Sarcophaga Crassipalpis Research Articles

Bigger isn't always better: Challenging assumptions about the associations between diapause, body weight, and overwintering survival.

During the winter, animals face limited food availability. Many animals enter dormancy to reduce their winter energy expenditure. Most insects spend the winter in diapause, a state of programmed dormancy. It is often assumed that diapausing insects need nutrient stores to fuel their many months of basal metabolism and must grow heavier than their non-diapause-programmed counterparts. However, the extent to which food limitation affects body weight during overwintering preparation as well as the likelihood and duration of diapause remainsunclear. We limited the duration of the feeding period and thus the total quantity of food available to diapause-destined larvae of the pupal-diapausing flesh fly, Sarcophaga crassipalpis, to test how food limitation affects body weight in the context of diapause programming. We also tested the extent to which food deprivation and body weight affect the likelihood and duration of diapause. We hypothesized that diapause-destined larvae grow more quickly and pupariate at a heavier body weight than non-diapause larvae. We also hypothesized that body weight is more dramatically reduced by food limitations when a larva is programmed for diapause. Finally, we hypothesized that larvae with lighter body weight (i.e., food limited) are less likely to enter pupal diapause and also stay in diapause for a shorter duration than heavier, well-fed, individuals. Contrary to our hypotheses that diapausing insects are heavier than their non-diapausing counterparts, we found diapausing pupae weighed less than non-diapausing pupae, especially when larvae received limited food. We found light pupae did not abort their diapause program. In both diapausing and non-diapausing pupae, body weight was positively correlated with simulated winter survival. However, above a weight threshold, body weight no longer affected simulated winter survival in diapausing pupae. Contrary to our predictions and the general consensus in much of the diapause literature, we also found that lighter pupae stayed in diapause longer than heavier pupae. Overall, our results challenge the precept that body weight and diapause are positively associated. The relationship between body weight and diapause is complex and may be affected by the availability of food before and after winter, the availability of high-quality overwintering sites, and the life history of a particular insect.

Effects of Tissue Type and Temperature on Selected Life-History Traits of the Flesh Fly, Sarcophaga crassipalpis (Macquart, 1839) (Diptera: Sarcophagidae).

The flesh fly, Sarcophaga crassipalpis Macquart 1839 (Diptera: Sarcophagidae), colonizes estimation of the minimum post-mortem interval (min-PMI). This study examined the effects of different types of tissues and temperature on the development of S. crassipalpis. To the best of our knowledge, the present study is the first to investigate the effects of life-history information of S. crassipalpis. Larvae were reared on three tissue types, chicken heart, bovine minced meat, and bovine tongue, at five temperatures, 15, 20, 25, 30, and 32°C. Pupal and larval development time, adult weight, and pupal and larval survival differed significantly for tissue type and temperature. Temperature had a significant effect on pupal weight but tissue type did not significantly affect pupal weight. The duration of the larval and pupal stages (except of chicken heart, 30°C) decreased with increasing temperature, except for 32°C, in all tissue types. Larval survival was lowest at 32°C in bovine minced meat, bovine tongue, and chicken heart, and at 32°C, all pupae failed to reach the adult stage in minced meat. The results of this study highlight the necessity of considering larval diet and temperature in forensic investigations.

Chasing Flies: The Use of Wingbeat Frequency as a Communication Cue in Calyptrate Flies (Diptera: Calyptratae).

Simple SummarySome of the fastest and most agile flying insects are the calyptrate flies which include blow flies, flesh flies, and house flies. The current study compared the wingbeat frequency of four species, representing four genera of these flies, recorded in free flight and analyzed using sound editor and analysis software. Wingbeat frequency was found to differ between the four species and between sexes. Such findings provide insight into how flies are communicating and show promise for the use of wingbeat frequency as a novel methodology to identify fly specimens.The incidental sound produced by the oscillation of insect wings during flight provides an opportunity for species identification. Calyptrate flies include some of the fastest and most agile flying insects, capable of rapid changes in direction and the fast pursuit of conspecifics. This flight pattern makes the continuous and close recording of their wingbeat frequency difficult and limited to confined specimens. Advances in sound editor and analysis software, however, have made it possible to isolate low amplitude sounds using noise reduction and pitch detection algorithms. To explore differences in wingbeat frequency between genera and sex, 40 specimens of three-day old Sarcophaga crassipalpis, Lucilia sericata, Calliphora dubia, and Musca vetustissima were individually recorded in free flight in a temperature-controlled room. Results showed significant differences in wingbeat frequency between the four species and intersexual differences for each species. Discriminant analysis classifying the three carrion flies resulted in 77.5% classified correctly overall, with the correct classification of 82.5% of S. crassipalpis, 60% of C. dubia, and 90% of L. sericata, when both mean wingbeat frequency and sex were included. Intersexual differences were further demonstrated by male flies showing significantly higher variability than females in three of the species. These observed intergeneric and intersexual differences in wingbeat frequency start the discussion on the use of the metric as a communication signal by this taxon. The success of the methodology demonstrated differences at the genus level and encourages the recording of additional species and the use of wingbeat frequency as an identification tool for these flies.

Molecular Species Identification of Six Forensically Important Iranian Flesh Flies (Diptera).

Background:Flesh flies (Diptera: Sarcophagidae) are considered as myiasis agents and important evidences in forensic investigations. However, their use has been restricted because, at all larval stages and female adults, morphological species identification is difficult or very challenging. This study investigated to test utility of mitochondrial cytochrome oxidase subunit I (mt-COI) sequences for differentiation of six forensically important Iranian flesh flies namely, Sarcophaga crassipalpis, S. flagellifera, S. hirtipes, S. aegyptica, S. africa and S. argyrostoma.Methods:Male specimens were morphologically identified to species level and then the genomic DNA of the flies were extracted and subjected to polymerase chain reaction (PCR) against mt-COI gene. The PCR products were sequenced and the obtained sequences were analyzed for the species specific restriction fragment length polymorphisms (RFLPs).Results:Rate of genetic variation between species was 6–10% which was enough to find restriction enzymes (RE) that were able to produce species-specific RFLP profiles. Combinations of three REs: BsrFI, RsaI and HinfI, provided diagnostic bands for identification of the six Sarcophaga species.Conclusion:The results of this study showed that molecular markers such as RFLPs enhancing the use of evidence from flesh flies in forensic investigation. However, lack proper restriction sites in the COI region inhibited introduction of a single restriction enzyme for easy species identification. It is recommended to apply larger part of DNA such as combination of COI and COII genes to provide better RFLP markers for species identification of flesh flies.

THE USE OF TWO FLY SPECIES TO DETECT THE ANTI-DEPRESSANT FLUOXETINE POST-MORTEM (DIPTERA: CALLIPHORIDAE: LUCILIA SERICATA MEIGEN, SARCOPHAGIDAE: SARCOPHAGA CRASSIPALPIS MACQUART)

The study of insects of forensic interest with the purpose of qualitatively and/or quantitatively detecting toxic substances is called forensic entomotoxicology. The present study was conducted to determine whether the antidepressant, fluoxetine, could be detected and quantified in two sarcosaprophagous fly species (Lucilia sericata, Sarcophaga crassipalpis) reared on pig muscle that had been mixed with 2000 mg/kg of the antidepressant. Samples of third larval instars, pupae and puparia were removed after certain periods of time. Fluoxetine was detected and quantified in larvae and pupae of both species using UV spectrophotometry at 270 and 277 nm. No significant differences were found between all the samples of both species. Puparia of L. sericata, but not S. crassipalpis were also positive for fluoxetine.

Effects of gender, age, and nutrition on circadian locomotor activity rhythms in the flesh fly Sarcophaga crassipalpis

In many animal species, circadian rhythms of behavior are not constant throughout the lifetime of the individual but rather exhibit at least some degree of plasticity. In the present study, we have examined the potential influences of gender, age, and nutrition (presence or absence of liver) on the expression of circadian locomotor activity rhythms in the flesh fly Sarcophaga crassipalpis. We found no significant differences in endogenous circadian period under constant dark conditions with respect to gender, nutrition, or age for the duration of our experiments. On the other hand, both male and female flesh flies, as expected, were predominantly diurnal under light-dark cycles, but the pattern of entrainment differed between the sexes. Females also displayed higher activity levels than males. Also, in contrast with males, female activity levels increased with age. Moreover, females exhibited an extraordinary, but transient (one to three days), departure from diurnality which we characterize as “extended dark activity” (EDA). This phenomenon appeared as a continuous bout of locomotor activity that extended at least three hours into the early half of the dark phase at levels at least twice the median of the overall locomotor activity for the individual fly. EDA occurred as an age-dependent response to liver consumption, never appearing prior to day 4 post-eclosion but, thereafter, transpiring within one or two days after a 48-h exposure to liver. These results suggest a linkage between physiological events associated with egg provisioning and locomotor activity in the anautogenous flesh fly. Furthermore, our findings identify the existence of multiple influences on the expression of circadian clock-regulated behavior.

Clock and Hormonal Controls of an Eclosion Gate in the Flesh Fly Sarcophaga crassipalpis.

The eclosion gate in insect development is controlled by the circadian clock and hormonal cascade. To study mechanisms underlying the eclosion gate, we examined eclosion-timing signals from the circadian clock, and the role of 20-hydroxyecdysone in the eclosion gate of the flesh fly, Sarcophaga crassipalpis. Phase responses of the eclosion rhythm were examined by applying a low-temperature pulse in the day prior to the first eclosion peak. A low-temperature pulse applied about 5.4 h before eclosion advanced an eclosion peak by 0.9 h. This indicates that an interval from the Zeitgeber (external environmental cues) input to the behavioral output by the circadian clock is 4.5 h. Signals released by the circadian clock in the last 4.5 h before eclosion could change eclosion time. In the prothoracic gland, daily changes in immunoreactivity against a circadian clock protein PERIOD were observed in the last two days before eclosion. Hemolymph titers of 20-hydroxyecdysone were very low in the last two days of the pupal period. 20-hydroxyecdysone injections caused a delay, not an advancement, in eclosion time in a time dependent manner: pharate adults were sensitive to 20-hydroxyecdysone about 20 and 16 h before eclosion, whereas no significant effects were observed about 12 and 8 h before eclosion. These results suggest that 20-hydroxyecdysone is not a timing signal submitted by the circadian clock but an indicator to suppress premature eclosion. The circadian clock in the prothoracic gland presumably sends a signal distinct from ecdysteroids from several hours before eclosion to time the onset of eclosion.

Entrainment of eclosion and preliminary ontogeny of circadian clock gene expression in the flesh fly, Sarcophaga crassipalpis

Timing of circadian activities is controlled by rhythmic expression of clock genes in pacemaker neurons in the insect brain. Circadian behavior and clock gene expression can entrain to both thermoperiod and photoperiod but the availability of such cues, the organization of the brain, and the need for circadian behavior change dramatically during the course of insect metamorphosis. We asked whether photoperiod or thermoperiod entrains the clock during pupal and pharate adult stages by exposing flies to different combinations of thermoperiod and photoperiod and observing the effect on the timing of adult eclosion. This study used qRT-PCR to examine how entrainment and expression of circadian clock genes change during the course of development in the flesh fly, Sarcophaga crassipalpis. Thermoperiod entrains expression of period and controls the timing of adult eclosion, suggesting that the clock gene period may be upstream of the eclosion pathway. Rhythmic clock gene expression is evident in larvae, appears to cease during the early pharate adult stage, and resumes again by the time of adult eclosion. Our results indicate that both patterns of clock gene expression and the cues to which the clock entrains are dynamic and respond to different environmental signals at different developmental stages in S. crassipalpis.

Characterization of the adipokinetic hormone receptor of the anautogenous flesh fly, Sarcophaga crassipalpis

Adipokinetic hormone (AKH) is an insect neuropeptide mainly involved in fat body energy mobilization. In flies (Phormia regina, Sarcophaga crassipalpis), bugs (Pyrrhocoris apterus) and cockroaches (Periplaneta americana) AKH was also demonstrated to be involved in the regulation of digestion. This makes AKH an important peptide for anautogenous female flies that need to feed on a supplementary protein meal to initiate vitellogenesis, the large scale synthesis of yolk proteins and their uptake by the developing oocytes.Flesh fly AKH, originally identified as Phormia terraenovae hypertrehalosemic hormone (PhoteHrTH), functions through activation of the AKH receptor (AKHR). This is a G protein-coupled receptor that is the orthologue of the human gonadotropin-releasing hormone receptor. Pharmacological characterization indicated that the receptor can be activated by two related dipteran AKH ligands with an EC50 value in the low nanomolar range, whereas micromolar concentrations of the Tribolium castaneum AKH were needed.Consistent with the energy mobilizing function of AKH, the receptor transcript levels were most abundant in the fat body tissue. Nonetheless, Sarcophaga crassipalpis AKHR transcript levels were also high in the brain, the foregut and the hindgut. Interestingly, the receptor transcript numbers were reduced in almost all measured tissues after protein feeding. These changes may enforce the use of ingested energy carrying molecules prior to stored energy mobilization.

Conservation and modification of genetic and physiological toolkits underpinning diapause in bumble bee queens.

Diapause is the key adaptation allowing insects to survive unfavourable conditions and inhabit an array of environments. Physiological changes during diapause are largely conserved across species and are hypothesized to be regulated by a conserved suite of genes (a 'toolkit'). Furthermore, it is hypothesized that in social insects, this toolkit was co-opted to mediate caste differentiation between long-lived, reproductive, diapause-capable queens and short-lived, sterile workers. Using Bombus terrestris queens, we examined the physiological and transcriptomic changes associated with diapause and CO2 treatment, which causes queens to bypass diapause. We performed comparative analyses with genes previously identified to be associated with diapause in the Dipteran Sarcophaga crassipalpis and with caste differentiation in bumble bees. As in Diptera, diapause in bumble bees is associated with physiological and transcriptional changes related to nutrient storage, stress resistance and core metabolic pathways. There is a significant overlap, both at the level of transcript and gene ontology, between the genetic mechanisms mediating diapause in B. terrestris and S. crassipalpis, reaffirming the existence of a conserved insect diapause genetic toolkit. However, a substantial proportion (10%) of the differentially regulated transcripts in diapausing queens have no clear orthologs in other species, and key players regulating diapause in Diptera (juvenile hormone and vitellogenin) appear to have distinct functions in bumble bees. We also found a substantial overlap between genes related to caste determination and diapause in bumble bees. Thus, our studies demonstrate an intriguing interplay between pathways underpinning adaptation to environmental extremes and the evolution of sociality in insects.

Male aggression, limited female choice and the ontogeny of mating behaviour in the flesh fly Sarcophaga crassipalpis

AbstractPrevious work has shown that male flesh flies (Sarcophaga crassipalpis Macquart) exhibit an ontogeny of behaviour from eclosion through sexual maturity that includes extensive changes in the expression of aggressive, non‐aggressive interactive and non‐interactive behaviours. To determine how the presence of a female flesh fly influences the manifestation of these behaviours, male flesh flies of different ages post‐eclosion are paired with same‐age females and their behaviours are monitored in a simple arena during a 50‐min observation period. All flies are socially isolated until pairing. Although the levels of expression of aggressive and non‐aggressive interactive behaviours are depressed relative to previous findings in male‐opponent pairs, the ontogeny of aggression still occurs as indicated by a significant increase, with age, in the agonistic behaviour ‘hold’. Similar to male‐opponent pairs and individual males, the performance by males of the non‐interactive behaviours ‘walking’ and ‘standing’ diminishes, whereas ‘upside‐down’ increases with age. By contrast, ‘grooming’ shows a significant age‐related decline. No courtship behaviours are observed in the males, although the aggressive behaviour ‘hold’ is a significant transition to mating. Females show no obvious courtship or rejection behaviours, although the significant increase in ‘upside‐down’ with age could possibly be a behavioural gateway to mating. The results of this study indicate that extensive age‐related changes encompassing the entire behavioural repertoire are intrinsic to male flesh flies and persist under a variety of different social contexts.

Flesh flies regulate the consumption of 3 macronutrients to maximize lifespan and egg production

Dietary macronutrient balance has been shown to have large effects on the growth, reproduction, and survival of a wide range of animals. Yet, most studies of dietary nutrient balance are limited to pairs of nutrients even though food items can differ in their concentrations of all 3 macronutrients. We used a right-angled mixture triangle design to quantify the self-selected nutrient intake of flesh flies, Sarcophaga crassipalpis , and to test the separate and interactive effects of all 3 macronutrients on lifespan and lifetime egg production. Flesh flies presented with 3 food dishes, each biased in 1 macronutrient, self-selected a nutrient intake that was highly carbohydrate-biased. When maintained on 1 of 7 diets with fixed macronutrient mixtures, flies maximized both lifespan and lifetime egg production on carbohydrate-biased diets. Despite overwhelming effects of carbohydrates on fitness, there were subtle but significant interactions between carbohydrate and lipid for lifespan and carbohydrate and protein for egg production. These results demonstrate that flesh flies are able to balance their intake of all 3 macronutrients simultaneously to reach an intake at which they achieve high fitness. Furthermore, the effects of carbohydrate and protein on the fitness of flesh flies were similar to that of fruit flies ( Bactrocera tryoni ) and vinegar flies ( Drosophila melanogaster ). This suggests that regardless of whether they feed on plant tissue or animal flesh as larvae, flies converge on similar dietary requirements as adults.

Imidazole derivative KK-42 boosts pupal diapause incidence and delays diapause termination in several insect species

The imidazole derivative KK-42 is a synthetic insect growth regulator known previously to be capable of averting embryonic diapause in several Lepidoptera, but whether it also affects diapauses occurring in other developmental stages remains unknown. In the present study, we examined the effect of KK-42 on pupal diapause in two species of Lepidoptera, the Chinese oak silkworm Antheraea pernyi and the corn earworm Helicoverpa zea, and in one species of Diptera, the flesh fly Sarcophaga crassipalpis. In A. pernyi, KK-42 delayed pupal diapause termination under the long day conditions that normally break diapause in this species. Likewise, in H. zea, KK-42 delayed termination of pupal diapause, a diapause that, in this species, is normally broken by high temperature. KK-42-treated pupae of these two species eventually terminated diapause and successfully emerged as adults, but the timing of diapause termination was significantly delayed. KK-42 also significantly increased the incidence of pupal diapause in H. zea and S. crassipalpis when administered to larvae that were environmentally programmed for diapause, but it was not capable of inducing pupal diapause in H. zea if larvae were reared under environmental conditions that do not normally evoke the diapause response. Experiments with H. zea showed that the effect of KK-42 on pupal diapause was dose- and stage-dependent, but not temperature-dependent. Results presented here are consistent with a link between KK-42 and the ecdysteroid signaling pathway that regulates pupal diapause.

Micromorphology of immature stages of Sarcophaga (Liopygia) cultellata Pandellé, 1896 (Diptera: Sarcophagidae), a forensically important fly.

The Sarcophagidae are one of the most numerous groups of Diptera in the world, consisting of many species of forensic interest, whose immature stages are useful in the estimation of postmortem interval. The immature stages of some species of forensic importance still remain unknown or undescribed, like in the case of Sarcophaga (Liopygia) cultellata Pandellé, 1986, a species restricted to the Iberian Peninsula, south of France and north of Italy, which shares a ecological niche with species of the same subgenus, e.g., Sarcophaga (Liopygia) argyrostoma (Robineau-Desvoidy, 1830) and Sarcophaga (Liopygia) crassipalpis Macquart, 1839, making it necessary to lay the groundwork for a proper specific differentiation before it can be successfully applied in forensic practice. This study provides the first micromorphological description of all preimaginal stages of S. (L.) cultellata using light microscopy and scanning electron microscopy (SEM), the results of which allow the morphology of the main features to be followed during the immature life cycle. We propose a combination of features for distinguishing Liopygia from other sarcophagid subgenera, based on the current level of morphological knowledge of immature stages. S. (L.) cultellata can be differentiated from S. (L.) argyrostoma and S. (L.) crassipalpis in every immature stage by both light microscopy and SEM. The presence of tegumental warts and a fan-shaped anterior spiracle with a single row of 15-18 respiratory papillae allow distinguishing the third instar larvae of S. (L.) cultellata from other Sarcophaga species described hitherto by SEM. Identification keys based on light microscopy observations are provided, covering all the immature stages of Liopygia subgenus occurring in the Iberian Peninsula.

A 454 sequencing approach to dipteran mitochondrial genome research

The availability of complete mitochondrial genome (mtgenome) data for Diptera, one of the largest metazoan orders, in public databases is limited. The advent of high throughput sequencing technology provides the potential to generate mtgenomes for many species affordably and quickly. However, these technologies need to be validated for dipterans as the members of this clade play important economic and research roles. Illumina and 454 sequencing platforms are widely used in genomic research involving non-model organisms. The Illumina platform has already been utilized for generating mitochondrial genomes without using conventional long range PCR for insects whereas the power of 454 sequencing for generating mitochondrial genome drafts without PCR has not yet been validated for insects. Thus, this study examines the utility of 454 sequencing approach for dipteran mtgenomic research. We generated complete or nearly complete mitochondrial genomes for Cochliomyia hominivorax, Haematobia irritans, Phormia regina and Sarcophaga crassipalpis using a 454 sequencing approach. Comparisons between newly obtained and existing assemblies for C. hominivorax and H. irritans revealed no major discrepancies and verified the utility of 454 sequencing for dipteran mitochondrial genomes. We also report the complete mitochondrial sequences for two forensically important flies, P. regina and S. crassipalpis, which could be used to provide useful information to legal personnel. Comparative analyses revealed that dipterans follow similar codon usage and nucleotide biases that could be due to mutational and selection pressures. This study illustrates the utility of 454 sequencing to obtain complete mitochondrial genomes for dipterans without the aid of conventional molecular techniques such as PCR and cloning and validates this method of mtgenome sequencing in arthropods.

Differential peptidomics highlights adipokinetic hormone as key player in regulating digestion in anautogenous flesh fly, Sarcophaga crassipalpis

Females of anautogenous flesh flies, Sarcophaga crassipalpis, need a protein meal in order to produce their first batch of eggs. This protein meal elicits an increase in midgut proteolytic activity that is under neuropeptidergic regulation. Time series of decapitation and rescue experiments of liver fed flies evidenced the need of a peptide factor released by corpora cardiaca (CC) within 4h post protein feeding in order to assure complete protein digestion. Q-Exactive quantitative differential peptidomics analysis on CC of sugar fed flies and flies 5h post protein feeding respectively, showed a unique consistent decrease in the stored amount of adipokinetic hormone (AKH) ranging between 16% up to 63%. Injection of AKH into liver fed decapitated flies as well as sugar fed intact flies resulted in dose dependent enhanced midgut proteolytic activity up to the level of intact protein fed flies. This suggests a key role of AKH in food depended reproduction.

Host diapause status and host diets augmented with cryoprotectants enhance cold hardiness in the parasitoid Nasonia vitripennis

Boosting cold hardiness in parasitoids is a goal that is particularly attractive for increasing shelf life and shipment of biological control agents. In the experiments reported here we use the parasitoid Nasonia vitripennis as a model to evaluate manipulations that may be capable of enhancing the wasp’s cold tolerance. We altered the parasitoid’s cold tolerance by manipulating the wasp’s diapause status, the diapause status of the host fly (Sarcophaga crassipalpis), and the diet of the host. Larval diapause in N. vitripennis dramatically increased cold tolerance and the diapause status of the host also exerted a positive, although less dramatic, effect. Augmenting the host fly’s diet with supplements of putative cryoprotectants (alanine, proline and glycerol) enhanced cold tolerance in parasitoids that fed on the flies, thus indicating a tri-trophic effect on parasitoid cold tolerance. The most pronounced improvement in cold tolerance was noted in parasitoids fed on fly hosts that had received a diet augmented with proline. These results suggest mechanisms that could be exploited for enhancement of cold tolerance in parasitoids of commercial interest.

Extensive Reorganization of Behavior Accompanies Ontogeny of Aggression in Male Flesh Flies

Aggression, costly in both time and energy, is often expressed by male animals in defense of valuable resources such as food or potential mates. Here we present a new insect model system for the study of aggression, the male flesh fly Sarcophaga crassipalpis, and ask whether there is an ontogeny of aggression that coincides with reproductive maturity. After establishing that reproductive maturity occurs by day 3 of age (post-eclosion), we examined the behavior of socially isolated males from different age cohorts (days 1, 2, 3, 4, and 6) upon introduction, in a test arena, with another male of the same age. The results show a pronounced development of aggression with age. The change from relative indifference to heightened aggression involves a profound increase in the frequency of high-intensity aggressive behaviors between days 1 and 3. Also noteworthy is an abrupt increase in the number of statistically significant transitions involving these full-contact agonistic behaviors on day 2. This elevated activity is trimmed back somewhat by day 3 and appears to maintain a stable plateau thereafter. No convincing evidence was found for escalation of aggression nor the establishment of a dominance relationship over the duration of the encounters. Despite the fact that aggressive interactions are brief, lasting only a few seconds, a major reorganization in the relative proportions of four major non-aggressive behaviors (accounting for at least 96% of the total observation time for each age cohort) accompanies the switch from low to high aggression. A series of control experiments, with single flies in the test arenas, indicates that these changes occur in the absence of the performance of aggressive behaviors. This parallel ontogeny of aggressive and non-aggressive behaviors has implications for understanding how the entire behavioral repertoire may be organized and reorganized to accommodate the needs of the organism.

The Flesh Fly Sarcophaga (Liopygia) crassipalpis Macquart 1839 as an Invader of a Corpse in Calabria (Southern Italy)

The first aim of forensic entomology is to help investigators estimate the time of death. Its application has become widespread in many countries because the entomological evidence on corpses (especially Diptera and Coleoptera) can be used to estimate the minimum Post Mortem Interval (mPMI) at both indoor and outdoor crime scenes.

Early changes in the pupal transcriptome of the flesh fly Sarcophagha crassipalpis to parasitization by the ectoparasitic wasp, Nasonia vitripennis

We investigated changes in the pupal transcriptome of the flesh fly Sarcophaga crassipalpis, 3 and 25 h after parasitization by the ectoparasitoid wasp, Nasonia vitripennis. These time points are prior to hatching of the wasp eggs, thus the results document host responses to venom injection, rather than feeding by the wasp larvae. Only a single gene appeared to be differentially expressed 3 h after parasitization. However, by 25 h, 128 genes were differentially expressed and expression patterns of a subsample of these genes were verified using RT-qPCR. Among the responsive genes were clusters of genes that altered the fly's metabolism, development, induced immune responses, elicited detoxification responses, and promoted programmed cell death. Envenomation thus clearly alters the metabolic landscape and developmental fate of the fly host prior to subsequent penetration of the pupal cuticle by the wasp larva. Overall, this study provides new insights into the specific action of ectoparasitoid venoms.