Potential Insect Problems for 1969

Insect problems will continue to be detrmined by the weather, say the authors. They analyze last year\u27s problems to gain insight into what might happen in 1969

Insect Prospects for 1965

Western corn rootworm, black cutworm, corn borer are among crop insects to watch. Mosquito-borne encephalitis has been increasing and warrants protective measures for both humans and livestock

Insect and Rodent Prospects for 1963

What insects will we have this year? We can expect heavy fly populations, and both 13-year and 17-yer cicadas will invade areas of Iowa in late May. Other insect and rodent problems will depend on the weather

Insect and Insect Control in 1966

Residues of soil insecticides found in milk and soybeans affect recommendations for 1966. Western corn rootworm continues spread. Southern corn rootworm and black cutworm did serious damage in 1965

Insect Prospects for 1964

Trouble expected from insecticide-resistant corn rootworms, corn borers and periodical cicadas plus heavy fly population. Weather to be big factor. Here are analyses and insect control recommendations

The Insect Situation in 1968

What happened last year will have some influence on insect conditions in 1968. The authors provice some suggestions on what to look for, and how to handle both crop and livestock insect problems

Insect and Rodent Prospects for 1962

What insects will we have this year? Insect problems depend a lot on weather conditions. Keeping this in mind and looking at the problems in 1961, here are the prospects for 1962 - and what to do about them

Insect Control in 1967

Advances in chemical control and farming procedures will let you win the battle agaisnt the bugs, but many questions concerning these measures need to be answered for you

Recovery of the Historical SN1957D in X-rays with Chandra

SN1957D, located in one of the spiral arms of M83, is one of the small number of extragalactic supernovae that has remained detectable at radio and optical wavelengths during the decades after its explosion. Here we report the first detection of SN1957D in X-rays, as part of a 729 ks observation of M83 with \chandra. The X-ray luminosity (0.3 - 8 keV) is 1.7 (+2.4,-0.3) 10**37 ergs/s. The spectrum is hard and highly self-absorbed compared to most sources in M83 and to other young supernova remnants, suggesting that the system is dominated at X-ray wavelengths by an energetic pulsar and its pulsar wind nebula. The high column density may be due to absorption within the SN ejecta. HST WFC3 images resolve the supernova remnant from the surrounding emission and the local star field. Photometry of stars around SN1957D, using WFC3 images, indicates an age of less than 10**7 years and a main sequence turnoff mass more than 17 solar masses. New spectra obtained with Gemini-South show that the optical spectrum continues to be dominated by broad [O III] emission lines, the signature of fast-moving SN ejecta. The width of the broad lines has remained about 2700 km/s (FWHM). The [O III] flux dropped precipitously between 1989 and 1991, but continued monitoring shows the flux has been almost constant since. In contrast, radio observations over the period 1990-2011 show a decline rate inf the flux proportional to t**-4, far steeper than the rate observed earlier, suggesting that the primary shock has overrun the edge of a pre-SN wind.Comment: 28 pages, including 3 tables and 7 figures, accepted for publication in Ap

A Study of Compact Radio Sources in Nearby Face-on Spiral Galaxies. I. Long Term Evolution of M83

We present analyses of deep radio observations of M83 taken with the Very Large Array spanning fifteen years, including never before published observations from 1990 and 1998. We report on the evolution of 55 individual point sources, which include four of the six known historical supernovae in this galaxy. A total of 10 sources have X-ray counterparts from a {\em Chandra} survey. Each of these sources show non-thermal spectral indices, and most appear to be X-ray supernova remnants. Comparing the radio source list to surveys in optical and X-ray, we identify three optical/X-ray supernova remnants. Nearly half of the detected radio sources in these observations are coincident with known H II regions lying in the spiral arm structures of the galaxy. We also report on changes in emission from the complex nuclear region, which has shown variability at 20cm wavelengths. We confirm that the peak radio emission from the nucleus is not coincident with the known optical center. One lesser nuclear peak is consistent with the optical/IR nucleus. Previous dynamical studies of a ``dark'' nuclear mass indicate a possible match to other radio nuclear emission regions in M83.Comment: 32 Pages, 8 figures, to appear in AJ. Full resolution figures can be obtained at http://nhn.ou.edu/~maddo