Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Insect Repellents”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources

Impact of reflective mulch on yield of strawberry plants and incidence of damage by tarnished plant bug (Heteroptera: Miridae).

The current study investigated the impact of reflective mulch on yield of strawberry plants and incidence of damage by tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois), for three strawberry cultivars: 'Honeoye', 'Earliglow', and two sibling Dayneutrals ('Tribute' and 'Tristar', herein considered as one cultivar). Of all cultivars tested, Honeoye was the most productive and least susceptible to tarnished plant bug. For Earliglow and Honeoye, reflective mulch enhanced productivity of strawberry plants and suppressed density of nymphs per flower cluster and proportion of damaged fruits, but did not significantly impact numbers of nymphs or damaged fruits per hectare, Results with Dayneutrals were not consistently significant. Both in the presence or absence of reflective mulch, proportion of damaged fruits increased with increasing density of nymphs per flower cluster and with decreasing number of fruits harvested per row section, suggesting that planting productive strawberry cultivars or maintaining cultural practices that promote high yield may provide an effective line of defense against tarnished plant bug. These results also suggest that reflective mulch may suppress incidence of damage by tarnished plant bug both directly, by reducing number of nymphs per flower cluster, and indirectly, by enhancing productivity of strawberry plants. Economic analyses evaluating costs and benefits of using reflective mulch, as well as studies investigating mechanisms that underlie the impact of reflective mulch on yield and incidence of damage by tarnished plant bug, are still needed before reflective mulch can be implemented as a management strategy in commercial strawberry fields.

Agriculture↗

Effects of aromatic cedar mulch on the Argentine ant and the odorous house ant (Hymenoptera: Formicidae).

In laboratory studies, the Argentine ant, Linepithema humile (Mayr), and the odorous house ant, Tapinoma sessile (Say), avoided aromatic cedar mulch as a nesting substrate. Both ant species were killed when confined with fresh aromatic cedar mulch in sealed containers. However, when confined with cedar mulch that had been aged outdoors for up to 140 d, mortality of L. humile was complete regardless of mulch age, whereas T. sessile mortality declined significantly over the mulch-aging period. Argentine ant susceptibility to aromatic cedar mulch was also greater than that of the odorous house ant when colonies were restricted to mulch in open trays. In addition, commercial aromatic cedar oil was lethal to both ant species. Our results suggest that aromatic cedar mulch may serve as an effective component of a comprehensive urban ant management program.

Animals↗

Mechanical barrier for preventing climbing by lesser mealworm (Coleoptera: Tenebrionidae) and hide beetle (Coleoptera: Dermestidae) larvae in poultry houses.

Mechanical barriers consisting of bands of polyethylene terepthalate resin attached to wooden posts by latex caulk adhesive and staples were 100% effective in preventing passage of dispersing lesser mealworm, Alphitobius diaperinus (Panzer), larvae in the laboratory. Barriers continued to be 100% effective after beinig held in a caged layer poultry house for 3 mo. Polyethylene terepthalate barriers installed on support posts in a pullet house in Brooker, FL, were >92% effective against natural populations of lesser mealworm larvae 6 mo after installation. The barriers also were >94% effective against natural populations of larvae of the hide beetle, Dermestes maculatus DeGeer, when fly populations were low. Fecal spot depositions by house flies in excess of 31 cumulative fly spots per square centimeter on spot cards reduced the effectiveness of the barriers to 79-90%, and barrier efficacy was reduced to 40-56% when fly spots covered >80% of the surface of the plastic. Washing the barriers with water to remove fly spots restored their effectiveness against hide beetle larvae to >99%.

Animals↗

Bioactivities of the leaf essential oil of Curcuma longa (var. ch-66) on three species of stored-product beetles (Coleoptera).

Essential oil extracted from the leaves of turmeric, Curcuma longa L., was investigated for contact and fumigant toxicity and its effect on progeny production in three stored-product beetles, Rhyzopertha dominica F. (lesser grain borer), Sitophilus oryzae L. (rice weevil), and Tribolium castaneum Herbst (red flour beetle). Oviposition-deterrent and ovicidal actions of C. longa leaf oil were also evaluated against T. castaneum. The oil was insecticidal in both contact and fumigant toxicity assays. The adults of R. dominica were highly susceptible to contact action of C. longa leaf oil, with LD50 value of 36.71 microg/mg weight of insect, whereas in the fumigant assay, adults of S. oryzae were highly susceptible with LC50 value of 11.36 mg/liter air. Further, in T. castaneum, the C. longa oil reduced oviposition and egg hatching by 72 and 80%, respectively at the concentration of 5.2 mg/cm2. At the concentration of 40.5 mg/g food, the oil totally suppressed progeny production of all the three test insects. Nutritional indices indicate >81% antifeedant action of the oil against R. dominica, S. oryzae and T castaneum at the highest concentration tested.

Animals↗

Catnip essential oil as a barrier to subterranean termites (Isoptera: Rhinotermitidae) in the laboratory.

The essential oil of catnip, Nepeta cataria (Lamiacae) was evaluated for behavioral effects on two populations of subterranean termite, Reticulitermes flavipes (Kollar) and R. virginicus (Banks) (Isoptera: Rhinotermitidae). The catnip essential oil contained approximately 36:64 E,Z-nepetalactone and Z,E-nepetalactone, respectively. The time to 50% dissipation (DT50) of the isomers in sand was dependent on dose, and ranged from 5.7 to 12.6 d for the E,Z-isomer and 7.7-18.6 d for the Z,E-isomer. For R. flavipes, the 24-h topical LD50 value was approximately 8200 microg/g termite. The 24-h fumigation LC50 value for R. flavipes was between 36 and 73 microg/ml air, and the 7-d fumigation LC50 value was between 14 and 36 microg/ml air. Exposure of R. virginicus to treated sand resulted in a 24-h LC50 value (95% F.L.) of 84 (67.6, 112) microg/cm2 and a 7-d LC50 value of 21.1 (16.4, 26.8) microg/cm2; for R. flavipes these values were 63.2 (53.7, 73.9) and 44.4 (34.6, 58.1) microg/cm2, respectively. Vertical tunneling through treated sand was eliminated at 500 ppm for R. virginicus and at 250 ppm for R. flavipes. Horizontal tunneling was stopped at 250 ppm for R. virginicus and reduced at doses above 250 ppm for R. flavipes. Although tunneling ceased in these tests, mortality was not high, indicating that the termites avoided the treated sand. Efficacy of catnip oil was equivalent to other monoterpenoids reported in the literature.

Animals↗

Response of the Formosan subterranean termites (Isoptera: Rhinotermitidae) to baits or nonrepellent termiticides in extended foraging arenas.

Distance effects of three treatments, noviflumuron, fipronil, and thiamethoxam, against laboratory populations of the Formosan subterranean termite, Coptotermesformosanus Shiraki, were tested in extended foraging arenas with foraging distances of 50 m. The results showed that during the 10-wk test period, all termites were killed by noviflumuron baits, whereas the nonrepellent termiticides fipronil and thiamethoxam divided the laboratory populations into two groups after causing 25-35% worker mortality. The horizontal transfer of lethal effects of fipronil was < or = 5 m. For thiamethoxam, the distance of transfer was substantially shorter. Because of their dose-dependent lethal time, the nonrepellent termiticides did not fulfill the requirements of a liquid bait model.

Animals↗

Biting deterrent activity of a deet analog, two DEPA analogs, and SS220 applied topically to human volunteers compared with deet against three species of blood-feeding flies.

An earlier in vitro screening of N,N-diethyl-3-methylbenzamide (Deet) and N,N-diethylphenylacetamide (DEPA) analogs showed that two DEPA analogs, N,N-diethyl(3-bromophenyl) acetamide and N,N-diethyl[(alpha,alpha,alpha-trifluoro-m-tolyl)]acetamide, and one Deet analog, N,N,diethyl[3-(trifluoromethyl)]benzamide, had biting-deterrent activities that were superior to Deet against Aedes aegypti (L.) and Anopheles stephensi Liston. In the current study, the three analogs and (1S,2'S)-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220) were applied topically to the skin of human volunteers at 24 nmol compound/cm2 skin and compared with the activity of Deet at the same dose against biting by Ae. aegypti, An. stephensi, and Phlebotomus papatasi Scopoli females. SS220 proved to be as effective as Deet against Ae. aegypti and P. papatasi but more effective than Deet against An. stephensi. Contrary to the earlier in vitro tests, results with humans (in vivo testing) showed that neither of the DEPA analogs nor the Deet analog performed more effectively than Deet against the insects. The in vivo results showed that the analogs were not sufficiently effective to warrant further development. Notably, in vivo and in vitro methods used in discovery of personal protection chemicals for human use against blood-feeding flies can both be effective discriminating tools, but results obtained with the respective methods may not always agree. Ultimately, we surmise that in vivo testing methods with humans must be used to discriminate among compounds that superficially seem effective when screened using an in vitro method.

Acetamides↗

Detection and characterization of amitraz resistance in the southern cattle tick, Boophilus microplus (Acari: Ixodidae).

Amitraz, a formamidine acaricide, plays an important role in the control of the southern cattle tick, Boophilus microplus (Canestrini), and other tick species that infest cattle, dogs, and wild animals. Although resistance to amitraz in B. microplus was previously reported in several countries, the actual measurement of the level of amitraz resistance in ticks has been difficult to determine due to the lack of a proper bioassay technique. We conducted a survey, by using a newly reported technique that was a modification of the standard Food and Agriculture Organization larval packet test, to measure the levels of resistance to amitraz in 15 strains of B. microplus from four major cattle-producing states in Mexico. Low-order resistance (1.68- to 4.58-fold) was detected in 11 of those strains. Our laboratory selection using amitraz on larvae of the Santa Luiza strain, which originated from Brazil, achieved a resistance ratio of 153.93 at F6, indicating the potential for high resistance to this acaricide in B. microplus. Both triphenylphosphate and piperonyl butoxide significantly synergized amitraz toxicity in both resistant and susceptible tick strains. Diethyl maleate synergized amitraz toxicity in one resistant strain but had no effect on the susceptible strain and had minor antagonistic effects on two other resistant strains. Target site insensitivity, instead of metabolic detoxification mechanisms, might be responsible for amitraz resistance observed in the Santa Luiza strain and possibly in other amitraz resistant B. microplus ticks from Mexico. The Santa Luiza strain also demonstrated high resistance to pyrethroids and moderate resistance to organophosphates. Multiple resistance shown in this strain and other B. microplus strains from Mexico poses a significant challenge to the management of B. microplus resistance to acaricides in Mexico.

Animals↗

Demodicosis in red-handed tamarins (Saguinus midas).

Two nonrelated but paired red-handed tamarins (Saguinus midas) presented with diffuse, multifocal, raised, nonpruritic, hyperkeratotic lesions on the appendages and face. Skin biopsies identified acarids and skin scrapings confirmed demodex-like mites. The animals were treated with ivermectin, at the endoparasite dose, which initially resulted in resolution of clinical signs; however, signs recurred after numerous treatments. After four treatments with amitraz dips, demodicosis lesions resolved.

Administration, Topical↗

Efficacy of an amitraz-impregnated collar in preventing transmission of Borrelia burgdorferi by adult Ixodes scapularis to dogs.

OBJECTIVE: To determine whether an amitraz-impregnated collar could prevent transmission of Borrelia burgdorferi by Ixodes scapularis to dogs. DESIGN: Laboratory trial. ANIMALS: 8 specific-pathogen-free Beagles. PROCEDURE: On days -15 and -1, all dogs had negative ELISA results for serum antibodies against B. burgdorferi. On day 0, 4 dogs were each fitted with an amitraz-impregnated (9%) collar, and 4 dogs served as untreated controls. On day 7, all dogs were infested with 100/scapularis (approx 50 females and 50 males) with a known B. burgdorferi infectivity rate of 39.4%. On days 21, 28, 35, 42, 56, 70, and 84, each dog was tested for serum antibodies against B. burgdorferi via ELISA and a western blot technique. Additional ELISA were also performed for serum antibodies against antigenically similar organisms. RESULTS: By day 70, all control dogs had developed serum ELISA responses ranging from 328 to 510 kinetics-ELISA units (equivalent to end-point titers of approx 43,500 to 60,000), whereas treated dogs remained seronegative throughout the study. Western blot assays performed on all serum samples confirmed that antibodies detected in control dogs reflected responses to specific antigens of B. burgdorferi, whereas treated dogs had no such antibodies. Additional serologic analyses confirmed that antibody responses observed in control dogs were not attributable to antigenically similar organisms. CONCLUSIONS AND CLINICAL RELEVANCE: Amitraz-impregnated collars prevented transmission of B. burgdorferi in 4 of 4 treated dogs and may be a useful management tool for prevention of borreliosis in dogs.

Animals↗

Protective behavior survey, West Nile virus, British Columbia.

We investigated personal protective behaviors against West Nile virus infection. Barriers to adopting these behaviors were identified, including the perception that DEET (N,N-diethyl-m-toluamide and related compounds) is a health and environmental hazard. Televised public health messages and knowing that family or friends practiced protective behaviors were important cues to action.

Animals↗

Eradication of ectoparasites in children. How to treat infestations of lice, scabies, and chiggers.

Infestations of head lice, body lice, scabies, and chiggers are common causes of rash and pruritus in children. Concern has arisen about development of resistance to often-used treatments, but a comprehensive approach to eradication is usually very effective. In this article, Dr Potts describes the presentation of ectoparasites and discusses conservative treatment and the safe use of pediculicides.

Adult↗

The effectiveness of permethrin and deet, alone or in combination, for protection against Aedes taeniorhynchus.

Field tests were conducted to compare the degree of protection from bites by the mosquito Aedes taeniorhynchus (Wiedemann) provided by wearing clothing treated with permethrin [(3-phenoxyphenyl)methyl (+/-) cis/trans 3-(2-dichloroethenyl)2, 2-dimethylcyclopropanecarboxylate] with that provided by applying deet (N,N-diethyl-m-toluamide) to exposed skin or by applying deet and wearing the treated clothing. Human test subjects were exposed to natural populations of mosquitoes for a 9-hour daytime period (total of 8 days/treatment) while using one or both protection methods. Unprotected test subjects were also exposed for short periods each day as a check to determine the overall biting rate of mosquitoes. The combined use of both protection methods was the most effective treatment in preventing bites, resulting in an average of 1.5 bites/9-hour day, compared with 53.5 and 98.5 bites on subjects protected only with treated clothing or deet, respectively, and 2,287 bites (extrapolated) on subjects who wore untreated clothing during the same time period. Measurements also indicated that the toxic effect of permethrin reduced biting rates by greater than 90% within the immediate area where subjects wore permethrin-treated uniforms for 9 hours.

Animals↗