28 research outputs found
Fire Ant Decapitating Fly Cooperative Release Programs (1994â2008): Two Pseudacteon Species, P. tricuspis and P. curvatus, Rapidly Expand Across Imported Fire Ant Populations in the Southeastern United States
Natural enemies of the imported fire ants, Solenopsis invicta Buren S. richteri Forel (Hymenoptera: Formicidae), and their hybrid, include a suite of more than 20 fire ant decapitating phorid flies from South America in the genus Pseudacteon. Over the past 12 years, many researchers and associates have cooperated in introducing several species as classical or self-sustaining biological control agents in the United States. As a result, two species of flies, Pseudacteon tricuspis Borgmeier and P. curvatus Borgmeier (Diptera: Phoridae), are well established across large areas of the southeastern United States. Whereas many researchers have published local and state information about the establishment and spread of these flies, here distribution data from both published and unpublished sources has been compiled for the entire United States with the goal of presenting confirmed and probable distributions as of the fall of 2008. Documented rates of expansion were also used to predict the distribution of these flies three years later in the fall of 2011. In the fall of 2008, eleven years after the first successful release, we estimate that P. tricuspis covered about 50% of the fire ant quarantined area and that it will occur in almost 65% of the quarantine area by 2011. Complete coverage of the fire ant quarantined area will be delayed or limited by this species' slow rate of spread and frequent failure to establish in more northerly portions of the fire ant range and also, perhaps, by its preference for red imported fire ants (S. invicta). Eight years after the first successful release of P. curvatus, two biotypes of this species (one biotype occurring predominantly in the black and hybrid imported fire ants and the other occurring in red imported fire ants) covered almost 60% of the fire ant quarantined area. We estimate these two biotypes will cover almost 90% of the quarantine area by 2011 and 100% by 2012 or 2013. Strategic selection of several distributional gaps for future releases will accelerate complete coverage of quarantine areas. However, some gaps may be best used for the release of additional species of decapitating flies because establishment rates may be higher in areas without competing species
Cuticular Hydrocarbon Cues Are Used for Host Acceptance by Pseudacteon spp. Phorid Flies that Attack Azteca sericeasur Ants
Parasitoids often use complex cues to identify suitable hosts in their environment. Phorid fly parasitoids that develop on one or a few host species often use multiple cues, ranging from general to highly specific, to home in on an appropriate host. Here, we describe the hierarchy of cues that Pseudacteon phorid flies use to identify Azteca ant hosts. We show, through behavioral observations in the field, that phorid flies are attracted to two cryptic Azteca species, but only attack Azteca sericeasur (Hymenoptera: Formicidae: Dolichoderinae). To test whether the phorid flies use cuticular hydrocarbons (CHCs) to distinguish between the two Azteca taxa, we first documented and compared cuticular hydrocarbons of the two Azteca taxa using gas chromatography/mass spectrometry. Then, using cuticular hydrocarbon-transfer experiments with live ants, we characterized the cuticular hydrocarbons of A. sericeasur as a short-range, host location cue used by P. lasciniosus (Diptera: Phoridae) to locate the ants
The ongoing pursuit of neuroprotective therapies in Parkinson disease
Many agents developed for neuroprotective treatment of Parkinson disease (PD) have shown great promise in the laboratory, but none have translated to positive results in patients with PD. Potential neuroprotective drugs, such as ubiquinone, creatine and PYM50028, have failed to show any clinical benefits in recent high-profile clinical trials. This 'failure to translate' is likely to be related primarily to our incomplete understanding of the pathogenic mechanisms underlying PD, and excessive reliance on data from toxin-based animal models to judge which agents should be selected for clinical trials. Restricted resources inevitably mean that difficult compromises must be made in terms of trial design, and reliable estimation of efficacy is further hampered by the absence of validated biomarkers of disease progression. Drug development in PD dementia has been mostly unsuccessful; however, emerging biochemical, genetic and pathological evidence suggests a link between tau and amyloid-ÎČ deposition and cognitive decline in PD, potentially opening up new possibilities for therapeutic intervention. This Review discusses the most important 'druggable' disease mechanisms in PD, as well as the most-promising drugs that are being evaluated for their potential efficiency in treatment of motor and cognitive impairments in PD
BIOLOGY OF SITOTROGA-CEREALELLA (OLIV) (LEPIDOPTERA, GELECHIIDAE) REARED ON 5 CORN (MAIZE) GENOTYPES
Laboratory experiments under controlled conditions of 30 +/- 1 degrees C, 60 +/- 10% r.h. and 14 h photophase were performed to study the biology of Sitotroga cerealella (Oliv.) reared on five natural diets of different corn (maize) genotypes. S. cerealella reared on the shrunken(2) genotype displayed the longest developmental time (43.5 d) and the lowest fecundity (85.2 eggs/female). Although the egg to adult developmental time (40.2 d) of S. cerealella reared on sugary-opaco(2) did not differ significantly from those on normal, opaco(2) and sugary, the survival of the pre-imaginal stage (42.2%) was significantly reduced on this genotype. Significant differences were not found between the number of eggs hatched from females reared on these genotypes. The egg hatch ranged from 86.8 to 95.3% for the shrunken(2) and opaco(2) genotypes, respectively. Further rearing studies to determine the effects of these genotypes an the biology of S. cerealella are needed, since significant differences were not observed in the data from two successive generations.31213914
Wing morph development and reproduction of the ectoparasitoid Melittobia digitata: nutritional and hormonal effects
Diapause induction in Trichogramma embryophagum Htg. (Hym., Trichogrammatidae): the dynamics of thermosensitivity
A list of mosquito species of the Brazilian State of Pernambuco, including the first report of Haemagogus janthinomys (Diptera: Culicidae), yellow fever vector and 14 other species (Diptera: Culicidae) Lista de espécies de mosquitos do Estado de Pernambuco e primeiro relato de Haemagogus janthinomys (Diptera: Culicidae) vetor de febre amarela silvestre e outras 14 espécies (Diptera: Culicidae)
INTRODUCTION: Besides mosquito species adapted to urban environments (Culex quinquefasciatus, Aedes aegypti and Aedes albopictus), only 15 species of Anopheles had been recorded in the State of Pernambuco. METHODS: Human-landing mosquitoes were collected in Dois IrmĂŁos Park, in Recife. RESULTS: The first report for the state of Haemagogus janthinomys, an important vector of yellow fever virus, and 14 other species, including Trichoprosopon lampropus, a first reported for Brazil. CONCLUSIONS: The mosquito fauna in the area is diversified and has potential medical and veterinary importance.<br>INTRODUĂĂO: AlĂ©m de mosquitos adaptados ao ambiente urbano (Culex quinquefasciatus, Aedes aegypti e Ae. albopictus), apenas 15 espĂ©cies de Anopheles haviam sido relatadas no Estado de Pernambuco. MĂTODOS: Mosquitos que pousavam em humanos no Parque Dois IrmĂŁos, em Recife foram coletados. RESULTADOS: Haemagogus janthinomys, importante vetor de vĂrus de febre amarela, e outras 14 espĂ©cies sĂŁo relatadas pela primeira vez no estado, incluindo Trichoprosopon lampropus, relatado pela primeira vez no Brasil. CONCLUSĂES: A fauna de mosquitos na ĂĄrea Ă© muito diversificada e tem potencial importĂąncia mĂ©dica e veterinĂĄria