Larval Medium Research Articles

Rendimiento de larvas de moscas en varias cosechas con tres proporciones de salvado de trigo y gallinaza

The aim of the research was to compare the yields of house fly larvae using different proportions of wheat bran and hens feces as larval development medium, in a randomized block experimental design with five replications in propylene containers with 3 cm of depth of substrates: A-100 % wheat bran; B- 50% wheat bran and 50% hens feces; C- 100% hens feces. Measurements of the temperature of the substrates, as well as the temperature and relative humidity of the place where the flies were developing were made every 24 hours. The larval yield per m2 and kg of substrate, (including the water used to moisten the larval media) were also registered. The temperature in the substrates ranged between 22.88 oC and 36.08 oC, always above the ambient temperature in the fly house, and relative humidity between 44 and 68%. Was used 32.91, 30.29 and 32.19 L of water per square meter for treatments A, B and C, respectively. The highest larval yield was obtained in the first harvest after six days for treatment B with 2290.59 g m2-1 y 112.07 g kg2-1. The transformation of the crude protein of the substrates by the fly larvae was between 28.0 and 37.0%. No presence of pathogenic agents (Salmonella spp., Escherichia coli, and Coccidia) was observed in the treatments, nor in the harvested larvae.

Probiotic consortium modulating the gut microbiota composition and function of sterile Mediterranean fruit flies

The sterile insect technique (SIT) remains a successful approach in managing pest insects. However, the long-term mass rearing and sterilizing radiation associated with SIT have been observed to induce physiological and ecological fitness decline in target insects. This decline may be attributed to various factors, including commensal microbiota dysbiosis, selection procedures, loss of heterozygosity, and other complex interactions.. There is evidence that the bacterial symbiont of insects may play critical roles in digestion, development, reproduction, and behavior. Probiotics are an increasingly common approach for restoring the intestinal microbiota structure and fitness parameters of sterile insects, particularly in the Vienna 8 genetic sexing strain (V8-GSS) of the Mediterranean fruit fly (medfly), Ceratitis capitata. Here, we explore the influence of the previously isolated bacterial strain, Lactococcus lactis, Enterobacter sp., and Klebsiella oxytoca, administration as probiotic consortia (LEK-PC) to the larvae and/or adult diet over the course of 20 rearing generations on fitness parameters. The experiment was carried out in four colonies: a control colony (C), one to which probiotics were not added, one to which probiotics were added to the larval medium (L+), one to which probiotics were added to the adult medium (A+), and one to which probiotics were added to both the larval and adult mediums (AL+). Emergence, flight ability, survival under stress conditions, and mating competitiveness, were all significantly improved by the LEK-PC treatment independently of the administration stage. The intestinal microbiota structure of various medfly V8-GSS colonies also underwent a significant shift, despite the fact that the core microbial community was unaffected by the LEK-PC administration stage, according to 16S metagenomics sequencing. Comparison of the metabolic function prediction and associated carbohydrate enzymes among colonies treated with “LEK-PC” showed an enrichment of metabolic functions related to carbohydrates, amino acids, cofactors, and vitamins metabolism, as well as, glycoside hydrolase enzymes in the AL+ colony compared to the control. This study enriches the knowledge regarding the benefits of probiotic treatment to modulate and restore the intestinal microbiota of C. capitata sterile males for a better effectiveness of the SIT.

Lethal and Sublethal Effects of Cyromazine on the Biology of Musca domestica Based on the Age-Stage, Two-Sex Life Table Theory.

Cyromazine is a triazine insect growth regulator insecticide that is recommended for control of Musca domestica worldwide. Cyromazine is highly effective in causing mortality of M. domestica; however, some aspects of its lethal and sublethal effects on the biology of M. domestica are still unknown. The present study explored lethal and sublethal effects on several biological traits and population parameters of M. domestica. Concentration-response bioassays of cyromazine against third-instar larvae of M. domestica exhibited sublethal and lethal effects from concentrations of 0.03 (LC10), 0.06 (LC25), and 0.14 (LC50) μg/g of a larval medium. Exposure of M. domestica larvae to these concentrations resulted in reduced fecundity, survival, longevity and oviposition period, and delayed development of immature stages (i.e., egg hatch time and larval and pupal durations) in the upcoming generation of M. domestica. The values of population parameters such as intrinsic rate of increase, finite rate of increase, net reproductive rate, age-specific survival rate and fecundity, and age-stage life expectancy and reproductive value, analyzed using the age-stage and two-sex life table theory, were significantly reduced in a concentration-dependent manner in comparison with the control group. In conclusion, the study highlights the significant effects of cyromazine on the biology of M. domestica that could help suppress its population in cases of severe infestations.

Bio-larvicidal Potential of Betel Leaves (Piper betle L) Ethanolic Extract in Addition of PEG 400 Diluent on Aedes aegypti Larvae

Dengue hemorrhagic fever (DHF) is a kind of vector transmitted disease, by Aedes aegypti. It is one of major public health problem around the world, including Indonesia, because it may lead to epidemics and death in a short time. The use of plant extracts as bio-larvicidal is thought to be a promising solution, and one of them is the betel leaves (Piper betle L). The addition of polyethylene glycol (PEG) as a diluent is thought may increase the dispersity of plant extract in the water which is larval medium of growth. Objectives: To determine the bio-larvicidal potential of 95% ethanolic extract of betel leaves (EEBL) in addition of PEG 400 diluent on the Aedes aegypti larval mortality. Material and Method: Betel leaves were extracted by maceration using 95% of ethanol. There are two kinds of EEBL concentration used, 0.2% dan 0.4%. PEG 400 was also added as diluent. The samples in this study were Aedes aegypti larvae at instar III-IV, with a total of 400 larvae. Evaluation was performed at 6, 12, 18, and 24 hours. The data obtained was then analyzed by Kruskall Wallis test and post-hoc Mann Whitney test. Result: In all of treatment groups, larval mortality was reached 100% at 24 hours. From the Kruskall Wallis test, p-value obtained was <0.05. From post-hoc Mann Whitney test, the p-value obtained in the comparation between treatment groups and positive control group was >0.05, and the p-value obtained in the comparation between treatment groups and negative control group was <0.05. Conclusion: EEBL in addition of PEG 400 diluent is potential as bio-larvicidal on Aedes aegypti larvae. It is also known that EEBL at concentration of 0.2% and 0.4% in addition of PEG 400 are as effective as temephos as larvicides on Aedes aegypti larvae.

Feeding on the Fruit Waste Orange Bagasse Modifies Immature Protein Content, Body Weight, Scent Bouquet Composition, and Copula Duration in Males of a Tephritid Frugivorous Fly.

Anastrepha ludens is a polyphagous frugivorous tephritid that infests citrus and mango. Here, we report the establishment of a laboratory colony of A. ludens reared on a larval medium that is a waste for the citrus industry, specifically, orange (Citrus × sinensis) fruit bagasse. After 24 generations of rearing on a nutritionally poor orange bagasse diet, pupae weighed 41.1% less than pupae from a colony reared on a nutritionally rich artificial diet. Larvae from the orange bagasse diet had 6.94% less protein content than larvae from the artificial diet, although their pupation rate was similar. Males from the orange bagasse diet produced a scent bouquet with 21 chemical compounds and were sexually competitive, but they had significantly shorter copulations when compared to males from the artificial diet and from the wild host, Casimiroa edulis, which had relatively simple scent bouquets. The chemical complexity in the odors of males from the orange bagasse diet might initially have attracted females to novel scent combinations, but, once in the copula, they may have been able to sense negative characteristics in males, leading them to terminate copulations soon after they began. We conclude that A. ludens can adjust morphological, life history, nutritional, and chemical traits when adapted to a larval environment consisting of fruit bagasse.

HOUSE FLY LARVAE HARVEST YIELD USING THREE DIFFERENT RATIONS OF WHEAT BRAND AND PIG MANURE AS LARVAL DEVELOPMENT MEDIA

The aim of the research was to compare the yields of house fly larvae using different proportions of wheat bran and swine feces as larval development medium, in a randomized block experimental design with five replications: A-100 % wheat bran; B- 50% wheat bran and 50% swine feces; C- 100% swine feces. Measurements of the temperature of the substrates, as well as the temperature and relative humidity of the place where the flies were developing were made every 24 hours. The larval yield per m2 and kg of substrate, (including the water used to moisten the larval media) were also registered. The wheat bran substrate presented the highest temperature values (36.78 oC), with values above the ambient temperature. The relative humidity varied between 44 and 68%. The amount of water used per square meter was 28.75; 27.72 and 28.87 L for A, B and C treatments, respectively. The highest yield for all substrates was obtained during the first harvest after six days with the highest values for treatment B with 2869.11 g m²-1 and 181.16 g kg-1, respectively. The transformation of the crude protein of the substrates by the fly larvae was between 28.0 and 41.0%, with the highest value for treatment B with 2869,11 g m² -1 and 181,16 g kg2-1 . No presence of pathogenic agents was observed in the harvested larvae.

Carbon quantum dots nanoparticles deteriorate the antioxidant cellular status and stimulate DNA damage in tissues of the house fly Musca domestica larvae

ABSTRACT The house fly Musca domestica, the medical pest is a vector of many pathogenic organisms, that had showed insecticide resistance against popular active chemical ingredients, which represents a global issue that hinders successful insect control. This study aimed at investigating the effect of carbon quantum dot nanoparticles (CQDNPs) on some biochemical and cellular parameters in cells of the house fly larvae. In this study, serial concentrations of CQDNPs were tested against the house fly larvae. For each concentration, four replicates of third instar larvae of Musca domestica (twenty-five larvae for each one) were involved. Control groups were regarded by adding plain dechlorinated water to the larval medium. The LC50of CQDNPs on the house fly larvae was determined after 24 hours of incubation. Levels of total protein and albumin were inspected along with the levels of antioxidant enzymes regarding superoxide dismutase, catalase and glutathione reductase and enzymes of oxidative stress regarding lipid peroxidase and nitric oxide. Moreover, comet assay was performed in tissues of the treated larvae. Results revealed that the LC50 (3.19 mg/ml) showed significant decrease in the total protein and albumin levels. Further, significant decrease in the activities of the antioxidant enzymes was implied along with significant increase of cellular damage enzymes in tissues of the treated larvae. Eventually, DNA damage was detected implying the larvicidal potency of carbon quantum dots against the house fly larvae. To conclude, CQDNPs exhibit insecticidal potency against the house fly larvae regarding cellular and molecular aspects.

Effect of Larval Diets on House Fly (Diptera: Muscidae) Production and Host Suitability for a Pupal House Fly Parasitoid (Spalangia gemina) (Hymenoptera: Pteromalidae).

A larval medium for house fly (Musca domestica L.) suitable for house fly parasitoid production was developed from locally available and inexpensive food ingredients. Biological parameters and life table parameters were estimated for house flies treated with five different diets. It was found that percentage survival of 1st-3rd instar larvae of house fly, percentage of pupation, percentage of hatching adults, growth index, and life table parameters (net reproductive rate [R0] the cohort generation time [T], intrinsic rate of increase [r], and finite rate of increase [λ]) were significantly highest on larvae produced on diet 5 (composed of rice barn and chicken feed). Diet composition and performance of house fly larvae in larval medium are discussed, based on the results. The results of Spalangia gemina Bouček (Hymenoptera, Pteromalidae) parasitization on house fly pupae revealed that the number of total parasitized pupa and number of parasitoids hatched from pupa reared with diet 5 (rice bran and chicken feed) were greater than with diet 1 (rice bran, powdered milk, dry yeast, fish meal, soybean meal, and chicken feed). Additionally, S. gemina offspring from diet 5 treatment had a higher proportion of females. Our results indicated that pupal size resulting from larval diet was an important factor for parasitization.

Age-stage two-sex life table analysis of Eristalinus aeneus (Diptera, Syrphidae) reared with two different larval media.

Eristalinus aeneus (Scopoli, 1763) is a suitable candidate for artificial rearing due to its pollination efficiency and subcosmopolitan distribution. However, the high mortality found at the larval stage of this species needs to be overcome. In this research, two different larval media were used to study the life cycle of E. aeneus: brewery spent grain (BSG) from a local craft-beer factory and soaked oat grains (SOG). The age-stage, two-sex life table method was used to analyze the results, which were compared using the paired bootstrap test. The greatest mortality was found at the larval stage with both media. Individuals fed on SOG presented a shorter preadult developmental time (22.05 days) than those reared with BSG (26.97 days). This fact had a direct impact on the total preoviposition period, it being shorter with SOG (34.36 days) than BSG (38.29 days), although the second provided a larger total number of eggs (19,242 eggs) and a faster adult maturation (10.67 days). The population parameters indicated that both populations will display a positive growth under the studied conditions, being the mean generation time (T) significantly shorter when using SOG (38.71 days) than BSG (45.95 days). Despite the preadult results pointing to SOG being a more efficient medium, the promising fecundity values provided by BSG, as well as it's lower cost and ecological benefits, suggest that this second medium could be improved and used as an alternative to SOG in the near future.

Evolution of the mineral concentration and bioaccumulation of the black soldier fly,Hermetia illucens, feeding on two different larval media

Intensive black soldier fly (BSF)Hermetia illucens (Diptera: Stratiomyidae) rearing has a great importance for the feed industry. The objective of the present work was to perform a systematic study about the effect of the feeding media on the concentration and bioaccumulation factor (BAF) of Ca, K, Mg, Na, Cr, Cu, Fe, Mn, Ni and Zn in BSF fractions. Therefore, the evolution of the concentration of these elements has been studied along the stages of the BSF life cycle (larva, pupa and adult) as well as during its growth (exuviae) and metamorphosis (empty puparia). Two diets consisting of beer bagasse and commercial hen feed moistened with water have been chosen. An inductively coupled plasma optical emission spectrometer has been used to perform the elemental analyses. The obtained results demonstrated that the behaviour was generally, similar for all the elements studied, i.e. an accumulation in exuviae and puparia followed by their further elimination. Moreover, no significant differences in the results as a function of the feeding media have been found. This may be attributed to the fact that the chosen diets were equally favourable for this insect’s growth. The obtained concentrations have been expressed on a dry as well as a wet sample basis. BAF results also suggested that exuviae and puparia could be used as supplements or as bioactive compounds.

Magnetite nanoparticles as a promising non contaminant method to control populations of fruit flies (DIPTERA: Tephritidae)

“True fruit flies” belong to the family Tephritidae. Among them, the Mediterranean fruit fly (Medfly) Ceratitis capitata (Wiedemann) is the most economically important agricultural pest insect in the world. Anastrepha fraterculus (Wiedemann) is the South American fruit fly and represents a serious problem for countries of America. Both species share hosts fruits. Traditionally the control of fruit flies bases on the use of pesticides with chemical components. Due to their massive use to crops, pesticides are associated to environmental pollution and toxicity in mammals. An emerging technology is the use of nanomaterials with pesticidal activity or for the delivery of pesticides. The present paper reports: a) the synthesis of iron oxide (magnetite) nanoparticles and b) the effects of Fe3O4 nanoparticles during the development of the tephritid flies C. capitata and A. fraterculus. We sampled guava fruits to recover immature stages of fruit flies. Magnetite nanoparticles Fe3O4 were synthesized by co-precipitation of Fe (III) and Fe (II). We suspended doses of 100, 200 and 400 µg/ml of magnetite nanoparticles in water and we added the suspensions to larval medium. NPs are spherical with a medium diameter of 11 ± 2 nm and unimodal size distribution. During larval-pupal development, we checked out difficulties in the capacity to complete the natural biological cycle. Only 40% of larvae feeded in medium 400 μg / ml Fe3O4 NPs were able to continue their life cycle, in contrast to 92% of the control. Application of iron oxide (or magnetite) nanoparticles to larval food resulted in larvae toxicity expressed as dose-dependent lethality

Larval Conditioning and Aging of Sand Fly Rearing Medium Affect Oviposition Site Selection in Phlebotomus papatasi (Diptera: Psychodidae) Sand Flies.

Sand fly larvae develop in sheltered humid habitats containing decaying organic matter on which they feed. Previously, we showed that gravid females of Phlebotomus papatasi Scopoli (Diptera: Psychodidae) are attracted to and stimulated to lay eggs on larval rearing medium containing larvae. That study, however, did not control for the possible effect of medium aging. Our goal in this study was to evaluate the effect of larval substrate conditioning on attraction and oviposition responses of Ph. papatasi sand flies while controlling for the effect of substrate aging. Initially, we confirmed that the pretreatment fresh larval food sources (to be used as larval conditioned and unconditioned media) did not differ with respect to their effect on attraction and oviposition responses. The larval conditioned medium was produced by rearing larvae to the second/third-instar stage over 3 wk using the same larval food source. To produce larval unconditioned medium, the same amount of fresh larval food was added to a control rearing cup that did not contain larvae but was aged under identical time and conditions. Two-choice bioassays were conducted to evaluate gravid female's attraction and oviposition response to larval conditioned and unconditioned media. We found that gravid females were significantly attracted (P < 0.05) to larval conditioned medium when compared with unconditioned medium under the same amount of time and conditions. However, no such difference was found with respect to oviposition response. Both attraction and oviposition responses were significantly increased for larval conditioned and unconditioned media in comparison to the initial fresh larval food source.

Exposure to copper during larval development has intra- and trans-generational influence on fitness in later life

Anthropogenic pollution has a disadvantageous influence on various life-history traits. Although direct effects are well known, potential fitness-related trans-generational costs are less studied. Previously, empirical findings have demonstrated that environmental conditions faced by the parental generation have an effect on the traits expressed by their offspring. Here, to study this conjecture larvae of the common fruit fly (Drosophila melanogaster) were either exposed to a sub-lethal concentration of copper or reared on uncontaminated larval medium. Adult flies were kept under uncontaminated conditions. For the next generation, individuals were mated with their own group and their offspring were either exposed to copper or fed with uncontaminated larval medium. We found that in the parental generation copper exposure reduced fecundity compared with uncontaminated controls. In the progeny, females suffered impaired fecundity only if their larval condition differed from the conditions experienced by their parents. If the progeny was raised under similar conditions than the parental generation, no effect on fecundity was discovered, suggesting acclimatization to the prevailing conditions after short-time copper exposure (two generations). Our results demonstrate that exposure to an environmental stressor like heavy metals causes intra-and trans-generational fitness costs. Further, individuals may be able to acclimatize in prevailing contaminated conditions, but this might in turn debase fitness under uncontaminated conditions. Our findings are consistent with the prediction of the adaptive parental effects hypothesis which states that parents may produce offspring that are more successful under conditions faced by their parents.

Sand Fly Colony Crash Tentatively Attributed to Nematode Infestation.

Maintenance of laboratory colonies of insects and other arthropod pests offers significant research advantages. The availability, age, sex, housing conditions, nutrition, and relative uniformity over time of biological material for research facilitate comparison of results between experiments that would otherwise be difficult or impossible. A laboratory research colony of Phlebotomus papatasi (Scopoli), old world sand flies, was maintained with high-colony productivity for a number of years, but within a relatively short (4-6 mo) time period, colony productivity declined from over 10,000 flies per week to less than 100 per week. Mites and nematodes were both visible in the larval medium; however, the mites had been present throughout high productivity periods; therefore, it seemed reasonable to investigate the nematodes. PCR amplification of 18S rRNA yielded a clean cDNA sequence identified by BLAST search as Procephalobus sp. 1 WB-2008 (Rhabditida: Panagrolaimidae) small subunit ribosomal RNA gene, GenBank EU543179.1, with 475/477 nucleotide identities. Nematode samples were collected and identified as Tricephalobus steineri, (Andrássy, 1952) Rühm, 1956 (Rhabditida: Panagrolaimidae) based on morphological characteristics of the esophagus and the male copulatory apparatus. Mites (Tyrophagus putrescentiae [Acariformes: Acaridae]) may have played an additional predatory role in the loss of sand fly colony productivity. We hypothesized that the origin of the nematode infestation was rabbit dung from a local rabbitry used in preparation of the larval medium. Colony productivity was fully restored within 3 mo (two sand fly generational periods) by replacement of the rabbit dung from a clean source for use to prepare sand fly larval medium.

Evaluation of Larval Medium in the Controlled Current Toxicity Test.

The Controlled Current Toxicity Test (CCTT) is a protocol used by the University of Georgia Black Fly Rearing and Bioassay Laboratory to evaluate the efficacy of larvicides based on Bacillus thuringiensis subsp. israelensis (Bti) against Simulium vittatum larvae. A standard CCTT provides a larval medium with suspended organic nutrients, a sustained current, and a clean surface for black fly larval attachment in each exposure vessel. In an effort to streamline the CCTT and eliminate a potential source of variability, 3 types of larval medium were evaluated: deionized water, distilled water, and moderately hard water, which were compared to the currently used protocol. A statistical significance in mean lethal concentration (LC50) rates was observed between the CCTT (deionized water with suspended organic nutrients) medium and the other 3 experimental media. The presence of suspended organic nutrients in the CCTT significantly improved the efficacy of the Bti-based larvicide. The interaction of the suspended organic nutrient particles and the Bti-based particles in the larvicide appears to produce a mixture that is more efficiently captured and ingested by the black fly larvae than the larvicide formulation particles alone.

Onchocerca volvulus is not detected in the cerebrospinal fluid of persons with onchocerciasis-associated epilepsy

ObjectivesEpidemiological evidence links onchocerciasis with the development of epilepsy. The aim of this study was to detect Onchocerca volvulus microfilariae or its bacterial endosymbiont, Wolbachia, in the cerebrospinal fluid (CSF) of persons with onchocerciasis-associated epilepsy (OAE). MethodsThirteen persons with OAE and O. volvulus skin snip densities of >80 microfilariae were recruited in Maridi County (South Sudan) and their CSF obtained. Cytospin centrifuged preparations of CSF were examined by light microscopy for the presence of O. volvulus microfilariae. DNA was extracted from CSF to detect O. volvulus (O–150 repeat) by quantitative real-time PCR, and Wolbachia (FtsZ gene) by standard PCR. To further investigate whether CSF from onchocerciasis-infected participants could induce seizures, 3- and 7-day old zebrafish larvae were injected with the CSF intracardially and intraperitoneally, respectively. For other zebrafish larvae, CSF was added directly to the larval medium. ResultsNo microfilariae, parasite DNA, or Wolbachia DNA were detected in any of the CSF samples by light microscopy or PCR. All zebrafish survived the procedures and none developed seizures. ConclusionsThe absence of O. volvulus in the CSF suggests that OAE is likely not caused by direct parasite invasion into the central nervous system, but by another phenomenon triggered by O. volvulus infection.

Response of two parasitoid species (Hymenoptera: Braconidae, Figitidae) to tephritid host and host food substrate cues

AbstractThe Neotropical‐native figitid Aganaspis pelleranoi (Brèthes) and the Asian braconid Diachasmimorpha longicaudata (Ashmead) are two parasitoids of Tephritidae fruit flies with long and recent, respectively, evolutionary histories in the Neotropics. Both species experienced a recent range of overlap. In Argentina, A. pelleranoi is a potential species in biological control programs against the pestiferous tephritid species, Anastrepha fraterculus (Wiedemann) and Ceratitis capitata (Wiedemann), whereas D. longicaudata is already used in open‐field releases against Medfly in central‐western Argentina. To characterize the host‐foraging strategies of A. pelleranoi and D. longicaudata, olfactometer experiments were conducted comparing responses to C. capitata and A. fraterculus larvae, in two kinds of food substrate: fruit and artificial larval medium. To control the possible influence of host larvae used for parasitoid rearing on olfactory response, two strains of both parasitoid species, reared on both tephrtid species, were studied. Volatiles directly emanating either from A. fraterculus or C. capitata larvae may be detected by both A. pelleranoi and D. longicaudata, although chemical stimuli originating from the combination of host larvae and the habitat of the host were preferred. However, olfactory cues associated with host larvae probably play a relevant role in host searching behaviour of A. pelleranoi, whereas for D. longicaudata, the host‐habitat olfactory stimuli would be highly essential in short‐range host location. The strain of the parasitoids did not affect host search ability on the two tephritid species evaluated. These evidences are relevant for mass production of both parasitoids and their impact following open‐field augmentative releases.

Larval Diet Affects Male Pheromone Blend in a Laboratory Strain of theMedfly, Ceratitis capitata (Diptera: Tephritidae).

The Mediterranean fruit fly (medfly) Ceratitis capitata is a polyphagous pest of fruits and crops with a worldwide distribution. Its ability to use different larval hosts may have multiple effects, including impacts on adult reproductive biology. The male sex pheromone, which plays a key role in attracting both other males to lekking arenas and females for mating, is a mixture of chemical compounds including esters, acids, alkanes and terpenes known to differ between laboratory strains and wild-type populations. The relationship between larval diet and adult pheromone composition remains unexplored. Here, we investigated the effect of larval diet, including laboratory media and fresh fruits, on the composition of the male pheromone mixture. Using HeadspaceSolid Phase Microextraction we collected the pheromone emitted by males reared as larvae on different substrates and found both qualitative and quantitative differences. A number of alkanes appeared to be typical of the pheromone of males reared on wheat bran-based larval medium, and these may be cuticular hydrocarbons involved in chemical communication. We also detected differences in pheromone composition related to adult male age, suggesting that variations in hormonal levels and/or adult diet could also play a role in determining the chemical profile emitted. Our findings highlight the plasticity of dietary responses of C. capitata, which may be important in determining the interactions of this pest with the environment and with conspecifics. These results also have appliedrelevance to increase the mating competitiveness of mass-reared C. capitata used in Sterile Insect Technique programs.

Growth Rate Differences of Chrysomya sp. Larvae on Rattus novergicus Wistar Strain Corpse Exposed and Unexposed to Ephedrine Toxic Dose

Post Mortem Interval (PMI) is used as a parameter to define the onset, cause, manner, and time of death to help maintenance of law and identify crime victims by the age of the larvae found. Larval growth is influenced by the temperature, humidity, and contaminant (drug or toxic). This experiment used two media of dead rats (200 grams), one given ephedrine of LD 50 = 266 mg/kg and the other without ephedrine. Both were put in 2 cages each containing 50 Chrysomya sp. Ten larvae were randomly taken every day for 14 days to be measured their length, weight, and duration of growth. The 3 rd larvae stage in the media with ephedrine had weight gain on 5th – 6 th day morning, while larvae in media without ephedrine had static weight gain on 5 th day morning - afternoon and weight decrement on 6 – 7 th day morning. Larva’s peak ratio of length/weight in the media with ephedrine was higher than that of larvae in the media without ephedrine. Larvae on media with ephedrine grew faster in 1 st , 2 nd , 3 rd larvae stage, and pupal stage compared to larvae without ephedrine. Therefore, this study indicates that ephedrine can accelerate the growth rate of Chrysomya sp. larvae.

Physical and Physiological Factors Influence Behavioral Responses of Cochliomyia macellaria (Diptera: Calliphoridae) to Synthetic Attractants.

Volatile chemicals from waste artificial larval media as well as from bovine blood inoculated with bacteria isolated from screwworm-infested wounds attract gravid females of Cochliomyia hominivorax Coquerel and Cochliomyia macellaria (F.). Chemicals identified from volatiles are dimethyl disulfide, dimethyl trisulfide, phenol, p-cresol, and indole; a blend of these attracted females to oviposit. Present studies investigated the effectiveness of these compounds, either in a blend or individually as potential oviposition attractants. Tests were conducted to determine the effects of gender, ovarian age, and the color and type of substrates on attraction response and oviposition of C. macellaria adults. Results showed that substrates treated with dimethyl trisulfide (DMTS) alone or the five-compound blend alone attracted significantly more gravid females than other chemicals. Black substrates treated with DMTS attracted more gravid flies than did the yellow substrates. Yellow substrates treated with indole attracted more males and nongravid females. In oviposition tests, females deposited significantly more eggs on meat-based substrates than those without meat. These findings suggest that several factors have to be considered for developing an effective oviposition attractant that should include effectiveness of individual chemicals used, the ratio of the chemicals in a blend, and their concentrations. Also, an effective trap design will need to consider using suitable color which will selectively attract gravid females.