Top Of Cage Research Articles

5-HT2CRs Expressed by Pro-Opiomelanocortin Neurons Regulate Energy Homeostasis

SummaryDrugs activating 5-hydroxytryptamine 2C receptors (5-HT2CRs) potently suppress appetite, but the underlying mechanisms for these effects are not fully understood. To tackle this issue, we generated mice with global 5-HT2CR deficiency (2C null) and mice with 5-HT2CRs re-expression only in pro-opiomelanocortin (POMC) neurons (2C/POMC mice). We show that 2C null mice predictably developed hyperphagia, hyperactivity, and obesity and showed attenuated responses to anorexigenic 5-HT drugs. Remarkably, all these deficiencies were normalized in 2C/POMC mice. These results demonstrate that 5-HT2CR expression solely in POMC neurons is sufficient to mediate effects of serotoninergic compounds on food intake. The findings also highlight the physiological relevance of the 5-HT2CR-melanocortin circuitry in the long-term regulation of energy balance.

Ethics and Refinement in Animal Research

Based on a case study we conclude that scientists and journals could and should do more to secure the ethical standards of animal use in biomedical research: Scientists often justify animal use referring to the scientific value and biomedical importance (2). However, except from a purely anthropocentric perspective, ethical concern about compromised animal welfare cannot be justified by human benefits alone (1). It is equally important that the benefits are achieved with a minimum of negative effects to the animals involved. Thus scientists must apply ’refinement’, the third R of the socalled 3Rs (3). But here scientists seem sometimes to do less than they should and journals fail in their duty to enforce high ethical standards. We studied the use of animals as models for the neurodegenerative Huntington’s Disease. Here refinement should focus on limiting the negative impact of declining sensorimotor function as the disease progresses: housing adaptations facilitating food and water intake and humane endpoints (using earlier, less severe clinical signs as endpoint parameters rather than awaiting spontaneous death) are two possible approaches (4). We asked to what extent animal welfare problems and refinements addressing them were reported in publications of the most common rodent models by analyzing 90 research reports published in international peer-reviewed journals during 2003-2004. These include quinolinic acid (5,6) and 3-nitropropionic acid (6,7) administration to rats and mice and R6/1, R6/2 and N171-82Q transgenic mice (8,9,10). Our results show that the majority of experiments (36+17) were in the two most severe categories, in which animals have sensorimotor deficits interfering with their capacity to eat and drink normally from the cage top (11, 12, 13). Very few papers reporting such severe experiments included information on refinement measures: Out of 14 survival studies of transgenic animals with a progressive neurodegenerative phenotype, only 6 referred to humane endpoints and only 2 to housing adaptations. Among the majority of studies referring to compliance with official regulations and / or efforts to reduce animal suffering, we also found experiments using far from best practice, such as administration of rising neurotoxin doses until high animal mortalities.

Evaluation of UVB reduction by materials commonly used in reptile husbandry

Ultraviolet B (UVB) irradiation (285-320 nm) is considered important for metabolic processes and reproduction in many reptile species by facilitating the synthesis of vitamin D(3). In captivity, UVB radiation reaching an animal may be diminished by the properties of the materials used in enclosure construction. We investigated the UVB-attenuating properties of 14 materials commonly used in cage tops for reptile enclosures. Irradiances were measured by two types of hand-held broadband radiometers and the D(3)-synthesizing potential was assessed by the use of an in vitro model. For UV-transmitting acrylic, a significant discrepancy between meter irradiances and in vitro model values for D(3)-synthesizing ability was observed, with meter readings underestimating the blocking effect. In contrast, attenuation of UVB irradiances by air-permeable materials, such as wire screen, measured with meters was generally comparable to the attenuation of D(3)-synthesizing ability as measured by in vitro models. Relatively simple meter readings can therefore be used to reflect reduction of D(3)-synthesizing ability through air-permeable materials. Zoo Biol 26:417-423, 2007. (c) 2007 Wiley-Liss, Inc.

Inactivation of NADPH oxidase organizer 1 Results in Severe Imbalance

Otoconia are biominerals of the vestibular system that are indispensable for the perception of gravity. Despite their importance, the process of otoconia genesis is largely unknown. Reactive oxygen species (ROS) have been recognized for their toxic effects in antimicrobial host defense as well as in aging and carcinogenesis. Enzymes evolved for ROS production belong to the recently discovered NADPH oxidase (Nox) enzyme family . Here we show that the inactivation of a regulatory subunit, NADPH oxidase organizer 1 (Noxo1), resulted in the severe balance deficit seen in the spontaneous mutant "head slant" (hslt) mice whose phenotype was rescued by Noxo1 transgenes. Wild-type Noxo1 was expressed in the vestibular and cochlear epithelia and was required for ROS production by an oxidase complex. In contrast, the hslt mutation of Noxo1 was biochemically inactive and led to an arrest of otoconia genesis, characterized by a complete lack of calcium carbonate mineralization and an accumulation of otoconial protein, otoconin-90/95 (OC-90/95). These results suggest that ROS generated by a Noxo1-dependent vestibular oxidase are critical for otoconia formation and may be required for interactions among otoconial components. Noxo1 mutants implicate a constructive developmental role for ROS, in contrast to their previously described toxic effects.

The effect of continuous exposure to electromagnetic fïeld on four successive generations of mice

The objective of this study is to know the biobgical effects of electromagnetic field treatment on four successive generations of mice. Fourty eight male and female mice of Swiss Webster Strain, 3 months of old, and 35 - 40 g body weight, were kept in a controlled environment and fed a standard diet. Mice were divided into 6 groups of four couples each. The first group was exposed to electromagnetic field of I kV/10 cm, the second group to 2 kV/10 cm, and the third group to 3 kV/10 cm. The remaining 3 groups were served as untreated controls of the first, second, and third group, respectively. Each couple of mice was placed in a cage (26x20x11 cm) with wire metal cage tops. The cages of experimental groups with mice inside, were then put on the negative terminal plate of a pair of parallel aluminium plate electrodes. These cages were perpendicular to the positive electrode plate at a distance of I0 cm. Subsequently, the electrodes were connected to stepup transformer as an alternating current power supply. All mice belonging to experimental and untreated control groups were allowed to mate, gastate, and deliver the first up to fourth generations, During investigation, all generations of experimental groups were continuously treated to electromagnetic field, while generations of untreated control groups received no treatment to electromagnetic field, During the study, all mice were housed in a room having a temperature of 26 ᵒ C and a light - dark cycle of 12:12 hours. The results of this study showed that exposure of mice to electromagnitic field results in reduced fertility with no change in sex ratio of the offspring. Exposure to electromagnetic field, however, were effective in inducing congenital anomalies, such as micropthalmy, white eyes, short hind legs, dwarf mice, and tumors in both sexes of the offspring which caused of death after 3 - 4 months of old. A large mortality rate were found, especially in the third and fourth generations. No congenital anomalies and tumors were noted in untreated controls. ln conclusion, we suggest that several facts which found in this study were the result of changes in genetic material of the sperm or eggs during spermatogenesis or oogenesis, respectively, i.e. a mutagenic effect. This interaction between electromagnetic field and the living cell, may then cause biological effects on cells, tissues, and organs, so that finally there are consequences for the whole organisms. (Med J Indones 2002; 11: 3-10) Keywords: electromagnetic field, fertility, mortality rate, congenital anomalies, tumor, mice

Why do male ICR(CD-1) mice perform bar-related (stereotypic) behaviour?

Prolonged interaction with cage bars by captive mammals (usually classed as stereotypic) may reflect poor welfare. Such behaviour may arise from motivation to investigate the external environment or to escape captivity. However, these hypotheses have not been explicitly tested. We raised mice, Mus musculus, to adulthood in modified laboratory cages with two sets of bars at the top and side of the cage. One set provided a potential escape route, and half of each set was backed by Perspex to reduce cues from the external environment. We predicted where mice should interact with the bars according to their motivational priorities. Body weights were recorded weekly to study the relationship between physical development and bar-related behaviour. Serum corticosterone was measured to monitor the effect of bar-related behaviour on stress physiology. Mice preferred to interact with bars where external cues were detectable. As adults, mice responded more to the bars providing a potential exit, though this was affected by the exit location. Corticosterone titres were higher in mice whose potential exit was situated at the cage top. Response to the bars was apparently restricted by the physical development of mice, particularly among those whose potential exit was situated in the cage top.

Mice Lacking the Basolateral Na-K-2Cl Cotransporter Have Impaired Epithelial Chloride Secretion and Are Profoundly Deaf

In chloride-secretory epithelia, the basolateral Na-K-2Cl cotransporter (NKCC1) is thought to play a major role in transepithelial Cl(-) and fluid transport. Similarly, in marginal cells of the inner ear, NKCC1 has been proposed as a component of the entry pathway for K(+) that is secreted into the endolymph, thus playing a critical role in hearing. To test these hypotheses, we generated and analyzed an NKCC1-deficient mouse. Homozygous mutant (Nkcc1(-/-)) mice exhibited growth retardation, a 28% incidence of death around the time of weaning, and mild difficulties in maintaining their balance. Mean arterial blood pressure was significantly reduced in both heterozygous and homozygous mutants, indicating an important function for NKCC1 in the maintenance of blood pressure. cAMP-induced short circuit currents, which are dependent on the CFTR Cl(-) channel, were reduced in jejunum, cecum, and trachea of Nkcc1(-/-) mice, indicating that NKCC1 contributes to cAMP-induced Cl(-) secretion. In contrast, secretion of gastric acid in adult Nkcc1(-/-) stomachs and enterotoxin-stimulated fluid secretion in the intestine of suckling Nkcc1(-/-) mice were normal. Finally, homozygous mutants were deaf, and histological analysis of the inner ear revealed a collapse of the membranous labyrinth, consistent with a critical role for NKCC1 in transepithelial K(+) movements involved in generation of the K(+)-rich endolymph and the endocochlear potential.

Control strategies for aeroallergens in an animal facility

Background: Prevalence of the occupational disease laboratory animal allergy could be reduced if aeroallergen reduction strategies are identified. Objective: To reduce worker exposure to Mus m 1, an allergen from laboratory mice, the effect of filter cage tops, increased room ventilation, negatively pressurized ventilated cages, and ventilated cage-changing tables were evaluated. Methods: Aeroallergen was collected in the ambient air and in the breathing zone and quantified by using a competitive immunoassay. Results: When mice were housed in unventilated cages, ambient allergen was reduced from 5.1 ng/m 3 with no cage top to 1.3 ng/m 3 with a simple filter-sheet top and 0.8 ng/m 3 with a fitted filter-bonnet top ( P < .05). Room ventilation was increased from 6 to 10, 15, and 20 air changes per hour and had little effect on aeroallergen levels and no impact on airborne particulate matter. When mice were housed in ventilated cages, ambient allergen was significantly reduced from 1.1 ng/m 3 at positive cage pressure to 0.3 ng/m 3 at negative cage pressure ( P < .05). Negative cage pressure combined with handling animals under a ventilated table reduced breathing zone allergen from 28 ng/m 3 with neither control strategy in place to 9 ng/m 3 ( P < .05). Use of a ventilated table controlled bacterial contamination, measured as colony forming units, found in negatively pressurized cages. Conclusion: Three aeroallergen control strategies are use of filter cage tops, operation of negatively pressurized cages, and use of ventilated changing tables. (J Allergy Clin Immunol 1999;103:139-46.)

Evaluation of Exp 61096A for Control of Rice Stink Bug in a Cage Study, 1997

Abstract A field study was conducted to compare RSB control using EXP 61096A and a standard, methyl parathion. The experimental design was a RCB with 3 replications. Plot size was 9 rows (7-inch spacing) by 15 ft. Rice was drill seeded in Crowley silt loam at 90 lb/acre on 6 May and emerged on 17 May. Nitrogen was applied in a 3-way split of 75 lb N/acre as urea on 16 Jun and 30 lb N/acre on 10 and 23 Jul. Permanent flood was established on 22 Jun. Rice was 50% headed (panicle emergence) on 6 Aug. Insecticides were applied on 25 Aug with a CO2-pressurized backpack sprayer at 18 gpa. Three days to applications, adult RSB were hand collected from rice fields and placed in 5-gal plastic buckets with bouquets of heading rice and weed host plants in water. Host plants were changed at 3 d intervals. Shortly before applications, 3 RSB were placed in nylon tulle sleeve cages, 4 inches diam by 14 inches long. Cage tops were closed with twist ties. RSB were herded to one end where a string was tied around the cage, effectively keeping the RSB confined to one end. Within 15 min after each insecticide application, 3 sleeve cages were pulled over 2 rice panicles and flag leaves and held in place with twist ties around the plants. Sleeve cages with RSB were also placed in plots 24, 72, and 120 h after insecticide application. After 72 h of exposure, plants were cut below the cage and taken to the laboratory where RSB mortality was determined. Data were analyzed with ANOVA and means separated by LSD.

Cage Studies with Tarnished Plant Bug Control Using Curacron, 1996

Abstract Field studies were conducted to compare tarnished plant bug control using Curacron and a standard, Orthene. Cotton was planted 9 May on the Cotton Branch Experiment Station in Marianna, AR in 8 row (38 inch centers) wide plots, 70 ft long with 10 ft alleys and separated by a 6.5 ft buffer planted in mustard. Treatments were arranged in a RCBD with 3 replications. Insecticides were applied 25 Jul using a 8-row CO2-charged hi-boy sprayer calibrated to deliver 8.5 gpa at 30 psi with TJ-60 8002 nozzles on 19 inch spacing. Prior to application, TBP were collected using sweep nets in blooming mustard then placed in 15 ml plastic vials (5 insects per vial) on ice. Three organdy sleeve cages, 6 inches diam by 18 inches long, were secured to randomly selected individual plants in the center 2 rows by tying the lower end of the each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatment the foil was removed, the cage pulled up, and 5 TPB nymphs (3 to 5th instar) were placed into each cage. Cage tops were secured with twist ties. After 96 h, plants were cut below the cage and taken to the laboratory where TPB mortality was determined. Bollworm infestation also was monitored during the test period. At 4 DAT, numbers of medium and large larvae per 20 terminals were surveyed in plants in the center 4 rows of each plot. All data were analyzed with ANOVA, and means separated with LSD.

Control of Tarnished Plant Bug with Karate and Fipronil, 1996

Abstract Field studies were conducted to evaluate tarnished plant bug control using fipronil and 2 different formulations of Karate. Cotton was planted 9 May on the Cotton Branch Experiment Station in Marianna, AR in 8 row (38 inch centers) wide plots 70 ft long with 10 ft alleys and separated by a 6.5 ft buffer planted in mustard. Treatments were arranged in a RCBD with 2 replications. Insecticides were applied 25 Jul using a 8-row CO2 charged hi-boy sprayer calibrated to deliver 8.5 gpa at 30 psi with TJ-60 8002 nozzles on 19 inch spacing. Prior to application, TPB were collected using sweep nets in blooming mustard then placed in 15 ml plastic vials (5 in-sects per vial) on ice. Three organdy sleeve cages, 6 inches diam by 18 inches long, were secured to randomly selected individual plants in the center 2 rows by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatment the foil was removed, the cage pulled up, and 5 TPB nymphs (3 to 5th instart) were placed into each cage. Cage tops were secured with twist ties. After 72 h plants were cut below the cage and taken to the laboratory where TPB mortality was determined. Mortality data were analyzed with AOV, and means separated with LSD.

Efficacy of Chlorpyrifos-Methvl to Control Tarnished Plant Bug in Cotton, 1996

Abstract Cotton was planted 9 May on the Cotton Branch Experiment Station in Marianna, AR in 8 row (38 inch centers) wide plots 70 ft long with 10 ft alleys and separated by a 6.5 ft buffer planted in mustard. Treatments were arranged in a RCBD with 3 replications. Insecticides were applied 10 Jul using a 8-row CO2 charged hi-boy sprayer calibrated to deliver 10.5 gpa at 30 psi with TJ-60 8002 nozzles on 19 inch spacing. Prior to application, TPB were collected using sweep nets in blooming mustard. The collected TPB were placed in 15 ml plastic vials (5 insects per vial) on ice. Three organdy sleeve cages, 6 inches diam by 18 inches long, were secured to randomly selected individual plants in the center 2 rows by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatments, the foil was removed, the cage pulled up, and 5 TPB nymphs (3 to 5th instar) were placed into each cage. Cage tops were secured with twist ties. After 72 h plants were cut below the cage and taken to the laboratory where TPB mortality was determined. Mortality data were analyzed with AOV, and means separated with LSD.

Efficacy of Chlorpyrifos-Methyl to Control Tarnished Plant Bug in Cotton, 1995

Abstract Two trials to evaluate the efficacy of chlorpyrifos-mefhyl to control TPB were conducted in cotton planted 17 May on the UA Cotton Branch Experiment Station in Marianna, AR. The 8 row (38 inch centers) X 50 ft plots were separated by 2 rows of buffer zone. Treatments were arranged in a RCBD with 3 replications. In Trial I insecticides were applied 21 Jul using a 2-row, CO2-charged back pack sprayer calibrated to deliver 10 gpa at 20 psi with 1, TX6 nozzle per row. In Trial II insecticides were applied 4 Aug using a 4-row CO2-charged back pack sprayer calibrated to deliver 13 gpa at 20 psi with 1, TJ-60 8002vs nozzle per row. For each study, 3 organdy sleeve cages, 9 inches diam by 22 inches long, had been secured to individual plants in each plot by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil. Following application the foil was removed, the cage pulled up, and 5 TPB were placed into each cage. Cage tops were secured with twist ties. Insects had been collected by sweep net on blooming mustard immediately prior to testing and held in 15 ml plastic vials (5/vial) on ice. After 72 hr, plants were cut below the cage and taken to the laboratory where TPB mortality was determined.

Cage Studies to Evaluate Foliar and Sidedressed Insecticide Applications for Control of Tarnished Plant Bug in Cotton, 1995

Abstract Efficacy studies were conducted using sleeve cages in cotton planted 15 May on the UA Cotton Branch Experiment Station in Marianna, AR. The 8 row (38 inch centers) X 50 ft plots were separated by 2 row buffer zones. Treatments were arranged in a RCBD with 3 replications. On 27 Jun after rain (0.7 and 0.1 inches on 24 and 26 Jun) the Temik treatment was knifed in as a sidedress at 2 to 3 inch depth within 8 to 14 inches on both sides of plants and covered. Foliar insecticides were applied 14 Jul using a 4-row CO2-charged back pack sprayer calibrated to deliver 13 gpa at 23 psi with 1, TJ-50 8002vs nozzle per row. In each plot 3 organdy sleeve cages, 9 inches diam by 22 inches long, had been secured to individual plants by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminium foil. Following application the foil was removed, the cage pulled up, and 5 TPB 3 to 5th instar nymphs were placed into each cage. Cage tops were secured with twist ties. Insects had been collected by sweep net on mustard immediately prior to testing and held in 15 ml plastic vials (5/vial) on ice. After 72 hr plants were cut below the cage and taken to the laboratory where TPB mortality was determined.

Tarnished Plant Bug Response to Provado Plus Sucrose, 1995

Abstract Field studies were conducted to determine the effect of sucrose on efficacy of Provado insecticide to control TPB caged on cotton plants. Cotton was planted 15 May 1995 on the UA Cotton Branch Experiment Station in Marianna, AR, in 6 row (38 inch centers) wide plots 50 ft long separated by 2 row buffer zones. Treatments were arranged in a RCBD with 3 replications. Insecticides were applied 21 Jul using a 4-row CO2 charged back pack sprayer calibrated to deliver 13 gpa at 23 psi with 1 TJ-50 8002vs nozzle per row. Prior to application, TPB were collected using sweep nets in blooming mustard and placed into 15 ml plastic vials (5 insects per vial) on ice. Three organdy sleeve cages, 9 inches diam by 22 inches long, were secured to individual plants by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatment the foil was removed, the cage pulled up, and 5 TPB adults were placed into each cage. Cage tops were secured with twist ties. After 72 hr, plants were cut below the cage and taken to the laboratory where they were inspected over white background for dead and living bugs.

Northern and Western Corn Rootworm Adult Emergence and Root Injury Ratings Associated with Labeled and Reduced Soil Insecticide Application Rates in Aurora, Sd, 1994

Abstract A dryland continuous corn site in east central SD was selected to measure northern and western corn rootworm adult beetle emergence from corn plots treated with planting-time soil insecticides. In addition to beetle emergence, treatment efficacy in preventing larval root feeding injury was also evaluated. Treatments included labeled and reduced application rates of 3 compounds arranged in a RCBD with 4 replications. Individual treatment plots consisted of single 15.2-m long rows spaced 96.5 cm apart. All insecticide treatments were applied in-furrow at planting time by directing granules between double-disk openers and into the open seed furrow. Delivery of granules was regulated using Noble metering units mounted on a specially adapted Kinze 4-row corn planter. All units were calibrated on the planter before insecticide applications. Plant injury evaluations consisted of extricating 5 roots per plot examining them for feeding injury, and rating them in accordance with the Iowa State 1 to 6 scale. Prior to rootworm beetle emergence, two 0.6 m wide by 1.0 m long by 15.2 cm high cages were placed (equidistant from each other and the end of the plot) over each treatment row. The exterior rectangular frame base of each cage was constructed of 26-gauge galvanized steel and the top was made of aluminum screening material (45-mesh per cm2). Screens were supported by galvanized steel strips that terminated at a central point (approximately 20.3 cm) above the frame to form a screened pyramid. All interior screen margins and seams were sealed with silicone rubber caulking material. The pyramidal shape of cage tops was designed to exploit the natural negatively geotactic response (crawling upward) of newly emerged beetles. A plastic cylindrical capture device was positioned at the apex of each screened pyramid to catch beetles as they crawled upward on the screened cage top, and an inverted aluminum screen cone was fastened to the bottom side of each capture device to prevent beetles from returning into the cage. Cages were monitored at 2-d intervals for the entire beetle emergence period. Monitoring consisted of collecting all beetles for the respective treatments from each replicate, and returning them to the laboratory for processing. Laboratory processing consisted of identification of emerged adults by sex and species respective to treatments. All data (root injury ratings and adult emergence) were analyzed with SAS’s General Linear Models procedure and means were compared using DMRT.

Efficacy of Provado When Applied with Feed Grade Molasses to Control Tarnished Plant Bug in Cotton, 1995

Abstract Field studies were conducted to determine if addition of feed grade molasses to Provado would affect mortality to TPB caged on cotton plants. Cotton was planted 4 Jun on the ASU farm in Jonesboro in 4 row (38 inch centers) wide plots 60 ft long separated by a 4-row buffer Treatments were arranged in a RCBD with 3 replications. Insecticides were applied 8 Aug using a 4-row CO2 charged tractor mounted sprayer calibrated to deliver 12.5 gpa at 40 psi with TI-50 8002 nozzles on 17 inch spacing. Prior to application, TPB were collected using sweep nets in mustard plants and placed into 15 ml plastic vials (5 insects per vial) on ice. Three organdy sleeve cages, 6 inches diam by 18 inches long, were secured to randomh selected individual plants in the center 2 rows by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil leaving plant terminals exposed. Following treatment the foil was removed, the cage pulled up, and 5 TPB adults were placed into each cage. Cage tops were secured with twist ties. After 72 hr, plants were cut below the cage and taken to the laboratory where TPB mortality was determined.

Evaluation of Tarnished Plant Bug Control with Dimethoate and Plex (Sticker-Extender), 1990

Abstract In Test I chemical treatments, applied 17 Jul at the Cotton Branch Experiment Station, Marianna, Ark., were replicated 4 times in a randomized complete block design. Plots were 4 rows × 20 ft. Spray was applied with three, 8X hollow cone nozzles/row using a CO2 powered 4-row backpack sprayer dispensing 14 gal/acre at 32 psi. Prior to treatment, 4 organdy sleeve cages, 9-inch diam by 22 inches long, were secured around individual plants by tying a twist-tie to the lower end of each cage about 1 ft from the terminal. The cages were rolled down to the tie and covered with aluminum foil. Terminals were left exposed. Following treatment the foil was removed, the cage was rolled up, and 5 tarnished plant bugs from the University of Arkansas stock culture were placed into each cage. Cage tops were secured with twist-ties. Infestations of plant bugs were made in the cages at 0, 24, and 48 h posttreatment. Insects were exposed to the plants for 72 h. Plants were then cut below the cage and taken to an enclosed area. Cages were removed and the terminal shaken over white paper. Living and dead insects were counted.

Plant Bug Mortality in Cages, 1989

Abstract The purpose of this test was to determine the mortality associated with insecticides that, if used in cotton, primarily would be directed at insects other than the tarnished plant bug. Chemical treatments, applied 11 Aug at the Cotton Branch Experiment Station, Marianna, AR, were replicated 3 times in a randomized complete block design. Plots were 4 row × 27 ft. Spray treatments were applied at a rate of 16.2 gal/acre of spray with 3 nozzles/row using a CO2 powered 4-row backpack sprayer and set at 32 psi. Prior to treatment, 3 organdy sleeve cages, 9-inch diam by 22 inches long, were secured to individual plants by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist-ties. The cages were rolled down to the tie and covered with aluminum foil. Terminals were left exposed. Following treatment the foil was removed, the cage was pulled up, and 5 tarnished plant bugs from the University of Arkansas stock culture were placed into each cage. Cage tops were secured with twist-ties. Cages were left on the plants for 72 hr, after which the plants were cut below the cage and taken to an enclosed area. Cages were removed and the terminal shaken over white paper. Living and dead insects were counted.

Life History of Helicopsyche borealis (Hagen) (Trichoptera: Helicopsychidae) in Oklahoma

The life history of Helicopsyche borealis was compared for 13 months in two Oklahoma streams that have different thermal regimes. Densities of H. borealis were usually higher in the thermally constant stream. The species was multivoltine with overlapping generations in the thermally constant stream and univoltine in the thermally fluctuating stream. INTRODUCTION Larvae of Helicopsyche (Trichoptera: Helicopsychidae) are unusual in that their sand-grain cases superficially resemble snail shells. In fact, the genus was first described as a snail based on the shape of the case alone (Lea, 1834). There are five species of Helicopsyche in North America N of Mexico (Wiggins, 1977; Denning and Blickle, 1979). Helicopsyche borealis (Hagen) is the most common species occurring in clear running water, springs and the littoral zone of lakes, and has been found in thermal springs exceeding 34 C (Wiggins, 1977). Mackay and Wiggins (1979) reported the occurrence of H. borealis in streams receiving domestic sewage and this species also tolerates petroleum-related pollution (Bugbee and Walters, 1973). The life history of Helicopsyche borealis has only been partially described. Ross (1944) and Williams and Hynes (1974) reported continual emergence of adults from spring to early autumn followed by an egg diapause of 5-6 months in Illinois and Ontario, respectively. Bane and Lind (1978) studied H. borealis in a tributary of the Rio Grande in Texas. Biomass was highest in the spring and lowest in the winter. Adults were found only in April. I collected Helicopsyche borealis from two Oklahoma streams with different thermal regimes for 13 months. I report on life history patterns of H. borealis in these two streams and present new information on egg masses and early case-building behavior. METHODS Study area and sampling method. -Pennington Creek is a second-order, spring-fed, thermally constant stream in the Arbuckle Mountains of S-central Oklahoma. Caney Creek is a third-order, thermally variable stream in the Ozark Mountain foothills of northeastern Oklahoma (Fig. 1). Helicopsyche borealis densities were sampled in each of these streams at monthly intervals from May 1981 through May 1982. A modified quadrat sampling technique was used. Stratified random samples of the substratum were collected with a 95 cm2 cylinder to a depth of 3 cm. The H. borealis were removed from the substratum, counted and assigned to an age class (see below for technique). Fifty samples per month were collected from each stream from May through August 1981, and 25 thereafter for the remainder of the sampling period. Temperature was measured with an Extech meter (model 651). Development. -The development of 20 egg masses was followed in the laboratory from the time they were laid through pupation of the resulting larvae. Egg masses were obtained from adults reared from pupae collected from Pennington Creek in July and August 1982. Adults were reared in 76-L artificial streams with screen cage tops. Floating pieces of styrofoam were provided as oviposition surfaces. Observations on hatching and early case-making were made in 8 x 2 cm glass finger bowls under a dissecting microscope. Larvae were reared in 3.8-liter glass aquaria. Cases of Helicopsyche borealis were measured to determine the range of sand particle sizes used in the