Velvetleaf,Abutilon theophrasti (malvaceae), history and economic impact in the United States

Velvetleaf,Abutilon theophrasti, a native of China, was originally introduced into the New World before 1750 as a potential fiber crop for the American colonies. Initial introductions may have come from England because of similar interests in the development of fiber crops. Commercial fiber production from velvetleaf was attempted by U.S. farmers for more than a century. The latest known attempts were made in the latter part of the 19th century in Illinois and New York. Velvetleaf never competed well with hemp, at least partly due to a lack of proper machinery for fiber processing. These early experimental plantings were apparently the source of velvetleaf as a weed in row crops. One velvetleaf plant is capable of producing as many as 8,000 seeds, and viability may extend beyond 50 yr. The plant is well adapted to our upper Midwest where maize (Zea mays) and soybeans (Glycine max) are the major row crops. The reservoir of velvetleaf seed in the soil is increasing. The current annual economic loss due to velvetleaf in maize and soybeans is estimated to be approximately $343 million per year.     

COMPLEX COLONY STRUCTURE IN SOCIAL INSECTS: I. ECOLOGICAL DETERMINANTS AND GENETIC CONSEQUENCES

For social insect species, intraspecific variation in colony social structure provides an opportunity to relate the evolution of social behavior to ecological factors. The species Myrmica punctiventris is a cavity-dwelling forest ant that exhibits very different colony structures in two populations in the northeastern United States. Combined data from seasonal censuses, allozyme electrophoresis, and worker hostility tests showed that a population of M. punctiventris in Vermont was strictly monogynous and seasonally polydomous. The same procedures showed that a population of M. punctiventris in New York was facultatively polygynous and predominantly monodomous. Genetic relatedness among colony-mates was not different from Hamilton's expected values in the Vermont population and was consistent with little exchange of ants between colonies and single-mating of queens. In contrast, relatedness was lower in New York, and examination of nest-mate genotypes revealed exchange of ants between colonies, high rates of colony loss and replacement of queens, or multiple-mating of queens. The genetic structure of the Vermont population was consistent with no inbreeding, but in New York, the population genetic structure reflected microgeographic subdivision and inbreeding. Previous study of the ant communities at these sites implicates nest-site limitation in New York as a primary constraint on social structure.     

FURTHER OBSERVATIONS ON JUVENILE AND ADULT HEDERA

Robbins , William J. (The New York Botanical Garden, New York, N. Y.) Further observations on juvenile and adult Hedera. Amer. Jour. Bot. 47(6) : 485–491. Illus. 1960.—Plants of arborescent Hedera helix sprayed with gibberellic acid produced juvenile shoots. Juvenile characters appeared in December to March from applications of gibberellic acid made from May to July. Gibberellic acid modified inflorescences toward a vegetative condition. Previous reports that seeds of arborescent Hedera helix produce juvenile plants were confirmed. Seedlings of a variant, Hedera helix ‘238th Street,‘ which has adult-shaped leaves on a vine type of growth produced vines with lobed leaves. Heavy pruning of arborescent Hedera helix caused the production of juvenile shoots.     

Content of a storage jar from the Late Neolithic site of Hódmez?vásárhely-Gorzsa, south Hungary: a thousand carbonized seeds of Abutilon theophrasti Medic.

The lucky find of 934 carbonized seeds of Abutilon theophrasti Medic. in a storage jar at the Late Neolithic site of Hódmezővásárhely-Gorzsa, south Hungary, suggests that the seeds of velvetleaf were intentionally gathered, processed and stored by the inhabitants of this Tisza culture tell-site. Today this ancient fibre and oil plant, the seeds of which can be used for food and medicine, has become a pestilential weed worldwide. Until now, there has been no archaeobotanical record of velvetleaf. Conflicting reports as to the native origin of velvetleaf exist, including India, China and even the Mediterranean area. Since the progenitors of velvetleaf have not yet been found the centre of origin of the species is still unidentified. The huge floodplain swamps and flood-free loess-silt areas in the heart of the Pannonian plain provide this temperate species with suitable growing conditions.     

ALLELOPATHIC MECHANISMS OF VELVETLEAF (ABUTILON THEOPHRASTI MEDIC., MALVACEAE) ON SOYBEAN

Sampling in a soybean field established that presence of velvetleaf (A. theophrasti) weeds interfered with soybean production. Number of soybean pods and number of pods/stem were significantly lower in transect segments adjacent to velvetleaf plants. In bioassays for phytotoxicity of velvetleaf, several dilutions of aqueous extracts from fresh field-collected leaves depressed germination of radish seeds and inhibited growth of soybean seedlings. Seed germination bioassays from eluates of chromatograms developed in one dimension showed that two of three bands containing phenolic compounds were inhibitory to radish seed germination. Soybeans inhibited by aqueous velvetleaf extracts had increased diffusive resistance, suggesting partial stomatal closure. Inhibited plants also gave evidence of water stress, with leaf water potentials often as low as –20 bars and reduced water content, when compared with controls. Quantification of chlorophyll on a leaf area basis showed that chlorophyll of inhibited plants was below controls. These data demonstrate the allelopathic potential of velvetleaf and suggest that interference with water balance and chlorophyll content may be two mechanisms of inhibitory action of toxins present in the leaves of velvetleaf.     

INTERACTION OF IONIZING AND VISIBLE RADIATION IN MUTATION INDUCTION IN NEUROSPORA CRASSA

Klein , Richard M. (New York Bot. Gdn., New York, N.Y.), and Deana T. Klein. Interaction of ionizing and visible radiation in mutation induction in Neurospora crassa. Amer. Jour. Bot. 49(8): 870–874. 1962.—Conidia of the purple adenineless strain of N. crassa were irradiated with 25 kr of X rays and then exposed to far-red or red radiations or to far-red followed by red radiation. Far-red light, without effect on un-irradiated conidia, augmented the genetic damage caused by X rays as measured by survival (colony count), back mutation to adenine prototrophy, and the induction of mutants affecting colony morphology. Post-X-irradiation with red light ameliorated the severity of X-radiation as measured by survival and back mutation. The potentiation of X-ray-induced genetic damage by far-red light could be completely negated by subsequent exposure to red light.     

Efficacy of inoculative releases of Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) against European corn borer Ostrinia nubilalis (Lepidoptera: Crambidae) in field corn

We evaluated the egg parasitoid Trichogramma ostriniae (Hymenoptera: Trichogrammatidae) to control European corn borer [Lepidoptera: Crambidae: Ostrinia nubilalis (Hübner)] in field corn in 2001 and 2002. Inoculative releases of 75,000 T. ostriniae/ha occurred in New York and Virginia in 5–10 cornfields per state when corn was at mid-whorl. Incidence of egg mass parasitism, number of stalk tunnels, incidence of ear damage, and whole-plant yield were evaluated. Parasitism of European corn borer egg masses ranged from 0 to 75% in release plots and was greater in release plots than in control plots. Individual comparisons between paired release and control plots showed no reductions in either stalk or ear damage. However, when data were combined across both years and fields, stalk and ear damage were significantly reduced in New York. In Virginia, no significant differences were detected using data obtained from one year. There were no differences in yield between release and control plots. Low densities of European corn borer, drought conditions in 1 year, and a larger plant canopy in field corn are possible reasons why T. ostriniae releases provided less control than has been observed in previous trials in sweet corn. Additional research focused on improved timing and frequency and number of releases is warranted.     

ANNUAL GERMINATION WINFOW IN OOSPORES OF NITELLA FURCATA (CHAROPHYCEAE)1

Oospores of Nitella furcata subsp. megacarpa (Allen emend. Wood) were collected from an oospore bank in the sediments of Lake George, New York. Incubated at constant temperatures, all or nearly all of the oospores germinated when exposed to a brief pulse of red light when the annual window of germinability was open. The window seems related to the annual cycle of sediment temperatures. It is open in spring and closes wit the onset of a secondary dormacncy in the summer. Oospores in storage follow a parallel path if held at 18°C, a summer equivalent temperature; the window remains open indefinitely if the oospores are held at 4°C. Attention is drawn to the similarity if the cyclic window of germinability in seeds of summer annuals and oospores of N. furcata.     

Germination inhibition by 5,7-dihydroxychromone, a flavanoid decomposition product

5,7-Dihydroxychromone1 isolated from seeds ofPolygonum lapathifolium L. inhibits the germination of velvetleaf (Abutilon theophrasti Medic) seeds. Effective molar concentrations ranged from 1 mM to 6 mM. Flavanoids reported or suspected to cause inhibition were not active at concentrations above 10 mM. Compound1 is a flavanoid moiety and can be formed during catabolic degradation, but its role in the allelopathic activity attributed to flavanoids remains to be determined.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned.     

Use of Honey Bees and Bumble Bees to Disseminate Trichoderma harzianum 1295-22 to Strawberries for Botrytis Control

The effectiveness of using honey bees and bumble bees to vector a commercial formulation of Trichoderma harzianum 1295-22 for the control of Botrytis cinerea on strawberries was evaluated from 1994 to 1997 in 2 strawberry fields at the New York State Agricultural Experiment Station in Geneva, New York and in 10 grower fields in eight counties of New York. Commercial bumble bee colonies were used to deliver the biocontrol agent in 1994 and 1995 and five-frame nuclear honey bee hives were used in 1995–1997. Each honey bee exiting the hive carried about 1 × 10⁵ colony-forming units of T. harzianum, with the majority found on the bees' legs (58%). Flowers collected from the bee-delivered treatment generally had half the density of T. harzianum as those from the sprayed treatment. However, during the 4 years of this study, T. harzianum delivered by bumble bees or honey bees provided better Botrytis control than that applied as a spray. In addition, the bee-delivered T. harzianum provided the same or a better level of control of Botrytis as commercial fungicides applied at bloom. Strawberries collected from the bee-visited treatments averaged 22% more seeds and weighed between 26 and 40% more than berries in nonvisited treatments. The number of seeds per berry and berry weight were reduced by 7–12% in plots treated with fungicides and visited by bees, indicating that the use of some commercial fungicides at bloom may impact pollination and yield. Bee delivery of T. harzianum 1295-22 is a viable option for strawberry growers interested in controlling Botrytis with minimal fungicide use.     

Science Summaries…

Ricciuti, Edward R. Plants in Danger New York: Harper &; Row, 1979 86 pp. $8.95. Reviewed by Emanuel D. Rudolph.

Dock, George, Jr. Audubon's Birds of America New York: Harry N. Abrams, Inc., 1979 170 pp. $19.95 hardcover, $7.95 paper. Reviewed by Karl L. Trever.

Hogg, Margaret E. Animals in Schools: Vertebrates Exeter, N. H.: Heinemann Educational Books, Inc., 1979 (U.S.) 100 pp. $6.25. Reviewed by Carl Gans.

Busch, Phyllis S. Cactus in the Desert New York: Thomas Y. Crowell Company, 1979 34 pp. $6.95, Reviewed by Emanuel D. Rudolph.

Ricciuti, Edward R. Wildlife of the Mountains (Wildlife Habitat Series) New York: Harry N. Abrams, Inc., 1979 232 pp. $16.95. Reviewed by Vagn Flyger.

Sutton, Ann and Myron Wildlife of the Forests (Wildlife Habitat Series) New York: Harry N. Abrams, Inc., 1979 232 pp. $16.95. Reviewed by Gilbert Wright.

Valenti, Christopher Keeping a Marine Aquarium: A Manual Newark: University of Delaware Sea Grant College Program, 1979 38 pp. $2.50 softcover (bulk discount). Reviewed by Donald J. Nash.

Simon and Schuster Complete Guide to Freshwater and Marine Aquarium Fishes New York: Simon and Schuster, 1977 295 pp., $6.95. Reviewed by Harold W. Puffer.     

Nosema Disease of the Parasitoid Muscidifurax raptor (Hymenoptera: Pteromalidae): Prevalence, Patterns of Transmission, Management, and Impact

The microsporidium Nosema muscidifuracis was found in 1.1 and 10.7% of wild Muscidifurax raptor collected on New York dairy farms in 1991 and 1992. Higher (84%) levels of infection were observed on farms where infected M. raptor from a commercial insectary were released. Adult M. raptor became infected (100%) after feeding on spore suspensions of N. muscidifuracis, whereas house fly (Musca domestica L.) adults and larvae did not. Adult M. raptor became infected (16-25%) after feeding on infected parasitoid immatures within host puparia. Transmission rates of N. muscidifuracis increased with increasing parasitoid crowding levels because of cannibalism by healthy parasitoid immatures on infected immatures in superparasitized hosts. Maternal transmission was 100% efficient but there was no paternal or venereal transmission. Disease was reduced 35-93% by immersing infected parasitoid eggs within fly puparia in a 47°C water bath for 30-60 min. Eliminating disease from an established laboratory colony of M. raptor resulted in a 10-fold increase in parasitoid fecundity.     

ALLELOPATHIC AND HERBICIDAL EFFECTS OF EXTRACTS FROM TREE OF HEAVEN (AILANTHUS ALTISSIMA)

Mature trees of Ailanthus altissima produce one or more potent inhibitors of seed germination and seedling growth. Inhibitor activity is highest in bark, especially of roots, intermediate in leaflets, and low in wood. Crude extracts of Ailanthus root bark and leaflets corresponding to 34 and 119 mg water extractable material/L, respectively, caused 50% inhibition of cress radicle growth. Ailanthus seeds also contain one or more inhibitors. These are bound within the seed by the pericarp but diffuse into water agar when the pericarp is removed. The inhibitor(s) could readily be extracted from Ailanthus tissues with methanol, but not dichloromethane, indicating polar characteristics. Ailanthus leaflets had highest inhibitory activity during expansion in spring, whereas activity of trunk bark peaked just before emergence of leaves. This pattern suggests transport of allelochemicals from bark into new leaves. A comparison of seven plant species for sensitivity to the inhibitor(s) from Ailanthus root bark showed little selectivity, although velvetleaf was somewhat more resistant. The inhibitor(s) from Ailanthus root bark exhibited strong herbicidal effects when sprayed pre- and postemergence on plants in soil in the greenhouse. Postemergence effects were striking, with nearly complete mortality of all species, except velvetleaf, at even the lowest doses tested. The results suggest the allelochemical(s) from Ailanthus may have potential for development as natural-product herbicides.     

ReleasingAmblyseius spp. [Acarina: Phytoseiidae] to controlThrips tabaci [Thysanoptera: Thripidae] on cabbage

Two species of predaceous mites,Amblyseius barkeri (Hughes) [=A. mckenziei Schuster & Pritchard] andA. cucumeris (Oudemans) [Acarina: Phytoseiidae] were evaluated as potential biological control agents forThrips tabaci Lindeman [Thysanoptera: Thripidae] on cabbage.A. barkeri colonized cabbage heads in preliminary trials. Field releases of different numbers of mites per plant during 1987 showed thatA. barkeri reduced the number of thrips in cabbage heads at harvest, and the reduction was proportional to the number of mites released, but thrips damage was unaffected. ReleasingA. cucumeris at different times during 1988, but releasing the same number of mites each time, we found that earlier releases resulted in fewer thrips and less damage at harvest; these relationships were not present, however, in plots treated with pyrethroid insecticides. We conclude that inoculative release ofAmblyseius spp. is a potentially useful thrips management strategy, but improvements in release timing and strategy will be required to provide commercially acceptable control.      

Differential Rhizosphere Establishment and Cyanide Production by Alginate-Formulated Weed-Deleterious Rhizobacteria

The effects of Pseudomonas putida ATH2-1RI/9 and Acidovorax delafieldii ATH2-2RS/1 on rhizosphere colonization, cyanide production, and growth of velvetleaf and corn was examined. When formulated in alginate beads and inoculated onto velvetleaf and corn plants (10⁹ CFU/plant), only P. putida ATH2-1RI/9 consistently reduced velvetleaf growth. Neither isolate inhibited corn growth. Interestingly the levels of P. putida ATH2-1RI/9 in the velvetleaf rhizosphere were 1000-fold higher (7 × 10⁷ CFU/g root) than the A. delafieldii ATH2-2RS/1 populations. Cyanide (53–68 mM/g root) was recovered from the P. putida ATH2-1RI/9-inoculated velvetleaf plants. In contrast both A. delafieldii ATH2-2RS/1 and P. putida ATH2-1RI/9 colonized the corn rhizosphere to the same extent (1–5 × 10⁷ CFU/g root), producing 1 mM and 14 mM/g root respectively. These results suggest that bacterial formulation methods can influence the effectiveness of deleterious rhizobacteria in reducing weed growth.     

Commercial inundative releases ofTrichogrammatoidea cryptophlebiae [Hym.: Trichogrammatidae] againstCryptophlebia leucotreta [Lep.: Tortricidae] in citrus

Inundative releases of the egg parasitoidTrichogrammatoidea cryptophlebiae Nagaraja were made againstCryptophlebia leucotreta (Meyrick) on 5 commercial citrus farms in the western Cape Province, South Africa, over 2 successive seasons. A target release volume of 80 000 parasitoids ha⁻¹ week⁻¹ was established for releases over 29 and 33 weeks during the 2 seasons. Total seasonal volumes reached an equivalent of 2.3 and 3.8 million parasitoids ha⁻¹ respectively. Compared with check treatments on each farm, larval population size was reduced in the release areas by 54% in the 1^st and by almost 60% in the 2^nd season. Percentage crop loss was reduced by 49.4±12.4 and 61.1±8.3% respectively. Treatment effects were clearly related to increases in rate of parasitism measured in both artificially-placed and in nativeC. leucotreta egg populations. Treatment efficacy is similar to that obtained with applications of chitin synthesis inhibitors but parasitoid production costs are 30% of insecticide costs. Manual distribution of parasitoids is labour intensive, however, and further studies should investigate whether inoculative releases at higher rates per week over a shorter period, are effective.      

Importation,colonization and establishment ofAnagyrus indicus [Hym.: Encyrtidae] onNipaecoccus viridis [Hom.: Pseudococcidae] in Jordan

Anagyrus indicus Shafeeet al. was collected on the island of Guam and released in the Jordan River Valley of Jordan in order to regulateNipaecoccus viridis (Newstead) on citrus.A. indicus was originally released in February 1984 and became colonized by April of the same year. It also dispersed by natural means up to 61 km following the original release and colonized that same year on infestedZizyphus sp. By spring of 1985 it became the dominant parasitoid attackingN. viridis. Another parasitoid,Anagyrus kamali Moursi, was collected in Jordan in June of 1985 for the first time. This latter parasitoid apparently moved into the Jordan River Valley by means of natural dispersal from a neighboring country. Infestations ofN. viridis have been greatly reduced in areas whereA. indicus became established. This paper reports the results of research only. Mention of a proprietary product does not constitute an endorsement for its use by USDA.     

Efficacy of spider and ant predators on the cotton fleahopper [Hemiptera: Miridae]

The efficacy of predators of immature cotton fleahoppers,Pseudatomoscelis seriatus (Reuter), was calculated using field and laboratory cage confinement tests for consumption rate. The predators tested were the striped lynx spider,Oxyopes salticus Hentz; the black and white jumping spider,Phidippus audax (Hentz); the celer crab spider,Misumenops celer Hentz; and the red imported fire ant,Solenopsis invicta Buren. The spider predators were evaluated in a cotton field using predator-prey confinement cages on cotton plants. Average percent control (sensuAbbott 1925) of fleahoppers byO. salticus, P. audax, andM. celer were 42%, 66% and 32% respectively. The rate of fleahopper consumption by red imported fire ants was measured in the laboratory using various numbers of ants and fleahoppers. Daily percent control by ants ranged from 0.5% (single ant and fleahopper) to 100% (colony linked). The functional response of the 4 arthropod species to different prey numbers is illustrated and discussed as is the relative potential usefulness of natural enemies to suppress fleahoppers on cotton.      

Differential foliar responses of northern hardwoods to fertilization

A 70-year-old thinned northeastern Fagus-Betula-Acer stand in the Adirondack Mountains of northern New York was fertilized with varying combinations of N, P, K, and lime in the spring of 1976.Betula alleghaniensis Brit.,Acer saccharum Marsh.,Acer rubrum L., andFagus grandifolia Ehrh. foliage was collected in the autumn for 1974 through 1977 and analyzed for foliage areas and weights, and levels of ash, N, P, K, Ca, Mg, Mn, Na, Fe, Zn, Al, Cu, and Co. Comparisons are made within species and among treatments, expressed as concentrations on a dry weight basis. Elemental composition is examined to determine the differential foliar responses to fertilization.Contribution of State University of New York College of Environmental Science and Forestry, Syracuse, New York, 13210.The authors are Graduate Research Assistant, Director of Huntington Forest, Technical Research Assistant, and Professor of Forest Soil Science (now deceased), SUNY, respectively.     

A NEW,HETEROTHALLIC SPECIES OF SORDARIA

Olive , L. S., and A. A. Fantini . (Columbia U., New York, N. Y.) A new, heterothallic species of Sordaria. Amer. Jour. Bot. 48(2): 124–128. Illus. 1961.—S. brevicollis, sp. nov., was isolated from zebra dung from the New York Zoological Park. It is the only species of the genus that has been found to be heterothallic and to have microconidia. The latter function readily in fertilization. Heterothallism is controlled by a single allelic pair of compatibility factors located about 14.2 crossover units from the centromere. Incomplete mating reactions involving this species, Gelasinospora autosteira, and Neurospora crassa indicate relationships among these 3 genera.