7,885 research outputs found
\u3ci\u3eEpinotia Nisella\u3c/i\u3e: an Unrecorded Host and Mode of Feeding (Lepidoptera: Tortricidae)
The larva of Epinotia nisella is best known as a feeder in female catkins of Populus, primarily P. tremuloides Michx. in North America. In Minnesota, adults were reared from larvae boring in current-growth branchlets of P. balsamifera L., with no sign of like infestation in neighboring P. tremuloides, which has thinner branchlets. The behavioral variance is explained as plasticity in feeding biology, a characteristic of insects utilizing host reproductive structures whose abundance is periodic
Weights of \u3ci\u3ePolia Grandis\u3c/i\u3e Pupae Reared at Two Constant Temperatures (Lepidoptera: Noctuidae)
Sibling Polia grandis (Boisduval) larvae were reared at two constant temperatures on fresh foliage of quaking aspen (Populus tvemuloides Michx.). Female pupae developing at 25°C were 24% heavier than those developing at 30°C and corresponding males were 32% heavier. Duration of the larval period averaged 51 days at the former temperature and 41 days at the latter. Based on other Lepidoptera, a 24% change in pupal weight affects fecundity by 28 to 130 eggs per female. Fluctuations in larval temperature regime might induce size and fecundity variation in natural populations of grandis and other Lepidoptera
Annual Variation in Starting Date of Spring Feeding by the European Pine Shoot Moth in a Michigan Planting
New tents spun in five successive springs by the European pine shoot moth (Rhyacionia buoliana [Schiff.] ) in a Michigan planting of red pine (Pinus resinosa Ait.) occurred about 2 days later each year. This trend is believed due to habitat cooling as trees grow larger. In another planting feeding was more advanced on small trees than on large trees
Change in Nutritional Quality of Detached Aspen and Willow Foliage Used as Insect Food in the Laboratory
Leaves of Populus tremuloides and Salix babylonica held in the laboratory as for feeding insects were analyzed for total nitrogen, total phenolics, and total sugars at 0, 3, and 6 days. More often than not, the three components varied due to leaf age, time since excision, or temperature. Temporal changes altered nutritional balance and probable impact on insect performance, Results suggest that other woody plant species would not remain nutritionally stable for long in the laboratory
\u3ci\u3ePammene Perstructana\u3c/i\u3e (Walker) (Lepidoptera: Tortricidae) Identified After More Than a Century
Sciaphila perstructana Walker has been known only from the female holotype, and Pammelle signifera (Heinrich) only from males. Based on associated males and females from the Great Lakes area. the two names apply to one species. The resulting synonymy leads to a new combination. Pammene perstructana, and finally associates a species with this long-battling specitlc name
A New Species of \u3ci\u3eLaspeyresia\u3c/i\u3e from Michigan (Lepidoptera: Olethreutidae)
Laspeyresia lacustrina is described from four specimens, all female, captured in flight at two locations in Lower Michigan. On the exterior, the moth most resembles L. populana Busck and several other eastern species; its genitalia most resemble the western L. lautiuscula Heinrich. With wing length 8.4 to 9.4 mm, L. lacustrina is among the largest North American members of the genus
Nearctic Rhyacionia Pine Tip Moths: a Revised Identity and a New Species (Lepidoptera: Tortricidae)
Moths now identified as Rhyacionia busckana are a mix of two long-confused sibling species. The name R. busckana applies to the species with male antennal pecten length subequal to antennal segment length. and with female sterigma width threecfold or more ostium bursae width. The name R. granti applies to the previously undescribed species ltype locality Iron Bridge, Algoma District, Ontario) with male antennal pecten length at least two-fold antennal segment length, and with female sterigma width less than three-fold ostium bursae width. Structural differences were discovered after sex attractant studies revealed differences in behavioral physiology and phenology. In the Great Lakes region, R. busckana larvae feed on Pinus resinosa and P. sylvestris, and Rhyacionia granti larvae feed on Pinus banksiana
Nearctic \u3ci\u3eAcleris\u3c/i\u3e: Resurrection of \u3ci\u3eA. Stadiana\u3c/i\u3e and a Revised Identity for \u3ci\u3eA. Semiannula\u3c/i\u3e (Lepidoptera: Tortricidae)
Type study showed that Acleris stadiana (Barnes & Busck), currently considered a junior synonym of A. semiannula (Robinson), is in fact a distinct taxon. Although superficially similar, these taxa differ markedly in genital structure. In males of A. semiannula, the aedeagus is short, broad, and virtually straight, whereas in those of A. stadiana, it is long, thin, and sharply bent. What was known in literature as A. semiannula proved to be A. stadiana. We redefine both A. semiannula and the resurrected A. stadiana
Effect of the NACA Injection Impeller on the Mixture Distribution of a Double-Row Radial Aircraft Engine
The NACA injection impeller was developed to improve the mixture distribution of aircraft engines by discharging the fuel from a centrifugal supercharger impeller, thus promoting a thorough mixing of fuel and charge air. Tests with a double-row radial aircraft engine indicated that for the normal range of engine power the NACA injection impeller provided marked improvement in mixture distribution over the standard spray-bar injection system used in the same engine. The mixture distribution at cruising conditions was excellent; at 1200, 15OO, and 1700 brake horsepower, the differences between the fuel-air ratios of the richest and the leanest cylinders were reduced to approximately one-third their former values. The maximum cylinder temperatures were reduced about 30 [degrees] F and the temperature distribution was improved by approximately the
degree expected from the improvement in mixture distribution. Because the mixture distribution of the engine tested improves slightly at engine powers exceeding 1500 brake horsepower and because the effectiveness of the particular impeller diminished slightly at high rates of fuel flow, the improvement in mixture distribution at
rated power and rich mixtures was less than that for other conditions.
The difference between the fuel-air ratios of the richest and the leanest cylinders of the engine using the standard spray bar was so great that the fuel-air ratios of several cylinders were well below the chemically correct mixture, whereas other cylinders were operating at rich mixtures. Consequently, enrichment to improve engine cooling actually increascd some of the critical temperatures. The uniform mixture distribution providod by the injection impeller restored the normal response of cylinder temperatures to mixture enrichnent
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