scholarly journals Introduced leafy spurge hawkmoth, Hyles euphorbiae L., appears in Saskatoon

Blue Jay ◽  
2007 ◽  
Vol 65 (2) ◽  
Author(s):  
Tyler J. Wist
Keyword(s):  
Leafy Spurge ◽  
Hyles Euphorbiae

Survival of Leafy Spurge Hawk Moths (Hyles euphorbiae) When Larvae Are Exposed to 2,4-D or Picloram

1989 ◽  
Vol 3 (2) ◽  
pp. 429-431 ◽  
Author(s):  
Norman E. Rees ◽  
Peter K. Fay
Keyword(s):  
Second Generation ◽  
Larval Survival ◽  
Leafy Spurge ◽  
Hawk Moth ◽  
Generation Adult ◽  
Hyles Euphorbiae

Larvae of the leafy spurge hawk moth were sprayed with and/or were fed leafy spurge plants sprayed with 2,4-D or picloram. Larval survival was not affected from contact with the chemicals, from feeding on contaminated foliage, or from a combination of both. Viable second-generation adult moths were produced in all treatments. Thus, leafy spurge infested with the leafy spurge hawk moth can be sprayed with 2,4-D or picloram without injury to larvae that have reached the fourth or fifth instar stages.

scholarly journals Control of Leafy Spurge (Euphorbia esula) in Nebraska with the Spurge Hawkmoth (Hyles euphorbiae)

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 235-240 ◽  
Author(s):  
J. R. Forwood ◽  
M. K. McCarty
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Soil Surface ◽  
Leafy Spurge ◽  
Control Agent ◽  
Euphorbia Esula ◽  
Two Generations ◽  
Hyles Euphorbiae

The feasibility of using the spurge hawkmoth (Hyles euphorbiaeL., Lepidoptera: Sphingidae), as a biological control agent on leafy spurge (Euphorbia esulaL.) was evaluated. Studies relating adult hawkmoth emergence from the pupal stage and spring growth of leafy spurge plants showed that the plants would provide food and oviposition sites for the insect. Two generations of the insect may occur each year. Winter temperatures at approximately 2.5 cm below the soil surface or in the litter would result in some mortality of hawkmoth pupae. Pupal release programs indicated that protection from insect and rodent predators was necessary for adult emergence to occur. Predator determination using32P indicated two specimens ofCalosoma calidumFab. and two specimens ofFormica subsericeaSay as possible predators. Predator determination using pitfall traps showed that several species listed by Canadian researchers as predators were present in leafy spurge stands in Nebraska. At this time it appears the spurge hawkmoth will not become a valuable biological control agent for leafy spurge in Nebraska.

scholarly journals Release of Postsenescent Dormancy in Leafy Spurge (Euphorbia esula) by Chilling

Weed Science ◽  
1988 ◽  
Vol 36 (6) ◽  
pp. 784-786 ◽  
Author(s):  
Stephen J. Harvey ◽  
Robert M. Nowierski
Keyword(s):  
Growth Rate ◽  
North America ◽  
Growth And Development ◽  
Leafy Spurge ◽  
Climatic Conditions ◽  
Euphorbia Esula ◽  
Flower Buds ◽  
Significant Growth ◽  
Number Of Stems

The growth and development of leafy spurge (Euphorbia esulaL. #3EPHES) collected during postsenescent dormancy and grown in the greenhouse was increasingly stimulated by chilling treatments longer than 14 days duration at 0 to 6 C. Production of stems with flower buds, primary flowers, and secondary flowers was greater in plants chilled for 42 days or more. The effects of chilling on total number of stems, number of strictly vegetative stems, or number of stems with vegetative branching were not significant. The height of the tallest stem per pot was influenced by chilling longer than 42 days. Growth rate also increased as a function of chilling duration. Based on our findings, we believe that there is little possibility that any significant growth can occur in the postsenescent period because of the prevailing climatic conditions found in areas of leafy spurge distribution in North America.

A Note on the Sugars and Amino Acids of Leafy Spurge, Euphorbia esula

Weeds ◽  
1956 ◽  
Vol 4 (3) ◽  
pp. 275 ◽  
Author(s):  
Duane Le Tourneau
Keyword(s):  
Amino Acids ◽  
Leafy Spurge ◽  
Euphorbia Esula

Seasonal Photosynthesis and Partitioning of Nonstructural Carbohydrates in Leafy Spurge (Euphorbia esula)

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 346-351 ◽  
Author(s):  
Russ W. Gesch ◽  
Debra Palmquist ◽  
James V. Anderson
Keyword(s):  
Late Summer ◽  
Leafy Spurge ◽  
Adventitious Bud ◽  
Adventitious Buds ◽  
Continuous Increase ◽  
Carbohydrate Partitioning ◽  
Growing Seasons ◽  
Autumn Leaf ◽  
Carbohydrate Status ◽  
New Strategies

Previous evidence indicates that changes in well-defined phases of dormancy in underground adventitious buds of leafy spurge in late summer and autumn are regulated by complex sensing and signaling pathways involving aboveground sugar signals. However, little information exists concerning seasonal photosynthesis and carbohydrate partitioning of leafy spurge, although such information would help to elucidate the involvement of sugar in controlling bud dormancy. An outdoor study was conducted over two growing seasons to determine and model seasonal patterns of photosynthesis and aboveground carbohydrate partitioning and their relationship to underground adventitious bud carbohydrate status. Photosynthesis and total nonstructural carbohydrate (TNC) content of aboveground tissues was greatest during vegetative growth. Photosynthesis gradually declined over the growing season, whereas TNC decreased sharply during flowering, followed by a gradual decline between midsummer and autumn. Leaf starch increased dramatically to midsummer before declining sharply throughout late summer and early autumn, whereas sucrose content responded inversely, indicating a mobilization of starch reserves and export of sugars to overwintering belowground sink tissues. Because newly formed underground adventitious buds showed a continuous increase in TNC from midsummer through autumn, export of sugars from aboveground tissues likely contributed to the increase in TNC. These results may facilitate new strategies for biological control of leafy spurge.

Spectral characteristics of leafy spurge (Euphorbia esula) leaves and flower bracts

Weed Science ◽  
2004 ◽  
Vol 52 (4) ◽  
pp. 492-497 ◽  
Author(s):  
E. Raymond Hunt ◽  
James E. McMurtrey ◽  
Amy E. Parker Williams ◽  
Lawrence A. Corp
Keyword(s):  
Remote Sensing ◽  
High Performance ◽  
Near Infrared ◽  
Spectral Characteristics ◽  
Leafy Spurge ◽  
Hyperspectral Remote Sensing ◽  
Total Carotenoids ◽  
Physiological Basis ◽  
Infrared Wavelengths ◽  
Pigment Concentrations

Leafy spurge can be detected during flowering with either aerial photography or hyperspectral remote sensing because of the distinctive yellow-green color of the flower bracts. The spectral characteristics of flower bracts and leaves were compared with pigment concentrations to determine the physiological basis of the remote sensing signature. Compared with leaves of leafy spurge, flower bracts had lower reflectance at blue wavelengths (400 to 500 nm), greater reflectance at green, yellow, and orange wavelengths (525 to 650 nm), and approximately equal reflectances at 680 nm (red) and at near-infrared wavelengths (725 to 850 nm). Pigments from leaves and flower bracts were extracted in dimethyl sulfoxide, and the pigment concentrations were determined spectrophotometrically. Carotenoid pigments were identified using high-performance liquid chromatography. Flower bracts had 84% less chlorophylla, 82% less chlorophyllb, and 44% less total carotenoids than leaves, thus absorptance by the flower bracts should be less and the reflectance should be greater at blue and red wavelengths. The carotenoid to chlorophyll ratio of the flower bracts was approximately 1:1, explaining the hue of the flower bracts but not the value of reflectance. The primary carotenoids were lutein, β-carotene, and β-cryptoxanthin in a 3.7:1.5:1 ratio for flower bracts and in a 4.8:1.3:1 ratio for leaves, respectively. There was 10.2 μg g−1fresh weight of colorless phytofluene present in the flower bracts and none in the leaves. The fluorescence spectrum indicated high blue, red, and far-red emission for leaves compared with flower bracts. Fluorescent emissions from leaves may contribute to the higher apparent leaf reflectance in the blue and red wavelength regions. The spectral characteristics of leafy spurge are important for constructing a well-documented spectral library that could be used with hyperspectral remote sensing.

scholarly journals Super Cooling Point Phenotypes and Cold Resistance in Hyles euphorbiae Hawk Moths from Different Climate Zones

Diversity ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 207
Author(s):  
Hana Daneck ◽  
Matthias Benjamin Barth ◽  
Martin Geck ◽  
Anna K. Hundsdoerfer
Keyword(s):  
Environmental Conditions ◽  
Cold Hardiness ◽  
Cold Treatment ◽  
Underlying Mechanism ◽  
Frost Tolerance ◽  
Cold Sensitivity ◽  
Cold Hardy ◽  
Hyles Euphorbiae

The spurge hawkmoth Hyles euphorbiae L. (Sphingidae) comprises a remarkable species complex with still not fully resolved taxonomy. Its extensive natural distribution range covers diverse climatic zones. This predestinates particular populations to cope with different local seasonally unfavorable environmental conditions. The ability of the pupae to overcome outer frosty conditions is well known. However, the differences between two main ecotypes (‘euphorbiae’ and ‘tithymali’) in terms of the inherent degree of frost tolerance, its corresponding survival strategy, and underlying mechanism have not been studied in detail so far. The main aim of our study was to test the phenotypic exhibition of pupae (as the relevant life cycle stadia to outlast unfavorable conditions) in response to combined effects of exogenous stimuli, such as daylight length and cooling regime. Namely, we tested the turnout of subitan (with fast development, unadapted to unfavorable conditions) or diapause (paused development, adapted to unfavorable external influences and increased resistance) pupae under different conditions, as well as their mortality, and we measured the super cooling point (SCP) of whole pupae (in vivo) and pupal hemolymph (in vitro) as phenotypic indicators of cold acclimation. Our results show higher cold sensitivity in ‘tithymali’ populations, exhibiting rather opportunistic and short-termed cold hardiness, while ‘euphorbiae’ produces a phenotype of seasonal cold-hardy diapause pupae under a combined effect of short daylight length and continuous cold treatment. Further differences include the variability in duration and mortality of diapause pupae. This suggests different pre-adaptations to seasonal environmental conditions in each ecotype and may indicate a state of incipient speciation within the H. euphorbiae complex.

Cattle Foraging Behavior in Leafy Spurge (Euphorbia esula)-Infested Rangeland

1987 ◽  
Vol 1 (4) ◽  
pp. 314-318 ◽  
Author(s):  
Rodney G. Lym ◽  
Donald R. Kirby
Keyword(s):  
Warm Season ◽  
Economic Loss ◽  
Leafy Spurge ◽  
High Density ◽  
Euphorbia Esula ◽  
Low Density ◽  
Forage Production ◽  
Grazing Season ◽  
Grazing Cattle ◽  
Early Fall

Leafy spurge causes economic loss by reducing both herbage production and use. Herbage use by grazing cattle in various densities of leafy spurge (Euphorbia esulaL. #3EPHES) was evaluated over a 3-yr period in North Dakota. Forage production and disappearance were estimated in four density classes of leafy spurge. Use of cool- and warm-season graminoids, forbs, and leafy spurge was estimated during the middle and the end of each grazing season. Cattle used 20 and 2% of the herbage in the zero and low density infestations, respectively, by mid-season. Moderate and high density infestations were avoided until the milky latex in leafy spurge disappeared in early fall, and herbage availability in zero and low density infestations declined. Herbage use in moderate and high density infestations increased to an average of 46% by the end of the grazing season compared to 61% in zero and low density infestations. An annual herbage loss of at least 35% occurred in pasture infested with 50% density or more of leafy spurge.

Sign in / Sign up

Export Citation Format

Share Document