Temperature-dependent development and parasitism rates of four species of Pteromalidae (Hymenoptera) parasitoids of house fly (Musca domestica) pupae

Parasitoid development, parasitoid-induced host mortality and parasitoid progeny emergence were determined at five constant temperatures for Muscidifurax raptor Girault and Sanders, Muscidifurax zaraptor Kogan and Legner, Spalangia cameroni Perkins and Spalangia endius Walker using pupae of the house fly, Musca domestica L., as hosts. At temperatures of 20, 25, 30 and 35 degrees C the median development times (days from oviposition to adult emergence), respectively, were M. raptor (28.4, 20.7, 14.3, 14.5), M. zaraptor (30.6, 22.8, 14.1, 14.2), S. cameroni (55.6, 35.2, 21.8, 25.0) and S. endius (52.4, 31.5, 16.3, 14.6). All species failed to emerge at 15 degrees C. Using densities of five parasitoids and 100 hosts and a 24 h exposure period, Muscidifurax species oviposited at a greater rate over a wider range of temperatures than Spalangia species. At 15, 20, 25, 30 and 35 degrees C the mean number of pupae killed per parasitoid were, respectively, M. raptor (1.4, 7.4, 10.5, 13.7, 14.1), M. zaraptor (0.0, 3.3, 8.9, 14.4, 15.0), S.cameroni (0.0, 7.8, 11.0, 11.9, 7.4), S.endius (0.6, 4.0, 7.5, 12.0, 11.7), and means of the number of parasitoid progeny per parasitoid were, respectively, M.raptor (0.2, 5.2, 7.9, 11.8, 11.6), M.zaraptor (1.3, 4.4, 8.2, 13.0, 13.7), S.cameroni (0.0, 2.4, 4.7, 5.1, 1.0), S.endius (0.0, 0.9, 3.4, 7.5, 4.9). Development and ovipositional activity in S.cameroni was strongly inhibited at 35 degrees C. The model by Sharpe & DeMichele (1977) was used to describe temperature-dependent development and the number of parasitoid progeny produced per parasitoid at temperatures of 15-30 degrees C in all species.     

Parasitism of house fly (Musca domestica) pupae by four species of Pteromalidae (Hymenoptera): effects of host–parasitoid densities and host distribution

Parasitoid-induced mortality of house fly, Musca domestica L., pupae and parasitoid progeny emergence by four species of pteromalid parasitoids, Muscidifurax raptor Girault & Sanders, M.zaraptor Kogan & Legner, Spalangia cameroni Perkins and S.endius Walker, were determined for a 24 h exposure period using parasitoid: host ratios ranging from 1:2 to 1:50. When the number of parasitoids was held constant (n = 5) and the numbers of hosts varied, and when the number of hosts was held constant (n = 100) and the number of parasitoids varied, both the number of pupae killed per parasitoid and the number of parasitoid progeny per parasitoid increased with increasing parasitoid:host ratios to reach an upper limit asymptotically. Maximum values were, respectively: M.raptor (14.7, 11.1), M.zaraptor (12.3, 9.3), S.cameroni (16.9, 5.5), S.endius (14.8, 9.7) with no consistent effects attributed to parasitoid interference. For M.raptor and S.cameroni at parasitoid:host ratios of 1:10, the pupal mortality and progeny emergence were determined for a 24 h exposure period when hosts were distributed in poultry manure at four levels of aggregation ranging from clumped to uniform. Pupal mortality was least in clumped distributions, while parasitoid progeny emergence was not significantly different.     

Evaluation of commercial and field‐expedient baited traps for house flies,Musca domestica L. (Diptera: Muscidae)

A comparison of nine commercial baited fly traps on Florida dairy farms demonstrated that Terminator traps collected significantly more (13,323/trap) house flies (Musca domestica L.) than the others tested. Final Flight, Fly Magnet, and FliesBeGone traps collected intermediate numbers of flies (834‐2,166), and relatively few were caught with ISCA, Advantage, Fermone Big Boy, Squeeze & Snap, or OakStump traps (<300). Terminator traps collected about twice as many flies (799.8/trap) as FliesBeGone traps (343.8) when each trap was baited with its respective attractant, but when the attractants were switched between the two trap types, collections were significantly lower (77‐108) than was observed with traps baited with their respective attractant. Solutions of molasses were significantly more attractive to house flies than honey, maple syrup, or jaggery (date palm sugar). Field‐expedient traps constructed from discarded PET water bottles were much less effective than commercial traps, but painting the tops of such traps with black spray paint resulted in a six‐fold increase in trap capture.     

Host age and pathogen exposure level as factors in the susceptibility of the house fly,Musca domestica (Diptera: Muscidae) to Beauveria bassiana

Adult house flies, Musca domestica L., of four ages, <1, 3, 7, and 14 day post-eclosion, were exposed to three strains of Beauveria bassiana (P89, L90 and 447). Flies were exposed to moistened filter paper treated with either a low (1.57×10⁴ conidia/cm²) or high (1.57×10⁵ conidia/cm²) concentration of each fungal strain for 6 h. Strain 447 was superior to the two house fly-derived B. bassiana strains in inducing host infection and mortality. Significant spikes in infection and mortality occurred as early as 5 days post-exposure with higher concentration exposures acting more quickly. Few differences were observed in either infection or mortality among the four fly age classes. On Day 10 post-exposure, 77% of the high-concentration, 447-exposed flies were infected, compared with only 24% of the flies from the P89 low-concentration exposure. Potential applications of these results in integrated house fly management programs are discussed.     

Early season dispersal of Muscidifurax zaraptor (Hymenoptera: Pteromalidae) utilizing freeze-killed housefly pupae as hosts

The pteromalid wasp, Muscidifurax zaraptor Kogan and Legner, was released at three locations at a dairy in May before housefly and stable fly breeding had begun. Freeze-killed housefly pupae were placed adjacent to the emerging parasites at biweekly intervals for a 6-week period. Hosts placed out weeks 0 and 2 were heavily parasitized. Decreased parasitism in hosts placed out at week 4 suggested that many of the M. zaraptor had dispersed or died. High parasitism of hosts placed in the field at week 6 was the result of second generation parasites emerging from pupae placed out at week 0. Parasitism of freeze-killed housefly pupae placed 6 m and in the four cardinal directions from the release points was similar but lower than for hosts placed adjacent to the emerging parasites. The study demonstrated that emerging M. zaraptor readily utilized nearby freeze-killed housefly pupae but the availability of these hosts did not deter the parasites from searching for additional hosts.     

Identification ofMuscidifuraxspp., Parasitoids of Muscoid Flies, by Composition Patterns of Cuticular Hydrocarbons

Gas chromatographic analysis of cuticular hydrocarbons ofMuscidifuraxspp. adult females revealed species-specific patterns of composition that allowed identification ofMuscidifurax raptorGirault and Sanders,Muscidifurax zaraptorKogan and Legner, andMuscidifurax raptorellusKogan and Legner. A total of 18 components, all C29–C37 alkanes and methylalkanes, accounted for over 90% of the total cuticular hydrocarbons for all three species.Muscidifurax zaraptorwas characterized by a high ratio (11.9) of 3-MeC₃₁:internal Me₂C₃₅'s, whereas this ratio was <3 for the other species.Muscidifurax raptorelluswas characterized by a low (<1) 3-MeC₃₁:3,7,15-Me₃C₃₇ratio compared with ratios of 3.1 and 6.3 for these components inM. raptorandM. zaraptor, respectively. Three populations ofM. raptorelluscould be distinguished from one another based on two other component ratios (5- and 7-MeC31:3MeC32, 5- and 7-MeC31:3,7- to 3,15-Me₂C₃₃) with either 100% (Nebraska population) or 90% (Chilean and Peruvian populations) certainty. Comparison ofM. raptorcolonies established from five different locations (Florida, France, Germany, Brazil, Hungary) indicated that the hydrocarbon pattern was highly conserved in this species. A dichotomous key to species based on ratios of cuticular hydrocarbon components unambiguously classified the 50 samples ofMuscidifuraxspp. used to construct the key, plus five additional samples from different geographic locations.     

Joint action of l-leucine and sodium phosphate buffer solutions as feeding stimulants for protein-deprived females of the house fly Musca domestica

ABSTRACT. Potentiation in joint action was demonstrated between solutions of L-leucine and sodium phosphate buffer (pH 6.3) as feeding stimulants for protein-deprived females of the house fly, Musca domestica L. Both components alone elicited feeding. In two-choice feeding tests, mixtures consisting of equi-stimulating concentrations of the two components were taken in greater quantities than either component alone at twice the concentration in the mixture.
The presence of 1×10^-1 M phosphate buffer markedly lowered the threshold for detection of L-leucine. The presence of phosphate buffer strengthened the preferences shown by flies given choices of concentrations of L-leucine differing by a factor of 2 and enabled them to display preferences at lower concentrations.
The presence of 1×10^-3 M L-leucine increased, somewhat, the ability of flies to detect low concentrations of phosphate buffer. Its presence had relatively little effect on the strength of preference shown between two-fold differences in concentration of phosphate buffer when the higher concentration was 6.3×10^-3 M or less, but markedly strengthened the preferences when the higher concentration was 2.5×10^-2M or greater. Leucine increased the optimal concentration of phosphate buffer by a factor of more than 2 and converted 2×10^-1 M phosphate buffer from a mild feeding deterrent to a powerful feeding stimulant.     

Evidence for activation of endogenous opioid systems in mice following short exposure to stable flies

Biting flies influence both physiology and behaviour of domestic and wild animals. This study demonstrates that brief (30 min) exposure of male and female mice to stable flies leads to significant increases in nociceptive responses, indicative of the induction of analgesia. The biting fly-induced analgesia was mediated by endogenous opioid systems as it was blocked by the prototypic opiate antagonist naloxone. Exposure for 30 min to the bedding of biting fly-exposed mice also induced significant opioid mediated analgesic responses in mice. Exposure to either house flies or the bedding of house fly-exposed mice had no significant effects on nociception. These results indicate that brief exposure to either stable flies, or to olfactory cues associated with mice exposed to stable flies, activates endogenous opioid systems leading to the induction of analgesia and likely other opioid mediated behavioural and physiological stress responses. These results suggest the involvement of endogenous opioid systems in the mediation of the behavioural and physiological consequences of biting fly exposure in domestic and wild animals.     

Stable fly, Stomoxys calcitrans, mouthpart removal influences stress and anticipatory responses in mice

Abstract Biting fly attack induces a variety of stress and anxiety related changes in the physiology and behaviour of the target animals. Significant reductions in pain, or more appropriately, nociceptive sensitivity (latency of a foot-lifting response to an aversive thermal stimulus), are evident in laboratory mice after a 1 h exposure to stable flies, Stomoxys calcitrans. The role of the various components of biting fly attack in the development of this stress-induced reduction in pain sensitivity (analgesia) is, however, unclear. This study demonstrates that fly-naive mice do not exhibit a stress-induced analgesia when exposed to stable flies whose biting mouthparts have been removed. In contrast, mice that have been previously exposed to intact stable flies exhibit significant analgesia when exposed to flies that are incapable of biting. However, the level of analgesia induced is lower than that elicited by exposure to intact stable flies. Exposure to non-biting house flies, Musca domestica , has no effect on nociceptive sensitivity. It appears that the actual bite of the stable fly is necessary for the induction of analgesia and probably other stress and anxiety associated responses in fly naive mice. However, mice rapidly learn to recognize biting flies and exhibit significant, possibly anticipatory analgesic responses to the mere presence of biting flies.     

Exposure to stable flies reduces spatial learning in mice: involvement of endogenous opioid systems

Abstract. Biting flies influence both the physiology and behaviour of domestic and wild animals. This study demonstrates that relatively brief (60min) exposure to stable flies, Stomoxys calcitrans (L.), affects the spatial abilities of male mice. Stable fly exposure resulted in poorer subsequent performance in a water maze task in which individual mice had to learn the spatial location of a submerged hidden platform using extramaze visual cues. Determinations of spatial acquisition and retention were made with mice that had been previously exposed for 60min to either stable flies or house flies, Musca domestica (L.). Mice exposed to stable flies displayed over one day of testing (six blocks or sets of four trials) significantly poorer acquisition and retention of the water maze task than either mice that had been exposed to house flies or fly-naive mice. This attenuation of spatial learning occurred in the absence of any evident sensorimotor or motivational impairments. The reduction in spatial abilites involved endogenous opioid systems, as the decreased performance resulting from stable fly exposure was blocked by pre-treatment with the prototypic opiate antagonist, naltrexone. These results indicate that relatively brief exposure to biting flies can lead to a decrease in spatial abilities which is associated with enhanced endogenous opioid activity. These results support the involvement of endogenous opioid systems in the mediation of the behavioural and physiological effects of biting fly exposure. They further suggest that decreases in spatial abilities and performance may be part of the behavioural consequences of biting fly exposure in domestic and wild animals.     

Survey of insect growth regulator (IGR) resistance in house flies (Musca domestica L.) from southwestern Turkey

Insect growth regulators (IGRs) are currently the fastest‐growing class of insecticides, and in Turkey these products represent a new approach to pest control. In recent years, several IGRs were also registered for the control of the house fly, Musca domestica L. (Diptera: Muscidae), in Turkey. A field survey was conducted in the summers of 2006 and 2007 to evaluate resistance to some agriculturally and medically used IGRs on house flies from livestock farms and garbage dumps in the greenhouse production areas (Merkez, Kumluca, Manavgat, and Serik) of Antalya province (Southwestern Turkey). The results of larval feeding assay with technical diflubenzuron, methoprene, novaluron, pyripoxyfen, and triflumuron indicate that low levels (RF<10‐fold) of resistance to the IGRs exist in the house fly populations from Antalya province. Exceptions, however, were two populations, Guzoren and Toptas, from the Kumluca area which showed moderate resistance to diflubenzuron with 11.8‐fold in 2006 and 13.2‐fold in 2007, respectively. We found substantial variation in susceptibility of field‐collected house fly populations from year to year and from product to product. We generally observed an increase in resistance at many localities sampled from 2006 to 2007. The implications of these results to the future use of IGRs for house fly control are discussed. It will be critically important to continue monitoring efforts so that appropriate steps can be taken if resistance levels start to increase.     

STUDIES ON A CADMIUM-INDUCED METALLOTHIONEIN IN HOUSEFLY LARVAE, MUSCA DOMESTICA

Abstract  The induction of metallothionein (MT) was studied in the housefly larvae ( Musca domestica ). Upon dietary exposure to Cd, two Cd-binding proteins were isolated from the whole body homogenates, using gel filtration and ion exchange chromatography. Mass spectrometric measurement revealed that they have high purity and the molecular weight are 9045.9Da and 11560.2Da, respectively. Amino acid analysis showed that the content of cysteine is the highest, attaining to 18.2%. However, aromatic amino acid residues such as tyrosine (2.5%) and phenylalanine (3.1%) were also detected. In addition, MT from housefly larvae has strong heat stability. All these results suggest that the properties of MT isolated from housefly are very similar to that of mammalian MT, but some differences still exist.     

Failure of Hydrotaea aenescens, a larval predator of the housefly, Musca domestica, to establish in wet poultry manure on a commercial farm in Florida, USA

Hydrotaea aenescens (Weidemann) (Diptera: Muscidae) larvae and pupae were released in high-rise pullet houses in Pascoe County, Florida, U.S.A., for biological control of houseflies, Musca domestica L. (Diptera: Muscidae), in three separate tests during a 14-month period (April 1994-May 1995) and did not become established. However, H. aenescens believed to be from our releases did become established at a caged-layer farm 0.3 km from the release farm. Moisture in pullet house manure generally exceeded 80%, which is above the level at which H. aenescens is reared in colony. Caged-layer manure was also very wet, but crusted areas provided sites for H. aenescens larval development. Results demonstrate that H. aenescens adults will disperse from release sites and populate preferred sites without becoming a nuisance.