A Computer Model for Simulating Population Development of the Indianmeal Moth (Lepidoptera: Pyralidae) in Stored Corn

The Indianmeal moth, Plodia interpunctella (Hu¨bner) (Lepidoptera: Pyralidae), is a common pest of stored corn, Zea mays L. We developed a computer model to simulate population development of the Indianmeal moth in stored corn by using previously published data describing immature developmental times and survivorship, and adult longevity and fecundity. The model accurately simulated population development of Indianmeal moths in corn stored during fall and into winter of three separate storage seasons in South Carolina. This is the period when the Indianmeal moth is a pest in stored corn in South Carolina. The model predicted that populations would increase after winter as grain temperatures rose, but observed populations in the grain bins never increased after winter. Despite this, the model should be useful from a management perspective because the corn is being sold off or used up after winter, and the observed Indianmeal moth populations never reached damaging levels after winter

Abundance of Plodia interpunctella (Hubner) and Cadra cautella (Walker) infesting maize stored on South Carolina farms: seasonal and non-seasonal variation

Seasonal trends and short-term fluctuations in abundance of Plodia interpunctella (Hubner) and Cadra cautella (Walker) infesting maize stored on two South Carolina farms were studied during three storage seasons (September 1990–June 1993). Coils of corrugated paper placed on the grain surface were used to trap mature larvae seeking pupation sites. Temperatures in the grain (18-cm-deep) and in the bin headspace were recorded hourly, and grain moisture content was measured weekly. Weekly mean numbers of moth larvae, and adults of two natural enemies, trapped in the coils were used for tracking changes in their abundance over time. The most significant findings were: (1) a seasonal pattern of abundance in both moth species that persisted from farm to farm and year to year, and (2) the coincidence of the highest population levels with the lowest temperatures. With few exceptions, the moth populations increased in the fall, reached their highest levels in winter, and then declined to low levels by early spring. The persistence of this pattern suggests a seasonal regulatory mechanism, with onset of low temperature as the primary initiator of population decline and adversely high temperature as a contributor to its protraction through spring into early summer. This view is supported by our observations of temperature and moth abundance, in conjunction with published information on the biological limitations of the two species. However, other factors, such as predators, parasitoids, and viral infection, may have contributed to the final population collapse. Superimposed upon the seasonal trends were short-term, non-seasonal cycles of abundance with variable periods. Population theory suggests that predation, parasitism, disease, and competition may have produced these cycles

Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe

Archaeological evidence indicates that pig domestication had begun by ~10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ~8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local Euro-pean wild boars, although it is also possible that European wild boars were domesticated independently without any genetic con-tribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process

A Computer Model for Simulating Population Development of the Indianmeal Moth (Lepidoptera: Pyralidae) in Stored Corn

The Indianmeal moth, Plodia interpunctella (Hu¨bner) (Lepidoptera: Pyralidae), is a common pest of stored corn, Zea mays L. We developed a computer model to simulate population development of the Indianmeal moth in stored corn by using previously published data describing immature developmental times and survivorship, and adult longevity and fecundity. The model accurately simulated population development of Indianmeal moths in corn stored during fall and into winter of three separate storage seasons in South Carolina. This is the period when the Indianmeal moth is a pest in stored corn in South Carolina. The model predicted that populations would increase after winter as grain temperatures rose, but observed populations in the grain bins never increased after winter. Despite this, the model should be useful from a management perspective because the corn is being sold off or used up after winter, and the observed Indianmeal moth populations never reached damaging levels after winter

Composition of volatiles from fermenting pollen dough and attractiveness to the small hive beetle Aethina tumida, a parasite of the honeybee Apis mellifera

The response of the small hive beetle (SHB), Aethina tumida Murray, to volatiles from a pollen-based diet conditioned by the feeding of 100 adult virgin female or male SHBs (4–8 weeks old) for 1, 3, 7 or 14 days is described and compared to that of the same diet inoculated with the yeast Kodamaea ohmeri (NRRL Y-30722), isolated from the beetle. In a wind tunnel, volatiles from pollen dough conditioned by beetles of either sex for 3 or 7 days lured significantly more beetles into traps than volatiles from unconditioned dough. In contrast, trap captures with volatiles from dough conditioned for 1 and 14 days were weakly attractive. In cage bioassays, when naïve, unfed, virgin, SHBs (3–4 days old) were given a choice between yeast-inoculated pollen dough and non-inoculated dough, the responses were similar to those obtained in the wind tunnel with dough conditioned by SHBs for 3 and 7 days. Chemical analysis revealed high levels of fermentation-related products in volatiles that attracted the beetle

Effect of number of masking talkers and auditory priming on informational masking in speech recognition

Three experiments investigated factors that influence the creation of and release from informational masking in speech recognition. The target stimuli were nonsense sentences spoken by a female talker. In experiment 1 the masker was a mixture of three, four, six, or ten female talkers, all reciting similar nonsense sentences. Listeners’ recognition performance was measured with both target and masker presented from a front loudspeaker ~F–F! or with a masker presented from two loudspeakers, with the right leading the front by 4 ms ~F–RF!. In the latter condition the target and masker appear to be from different locations. This aids recognition performance for one- and two-talker maskers, but not for noise. As the number of masking talkers increased to ten, the improvement in the F–RF condition diminished, but did not disappear. The second experiment investigated whether hearing a preview ~prime! of the target sentence before it was presented in masking improved recognition for the last key word, which was not included in the prime. Marked improvements occurred only for the F–F condition with two-talker masking, not for continuous noise or F–RF two-talker masking. The third experiment found that the benefit of priming in the F–F condition was maintained if the prime sentence was spoken by a different talker or even if it was printed and read silently. These results suggest that informational masking can be overcome by factors that improve listeners’ auditory attention toward the target

Effect Of Number Of Masking Talkers And Auditory Priming On Informational Masking In Speech Recognition

Three experiments investigated factors that influence the creation of and release from informational masking in speech recognition. The target stimuli were nonsense sentences spoken by a female talker. In experiment 1 the masker was a mixture of three, four, six, or ten female talkers, all reciting similar nonsense sentences. Listeners’ recognition performance was measured with both target and masker presented from a front loudspeaker ~F–F! or with a masker presented from two loudspeakers, with the right leading the front by 4 ms ~F–RF!. In the latter condition the target and masker appear to be from different locations. This aids recognition performance for one- and two-talker maskers, but not for noise. As the number of masking talkers increased to ten, the improvement in the F–RF condition diminished, but did not disappear. The second experiment investigated whether hearing a preview ~prime! of the target sentence before it was presented in masking improved recognition for the last key word, which was not included in the prime. Marked improvements occurred only for the F–F condition with two-talker masking, not for continuous noise or F–RF two-talker masking. The third experiment found that the benefit of priming in the F–F condition was maintained if the prime sentence was spoken by a different talker or even if it was printed and read silently. These results suggest that informational masking can be overcome by factors that improve listeners’ auditory attention toward the target