 67.00 ± 8.00. Natural enemies of L. invasa might have contributed to thedecreased gall infestation in coppices of E. camaldulensis observed recently in Maragamuwaplantation.

Changes in Clonal Poplar Leaf Chemistry Caused by Stem Galls Alter Herbivory and Leaf Litter Decomposition

Gall-inducing insects are highly specialized herbivores that modify the phenotype of their host plants. Beyond the direct manipulation of plant morphology and physiology in the immediate environment of the gall, there is also evidence of plant-mediated effects of gall-inducing insects on other species of the assemblages and ecosystem processes associated with the host plant. We analysed the impact of gall infestation by the aphid Pemphigus spirothecae on chemical leaf traits of clonal Lombardy poplars (Populus nigra var. italica) and the subsequent effects on intensity of herbivory and decomposition of leaves across five sites. We measured the herbivory of two feeding guilds: leaf-chewing insects that feed on the blade (e.g. caterpillars and sawfly larvae) and skeletonising insects that feed on the mesophyll of the leaves (e.g. larvae of beetles). Galled leaves had higher phenol (35%) and lower nitrogen and cholorophyll contents (35% respectively 37%) than non-galled leaves, and these differences were stronger in August than in June. Total herbivory intensity was 27% higher on galled than on non-galled leaves; damage by leaf chewers was on average 61% higher on gall infested leaves, whereas damage by skeletonising insects was on average 39% higher on non-galled leaves. After nine months the decomposition rate of galled leaf litter was 15% lower than that of non-galled leaf litter presumably because of the lower nitrogen content of the galled leaf litter. This indicated after-life effects of gall infestation on the decomposers. We found no evidence for galling x environment interactions.

Suppression of root-knot nematodes in potting mixes amended with different composted biowastes

Abstract Suppressiveness of soil amendments with different rates of composted biowaste materials, olive pomace, municipal green wastes, sewage sludge and spent mushroom substrate, was evaluated against the root-knot nematode Meloidogyne incognita on tomato in potting mixtures. Soil amendments were applied at 0, 10, 25, 50 and 100 g kg−1 soil, according to a randomized block design with five replications for each treatment. Sixty days after tomato transplanting, nematode population density on plant roots and in soil and root gall infestation were assessed on each root system, and plant top and root weight were also recorded. Soil pH, dry and organic matter content, total and ammoniacal nitrogen were analyzed at the same time. Olive pomace-based composts resulted in the highest nematode suppression (73–97 %, according to the rate) and significantly reduced gall formation on tomato roots. Olive-waste compost affected positively tomato growth only in combination with sheep wool wastes, but it caused phytotoxicity when mixed with chicken manure and urea. Soil amendments with composted mushroom substrate also provided a consistent nematode suppression and a significant increase of plant growth, whereas composted municipal green wastes were more suppressive and positively affected tomato growth when combined with sewage sludge. Soil chemical parameters were scarcely affected by compost amendments, as organic matter was significantly increased only by the olive pomace-derived composts and nitrogen content only at the highest rate of the five composts. Data from the experiment confirmed the potential of compost amendments for sustainable management of root-knot nematodes both in field and greenhouse container media, though their technical effectiveness and economic convenience are strictly dependent on a correct proportion and local availability of raw materials used in the composting process.

Gall mite (Eriophyes laevis) infestation and leaf removal affect growth of leaf area in black alder (Alnus glutinosa) short shoots.

We measured the effects ofEriophyes laevis mite galls on the relative growth of short shoot leaf area ofAlnus glutinosa. A portion of leaves was artificially removed from a set of short shoots with both high and low gall density to cause local stress conditions. Nontreated high and low gall density short shoots were used as controls. The results show that the relative growth of leaf area measured for short shoots is negatively affected by high gall density. Artificial leaf removal, on the other hand, had positive effects on leaf area growth. Interestingly, the growth of leaf area did not differ for high gall density short shoots with leaf removal and noninfested short shoots with no leaf removal. This result may be caused by the combined, opposite effects of leaf removal and gall infestation.

The Effects of Stem Gall Insects on Life History Patterns in Solidago Canadensis

Populations of goldenrods (Solidago canadensis) were sampled to determine the effects of three stem gall insects, Gnorimoshema gallaesolidaginis (Gelechiidae), Eurosta solidaginis (Tephritidae), and Rhopalomyia solidaginis (Cecidomyiidae) on resource allocation patterns in the plants. Gall infestations were as high as 38.5% and the dominant gall insect differed from site to site. The gall insects caused significant and highly specific effects on the plants. Each of the three gall types increased stem production, decreased current rhizome production, and lowered seed reproductive allocation as measured both by inflorescence production and propagule production. Vegetative reproductive allocation (the proportion of biomass allocated to new rhizome) was unaffected. With the exception of ball gall—beaing ramets, the number of new rhizomes produced was unaffected by the presence of galls. Growth of the elliptical gall significantly reduced shoot height and significantly increased lateral branching and propagule weight. Formation of the ball significantly reduced propagule weight and the number of new rhizomes produced. Thus gall insect—plant interactions may play an important role in the evolution of plant life history patterns in certain taxa. Future studies are needed to determine the effects of galls on entire clones (genets) and the implications of gall infestation on future growth, survivorship, and reproduction.