Egg Hatch Rate and Nymphal Survival of the Bed Bug (Hemiptera: Cimicidae) After Exposure to Insecticide Sprays.

Few studies have addressed the efficacy of insecticides used against eggs and first-instar nymphs of the bed bug, Cimex lectularius L. (Hemiptera: Cimicidae). Insect eggs are often resistant to insecticides; therefore, information on which products are effective is important. We evaluated the efficacy of four commonly used insecticide sprays applied directly to bed bug eggs. We also evaluated the efficacy of these insecticides to first-instar nymphs exposed to residuals resulting from directly spraying eggs. Temprid SC (beta-cyfluthrin, imidacloprid) was the most effective insecticide at preventing egg hatch (13% hatch rate) for pyrethroid-resistant, field-strain (Jersey City) bed bugs compared with a control (water [99% hatch rate]), Bedlam (MGK-264, sumithrin [84% hatch rate]), Demand CS (lambda-cyhalothrin [91% hatch rate]), and Phantom SC (chlorfenapyr [95% hatch rate]). Demand CS and Temprid SC were most effective at preventing egg hatch (0%) for an insecticide-susceptible (Harold Harlan) strain, followed by Bedlam (28%). Phantom SC produced a hatch rate similar to the control (97% and 96%, respectively). Harold Harlan-strain nymphs showed 100% survival for the control but 0% survival for Bedlam and Phantom SC. Jersey City-strain nymphs showed 100% survival for the control, 99% survival for Bedlam, 0% survival for Demand CS, 4% survival for Phantom SC, and 38% survival for Temprid SC. Demand CS was less effective at preventing hatch (91% hatch rate) of Jersey City-strain nymphs but was the only product to kill all nymphs (0% survival). One of the least effective products for preventing Jersey City-strain egg hatch (Phantom SC, 95% hatch rate) was the second most effective at killing nymphs, leaving only six of 141 alive. These findings indicate that survival of directly sprayed eggs and residually exposed, first-instar nymphs varies by strain, life stage, and product used.

Durability of a novel durable bait for control of subterranean termites (Isoptera: Rhinotermitidae): results of five-year field aging studies.

A durable termite bait containing 0.5% noviflumuron was evaluated for physical durability, retention of active ingredient, consumption by termites, and toxicity to termites over 5 yr in field studies at locations in Indiana, Mississippi, and South Carolina. Plots in Indiana and Mississippi included both natural rainfall and irrigated plots, while plots in South Carolina received only natural rainfall. Samples collected every 3 mo for the first 4 yr were evaluated for consumption with a 7 d no-choice bioassay using Reticulitermes flavipes (Kollar). Consumption and toxicity of 5 yr samples were evaluated in similar bioassays conducted for 42 d. Durable baits received from field sites had some cracking, and a small amount of external flaking, but no major deterioration based on visual observation. There were no significant differences in noviflumuron concentration over the 5-yr period and no trend toward reduced concentrations of noviflumuron over time. Consumption of aged durable baits over 4 yr was variable, but termites usually consumed more aged durable bait than fresh durable bait and the differences were frequently significant. There were some exceptions, but termites consumed significantly more fresh durable bait than aged durable bait in only 4% of observations. When 5 yr samples were evaluated, consumption was lowest for fresh durable bait and termites consumed significantly more aged durable bait from irrigated plots in Indiana and from both natural and irrigated plots in Mississippi than fresh durable bait. Survival of termites fed blank durable bait was significantly higher than that for termites fed any of the baits containing noviflumuron and there were no significant differences in survival among the noviflumuron durable baits. Our results suggest that the bait would be durable for at least 5 yr and possibly longer under most environmental conditions.

Evaluation of methods of insecticide application for control of smokybrown cockroaches (Dictyoptera: Blattidae).

The insecticide components of a previously developed integrated pest management system for smokybrown cockroaches, Periplaneta fuliginosa (Serville), were tested individually and at reduced application rates in 4 separate trials over 2 yr. A 2-bait combination (pellet and gel baits) did not significantly reduce cockroach abundance more than a single constituent bait alone. A targeted spray of trelamethrin was significantly less effective than a 2-bait combination. Residual activity of insecticides was determined with American cockroaches, P. americana (L.), in a laboratory bioassay. Chlorpyrifos wettable powder remained active < 12 d in the field, after which time its activity was not different from an experimental control (no insecticide residues), whereas chlorpyrifos pellet and hydramethylnon paste baits retained initial activity for > 27 d. Nematodes [Steinernema carpocapsae (Weiser)] applied as a spray solution did not effect the abundance of smokybrown cockroaches, and no cockroaches were recovered that exhibited nematode infection. Time needed to apply various insecticide treatments did not differ substantially (15-25 min per house), even for lower application rates.

Comparative effectiveness of an integrated pest management system and an insecticidal perimeter spray for control of smokybrown cockroaches (Dictyoptera: Blattidae).

Two treatments were compared for effectiveness in reducing abundance of smokybrown cockroaches, Periplaneta fuliginosa (Serville), around houses; an integrated pest management strategy consisting of sanitation, landscape management, and reduced insecticide usage, and a perimeter insecticide treatment applied according to label directions. Regression of means through time indicated that the integrated pest management treatment lasted approximately 60 d, whereas the perimeter treatment lasted only 30 d. The greater duration of control in the integrated pest management treatment was likely the result of decreased abundance of cockroaches outside the spray zone. In the perimeter treatment, cockroach abundance was unaffected outside the spray zone with no reduction in adult abundance in the spray zone except in the week following treatment application. The difference between the integrated pest management and perimeter treatments suggests that reinvasion of cockroaches from peripheral habitats decreases the duration of cockroach suppression. Abundance of 1st instars and small and medium nymphs was reduced for the duration of the experiment by both methods. Sampling procedures did not influence cockroach abundance. Reduction in abundance of cockroaches outside of houses reduced abundance of cockroaches inside houses.

Performance of abamectin bait formulations against German cockroaches (Dictyoptera: Blattellidae).

Commercial and experimental formulations of abamectin-based baits were evaluated in laboratory and field studies against the German cockroach, Blattella germanica (L.). In continuous exposure tests with adult males, toxicity and presumably bait consumption varied with the design of the bioassay. LT50s ranged from approximately 0.9 to > 41 d for an aerosol gel formulation for males deprived of water for 72 h before the test and for undeprived males tested with alternative food and water, respectively. Dry formulations had lower LT50s than water containing formulations for nondeprived males. There was no difference in bait toxicity between males deprived of food or water, but in arena tests, moist formulations were preferred by mixed-stage populations of cockroaches. Powder formulations were more repellent (approximately 14.9%) than moist formulations (approximately 6.4%) in Ebeling choice boxes assays, but all abamectin formulations had positive performance indices. A powder formulation reduced cockroach trap catch in infested apartments more rapidly when applied to 50, rather than 12 sites, even when the same amount of bait was applied per apartment. When applied at approximately 50 sites as a series of thin smears, an aerosol formulation provided nearly an 80% reduction in trap catch. Other abamectin formulations provided substantial, but smaller reductions in trap catch. Abamectin-based baits can reduce German cockroach populations when properly applied.

Pathogenicity and limited transoothecal transmission of Steinernema carpocapsae (Nematoda: Steinernematidae) in adult female German cockroaches (Dictyoptera: Blattellidae).

Nongravid female German cockroaches, Blattella germanica (L.), and females with young or old oothecae were exposed to infective stage juvenile (L3) Steinernema carpocapsae (Weiser) All strain by topical application and continuous exposure. Topically applied nematodes resulted in < or = 40% mortality 7 d after inoculation, whereas 100% of females continuously exposed to nematodes were dead within 7 d. Females carrying old oothecae had significantly lower LT50s (0.07 h) than females with young oothecae (42.71 h) and females without oothecae (38.49 h). Fully formed oothecae were not penetrated by the nematodes, even though infective juveniles were found in the vestibulum between the female genitalia and on the proximal end of the ootheca. Partially formed oothecae were infested (100%) by nematodes derived from the female. Topical application of nematodes to the proximal end, side, or keel of mature oothecae that were detached from females did not result in nematode infestation, and the nymphs emerged normally. Oothecae continuously exposed to nematodes were similarly not infested but exhibited significant mortality, probably caused by bacterial infection.

Metabolism of cholesterol and triacylglycerol in cultured chick neuronal cells, glial cells, and fibroblasts: accumulation of esterified cholesterol in serum-free culture.

Metabolism of free and esterified cholesterol and triacylglycerol was compared in cultured neuronal cells, glial cells, and fibroblasts grown from chick embryos. Cellular contents of free and esterified cholesterol were comparable in these cells and triacylglycerol content in the neuronal cells was about 40% of that in the other cell types. Cholesterol synthesis from [3H]acetate was high in all these cells and was not affected by fetal calf serum in the culture medium. Monensin, which has been shown to influence cholesterol metabolism through the inhibition of low-density lipoprotein receptor recycling in human fibroblasts, did not induce profound effects on cholesterol metabolism in these cells. Higher incorporation of [3H] oleic acid into esterified cholesterol was observed in the glial cells and fibroblasts when fetal calf serum was removed from the culture medium. Cellular content of the esterified cholesterol also increased in the glial cells under a serum-free arrangement. 25-Hydroxycholesterol induced higher incorporation of both [3H]acetic acid and [3H]oleic acid into esterified cholesterol in all of these cells. The results indicate that the active metabolism of cholesterol found in cultured chick neural cells and fibroblasts may not be regulated by an LDL receptor-mediated system and some factors in fetal calf serum inhibit cellular accumulation of esterified cholesterol.

Ultrasound findings of renal angiomyolipoma.

Angiomyolipoma (AML) IS A BENIGN RENAL NEOPLASM. Preoperative diagnosis is important because of the different surgical approaches to benign and malignant tumors. Angiographic findings of AML and renal carcinoma may be similar and differentiation difficult. B-mode ultraslund examination of AML demonstrates a different image pattern which may be helpfou in differentiation.