Telescopic Observation of the Moon as a Means for Observing Migration of the Army Cutworm, \u3ci\u3eChorizagrotis auxiliaris\u3c/i\u3e (Lepidoptera: Noctuidae)

Nocturnal insect activity was observed through telescopes focused on the moon. Flight direction was computed and methods were developed for estimating height and determining vertical distribution. Total density was correlated with light-trap catches; effective range of a light-trap was about 7 meters. Species identification was impossible but the method was selective for larger and higher-flying insects. Characteristics of insect activity observed during periods of army cutworm abundance indicate that it orients to the west during spring migration. Activity and altitude of flight were modified by wind direction and velocity, but flight direction during migration was independent of wind

Oviposition Response of the Army Cutworm, \u3ci\u3eChorizagrotis auxiliaris\u3c/i\u3e, to Different Media

Moths of the army cutworm, Chorizagrotis auxiliaris (Grote), (Lepidoptera: Noctuidae) responded ovipositionally to differences in soil color, texture, and depth. Number of eggs laid increased with amount of light reflected. A combination of loose surface over a solid substrate was required. A light-colored sand fulfilled all requirements and was preferred over soil. Soil was acceptable when a loose surface of correct depth was provided. Solid surfaces were refused

Distribution of Army Cutworm Larvae in Wheat and Barley Fields

Populations of the army cutworm, Chorizagrotis auxiliaris (Grote), tended to be higher in winter barley than winter wheat planted side by side in the same field. Highest populations occurred in barley within 30 feet of the adjoining wheat. Distribution of larvae in linear 1-foot samples agreed closely with the Poisson. Practical application of these results are discussed

Effects of Food, Temperature, and Oviposition Site on Longevity and Fecundity of the Army Cutworm

Longevity of the army cutworm, Chorizagrotis auxiliaris (Grote), following mating was inversely related to temperature. Females lived longer than males at all temperatures, and food increased longevity of both sexes. Oviposition occurred at 70° and 55° but not at 32° F. None of the variables tested affected total fecundity but oviposition was completed sooner at 70° than at 55°, in sand as an oviposition site vs. paper toweling and by unfed than by fed moths. Starvation preceding oviposition did not affect fecundity but speeded completion of oviposition when moths were returned to favorable conditions

Oviposition Response of the Army Cutworm, \u3ci\u3eChorizagrotis auxiliaris\u3c/i\u3e, to Different Media

Moths of the army cutworm, Chorizagrotis auxiliaris (Grote), (Lepidoptera: Noctuidae) responded ovipositionally to differences in soil color, texture, and depth. Number of eggs laid increased with amount of light reflected. A combination of loose surface over a solid substrate was required. A light-colored sand fulfilled all requirements and was preferred over soil. Soil was acceptable when a loose surface of correct depth was provided. Solid surfaces were refused

Food Preference as a Factor in Distribution and Abundance of \u3ci\u3ePhoetaliotes nebrascensis\u3c/i\u3e

Western wheat grass, Agropyron smithii, was the plant most frequently ingested by Phoetaliotes nebrascensis (Thomas) in 4 of 5 habitats and was preferred in all. All grasses were eaten to some extent; nonpreferred plants may support populations in otherwise suitable habitats. Most forbs were unattractive but all tested species of Cichoriaceae were acceptable. Plant-finding was by random searching; selection was made only after contact through the mouthparts. While habitats in which preferred hosts were more abundant had higher grasshopper populations, annual changes in grasshopper abundance within a habitat were independent of abundance of primary food plants

Tarnished and Alfalfa Plant Bugs in Alfalfa: Population Suppression with ULV Malathion

ULV malathion (9.7 oz AI/acre) was applied to a 16 mi2 area in August 1968, 1969, and 1970 for western corn rootworm, Diabrotica virgifera LeConte, adult control. Nontarget insects in alfalfa, also treated, were monitored. Tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), was reduced 89–98%. Survival of eggs and adult migration resulted in rapid reinfestation of the treated area in 1969 and 1970; adult migration alone was important in 1968. Alfalfa plant bug, Adelphocoris lineolatus (Goeze), was reduced 96–98%. Repopulation following the 1969 and 1970 treatments was by development from eggs surviving the treatment. The 1969 treatment resulted in lower populations in the treated area through 3 generations the following year. Migration appeared to be a factor in repopulation only following the 1968 treatment, which failed to reduce the 1st generation the next year. Timing of alfalfa harvest during nymphal development is equally effective in population suppression

Effect of Host Condition on the Clover Root Borer

Oviposition by the clover root borer, Hylastinus obscurus (Marsham), is completed earlier in weakened than in vigorous plants, but development is more rapid in vigorous or lightly infested roots. High populations occurring early in the season result in plant mortality with subsequently slowed borer development

Effects of Food, Temperature, and Oviposition Site on Longevity and Fecundity of the Army Cutworm

Longevity of the army cutworm, Chorizagrotis auxiliaris (Grote), following mating was inversely related to temperature. Females lived longer than males at all temperatures, and food increased longevity of both sexes. Oviposition occurred at 70° and 55° but not at 32° F. None of the variables tested affected total fecundity but oviposition was completed sooner at 70° than at 55°, in sand as an oviposition site vs. paper toweling and by unfed than by fed moths. Starvation preceding oviposition did not affect fecundity but speeded completion of oviposition when moths were returned to favorable conditions

Drift of Terrestrial Arthropods in an Irrigation Canal Following a Wide-Area Application of ULV Malathion

Numbers of arthropods drifting in an irrigation canal were recorded at 30-min intervals during and after an upstream application of ULV malathion. Flower-visiting and parasitic Hymenoptera were the first insects to increase; a bimodal drift pattern resulted from an interruption in the spray application. Diptera exhibited a delayed response but the numbers collected, especially Paracantha culta (Wiedemann), suggest high susceptibility. Ants occurred in large numbers over a long period, but mortality was probably low. Miridae and Cicadellidae were probably more susceptible than Orthoptera and adult Odonata but had similar delayed drift patterns. Tetragnathidae were the most, and Thomiscidae the least, susceptible spiders