Insecticide and Growth Regulator Effects on the Leafminer, \u3ci\u3eLiriomyza Trifolii\u3c/i\u3e (Diptera: Agromyzidae), in Celery and Observations on Parasitism

The effects of different insecticides were compared on survival and development of the leafminer, L. trifolii, in celery in Michigan and parasitism was assessed in this non- resident population. Avermectin, thiocyclam, and cyromazine effectively controlled L. trifolii larvae or prevented successful emergence as adults. Moderate to high levels of resistance to permethrin and chlorpyrifos were present. Avermectin caused high mortality of all larval stages and no adults successfully emerged. Thiocyclam caused high mortality to all larval stages, but did not affect adult emergence from the surviving larvae. Cyromazine acted most strongly against early stage larvae before visible mines were present, caused little direct mortality of larger larvae, but prevented successful adult emergence. No parasitoids emerged from 2029 larvae collected and reared, in contrast to studies in sites where L. trifolii is a year-round resident

Evidence of Pre-Imaginal Overwintering of Diamondback Moth, \u3ci\u3ePlutella Xylostella\u3c/i\u3e (Lepidoptera: Plutellidae) in Michigan

We investigated the possibility of overwintering of the diamondback moth, Plutella xylostella L., in central Michigan. In the spring of 1993, counts of immature stages on brassicaceous weeds in a field previously planted to broccoli revealed a small but significant number of late instars that could not be attributed to oviposition of immigrant moths from the southern United States. We suggest that crop debris and snow cover played an important role in sheltering the larvae, which are known to tolerate sub·freezing temperatures. There was no indication of adult survival

Movement of Adult Colorado Potato Beetles, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae), in Response to Isolated Potato Plots

Mark recapture techniques were used to determine Colorado potato beetle movement in circular arenas with isolated plots of potatoes at each ordinal direction. Post-diapause beetles aggregated on one or a few of the plants in one of the plots for each release, but not on the same plants in different releases. Differences in plant attractiveness were therefore not likely responsible for the aggregatory behavior. Aggregations were probably a result of either coordinated movement from the release site to the plants or an aggregatory signal with a range of at least 15 m. Summer adults did not aggregate on plants. Correlations of summer beetle recapture distributions to wind direction showed that anemotactic behavior could not account for the major portion of variation in beetle orientation to the potato plots. Some positive attraction to the plots was indicated because more beetles were recaptured at the plots than would be expected from random motion. The number of beetles recaptured at plots covered by cheesecloth was not significantly different from recaptures on uncovered plots, indicating little reliance on visual cues specific to potatoes for location of the plants

First Record of \u3ci\u3eAphis Helianthi\u3c/i\u3e (Homoptera: Aphididae) as a Pest of Celery

In 1989, the aphid Aphis helianthi severely damaged five of 10 scouted celery fields in west central Michigan. In 1990 and in 1991, A. helianthi again was a problem. reaching pestiferous levels in three of 10 and two of 10 scouted fields. respectively. This insect has not been reported previously as a pest of celery or any other commercial crop. Insecticide efficacy studies showed that some of the most commonly used insecticides are ineffective against A. helianthi. Resistance or tolerance to insecticides may explain its new status as a pest

Marking Adult Colorado Potato Beetles, \u3ci\u3eLeptinotarsa Decemlineata\u3c/i\u3e (Coleoptera: Chrysomelidae) Using Paper Labels

The smooth elytra of adult Colorado potato beetle, Leptinotarsa decemlineata, make this insect difficult to make efficiently for long-term field studies. Enamel paint marks fell off rapidly, and after 28 days, 25010 of marked beetles had lost all four original marks. Use of small paper labels glued to the elytra after an acetone wash and sanding pretreatment was the most effective method for long term marking of individual beetles. Mortality in labeled laboratory-reared and field-collected beetles did not increase when compared to unmarked beetles

A Statistical Model for Estimating Components of Genetic Variance in Bulk Yield Tests of Self-Pollinated Small Grains

Comstock and Robinson have given a statistical model for the isolation of the components of genetic variance in populations of biparental progenies. Their model has made possible the construction of one for self-pollinated progenies to be applied to the method of small grain breeding, wherein large numbers of bulked F2 and F3 progenies are tested for yielding ability. Inasmuch as the genetic variance of high yielding progenies will be due to both additive and non-additive genetic effects, it is important that these effects be separated

Giving the Devil His Due: Satan and Cinema

This is a book review of Jeffrey Andrew Weinstock and Regina M. Hansen, eds., Giving the Devil His Due: Satan and Cinema (New York: Fordham University Press, 2021)

Feebar Barley

High yield, resistance to stem rust, stiff straw and high protein are some of the advantages that recommend Feebar, a new variety of feed barley, to South Dakota farmers. About 4500 bushels of this new barley were released by the South Dakota Agricultural Experiment Station to the South Dakota County Crop Improvement Associations in the spring of 1947. Tests made in different areas of South Dakota on widely different soil types show Feebar to be adapted and capable of displacing some of the older barley varieties commonly grown

Biomass distributions in dwarf tree, krummholz, and tundra vegetation in the alpine treeline ecotone

Alpine treeline ecotones are expected to respond to climate change with shifts in biomass patterns and carbon dynamics; however, the nature of these shifts and the current structure of carbon storage at treeline remain poorly understood. Biomass at treeline sites in Glacier National Park (GNP), Montana was measured in different aboveground carbon pools. Notably large proportions of biomass were recorded in compartments of dead material (~64% in upright tree cover, ~82% in krummholz). The storage of proportionally so much carbon in dead material complicates predictions of alpine treeline response to climate change, given the expectation of increased respiration losses through decomposition in a warmer climate. Although conventional belief holds that treeline advance will result in sequestration of carbon as tundra is replaced by trees, carbon release by decomposition may deviate from this expectation. This work represents a descriptive study that highlights the importance of conducting similar work at broader spatial scales and in more varied locations to further determine the magnitude and extent of its implications