Management and population dynamics of diamondback moth (Plutella xylostella): planting regimes, crop hygiene, biological control and timing of interventions.

Using an age-structured process-based simulation model for diamondback moth (DBM), we model the population dynamics of this major Brassica pest using the cropping practices and climate of Guangdong, China. The model simulates two interacting sub-populations (demes), each representing a short season crop. The simulated DBM abundance, and hence pest problems, depend on planting regime, crop hygiene and biological control. A continuous supply of hosts, a low proportion of crop harvested and long residue times between harvest and replanting each exacerbate pest levels. Biological control provided by a larval parasitoid can reduce pest problems, but not eliminate them when climate is suitable for DBM and under certain planting practices. The classic Integrated Pest Management (IPM) method of insecticide application, when pest threshold is reached, proved effective and halved the number of insecticide sprays when compared with the typical practice of weekly insecticide application.

InP-based quantum cascade lasers monolithically integrated onto silicon.

Lasing is reported for ridge-waveguide devices processed from a 40-stage InP-based quantum cascade laser structure grown on a 6-inch silicon substrate with a metamorphic buffer. The structure used in the proof-of-concept experiment had a typical design, including an Al0.78In0.22As/In0.73Ga0.27As strain-balanced composition, with high strain both in quantum wells and barriers relative to InP, and an all-InP waveguide with a total thickness of 8 µm. Devices of size 3 mm x 40 µm, with a high-reflection back facet coating, emitted at 4.35 µm and had a threshold current of approximately 2.2 A at 78 K. Lasing was observed up to 170 K. Compared to earlier demonstrated InP-based quantum cascade lasers monolithically integrated onto GaAs, the same laser structure integrated on silicon had a lower yield and reliability. Surface morphology analysis suggests that both can be significantly improved by reducing strain for the active region layers relative to InP bulk waveguide layers surrounding the laser core.

Involvement of microRNA miR-2b-3p in regulation of metabolic resistance to insecticides in Plutella xylostella.

The diamondback moth, Plutella xylostella, has developed extremely high levels of resistance to chlorantraniliprole and other classes of insecticides in the field. As microRNAs (miRNAs) play important roles in various biological processes through gene regulation, we examined the miRNA profile of P. xylostella in response to chlorantraniliprole exposure. RNA sequencing analysis showed that insecticide treatment caused significant changes in the abundance of some miRNAs. Increasing exposure time and insecticide concentration induced more dysregulated miRNAs in P. xylostella larvae. We also screened potential target genes for some of the differentially expressed miRNAs (such as miR-2b-3p, miR-14b-5p and let-7-5p), which may play important roles in insecticide resistance development. Exposure of P. xylostella larvae to chlorantraniliprole caused considerable overexpression in the transcript levels of potential target genes cytochrome P450 9f2 (CYP9F2) and 307a1 (CYP307a1). Application of miR-2b-3p and miR-14b-5p mimics significantly suppressed the relative transcript levels of CYP9F2 and CYP307a1, respectively, in a P. xylostella cell line. Furthermore, enrichment of P. xylostella diet with miR-2b-3p mimics significantly increased mortality in deltamethrin-resistant larvae when exposed to deltamethrin. The results suggest that miR-2b-3p may suppress CYP9F2 transcript levels in P. xylostella and consequently inhibit larval detoxification pathways. The findings provide an insight into possible role of miRNAs in regulation of metabolic resistance of insects to insecticides.

Behavior as a mechanism of insecticide resistance: evaluation of the evidence.

'Behavioral resistance' must be defined in a manner consistent with other mechanisms of resistance and be based on heritable changes. Most claimed cases of behavioral resistance to insecticides are simply aversion behaviors either learned or based on simple repellency or avoidance. Although studies have shown changes in taste/odour receptors (e.g., cockroaches), unequivocal demonstration of behavioral resistance to insecticides is rare. The fundamental problems are: 1. Inferring resistance from observations, with little evidence of 'normal' behavior prior to exposure to insecticides. 2. Interpreting behaviors as insecticide resistance with no evidence that either resistance is detectable or testing the hypothesis that it is responsible. We suggest a way forward that may not be that novel but would advance our understanding and the field.

Development, Survival, and Fecundity of Amblypelta lutescens lutescens (Hemiptera: Coreidae) on Distinct Phenological Stages of Different Fruit-Crop Host Plants.

The banana-spotting bug, Amblypelta lutescens lutescens Distant (Hemiptera: Coreidae), is native to Australia and a major polyphagous pest of many tropical and subtropical horticultural crops in the east and north of the country. Different plant structures (flowers, vegetative flush, and different sized fruit) of avocado, lime, and papaya crops and green bean pods (a known suitable host) were evaluated for their suitability as hosts for A. l. lutescens Neonate to imago survivorship, the time taken to complete neonate to imago development, preovipositional period, and fecundity were assessed for each crop. Of all the different phenological stages of the plants investigated, A. l. lutescens could complete development to imago on vegetative flush of papaya and lime, papaya flowers, and green bean pods but on no other structures tested. There was higher survivorship to the second instar when neonates fed on green bean pods or flowers or vegetative flush of avocado, lime, or papaya crops than when neonates fed on small, medium, or large fruit of these crops. Insects that developed to the imago on green bean pods were significantly heavier than insects that developed on papaya flowers or papaya vegetative flush. The mean preoviposition period was shorter, and adult females more fecund, if they completed immature development and then fed as adults on papaya vegetative flush or green beans rather than papaya flowers. The data indicate that avocado is not a suitable host for A. l. lutescens, suggesting that adult populations that cause significant pest damage to the fruit of this crop originate elsewhere.

The effect of rearing temperature on development, body size, energetics and fecundity of the diamondback moth.

Temperature is arguably the most important abiotic factor influencing the life history of ectotherms. It limits survival and affects all physiological and metabolic processes, including energy and nutrient procurement and processing, development and growth rates, locomotion ability and ultimately reproductive success. However, the influence of temperature on the energetic cost of development has not been thoroughly investigated. We show that in the diamondback moth [Plutella xylostella L. (Lepidoptera: Plutellidae)] rearing temperature (range 10-30°C) affected growth and development rates, the energetic cost of development and fecundity. Rearing at lower temperatures increased development times and slowed growth rate, but resulted in larger adult mass. Fecundity was lowest at 10°C, highest at 15°C and intermediate at temperatures of 20°C and above. At a given rearing temperature fecundity was correlated with pupal mass and most eggs were laid on the first day of oviposition, there was no correlation between total eggs laid and adult longevity. The highest production cost was incurred at 10°C; this decreased with increasing temperature, was minimized in the range 20-25°C, and then increased again at 30°C. These minimized production costs occurred at temperatures close to the intrinsic optimum temperature for this species and may reflect the rearing temperature for optimal fitness. Thus at sub-optimal temperatures greater food resources are required during the development period. Predicted increased temperatures at the margins of the current core distribution of P. xylostella could ameliorate current seasonal effects on fecundity, thereby increasing the probability of winter survival leading to more resilient range expansion and an increased probability of pest outbreaks.

Population dynamics and management of diamondback moth (Plutella xylostella) in China: the relative contributions of climate, natural enemies and cropping patterns.

Diamondback moth or DBM is the major pest of Brassica vegetable production worldwide. Control has relied on insecticides, and DBM resistance to these compounds has evolved rapidly. We review and summarize data on DBM population dynamics across a large latitudinal gradient from southwest to northeast China: DBM is, on average, more common in southern locations than in northern locations. The species' phenology is consistent: in southern and central locations there is a decline during hot summer months, while in the north, the species can only exist in the summer following migrations from the south. A cohort-based discrete-time model, driven by daily maximum and minimum temperatures and rainfall, which was built using the DYMEX modelling software, captures the age-structured population dynamics of DBM at representative locations, with year round cropping and threshold-based insecticide applications. The scale of the simulated pest problem varies with cropping practices. Local production breaks and strict post-harvest crop hygiene are associated with lower DBM populations. Biological control appears to improve the management of DBM. Of the management strategies explored, non-threshold based applications of insecticides with reduced spray efficacy (due to poor application or resistance) appear the least effective. The model simulates the phenology and abundance patterns in the population dynamics across the climatic gradient in China reasonably well. With planned improvements, and backed by a system of field sampling and weather inputs, it should serve well as a platform for a local pest forecast system, spanning the range of DBM in China, and perhaps elsewhere.

The longer term experiences of parent training: a qualitative analysis.

BACKGROUND: Child conduct problems are a major public health priority. Group-based parenting programmes are popular in addressing such problems, but evidence for their longer-term effectiveness is limited. Moreover, process evaluations are rare and little is understood about the key facilitative and inhibitive factors associated with maintaining outcomes in the longer term. METHOD: This study involved the use of qualitative methods as part of a larger process evaluation to explore the longer-term experiences of parents who participated in a randomized controlled trial (RCT) of the Incredible Years Parenting Programme (IYPP) in disadvantaged settings in Ireland. A series of one-to-one in-depth interviews was conducted with parents at 12- (n = 20) and 18-month follow-up (n = 8) and analysed using constructivist grounded theory. RESULTS: Most parents reported positive child behaviour despite several challenges, but a substantial subset reported periods of relapse in positive outcomes. A relapse in child behaviour was linked to relinquishing skills in stressful times, the negative influence of an unsupportive environment, and the perceived ineffectiveness of parenting skills. Resilience in implementing skills despite adversity, and the utilization of available social supports, were associated with the maintenance of positive outcomes. CONCLUSIONS: Strengthening resilience and social support capacities may be important factors in maintaining positive longer-term outcomes. Those who design, research and deliver parenting programmes might consider the possibility of including a relapse-prevention module and/or the provision of post-intervention supports for more vulnerable families.

Developmental responses of the diamondback moth parasitoid Diadegma semiclausum (Hellén) (Hymenoptera: Ichneumonidae) to temperature and host plant species.

Effects of constant rearing temperature and the plant species fed upon by its hosts were investigated for several developmental parameters of Diadegma semiclausum (Hellén), an important parasitoid of the diamondback moth, Plutella xylostella (L.). Temperature had highly significant effects on all developmental parameters measured, and effects were usually both linear and quadratic with increasing temperature. Host plant species, comprising Brassica napus L., Brassica rapa L. ssp. pekinensis and Brassica oleracea L. var. capitata, also affected development of the parasitoid, and significant interactions were observed between plant species and rearing temperature for all developmental parameters measured. Development of D. semiclausum occurred successfully on all host plant species tested for the temperature range of 10 to 25°C. However, when its P. xylostella hosts consumed leaf tissue of B. napus, no specimens survived to pupate at 30°C, whilst pupation and adult eclosion occurred at 30°C on B. rapa ssp. pekinensis and B. oleracea var. capitata. At high ambient temperatures, such as those characteristic of tropical or subtropical regions (especially at low elevations) or regions that undergo temperature increases due to climate change, P. xylostella is predicted to occur at a higher range of temperatures than its biocontrol agent, D. semiclausum. Effects of high temperatures are expected to be more profound on the parasitoid for some host plants than others, with greater developmental limitations for the parasitoid on B. napus than on B. rapa or B. oleracea.

Validation of fixed sample size plans for monitoring lepidopteran pests of Brassica oleracea crops in North Korea.

The combined action of two lepidoteran pests, Plutella xylostella L. (Plutellidae) and Pieris rapae L. (Pieridae),causes significant yield losses in cabbage (Brassica oleracea variety capitata) crops in the Democratic People's Republic of Korea. Integrated pest management (IPM) strategies for these cropping systems are in their infancy, and sampling plans have not yet been developed. We used statistical resampling to assess the performance of fixed sample size plans (ranging from 10 to 50 plants). First, the precision (D = SE/mean) of the plans in estimating the population mean was assessed. There was substantial variation in achieved D for all sample sizes, and sample sizes of at least 20 and 45 plants were required to achieve the acceptable precision level of D < or = 0.3 at least 50 and 75% of the time, respectively. Second, the performance of the plans in classifying the population density relative to an economic threshold (ET) was assessed. To account for the different damage potentials of the two species the ETs were defined in terms of standard insects (SIs), where 1 SI = 1 P. rapae = 5 P. xylostella larvae. The plans were implemented using different economic thresholds (ETs) for the three growth stages of the crop: precupping (1 SI/plant), cupping (0.5 SI/plant), and heading (4 SI/plant). Improvement in the classification certainty with increasing sample sizes could be seen through the increasing steepness of operating characteristic curves. Rather than prescribe a particular plan, we suggest that the results of these analyses be used to inform practitioners of the relative merits of the different sample sizes.

Echocardiographic, electrocardiographic and blood pressure changes induced by icodextrin solution in diabetic patients on peritoneal dialysis.

The use of icodextrin as an osmotic agent in solutions for peritoneal dialysis (PD) has important cardiovascular effects related with better control of extracellular volume. Among them, reduction of arterial pressure and an improvement in echocardiographic parameters stand out. In diabetic patients, icodextrin has additional potential advantages related with better metabolic control. In a multicenter, open-label randomized controlled trial, the effects of icodextrin solutions were compared to glucose solutions on echocardiographic, electrocardiographic, and blood pressure changes in diabetic patients on PD. Two phases were noted in the follow-up. In the early phase (6 months), reduction in ambulatory blood pressure (ABP) and left ventricular end diastolic diameter were found in the icodextrin group. These changes correlated with changes in body fluids. In the late phase (12 months), a trend towards baseline values in ABP was seen. Changes in inferior vena cava diameter and in low frequency R-R variability spectral analysis in the icodextrin group suggest that icodextrin increases circulating blood volume and sympathetic tone, probably by accumulation of icodextrin metabolites in the bloodstream and improvement in diabetic neuropathy as a result of lower peritoneal glucose absorption. The effects of icodextrin in diabetic patients were related to better fluid management and metabolic control.

Identification of Thiothrix unzii in two distinct ecosystems.

AIMS: Molecular procedures were used to identify Thiothrix spp. in biofilms from sulphide-rich waters in two distinct ecosystems. METHODS AND RESULTS: Biofilm samples were obtained from two groundwater-fed systems in central and northern Florida, including an artesian spring and municipal water tank. The 16S rDNA in each sample was directly amplified by polymerase chain reaction. CONCLUSIONS: Clonal libraries of biofilm 16S rDNA from each site contained rDNA sequences that were 99-99.5% similar to Thiothrix unzii. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first report of T. unzii in a natural system. Biofilm formation by Thiothrix spp. can cause fouling in groundwater processing equipment, including municipal water-processing facilities, agricultural irrigation systems and spring water bottling plant filters. Biofouling can have severe economic and human health impacts as it will influence flow rates and related water treatments. Characterization of specific fouling bacteria and their molecular ecology is essential for their regulation.

Gastrointestinal stromal tumors, intramural leiomyomas, and leiomyosarcomas in the rectum and anus: a clinicopathologic, immunohistochemical, and molecular genetic study of 144 cases.

Gastrointestinal stromal tumors (GISTs), the specific KIT-positive mesenchymal tumors of the gastrointestinal tract, have been sporadically reported in the rectum, but there are few clinicopathologic series. In this study we analyzed the clinicopathologic features of 133 anorectal GISTs, 3 intramural leiomyomas (LMs), and 8 leiomyosarcomas (LMSs) from the files of the Armed Forces Institute of Pathology and the Haartman Institute of the University of Helsinki. Ninety-six GISTs were documented as KIT-positive and three additional ones as CD34-positive. Thirty-four tumors were included by their histologic similarity to KIT- or CD34-positive cases. GIST-specific c-kit gene mutations, mostly in exon 11, were documented in 18 of 29 cases (62%). The GISTs occurred in adults with the age range of 17-90 years (median 60 years) with a significant male predominance (71%). The tumors ranged from small asymptomatic intramural nodules to large masses that bulged into pelvis causing pain, rectal bleeding, or obstruction. They were mostly highly cellular spindle cell tumors; four tumors had an epithelioid morphology. The tumors coexpressed CD34 and KIT and were rarely positive for smooth muscle actin or desmin and never for S-100 protein. Seventy percent of patients with tumors >5 cm with more than 5 mitoses/50 high power fields (HPF) (n = 31) died of disease, whereas only one tumor <2 cm with <5 mitoses/50 HPF (n = 21) recurred and none caused death. Long latency was common between primary operation and recurrences and metastases; either one occurred in 60 of 111 patients with follow-up (54%). Distant metastases were in the liver, bones, and lungs. Three benign actin- and desmin-positive and KIT-negative intramural LMs, similar to those seen in the esophagus, were identified. There were eight LMSs, six of which formed a polypoid intraluminal mass and were actin-positive and KIT-negative. Despite high mitotic counts, only one LMS patient died of disease. A great majority of rectal smooth muscle and stromal tumors are GISTs, which have a spectrum from minimal indolent tumors to overt sarcomas. Intramural LMs are exceptional, and true LMSs are rare, and similar to colonic ones, often present as intraluminal polypoid masses that appear to have a better prognosis than GISTs with similar mitotic rates.

Pleomorphic rhabdomyosarcoma in children: four cases in the pediatric age group.

Pleomorphic rhabdomyosarcoma is considered rare and controversial, especially in children. Although pleomorphic rhabdomyosarcoma has been observed in children, its sparcity has taken it out of current childhood rhabdomyosarcoma classifications. We report four pediatric cases of pleomorphic rhabdomyosarcoma, review morphologic, immunohistochemical, and ultrastructural features, and discuss the rare need to include this category in children. The Soft Tissue Registry of the Armed Forces Institute of Pathology was searched for cases coded as "pleomorphic rhabdomyosarcoma" from 1970 to the present. Only cases in patients less than 21 years old were included. Clinical data, morphology, and immunohistochemical stains were reviewed and follow-up was obtained. Electron microscopy was performed on two cases. Molecular analysis by polymerase chain reaction was performed on one case with available material. Of four patients included, there were three boys and one girl. Patient ages ranged from 9 months to 10 years (median, 4.5 years). Tumors were located on the chest wall (n = 2) and one each on the upper and lower extremities. Tumor size ranged from 4.0 to 10.0 cm (median, 7 cm). Grossly, the tumors were lobulated and circumscribed. Microscopically, architectural patterns varied from solid to fascicular or storiform. All tumors had large, often multinucleated, polygonal, spindled or strap-like rhabdomyoblasts with abundant eosinophilic cytoplasm. Nuclear characteristics ranged from hyperchromatic to vesicular. Most tumor cells had large prominent nucleoli. Background rhabdomyoblasts varied from spindled to polygonal. No tumors displayed areas typical of embryonal or alveolar rhabdomyosarcoma. All tumors exhibited atypical mitotic figures. Immunohistochemistry revealed that the tumors were positive for the following markers: desmin (3/4), myoglobin (4/4), myoD1 (3/3), myf4 (3/3), and MSA (4/4). The two cases studied by electron microscopy both showed evidence for skeletal muscle differentiation. One case showed no evidence for a t(2;13) or t(1;13) translocation. Two patients were alive with no evidence of disease at 12 and 25 years. One patient was dead of disease at 9 years. Pleomorphic rhabdomyosarcoma is rare but exists in children. The diagnosis should be considered in pleomorphic sarcomas exhibiting skeletal muscle differentiation, which are otherwise devoid of typical areas or chromosomal changes of embryonal or alveolar rhabdomyosarcoma.

Quantitative comparisons of 16S rRNA gene sequence libraries from environmental samples.

To determine the significance of differences between clonal libraries of environmental rRNA gene sequences, differences between homologous coverage curves, CX(D), and heterologous coverage curves, CXY(D), were calculated by a Cramér-von Mises-type statistic and compared by a Monte Carlo test procedure. This method successfully distinguished rRNA gene sequence libraries from soil and bioreactors and correctly failed to find differences between libraries of the same composition.

Pleomorphic rhabdomyosarcoma in adults: a clinicopathologic study of 38 cases with emphasis on morphologic variants and recent skeletal muscle-specific markers.

Pleomorphic rhabdomyosarcoma (PRMS) is a rare and controversial tumor of skeletal muscle phenotype. Diagnostic criteria for PRMS by combined histology and currently available immunohistochemistry have not been clearly defined. We report 38 pleomorphic rhabdomyosarcomas in adults, explore morphologic variants, and discuss our experience with both specific and nonspecific skeletal muscle markers in these tumors. Clinical data, morphology, and immunohistochemistry were reviewed. Electron microscopy was performed. Of 38 cases, there were 28 males and 10 females. Patient ages ranged from 21 to 81 years (median = 54 y; mean = 51 y). Tumors were located in the lower extremity (n = 18), abdomen/retroperitoneum (n = 6), chest/abdominal wall (n = 5), spermatic cord/testes (n = 4), upper extremity (n = 3), and one each in the mouth and orbit. Tumor sizes ranged from 1.5 to 15.0 cm (mean = 7.3 cm; median = 6.8 cm). The cases were divided into three variants, each with large, atypical, pleomorphic polygonal rhabdomyoblasts (PRMB) with abundant eosinophilic cytoplasm in varying numbers and different morphologic backgrounds of round or spindled rhabdomyoblasts (RMB). 1. Classic PRMS: Predominantly atypical PRMB in sheets (n = 8). 2. Round cell PRMS: Clusters of PRMB throughout the tumor with a background of slightly atypical, medium-sized, round, blue RMB (n = 13). 3. Spindle cell PRMS: Scattered PRMB in a predominance of atypical spindled RMB arranged in a storiform growth pattern (n = 17). Immunohistochemistry revealed the following: myoglobin (37/38), MyoD1 (19/36), skeletal muscle myogenin (myf4; 19/34), fast skeletal muscle myosin (4/5), desmin (36/38), muscle-specific actin (MSA; 25/35), smooth muscle actin (SMA; 15/33), and muscle specific myogenin (myf3; 25/35). Immunohistochemistry was supportive of skeletal muscle differentiation with at least one positive skeletal muscle-specific marker (myoglobin, MyoD1, fast skeletal muscle myosin, or myf4). In addition, all cases had some positivity for nonspecific muscle markers (desmin, MSA, SMA, myf3). Electron microscopy (EM), performed on eight selected cases from all three morphologic groups, demonstrated definitive skeletal muscle differentiation in all cases. Follow-up, available on 30 (79%) cases, revealed that 70% of patients died of disease (mean 20 months, range 1 month-108 months), 3% were alive with disease at 12 months (n = 1); and 27% had no evidence of disease (mean, 83 mo; range, 18 to 108 mo). PRMS, a tumor of predominantly middle-aged adult males in the lower extremity, can be diagnosed by the morphologic presence of scattered PRMB with immunohistochemical evidence of at least one skeletal muscle-specific marker. There are three morphologic variants of PRMS. The appropriate diagnosis of PRMS is significant as it is a high-grade sarcoma, with an aggressive clinical course.

The morphologic spectrum of hibernoma: a clinicopathologic study of 170 cases.

Hibernoma, an uncommon tumor of brown fat, has been described only in a few case reports and small series. The authors reviewed 170 cases of hibernoma and evaluated the morphologic features and the behavior of this tumor. The records from the Soft Tissue Registry of the Armed Forces Institute of Pathology from 1970 were searched for cases coded as "hibernoma." Clinical information and available slides from 170 hibernomas were reviewed. Immunohistochemical staining for S-100 and CD34 was performed on select cases. Follow-up information was obtained from the patients' medical records, the patients' physicians, and the patients themselves. Of 170 patients with hibernoma, 99 were men and 71 were women. The tumor occurred most commonly in adults, with a mean age of 38.0 years (age range, 2-75 years). Nine tumors occurred in pediatric patients. The most common anatomic locations included the thigh (n = 50), shoulder (n = 20), back (n = 17), neck (n = 16), chest (n = 11), arm (n = 11), and abdominal cavity/retroperitoneum (n = 10). The average duration of the tumor was 30.6 months. Tumor size ranged from 1 to 24 cm with an average dimension of 9.3 cm. All tumors were composed partly or principally of coarsely multivacuolated fat cells with small, central nuclei and no atypia. Four morphologic variants of hibernoma were identified: typical, myxoid, spindle cell, and lipoma-like. "Typical" hibernoma (n = 140) included eosinophilic cell, pale cell, and mixed cell types based on the tinctorial quality of the hibernoma cells. The myxoid variant (n = 14) contained a loose basophilic matrix. Spindle cell hibernoma (n = 4) had features of spindle cell lipoma and hibernoma; all occurred in the neck or scalp. The lipoma-like variant (n = 12) contained only scattered hibernoma cells. Immunohistochemically, 17 of 20 cases (85%) were positive for S-100 protein. Only one hibernoma of 20, a spindle cell variant, was positive for CD34, whereas other hibernoma variants were negative. Follow-up was obtained for 66 cases (39%) over a mean period of 7.7 years (range, 6 months-28 years). None of the patients with follow-up had a recurrence or metastasis, including eight with intramuscular tumors. No patient died of disease. Hibernoma is a tumor found most often in adults and most commonly in the thigh, with several morphologic variants. It is a benign tumor that does not recur with complete excision. Hibernomas should not be confused with atypical lipomas or well-differentiated liposarcoma.

The effect of mode of exposure to Beauveria bassiana on conidia acquisition and host mortality of Colorado potato beetle, Leptinotarsa decemlineata.

The effects of the mode of exposure of second instar Colorado potato beetles to Beauveria bassiana on conidia acquisition and resulting mortality were investigated in laboratory studies. Larvae sprayed directly with a B. bassiana condial suspension, larvae exposed to B. bassiana-treated foliage, and larvae both sprayed and exposed to treated foliage experienced 76, 34, and 77% mortality, respectively. The total number of conidia and the proportion of germinating conidia were measured over time for four sections of the insect body: the ventral surface of the head (consisting mostly of ventral mouth parts), the ventral abdominal surface, the dorsal abdominal surface, and the legs. From observations at 24 and 36 h posttreatment, mean totals of 161.1 conidia per insect were found on sprayed larvae, 256.1 conidia on larvae exposed only to treated foliage, and 408.3 conidia on larvae both sprayed and exposed to treated foliage. On sprayed larvae, the majority of conidia were found on the dorsal abdominal surface, whereas conidia were predominantly found in the ventral abdominal surface and mouth parts on larvae exposed to treated foliage. Between 24 and 36 h postinoculation the percentage of conidia germinating on sprayed larvae increased slightly from 80 to 84%). On the treated foliage, the percentage of germinated conidia on larvae increased from 35% at 24 h to 50% at 36 h posttreatment. Conidia germination on sprayed larvae on treated foliage was 65% at 24 h and 75% at 36 h posttreatment. It is likely that the gradual acquisition of conidia derived from the continuous exposure to B. bassiana inoculum on the foliar surface was responsible for the increase in germination over time on larvae exposed to treated foliage. The density and germination of conidia were observed 0, 4, 8, 12, 16, 20, and 24 h after being sprayed with or dipped in conidia suspensions or exposing insects to contaminated foliage. Conidia germinated twice as fast on sprayed insects as with any other treatment within the first 12 h. This faster germination may be due to the pressure of the sprayer enhancing conidial lodging on cuticular surfaces.

Evaluation of synergistic interactions between the Colorado potato beetle (Coleoptera: Chrysomelidae) pathogen Beauveria bassiana and the insecticides, imidacloprid, and cyromazine.

Laboratory studies investigated the interaction between the fungal entomopathogen Beauveria bassiana (Balsamo) Vuillemin and sublethal doses of the insecticides imidacloprid and cyromazine when applied to larvae of the Colorado potato beetle, Leptinotarsa decemlineata (Say). When second instars were fed potato leaf discs treated with sublethal doses of imidacloprid and a range of doses of B. bassiana, a synergistic action was demonstrated. Similar results were observed when larvae were sprayed directly with B. bassiana conidia and immediately fed leaf discs treated with imidacloprid. No synergistic interaction was detected when larvae were fed leaf discs treated with sublethal doses ofimidacloprid 24 h after application of B. bassiana conidia to larvae. However, a synergistic interaction was detected when larvae were fed leaf discs treated with imidacloprid and sprayed with B. bassiana conidia 24 h later. Although sublethal doses of both imidacloprid and the triazine insect growth regulator (IGR) cyromazine prolonged the duration of the second instar, only imidacloprid interacted with B. bassiana to produce a synergistic response in larval mortality. In leaf consumption studies, the highest dose of B. bassiana tested promoted feeding in inoculated second instars. Feeding was inhibited when larvae were fed foliage treated with sublethal doses of imidacloprid and significantly reduced when fed foliage treated with a sublethal dose of cyromazine. Starvation of larvae for 24 h immediately after B. bassiana treatment produced a similar result to the combined treatment of B. bassiana and imidacloprid and increased the level of mycosis when compared with B. bassiana controls. Imidacloprid treatment affected neither the rate of germination of B. bassiana conidia on the insect cuticle nor the rate at which conidia were removed from the integument after application. The statistical analysis used to detect synergism and the possible role of starvation-induced stress factors underlying the observed synergistic interactions are discussed.

School expulsion as a process and an event: before and after effects on children at risk for school discipline.

A better understanding of expulsion as an act, a process, and an educational intervention leads to an entirely different understanding of student behavior and disciplinary consequences.