scholarly journals Comparison of buckwheat, red clover, and purple tansy as potential surrogate plants for use in semi-field pesticide risk assessments withBombus impatiens

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2228 ◽  
Author(s):  
Angela E. Gradish ◽  
G. Christopher Cutler ◽  
Andrew J. Frewin ◽  
Cynthia D. Scott-Dupree

Background.Bumble bees (Bombusspp.) are important wild and managed pollinators. There is increased interest in incorporating data on bumble bees into risk assessments for pesticides, but standardized methods for assessing hazards of pesticides in semi-field and field settings have not yet been established for bumble bees. During semi-field studies, colonies are caged with pesticide-treated flowering surrogate plants, which must be attractive to foragers to ensure colony exposure to the test compound, and must produce an ample nectar and pollen to sustain colonies during testing. However, it is not known which plant(s) are suitable for use in semi-field studies with bumble bees.Materials and Methods.We comparedB. impatiensforaging activity and colony development on small plots of flowering buckwheat (Fagopyrum esculentum, var. common), red clover (Trifolium pratense), and purple tansy (Phacelia tanacetifolia) under semi-field conditions to assess their suitability as surrogate plants for pesticide risk assessment studies with bumble bees. We also compared the growth characteristics and input requirements of each plant type.Results.All three plant types generally established and grew well. Red clover and purple tansy experienced significant weed pressure and/or insect pest damage. In contrast, pest pressure was extremely low in buckwheat. Overall,B. impatiensforaging activity was significantly greater on buckwheat plots than red clover or purple tansy, but plant type had no effect on number of individuals produced per colony or colony weight.Discussion.Because of the consistently high foraging activity and successful colony development observed on buckwheat plots, combined with its favourable growth characteristics and low maintenance requirements, we recommend buckwheat as a surrogate plant for use in semi-field pesticide toxicity assessments withB. impatiens.

1995 ◽  
Vol 73 (11) ◽  
pp. 2052-2058 ◽  
Author(s):  
Robert J. Gegear ◽  
Terence M. Laverty

Pollinators often forage sequentially among the flowers of the same plant species while bypassing flowers of other rewarding species. Darwin proposed that it is more efficient for pollinators to remain constant to one plant species because switching to a second species interferes with their ability to recall a previously learned flower-handling technique. This interference hypothesis was tested using Bombus impatiens workers. Bees that had learned to handle one type of flower (species A) were retested on species A after they had learned to handle a second type of flower (species B). Interference effects were detected by comparing flower access times (time to insert the tongue into the flower) during the retesting period with initial access times on species A. Bees retested on both simple (red clover, Trifolium pratense) and complex (toadflax, Linaria vulgaris) flowers showed no evidence of interference after learning simple-flowered plant species (blueweed, Echium vulgare; purple loosestrife, Lythrum salicaria). However, bees relearning the complex flowers of toadflax showed a 2.2-s (81%) increase over their initial access time after switching to a second complex-flowered species (orange touch-me-not, Impatiens capensis). These results suggest that the interference effects incurred by bees switching between toadflax and orange touch-me-not under biologically realistic conditions are relatively small, and are unlikely to account for flower constancy in bumble bees.


2012 ◽  
Vol 151 (4) ◽  
pp. 506-518 ◽  
Author(s):  
M. KRAWUTSCHKE ◽  
N. WEIHER ◽  
J. THAYSEN ◽  
R. LOGES ◽  
F. TAUBE ◽  
...  

SUMMARYRed clover (Trifolium pratense L.) silage usually contains lower contents of non-protein nitrogen (NPN) compared with other forage legumes. This is often attributed to the polyphenol oxidase (PPO) activity in red clover, although in most field studies the PPO activity was not measured. Therefore, a laboratory ensiling experiment with three red clover cultivars and one white clover cultivar as control grown in two management systems (with and without mechanical stress) over 2 consecutive years was conducted. Fresh, wilted and ensiled clover herbage was sampled at four cutting dates per year to determine the crude protein (CP) fractions according to the Cornell Net Carbohydrate and Protein System. The specific PPO activity was measured photometrically in fresh clover leaves. The content of CP fraction A (NPN) increased from fresh over wilted to ensiled clover herbage at the expense of the content of CP fraction B (true protein), irrespective of species, cultivar and year. The most important source of variation for all CP fractions and the calculated rumen-undegradable protein contents was generally the herbage condition, except for CP fraction C (unavailable protein). White clover silage consisted of higher contents of CP fraction A and lower contents of CP fraction B3 in CP compared with red clover silage. As a result, the calculated rumen-undegradable protein content of white clover silage was lower than that of all red clover cultivars. In conclusion, the extent of proteolysis during ensiling among the silages made from the herbage of different red clover cultivars was primarily influenced by the stage of maturity at harvesting and the degree of wilting at ensiling. The variation in specific PPO activity could not be related to the extent of proteolysis.


1879 ◽  
Vol 11 (3) ◽  
pp. 44-45 ◽  
Author(s):  
J. A. Lintner

In the summer of 1877, my attention was called to some “worms” which had been discovered in the heads of red clover (Trifolium pratense), and were said to be preying upon the seeds. They were found to be minute maggot-like creatures, hidden within the seed-pods and entirely destroying the seeds which they attacked.


1961 ◽  
Vol 93 (6) ◽  
pp. 409-419 ◽  
Author(s):  
G. A. Hobbs ◽  
W. O. Nummi ◽  
J. F. Virostek

In the prairie region of Western Canada certain species of bumble bees are the principal pollinators of red clover, Trifolium pratense L. (Hobbs, 1957). Certain bumble and leaf-cutter bees are the only effective pollinators of alfalfa, Medicago sativa L., in Western Canada (Hobbs and Lilly, 1954; Hobbs, 1956; Peck and Bolton, 1946; Stephen, 1955). Unfortunately, bumble and leaf-cutter bees are seldom very abundant.


1985 ◽  
Vol 65 (2) ◽  
pp. 363-368 ◽  
Author(s):  
J. A. IVANY ◽  
J. M. SADLER ◽  
E. R. KIMBALL ◽  
K. B. McRAE

Field studies on Prince Edward Island (P.E.I.) loam to fine sandy loam soils from 1977 to 1980 determined the rate of breakdown of atrazine and soil residue effects on crops grown in rotation with silage corn (Zea mays L.). The rate of breakdown was rapid during the first 30 days after application with an estimated half-life of 23 days when averaged over rates and years. Timothy (Phleum pratense L.) and red clover (Trifolium pratense L.) were most sensitive to atrazine residues; yields of red clover were reduced significantly from the 1.13-kg/ha rate and of timothy after the 2.25-kg/ha rate. Yields of winter rye (Secale cereale L.) broadcast seeded in standing corn in August and barley (Hordeum vulgare L.) seeded the next spring were not affected, or reduced only slightly, by atrazine residues from initial applications of 1.13 kg/ha but showed significant yield losses at the 2.25- and 4.50-kg/ha rates. Alfalfa (Medicago sativa L.) seeded the next spring after atrazine use was tolerant of residues showing significant yield losses only at the 4.50-kg/ha rate. In this study, atrazine applied at 1.13 kg/ha in silage corn was sufficiently broken down to permit production of all crops studied except red clover.Key words: Atrazine, residue, clover (red), timothy, alfalfa, rye (winter), barley


Crop Science ◽  
1965 ◽  
Vol 5 (5) ◽  
pp. 425-428 ◽  
Author(s):  
R. J. Bula ◽  
R. G. May ◽  
C. S. Garrison ◽  
C. M. Rincker ◽  
J. G. Dean

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