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Leaf-feeding ratings (infestations with ca. 450 European corn borers [ECB], Ostrinia nubilalis (Hubner), eggs per plant) were made during midwhorl stage of plant development, and DIMBOA (2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one) contents of midwhorl leaf tissue were determined for four inbred lines of dent maize, Zea mays L., grown under field and greenhouse conditions. CI31A, B75, and B85 (grown in the field) were almost immune to leaf feeding by first-generation ECB larvae, but were susceptible when grown in a greenhouse. WF9 was susceptible under both field and greenhouse conditions, but the leaf-feeding damage was more intense in the greenhouse. In general, DIM BOA concentrations in leaf tissue were the same or were higher for the four inbred lines grown under greenhouse conditions compared with the lines grown under field conditions. Thus, high DIMBOA content in resistant inbred lines grown in a greenhouse did not prevent severe leaf-feeding damage by ECB larvae.

A method of simulating a flat belt drive under power-transmission conditions is given. Stress-strain data are obtained using a photoelastic coating technique. Tension-strain equations are evaluated using a computer program based on Forsythe's method of orthogonal polynomials. An indication of how the data may be used to arrive at the operating tensions of an actual belt drive is given.

An ecological study of the European corn borer (ECB), Ostrinia nubilalis (Hbn.), was conducted in Boone County, Iowa, from 1950 through 1965. The average date of the beginning of first-generation pupation was 12 May, with completion 8 June. Moth flight usually began in late May, peaked during the 2nd and 3rd weeks of June, and ended in early July. First-generation oviposition was greatest during the last half of June. Most (69.0%) first-generation ECB eggs hatched; a significant number (25.5%) were lost, probably due to heavy rains and violent winds. Greatest total numbers of first-generation ECB egg masses and larvae occurred in maize planted 6–10 d after the first planting date. The average date of the beginning of second-generation pupation was 16 July, with the average completion 14 August. Peak second-generation moth flight was during the first half of August. Peak oviposition was in early to mid-August. Percentage of second-generation eggs missing was less than that of the first generation, probably because severe storms were less frequent during August than in June. Heavy second-generation infestations often occurred in early-planted maize; more than 65% of second-generation larvae were found in maize planted during the first 10 d of the planting period. Heaviest infestations were in maize planted 21–30 d after the first planting date. A small third-generation moth flight occurred in some years. Predators were much more numerous during the second-generation oviposition period than during the first-generation oviposition. More second-generation eggs were eaten by predators than were first-generation eggs. The most common parasitoid of the ECB was Lydella thompsoni Herting; this species was uncommon after 1959. Other parasitoids were recorded but were not numerous.

Two maize (Zea mays L.) hybrids with varying degrees of resistance to damage by corn earworm (CEW) (Heliothis zea Boddie) were grown in Iowa, Georgia, and Missouri. Treatments included: introduction of Aspergillus flavus Link ex. Fr. spores onto newly-emerged silks, application of a fungicide as an aqueous spray onto test ears during the first three weeks after flowering, infestation of ears with CEW eggs, and combinations of these variables. CEW larvae were collected from developing ears and examined for the presence of internal A. flavus group propagules. Aflatoxin levels were determined in mature kernels. Toxin concentrations exhibited a distinct regional variation with relatively high levels in Georgia samples, intermediate concentrations in Missouri kernels and low levels in Iowa samples. No treatment effects were noted in Georgia samples but introduction of A. flavus and CEW increased toxin accumulation in Missouri kernels. Although the CEW-susceptible hybrid exhibited a trend towards increased damage by the insect, no treatment-related differences were observed in the presence of the fungus in larvae or in aflatoxin contamination. Fungicide applications did not significantly reduce aflatoxin levels in mature kernels.

Strain data for a simple two pulley belt drive was obtained using a photoelastic coating technique. The operating strains present were not constant along the driving and load sides but varied in an irregular manner. The average strain gradually increased on the driving side and decreased on the load side as the power transmitted was increased.

During a 2-year period, two popcorn hybrids (Iopop 12 and Indiana AES experimental hybrid 8365) were infested with European corn borer (ECB), Ostrinia nubilalis (Hubner), egg masses at five plant-growth stages (mid-whorl, late whorl, tassel emergence, anthesis, and 14 days after anthesis). Six levels of infestations were used (none, natural, 0.5, 1, 2, and 4 egg masses per plant). Considerable yield loss occurred in Iopop 12 from as few as 0.5 egg masses per plant at all plant-growth stages. Yield losses in hybrid 8365 were significant but less than in Iopop 12. Yield potential of Iopop 12 was greater than that of hybrid 8365, but potential yield losses and damage from ECB infestation were also greater. ECB infestation had no effect on popping expansion of either hybrid.

Using a birefringent coating technique, stress separation is carried out on a tooth of a timing belt by two approaches to the shear difference method. The analysis is performed by approximating the composite belt to a non-homogeneous body made up of two distinctly different homogeneous isotropic materials. The results from the two approaches are found to be in very close agreement.

Yield losses due to second-generation European corn borer (ECB), Ostrinia nubilalis (Hubner), infestations in long-season maize, Zea mays L., hybrids (B79 × Mo17 and Pioneer 3535) planted early were compared with losses in short-season hybrids (A619 × A632, Mo17 × A634, Pioneer 3572, and Pioneer 3732) planted late. Yields of long-season hybrids in both ECB-infested and noninfested plots were much greater than those of short season hybrids. Pioneer 3535 had less yield loss, less kernel weight loss, and fewer cavities than did B79 × Mo17. Losses due to ECB were greater in short-season hybrids planted late. Losses from stalk breakage and dropped ears were greater in short-season hybrids. Growers should plant long-season hybrids early; if a short-season hybrid is planted late, ECB infestation should be closely monitored.

Tension relaxation tests are made on composite flat belt drive materials under simulated drive conditions. A non-linear equation is obtained relating belt tension at time t to the initial tension at time t=0. The parameters in the equation are evaluated using a non-linear estimation computer program. Differentiation of the equation enables the time to be predicted when the rate of change of relaxation of the material becomes insignificant.

Concepts concerning the etiology of radiation sickness have been numerous and varied. In 1906, Edsall and Pemberton suggested that the vomiting was toxic in nature and was due to unknown decomposition products of tissue destruction (5). Later, Hall and Whipple (7) attributed the effects to injury of the epithelial cells, and Rolleston (14) felt that proteins liberated by the destruction of cells were responsible for the symptoms. Holmes and Hunter noted that the manifestations closely resembled those seen in patients with catarrhal jaundice, and suggested the possibility of a disturbance of liver function as the underlying cause (8). More recently, there has been much interest in the relationship of vitamins to radiation sickness. Martin and Moursund, in 1938, pointed out that this condition resembled a vitamin B1 deficiency and stated that vitamin B1 protected guinea-pigs from sickness following small doses of radiation over the abdomen (10). In the same year, Spies and his co-workers found that patients...

Hyadaphis pseudobrassicae (Davis) was tested as a pest of 19 species and botanical varieties of cruciferous oilseeds Only PI 171538, an introduction of Brassica napus L., was resistant of the 390 plant introductions and varieties of Brassica spp. screened. Also, no resistance was found in Any introductions of Eruca sativa Mill., Camelina sativa (L.) Crantz, Raphanus raphanistrum L., R. sativus L. Thalaspi arvense L., or Lepidiurn sativum L. However, Alyssum dasycarpum Steph. ex Willd., was highly resistant and may not be a host. In general, the winged forms of the aphid were most attracted by crucifers on which the rate of reproduction was greatest, but C. sativa was an exception: this species was unattractive to winged aphids, though it was highly susceptible to aphid feeding. A sta tistically significant correlation (r = 0.675 with 47 df) was found between the attractiveness of Cruciferae to winged aphids and the rate of reproduction of the aphids.

Inbred line DE811 was crossed with 12 dent maize, Zea mays L., inbred lines. The 12 inbred lines, plus DE811 and a check inbred line, and 12 single crosses, plus two single-cross checks, were planted in a modified randomized block design for 3 yr, with five replications each year. First-generation European corn borer, Ostrinia nubilalis Hubner, plots were separate from the second-generation European corn borer plots (two hills of three plants for each plot in each experiment). Plants in the first-generation tests were infested during the midwhorl stage of plant development, whereas plants in the second-generation tests were infested during anthesis. Plants in each test were infested with 12 egg masses (300 eggs) per plant in six applications of two masses, spaced 1 d apart. Leaf-feeding ratings in the first-generation tests were made 3 wk after egg hatch. Sheath-collar feeding ratings and stalk damage were made 60 d after egg hatch in the second-generation tests. In combination with several susceptible inbred lines, DE811 resistance showed partial dominance for resistance to leaf feeding by first-generation European corn borers and for resistance to sheath-collar feeding and stalk damage by second-generation European corn borers. Single crosses of DE811 × resistant inbred lines had high resistance to both European corn borer generations.

Resistance to leaf feeding by first-generation Ostrinia nubilalis (Hubner) is conditioned by several genes. A polygenic system in maize plants probably does not guarantee against development of European corn borer biotypes. A biotype problem, however, should be less in a polygenic system than in a monogenic system. Our data support this statement because European corn borer cultures reared for 16 generations on inbred lines of dent maize, Zea mays L., (CI31A and Oh43) did not increase their ability to damage these highly resistant (nearly immune) or resistant genotypes of maize, and larvae reared for 16 generations on inbred line WF9 maintained their ability to damage this susceptible dent genotype of maize. The corn borer cultures were reared one generation each year on three inbred lines and eight generations each year on a meridic diet.

The rate of first-generation European corn borer (ECB), Ostrinia nubilalis Hubner, larval survival on four sorghum, Sorghum bicolor (L.) Moench, hybrids, and two inbred lines of maize, Zea mays L., was determined by dissecting plants 3, 6, 9, 12, and 15 days after egg hatch. Infestations with ca. 200 eggs per plant were made during the mid whorl stage of plant development. Larval survival was much greater on a susceptible maize inbred line (B73) at all dissection intervals than was larval survival on four sorghum hybrids (P846, P8475, P8680, P8324) and on a resistant inbred line of maize (B85). Larval mortality was rapid on four sorghum hybrids within 6 days after egg hatch, but was not as rapid on the four sorghum hybrids as was larval mortality on a resistant maize inbred within 6 days after egg hatch. Feeding sites were determined for 22,827 first-generation larvae. Most larvae fed on leaf tissue in the moist area deep in the whorl of sorghum and maize plants through 9 days after egg hatch. Resistance in sorghum to first-generation O. nubilalis, therefore, is resistance to leaf feeding—i.e., antibiosis against first and second instars and is similar to first-generation resistance in maize.

A study was conducted to compare direct feeding by European corn borer (ECB), Ostrinia nubilalis (Hubner), to popcorn kernels with direct feeding on sweet and dent corn kernels to determine the damage potential of the ECB to popcorn kernels. To maximize kernel damage, ears were artificially infested by pinning ECB egg masses to the husks as soon as fresh silks appeared. Most damaged or consumed kernels were at the tip of the ear. The greatest amount of damage occurred in sweet corn. Damage to popcorn kernels was much lower than to those of sweet corn and similar to those of dent corn.

Occasionally, fall field populations of European corn borers (ECB), Ostrinia Nubilalis Hubner, are so small that it is difficult to collect sufficient numbers of larvae to start a new culture. Our data show that diapausing larvae can be collected from a second-generation ECB maize, Zea mays L., nursery for at least 5 years consecutively without loss in virulence of the insect to cause extensive damage to susceptible genotypes of maize.

Laboratory techniques and a balanced lattice design were developed for testing a large number of plant species for insect feeding preferences. Cuttings of plants were placed in glass vials filled with water and plugged with cotton, and the vials were then placed in aluminum-foil boxes containing white-fringed beetles, Graphognathus peregrinus (Buchanan). With a balanced lattice, an incomplete block design, only a small number of plants was necessary each box to test a large number of plant species. The advantage of the balanced lattice was that the feeding preferences of the beetles to all possible pairs of plants were compared with equal precision. The beetles showed definite feeding preferences by feeding on certain plants heavily, on others moderately or lightly, and on others not at all.

Seasonal development of the European corn borer, Ostrinia nubilalis (Hubner), was followed in the Boone County, Iowa, area from 1950 through 1961. The relationship between temperature accumulations and cumulative percentages of first- and second-generation moth flight and oviposition was shown to follow a sigmoid curve. An equation for use in predicting the date on which any desired percentage of first- and second-generation moth Hight or oviposition may be expected is presented.

When 20 accessions of Crambe abyssinica Hochst. ex R.E. Fries and I of C. hispanica (L.) were tested in the greenhouse to determine the potential importance of the turnip aphid, Hyadaphis pseudobrassicae (Davis), and the green peach aphid, Myzus persicae (Sulzer), as pests of C. abyssinica and C. hispanica , both species of aphids were found capable of causing severe damage to both species of crambe in the proper environment. PL 247310 (an accession of C. abyssinica ) was resistant to the turnip aphid; all plants tested of other accessions of crambe were susceptible. Also, all plants tested of all accessions were susceptible to the green peach aphid. An infestation of turnip aphids will cause more damage to susceptible crambe than a comparable infestation of green peach aphids.