Leaf Galls Research Articles

Leafhopper transmission of a virus causing maize wallaby ear disease.

SUMMARYA virus causing maize wallaby ear disease was transmitted experimentally by Cicadulina bimaculata to fourteen species of monocotyledonous plants. It was also transmitted by Nesoclutha pallida, and by grafting. The symptoms obtained resemble closely those reported for maize leaf gall disease in the Philippines and maize rough dwarf virus in Italy and Israel.About 85% of C. bimaculata caught in the field carried maize wallaby ear virus (MWEV), and many of their progeny were viruliferous even when not allowed access to infected plants. The proportion of infective individuals in clones bred for nine generations from selected non‐transmitting adults decreased from 85% in the first nymphs to less than 1%; such individuals were difficult to rear, as their fecundity and longevity decreased greatly. N. pallida transmitted MWEV after injection with partially purified extracts of infected plants.Spherical particles c. 85 nm in diameter were found in the salivary glands of viruliferous C. bimaculata, but not in those of non‐transmitting individuals. The particles occurred in tubules in the cytoplasm and each had a densely stained core c. 50 nm in diameter. Particles similar in size to the core were found in extracts of infected but not uninfected maize, and in extracts of viruliferous but not in non‐viruliferous C. bimaculata and N. pallida.

Purification and serology of viruslike particles from Fiji disease virus-infected sugar cane

Roughly spherical particles 55–60 nm in diameter have been purified from leaf galls of sugar cane infected with Fiji disease virus (FDV) by differential centrifugation, treatment with the nonionic detergent Nonidet P40 and sucrose density-gradient centrifugation; they are probably subviral particles. Immunization of mice with preparations of these particles resulted in the production of antibodies to both protein and RNA of FDV. These antibodies were present in both the blood serum and ascitic fluid produced in response to injection with Krebs 2 Ascites tumor cells. However, both the antisera and ascitic fluids were free of antibodies to host plant antigens.

THE COMPLEX OF THYSANOPTERA IN ROLLED LEAF GALLS ON GEIJERA

AbstractTen closely related species are recorded from rolled leaf galls of Geijera in northern N. S. W. and southern Queensland. The genera and species discussed are Choleothrips geijerae Moulton, C. percnus sp. n., Moultonides geijerae (Moulton), Sacothrips bicolor Moulton, S. catheter sp. n., S. corycidis sp. n., S. galbus sp. n., S. ingens sp. n., S. mantoideus (Girault) comb. n. and S. milvus sp. n. These species are placed in three preexisting nominal genera which are also re‐defined. Keys are provided to these genera and species, and their relationships are discussed.

Heterogony in Some Gall-Forming Cynipidae (Hymenoptera) with Notes on the Biology of Neuroterus saltatoriusx

The alternating bisexual generations of Bassettia ligni Kinsey and Heteroecus dasydactyli (Ashmead) were found to inhabit previously unidentified, nondetachable leaf galls. Andricus kingi Bassett and Liodora dumosae Weld are alternating generations of the same species. Neuroterus decipiens Kinsey was found to be the alternating generation of N. saltatorius H. Edwards. An account of the biology of the 2 generations of N. saltatorius is given, including a description of their seasonal and diurnal flight patterns.

New Distribution Record for the Parasitic Wasp Moserina maculata (Hymenoptera: Eulophidae)

Moserina naculata Delucchi was reared from leaf galls of Pithecellobium unguis-Cati (Linnaeus) found in northern Dade County, Florida.

Differential sensitivities to gamma radiation of Phylloxera gall and normal grape stem cells in tissue culture

The differential responses were observed of cells from tissue cultures of normal grape stem (GS6-24) and Phylloxera vastatrix Planch leaf gall (GP4-21) exposed to gamma radiation of 100 to 500 000 R from cobalt-60. The percentage survival of cells decreased with increased intensity of radiation. The mitochondria, spherosomes, and nucleus were visibly affected by radiation. The percentage survival of gall cells was lower than that of normal cells after exposure to the same radiation intensity. The irradiated cells did not recover regeneration even when exposed to the smallest dose of 100 R, though a certain percentage of cells survived during 28 days of observation. The effectiveness of 2-mercaptoethylamine hydrochloride (MEA), and 2-aminoethylisothiouronium bromide hydrobromide (AET) at 1 × 10−2–1 × 10−8 M in protecting the cells against gamma radiation was tested by incorporating them in liquid medium containing actively growing cells of normal and gall types. Observation of cells in microcultures exposed to 1000 R showed that MEA at 1 × 10−4 M and AET at 1 × 10−3 M decreased the lethality of radiation to normal grape cells considerably more than to the gall cells. The normal cells treated with 1 × 10−3 M AET and exposed to 1000-R radiation also divided.

Biosystematics and Morphology of Symphyta. I. Stem-Galling Euura1 of the California Region, and a New Female Genitalic Nomenclature2

The sawfly genera Phyllocolpa, Pontania, and Euura incite galls on Salicaceae by injecting colleterial fluid into the plant meristem during oviposition. The Phyllocolpa make open galls by deforming leaf margins of Populus and Salix, and are not host species-specific. Each species of Pontania makes a distinctive closed leaf gall on a particular species or within a certain species group of willow. Species of Euura subgenus Gemmura make closed bud galls on related species of Salix, and the host species-specific subgenus Euura make closed petiole or stem galls on individual species of willow. Stem-galling Euura may form sibling arrays within related species groups of Salix, and 3 new sibling species (Euura lasiolepis , E. lemmoniae , E. scoulerianae ) are described here. Descriptions of 3 other new sitm-Euura (E. breweriae , E. exiguae , E. geyerianae ) and a new subgenus of Euura ( GEMMURA ) are also included. A diagnosis of the genus Euura and its subgenera, a key distinguishing the gall-making genera of the Euura group from one another and from other genera of specialized Nematini, and keys to the adults and galls of the stem-galling Euura of the California region are presented. The morphology of the female ovipositor (gonapophyses) reflects the physical structure and ecology of the host plant and the site galled, as well as the phylogeny of the insect, and can be used to delineate both willow and sawfly taxa. Genitalic structure and function of taxonomic significance are described in a revised terminology applicable to many female Symphyta.

LEUCOPIS SIMPLEX (DIPTERA: CHAMAEMYIIDAE) AND OTHER SPECIES OCCURRING IN GALLS OF PHYLLOXERA VITIFOLIAE (HOMOPTERA: PHYLLOXERIDAE) IN ONTARIO

AbstractAt least seven species of arthropods were found in or associated with leaf galls of the grape phylloxera, Phylloxera vitifoliae (Fitch), on cultivated and wild grapes in Ontario, Leucopis simplex Loew and Lestodiplosis grassator (Fyles) were the most common species. Larvae of both preyed upon eggs of the phylloxera; whether they attacked other stages was not determined, nor was their effect on gall populations. L. grassator occurred almost exclusively on wild grapes; L. simplex was found in galls on both cultivated and wild grapes, associated with all generations of the leaf form of phylloxera. L. simplex was parasitized by Melanips sp. and Lygocerus sp. Another predator, Scymnus cervicalis Muls., occurred rarely. Thrips, mites, and neuropterous larvae were also found occasionally, but predation by these species was not demonstrated.

Sugar Contents of Single Cell Clones of Stem and Phylloxera Leaf Galls of the Grape Vine

INSECTS induce galls of many sizes and degrees of complexity in plants. The mechanism of gall induction and why growth finally ceases are not clearly understood. Phylloxera induces leaf gall in the grape vine which is typical of such abnormal growth in the sense that it is restricted in its development. Some of the biochemical and physiological changes which occur in these abnormal structures have been investigated by means of the tissue culture technique1.

Accumulation of Anthoxanthins and Iminoacids in Leaf Galls of Salix fragilis L.

GALL formation in the Salicaceae is common, and sawflies are frequently responsible. Investigation of the chemical changes initiated by the insects was made on the leaf galls of Salix fragilis L. produced by the sawfly Pontania proxima Lep. In preliminary studies, Challen1 suggested that one phytochemical change initiated by P. proxima might be an accumulation of catechins, leucoanthocyanidins and a ninhydrin positive substance. A red pigment, cyanidin-3-monoglucoside, was found in young leaves and galls by Blunden and Challen2. In the present investigation a concentrated methanolic extract of fresh galls was purified by band chromatography on Whatman No. 3MM paper, using distilled water as the solvent. The leucoanthocyanidin and cateohin band, detected by spraying a marker strip of the chromatogram with vanillin (equal volumes of hydrochloric acid B.P., and a mixture of vanillin 2 per cent w/v + acetaldehyde 1 per cent v/v in 95 per cent ethanol), was cut out and eluted with 2 N hydrochloric acid. The leucoanthocyanidins were converted to their anthocyanidins by the method of Bate-Smith3 and purified by band chromatography. The eluted pigment was subjected to paper chromatography using methods recommended by Harborne4. The anthocyanidin had similar RF values to a reference sample of cyanidin chloride in all three solvent systems used.

Life History, Habits, and Damage of the Boxelder Leaf Gall Midge, Contarinia negundifolia Felt (Diptera: Cecidomyiidae) in Michigan

AbstractThe boxelder leaf gall midge is univoltine in Michigan. Adults emerge after the first few warm days in April, and deposit numerous eggs within the folded young leaves of boxelder (Acer negundo L.). Larval eclosion occurs a few days later, and gall development begins shortly after. Head capsule measurements revealed three larval instars. Third-instar larvae drop to the ground near the end of May, work their way into the soil, and construct cocoons. Pupation occurs in late August, and overwintering takes place in the pupal stage. Because oviposition occurs almost always on leaves in a certain stage of development and an estimated 50% of leaves will therefore escape attack, host mortality apparently cannot be caused by this insect.

Free Amino Acid Contents of Stem and Phylloxera Gall Tissue Cultures of Grape

Free amino acid constituents were determined of grape stem and Phylloxera leaf gall callus in tissue culture. Fast, medium and slow growing single cell clones of, respectively, stem and gall origins were grown on a mineral salt-sucrose medium supplemented with coconut milk and alpha-naphthaleneacetic acid. Stem and gall clones showed qualitative similarities and quantitative variations in the amino acids and nitrogenous constituents. Nineteen amino acids, glucosamine, ethanolamine, sarcosine, methionine sulfoxides and ammonia were identified. Two free polypeptides accounted for over 30% of the amino compounds in the stem and gall callus tissues which were not found in the intact plant parts. Stem clones of different growth rates grown on agar showed generally an excess of amino acid constituents over gall tissues of similar growth rates, except for the free polypeptides. Fast growing stem clones grown on agar medium contained lower amounts of certain amino acids than the fast growing gall clones, but when grown in liquid medium they contained higher amounts of these acids than the gall clones. The total and nonsoluble nitrogen of stem clones were higher than in the gall clones. Tissue cultures differed from the original plant parts with respect to their free polypeptides and high amino acid contents.

An electron microscope study on the size of sammons' opuntia virus

Fiji leaf gall has been a major disease in the Australian sugarcane industry, causing extensive crop losses in the 1970–1990 period. The disease has been managed via a number of measures including varietal resistance, disease-free plant sources, termination of heavily-infested crops, quarantine and rogueing of disease stools. These measures have been highly effective and reduced detected disease incidence to zero in several districts. Over 32,000 crop inspections have been undertaken since the last known diseased crop was sighted in the Central Queensland region. All disease inspection data were collated and analysed for this region, with modelling undertaken to determine the probability of the disease being present but remaining undetected. These analyses suggest that it is very highly unlikely to be present; a proposal is made therefore to declare ‘area freedom from Fiji leaf gall’ for the Central Queensland region.

Control of Asterolecanium Scales and Cynipid Leaf Galls on Oak in Northern California

Field trials conducted during 1962-63 in northern California on valley oak, Quercus lobata Nee, showed that sprays of carbaryl, dimethoate, diazinon, and malathion, all with oil, gave effective control of Asterolecanium pit scales when applied in early May. Studies on timing of application indicated that good control of scales is possible with applications made from late April until at least early June. Bidrin® (3-hydroxy- N,N -dimethyl- cis -croton-amide dimethyl phosphate), applied as a trunk injectant, reduced scale numbers only 69% but gave excellent control of leaf galls caused by 6 species of Cynipidae. The use of carbaryl as a spray in late April or early May also resulted in outstanding control of certain leaf galls.

Thimet Soil Treatments for Control of Leaf Miners, Galls, and Lace Bugs

Application of Thimet® ( O,O -diethyl S -(ethylthio)methyl phosphorodithioate) granules to the soil around birch, holly, and boxwood in 1957 controlled all season the birch leaf miner ( Fenusa pusilla (Lep)), the holly leaf miner ( Phytomyza ilicis (Curt.)), and the boxwood leaf miner ( Monarthropalpus buxi (Lab.)) on the treated trees. In 1958 the higher dosages used in each experiment continued to control leaf miners. Treatments of Thimet on soil gave good control of the first brood of honey locust pod gall maker ( Dasyneura gleditschiae (O.S)), but were ineffective for later broods. Similar treatments of andromeda and azalea plants controlled lace bugs.

Heterogony in Dryocosmus (Hymenoptera, Cynipidae)

Laboratory experiments show that adults of Dryocosmus dubiosus (Fullaway) reared from ament galls of the California live oak, Quercus agrifolia Nee, are bisexual. The females from this generation oviposit in the leaf veins of black oaks where they produce an agamic generation of females in characteristic bicornate galls. The females produced in these leaf galls were formerly thought to be Dryocosmus bicornis (McCracken and Egbert), but now must be considered as the agamic generation of D. dubiosus. The agamic generation is composed of two types of females, one producing only males and the other producing only females. Both generations are attacked by the parasite, Torymus fullawayi (Huber).

Shade Tree Insects in 1929

The Norway maple leaf stem miner, Nepticula sericopeza Zell., is somewhat generally distributed in southeastern New York and southwestern New England. Spraying with a nicotine molasses soap combination in May apparently gives excellent control. The red cedar aphis, Lachnus sabinae Gill., provided an excellent outdoor demonstration of injuries earlier associated provisionally with this species. The hackberry nipple gall, Pachypsylla mamma Riley, and the hackberry bud gall, Pachypsylla gemma Riley, are both common on hackberry. The former is readily controlled with a nicotine molasses spray applied about the middle of May and the latter with the same materials applied about June 10th. The insecticide kills many adults and apparently destroys the eggs. The knotty oak galls, Andricus punctatus Bass, A. cornigerus O. S., and A. clavigerus Ashm. are common on the red oak, pin oak and willow oak respectively, in some instances causing serious injury. The alternate generation of the former two develops in a small blister leaf gall. The hackberry leaf aphid, Myzocallis fumipennellus Fitch, is responsible for a very general yellowish spotting and browning of hickory leaves in early fall, in some cases, most of the leaves being killed. The bronze birch borer, Agrilus anxius Gory, and the two-lined chestnut borer, Agrilus bilineatus Weber, are generally distributed pests. Available data show that feeding of birches frequently enables the trees to outgrow somewhat serious infestations. Work by the two-lined chestnut borer is very frequent on trees indirectly injured by grading or building operations. The filbert bud mite, Eriophyes avell.anae Nal., produces greatly enlarged buds on European filberts and has been associated with some severe injury. A paste of calcium cyanide and castor oil applied to areas infested by the linden borer, Saperda vestita Say, have given very encouraging results.

THE BIONOMICS OF TETRASTICHUS VERRUCARII (CHALCIDO-IDEA) WITH NOTES ON ITS HOSTS (NEUROTERUS SPP., CYNIPIDAE) ON BUR OAK

In an earlier volume (I) the writer presented observations on the bionomics of the parasites and inquilines from the galls of Disholcaspis mamma (Walsh) on a bur oak (Quercus macrocarpa) near Urbana, Illinois. Not less than fifteen species of Hymenoptera were then associated with that gall. In the last two years this gall and its several inhabitants were rare or lacking there, but the leaf galls of Neuroterus verrucarum O.S. and N. niger Gillette were abundant on the same tree. The larvae of the latter cynipids are heavily parasitized by a chalcid, Tetrastichus verrucarii Balduf of the family Tetrastichidae. Observations on the habits and stages of the parasite and its hosts are given below. These records incidentally extend the known hymenopterous fauna of the above tree by four or more species.

The Houghton Gooseberry Aphis (Myzus Houghtonensis) as a Pest in Ohio

The Houghton Gooseberry Aphis injures gooseberries by forming leaf galls. The leaves are stunted, tightly curled and soon die. Very little fruit is produced and it is inferior in quality. The gall gives rise to a witch's broom by the formation of numerous abnormal shoots. The insect overwinters as an egg on the canes. The eggs begin hatching early in April. The first winged generation appears about the middle of May and migration takes place. They become re-established on the gooseberry and several wingless generations are found here during the summer and autumn. A second winged generation is produced in late October and the eggs are deposited a little later on gooseberry. This insect may have an alternate food plant but is able to survive normally on gooseberry alone.