Search

Experiments were conducted in Alabama from 1951 through 1954 to determine the influence of the honey bee, A pis mellifera L., on the yield of seed of crimson clover, Trifolium incarnatum L. Colonies of bees were available in known concentrations to crimson clover fields. Observations were made during the blooming period of the clover to determine the condition of the clover plants and the number of bees visiting the clover. Cages were used to exclude the bees from small plots of blooming clover, and yields of seed from these plots were compared with those from adjacent areas to which the bees had access. The presence of honey bees resulted in highly significant increases in seed yields of crimson clover. Under ordinary field conditions in Alabama, two colonies of bees per acre of crimson clover resulted in most efficient seed production. The average gains in total yield of seed per acre where bees were present at a rate of two colonies per acre over the yields where bees were excluded were from 281 to 509 pounds. Where the best agronomic practices were followed, the gain in total yield of seed using three colonies of bees per acre was 1019 pounds, or a gain in yield by combine harvest of more than 800 pounds. The number of pods formed in the clover heads was not affected by the various treatments. The percentage of the pods that contained seed was in direct proportion to seed yields. The reduction of wind or shade as caused by cages or partial cages in the clover plots had only a minor effect on yield of seed of crimson clover.

The thirty-second annual meeting of the Cotton States Branch, E.H.A., was held in the Hotel Peabody, Memphis, Tennessee, on December 2, 3, 4, and 5, 1957. The meeting was heldin conjunction with the parent association of the Entomological Society of America. One hundred twenty-eight members and guests registered for the four-day meeting. Chairman Norman Allen opened the first of two branch business meetings promptly at 4:30 P.M. on December 2.

Chlordane, dieldrin, heptachlor, or Telodrin® (1,3,4,5,6,7,8,8-octachloro-1,3,3a,4,7,7a,-hexahydro-4,7-methanoisobenzofuran) afforded significant control of the alfalfa weevil, Hypera postica (Gyllenhal), when applied in the fall in granular formulation at the rate of 2, 1, 1, or 0.1 lb/acre, respectively. Heptachlor was equally effective when applied alone or as a physical mixture with recommended fertilizers. Optimum time of fall application of heptachlor was about November 15.

Of 37 insecticidal spray formulations tested for effectiveness against the alfalfa weevil, Hypera postica (Gyllenhal), a satisfactory reduction in larval population resulted from application of the following insecticides (rates in pounds per acre in parentheses): malathion (1), methoxychlor (2), endrin (0.5), heptachlor (0.5), dieldrin (0.5), benzene hexachloride (0.5), Bayer 39007 ( o -isopropoxyphenyl methylcarbamate) (2), or AC-43064 (cyclic ethylene(diethoxyphosphinothioyl) dithioimidocarbonate) (2). Eight dust formulations were tested and a satisfactory reduction in larval population resulted from the application of either heptachlor (0.5) or parathion (0.4).

The LD50 values and dosage-mortality curves for 41 insecticides were determined for the 4th-instar larvae of the alfalfa weevil, Hypera postica (Gyllenhal). Based on the LD50 the most toxic material was benzene hexachloride, followed by heptachlor epoxide, EPN, methyl parathion, Zectran® (4-dimethylamino-3,5-xylyl methylcarbamate), and parathion in that order. Dosage-mortality curves with the greatest slope included those for Meta-Systox - R® ( S -2 - (ethylsulfinyl) ethyl O , O -dimethylphos-phorothioate), demeton, dichlorvos, mevinphos, naled, and Guthion® ( O , O -dimethyl S- (4-oxo-1,2,3-benzotriazin-3 (4 H ) -ylmethyl) phosphorodithioate). Those with very little slope included Kepone® (decachlorooctahydro-- 1,3,4- metheno-2 H -cyclobuta[ cd ]pentalen-2-one), phosphamidon, rotenone, Dilan® (a mixture of 1 part of 1,1-bis ( p -chlorophenyl) -2-nitropropane (Prolan®) and 2 parts of l,l-bis ( p -chlorophenyl) -2-nitrobutane (Bulan®)), TDE, and ronnel.