Diptera Calliphoridae Research Articles

Toxicity and oviposition deterrence of essential oils of Clinopodium nubigenum and Lavandula angustifolia against the myiasis-inducing blowfly Lucilia sericata.

Cutaneous myiasis is a severe worldwide medical and veterinary issue. In this trial the essential oil (EO) of the Andean medicinal plant species Clinopodium nubigenum (Kunth) Kuntze was evaluated for its bioactivity against the myiasis-inducing blowfly Lucilia sericata (Meigen) (Diptera Calliphoridae) and compared with that of the well-known medicinal plant species Lavandula angustifolia Mill. The EOs were analysed and tested in laboratory for their oviposition deterrence and toxicity against L. sericata adults. The physiology of EO toxicity was evaluated by enzymatic inhibition tests. The antibacterial and antifungal properties of the EOs were tested as well. At 0.8 μL cm-2, both EOs completely deterred L. sericata oviposition up to 3 hours. After 24 h, the oviposition deterrence was still 82.7% for L. angustifolia and the 89.5% for C. nubigenum. The two EOs were also toxic to eggs and adults of L. sericata. By contact/fumigation, the EOs, the LC50 values against the eggs were 0.07 and 0.48 μL cm-2 while, by topical application on the adults, LD50 values were 0.278 and 0.393 μL per individual for C. nubigenum and L. angustifolia EOs, respectively. Inhibition of acetylcholine esterase of L. sericata by EOs (IC50 = 67.450 and 79.495 mg L-1 for C. nubigenum and L. angustifolia, respectively) suggested that the neural sites are targets of the EO toxicity. Finally, the observed antibacterial and antifungal properties of C. nubigenum and L. angustifolia EOs suggest that they could also help prevent secondary infections.

Experimental study of Lucilia sericata (Diptera Calliphoridae) larval development on rat cadavers: Effects of climate and chemical contamination

Household products such as bleach, gasoline or hydrochloric acid have been used to mask the presence of a cadaver or to prevent the colonization of insects. These types of chemicals affect insect development and alter the forensic entomology analysis. This study was designed to test the effects of six household products (bleach, mosquito repellent, perfume, caustic soda, insecticide and unleaded gasoline) on blowfly (Lucilia sericata, Diptera: Calliphoridae) larval development. Furthermore, the effects of climate (rain or dry conditions) on larval development were analyzed. For each replication, 100 first instars were placed on a rat cadaver on which one household product was spilled. We observed a decrease in the survival rates of the larvae but no significant effect on their development times or the adult size. The same trends were observed under rainy conditions. However, the rain altered the effects of some tested household products, especially gasoline. These results demonstrate for the first time the successful development of necrophagous larvae on chemically contaminated cadavers, and provide evidence for the range of possible effects to expect.

Cryopreservation of embryos of Lucilia sericata (Diptera: Calliphoridae).

Embryos of Lucilia (Phaenicia) sericata (Meigen) (Diptera Calliphoridae), the green blowfly, were successfully cryopreserved by vitrification in liquid nitrogen and stored for 8 yr. Embryos incubated at 19 degrees C for 17 h after oviposition were found to be the most appropriate stage to cryopreserve. Removal of the embryonic surface water was done using 2-propanol before the alkane treatment to permeabilize the embryo. Exposure to 2-propanol for > 10 s caused necrotic tissue damage in the embryos. Among the alkanes used, hexane was found to be a superior permeabilizing solvent compared with heptane or octane, with embryo hatching rates on par with the controls. Treatment with the vitrification solution for < 12 min was insufficient to vitrify the embryos. Treatment time in the solution beyond 15 min reduced embryo viability. However, the percentage of embryos vitrifying upon exposure to liquid nitrogen vapor remained constant after 12 min of treatment. Long-term storage was initiated in 2004, and the mean hatch percentage recorded then for the short-term cryopreserved embryos was 9.51%. When the long-term stored samples were retrieved in 2012, 8.47% of the embryos hatched, 66.36% larvae pupariated, and 36.96% of the pupae eclosed. Recent optimization of the technique has resulted in a hatch rate of 34.08 +/- 15.5%, of which 67.5% of the larvae pupariated and 72% of the pupae eclosed to normal flies.

Effect of Lunar Phases, Tides, and Wind Speed on the Abundance of Diptera Calliphoridae in a Mangrove Swamp

Abiotic factors, such as lunar phases and tides, have a significant effect on insect development. Reproduction and immature development are usually interlinked to these abiotic factors. The tide is at its highest levels at full moon or new moon, hindering the feeding of the immature or causing their drowning. The oviposition by adult females is also compromised on these days because much of the available food is submerged. Another important abiotic factor is the wind, which displaces odoriferous particles in the air. Wind speed and direction are important elements to indicate potential sources of food for insects. I report on the effects of lunar phases, tides, and wind speed on the Calliphoridae fauna in mangrove swamps. The different species collected were identified, and the predominant species in the area were quantified. A total of 1,710 flies were collected over a 1-year period. Six Calliphoridae flies, Chloroprocta idioidea (Robineau-Desvoidy), Chrysomya megacephala (Fabricius), Chrysomya albiceps (Wiedemann), Chrysomya putoria (Wiedemann), Cochliomyia macellaria (Fabricius), and Lucilia eximia (Wiedemann) were collected. Data indicated that lunar phases have a significant effect on the abundance of C. albiceps (r = 0.39, p < 0.01), and that the variation of the tides also affected the abundance of C. putoria (r = 0.40, p < 0.00), C. macellaria (r = 0.41, p < 0.00), and C. idioidea (r = 0.31, p < 0.04). The wind speed, however, did not affect these species.

Discontinuous foraging behavior of necrophagous Lucilia sericata (Meigen 1826) (Diptera Calliphoridae) larvae

Larvae of the necrophagous Blowfly Lucilia sericata (Diptera Calliphoridae) live on vertebrate cadavers. Although continuously feeding was previously assumed for this species, we hypothesized that larvae do not feed constantly. According to this hypothesis, their crop should not always be full, which should be reflected in crop surfaces. We dissected and measured the crops of larvae of the same age and bred in the same conditions. Crop surfaces of 117 larvae just removed from the food ranged from 0 to 16.6mm2 (mean=5.325±2.84mm2). The distribution of these crop surfaces indicates a continuous variation of satiation/feeding activity in the population. Starving experiments showed a quite long digestive process. After 90min of starving, the decrease in crop surfaces became obvious, but 150min were necessary to observe more than a half of the population with an empty crop (less than 2mm2). No more differences were observed after 150, 180 and 240min of starving. We finally used starved larvae to observe the kinetic of food absorption and the duration of the food-intake phase. Our results indicates that larvae can ingest faster than they digest. After 5min spent in the food, 70% of the larvae had a crop surface larger or equal to 8mm2. We observed for the first time an over-feeding of the larvae, with high crop surfaces overrepresented compared to larvae never starved (control).Together, these results indicate that larvae do not feed continuously, and regulate their foraging behavior. We propose that the foraging behavior of the larvae creates a permanent movement inside the larval masses. This turnover/scramble competition may be linked to the larval-mass effect, i.e. the local temperature increase observed in large necrophagous larvae aggregates.

Insect Fauna and Degradation Activity of Thanatophilus species on Carrion in Southern Italy (Coleoptera: Silphidae)

Necrophagous insects (Diptera, Coleoptera, Hymenoptera) can colonize the decomposing corps and everyone play an important ecological role in forensic investigations. The aim is to identify seasonal succession of major arthropod taxa of forensic importance in a rural area in southern Italy, during winter 2008. The principal fly invaders were Calliphora vicina Robineau-Desvoidy 1830, C vomitoria (L), Lucilia caesar (L), L sericata (Meigen 1826), Sarcophaga (Meigen 1826) spp, Musca domestica (L) and Muscina stabulans (Fallen 1817). The beetle species collected in winter belonged to Silphidae (Thanatophilus rugosus and T sinuatus), Dermestidae (Dermestes maculatus (De Geer 1774), Cleridae (Necrobia rufipes (De Geer 1775), and Histeridae (Margarinotus (Ptomister) brunneus Fabricius 1775 = cadaverinus). It is well known that the successional pattern of the carrion insects is quite unique and that Diptera Calliphoridae are usually the most important necrophagous colonizers but in particular environmental conditions, other invaders can replace them. This is a report on the carrion-frequenting insects in Calabria (southern Italy). A case is described in which maggots (Diptera: Calliphoridae) were not able to consume the pig bodies during winter months. It was observed that both Silphidae species, Thanatophilus rugosus (L) and T sinuatus (Fabricius 1775), were the major vector in the breakdown of the carcasses.

Effect of body length and temperature on the crawling speed of Protophormia terraenovae larvae (Robineau-Desvoidy) ( Diptera Calliphoridae)

This work investigates variation in the crawling speed of Protophormia terraenovae larvae (Robineau-Desvoidy) (Diptera Calliphoridae) as a function of body length and ambient temperature. A video-tracking system was used to follow the movement of larvae in an experimental arena, and to estimate their average crawling speed. Recordings were carried out at various temperatures using larvae of different developmental stages. As temperature increased, the larvae crawled at a faster speed. Furthermore, speed increased as a function of body length. We present a general allometric relationship to express the average crawling speed of larvae as a combined function of temperature and body length, expressed in the following equation: speed ( cm / min ) = 5.45 × log [ length ( mm ) ] + 0.66 × temperature ( ∘ C ) - 12.8 These results are particularly useful in forensic entomology for estimating the time that elapsed following the larva's departure from the corpse. This information can provide more accuracy for post-mortem interval estimations and a better comprehension of larvae behaviour and displacement.

Seed Production of Field- and Greenhouse-Grown Herbaceous Ornamental Plants: Flowering and Pollinator Effects

Seeds of herbaceous ornamental accessions conserved by the USDA National Plant Germplasm System (NPGS) are traditionally produced in summer field cages with honey bees (Apis mellifera) when pollinators are required. Efficient methods to produce high-quality seed in greenhouses may allow for year-round seed production. Flower quantities and effects of pollinators on number and weight of seed produced were studied in field cages and greenhouses at the Ornamental Plant Germplasm Center in 2003 in a randomized complete-block experiment. Honey bees, bumblebees (Bombus impatiens), or blue bottle flies (Diptera calliphoridae) were used as pollinators. Field cages and greenhouse compartments with no pollinator were controls. Cultivars used were Antirrhinum majus `Gum Drop', Coreopsis tinctoria `Plains Bicolor', Dianthus chinensis `Carnation' (NPGS accession NSL 15527), Rudbeckia hirta `Indian Summer', and Tagetes patula `Jaguar'. Seeds were harvested, cleaned, weighed, and 100-seed weights calculated. On average Antirrhinum, Dianthus, Rudbeckia and Tagetes produced more flowers in greenhouses, Coreopsis produced more flowers in the field. Coreopsis and Rudbeckia produced more seed per flower on average with field pollination by honey bees, Antirrhinum and Dianthus produced most with bumblebees in the field, and Tagetes produced most with blue bottle flies in the greenhouse. Each genus had similar 100-seed weights on average in all treatments. Results show pollinators other than honey bees are useful for herbaceous ornamental seed production and that seed production in greenhouses may be an alternative method for seed production of herbaceous ornamentals.

A Comparison of the Development Rate of Protophormia Terraenovae (Robineau-Desvoidy) Raised under Constant and Fluctuating Temperature Regimes

ABSTRACTExperiments were conducted to compare development rates of the blow fly species Protophormia terraenovae (Robineau-Desvoidy) (Diptera Calliphoridae) at constant and fluctuating temperatures. Protophormia terraenovae were raised from egg to adult outdoors under naturally fluctuating temperatures. Minimum times to reach five stages of development were noted (1st, 2nd, and 3rd instar, pupae, and adult). A data logger recorded temperature every 30 minutes. Once the adult stage was reached, the overall mean temperature during the experiment was calculated (19.7°C ± 0.1 °C). Next, P. terraenovae were raised from egg to adult within an incubator in the laboratory at a constant temperature of 20°C ± 0.1°C. Accumulated degree hours (ADH) were calculated for both experiments, at all five stages of development. Protophormia terraenovae raised under a constant temperature regime reached 1st, 2nd, and 3rd instar stages significantly faster than those raised under a fluctuating temperature regime (P = 0.016, t = 3.99, df = 4; P = 0.007, t = 6.79, df = 3; P = 0.043, t = 2.92, df = 4, respectively). At the pupae and adult stages, there was no difference in the development rate between the two temperature regimes (P < 0.05).