Chemical‐Mediated Predator Avoidance in the European House Cricket (Acheta domesticus) is Modulated by Predator Diet

Chemical information often mediates interactions between predators and prey, and threat‐sensitivity theory includes predictions that prey species should respond to chemical signatures of predators in a manner that is commensurate with the level of the assessed threat. Using the European house cricket (Acheta domesticus), we explored the influence of diet‐derived cues from the centipede Scolopocryptops sexspinosus on anti‐predator behavior in three laboratory experiments. In experiment 1, we compared the amount of time that adult female crickets spent on untreated filter paper and filter paper exposed to centipedes fed either the larvae of Hermetia illucens (black soldier fly), crickets, or a mixture of fly larvae and crickets. We discovered that crickets spent significantly less time on filter paper exposed to centipedes fed crickets only or a mixture of crickets and fly larvae compared with blank filter paper or filter paper exposed to centipedes fed fly larvae only. In our second experiment, we compared the amount of time that crickets spent on blank filter paper and filter paper exposed to adult female conspecifics to rule out the possibility that crickets simply avoid all filter paper exposed to metabolic by‐products, and crickets exhibited no discrimination. In our third experiment, we tested the potential effects of diet order on anti‐predatory behaviors. Specifically, we compared the amount of time that adult female crickets spent on filter paper exposed to centipedes fed fly larvae followed by crickets and filter paper exposed to centipedes fed crickets followed by fly larvae. We discovered no diet sequence effect. Our study demonstrates that European house crickets are sensitive to the chemical cues of their centipede predators, but only when centipedes have fed upon crickets.     

Susceptibility of black soldier fly (Diptera: Stratiomyidae) larvae and adults to four insecticides

Dosage-mortality regressions were determined for black soldier fly, Hermetia illucens (L.), larvae fed cyromazine or pyriproxifen treated media. Cyromazine LC50 for larvae dying before becoming prepupae ranged from 0.25 to 0.28 ppm with dosage-mortality regression slopes between 5.79 and 12.04. Cyromazine LC50s for larvae dying before emergence ranged from 0.13 to 0.19 ppm with dosage-mortality regression slopes between 3.94 and 7.69. Pyriproxifen dosage-mortality regressions were not generated for larvae failing to become prepupae since <32% mortality was recorded at the highest concentration of 1,857 ppm. LC50s for larvae failing to become adults ranged from 0.10 to 0.12 ppm with dosage mortality-regression slopes between 1.67 and 2.32. Lambda-cyhalothrin and permethrin dosage-mortality regressions were determined for wild adult black soldier flies and house flies, Musca domestica L., and for susceptible house flies. Our results indicate that the wild house fly, unlike the black soldier fly, population was highly resistant to each of these pyrethroids. Regression slopes for black soldier flies exposed to lambda-cyhalothrin were twice as steep as those determined for the wild house fly strain. Accordingly, LC50s for the black soldier fly and susceptible house fly were 10- to 30-fold lower than those determined for wild house flies. The differential sensitivity between wild black soldier flies and house flies might be due to behavioral differences. Adult house flies usually remain in animal facilities with the possibility of every adult receiving pesticide exposure, while black soldier fly adults are typically present only during emergence and oviposition thereby limiting their exposure.     

Biochemical characterization of digestive enzymes in the black soldier fly,Hermetia illucens (Diptera: Stratiomyidae)

The black soldier fly, Hermetia illucens, is beneficial because its larvae feed on organic materials derived from plants, animals and humans and promote the recycling of food waste and organic materials. We investigated the biochemical properties of digestive enzymes released from the salivary gland and gut of the black soldier fly. Because the gut extracts of the black soldier fly larvae had high amylase, lipase and protease activities, we suggested that the black soldier fly might belong to the polyphagous insect group. In addition, a strong trypsin-like protease activity was observed in the gut extracts of the black soldier fly larvae. Higher activities of leucine arylamidase, α-galactosidase, β-galactosidase, α-mannosidase and α-fucosidase were observed from the gut extracts of the black soldier fly larvae compared with those of house fly larvae. These findings may explain previous reports that the black soldier fly larvae can digest food wastes and organic materials more efficiently than any other known species of fly.     

Using black soldier fly larvae for processing organic leachates

A large number of biodegradable byproducts including alcohols, soluble saccharides, volatile organic acids, and amines accumulate in the liquid fraction (leachate) produced as vegetal and food scrap waste decomposes. Untreated leachate, because it is rich in nutrients and organic byproducts, has a high chemical oxygen demand and is normally cleared of soluble organic byproducts by mineralization before its discharge into waterways. Mineralizing leachates using chemical and microbial biotechnologies is, however, a lengthy and costly process. We report here that the larvae of the black soldier fly Hermetia illucens (L.) (Diptera: Stratiomyidae), an insect rich in protein and lipids, and having significant commercial value, while feeding and growing off of compost leachate, lowers its chemical oxygen demand relative to that of leachate unexposed to larvae, neutralizes its acidity, and clears it of volatile organic acids, amines, and alcohols. These observations demonstrate that black soldier fly larvae could be used to help offset the cost and clean up of organic solutes in leachate waste streams while recycling carbon, nitrogen, and phosphate into usable and commercially valuable biomass.     

Development of black soldier fly (Diptera: Stratiomyidae) larvae fed dairy manure

Black soldier flies, Hermetia illucens L., are a common colonizer of animal wastes. However, all published development data for this species are from studies using artificial diets. This study represents the first examining black soldier fly development on animal wastes. Additionally, this study examined the ability of black soldier fly larvae to reduce dry matter and associated nutrients in manure. Black soldier fly larvae were fed four rates of dairy manure to determine their effects on larval and adult life history traits. Feed rate affected larval and adult development. Those fed less ration daily weighed less than those fed a greater ration. Additionally, larvae provided the least amount of dairy manure took longer to develop to the prepupal stage; however, they needed less time to reach the adult stage. Adults resulting from larvae provided 27 g dairy manure/d lived 3-4 d less than those fed 70 g dairy manure. Percentage survivorship to the prepupal or adult stages did not differ across treatments. Larvae fed 27 g dairy manure daily reduced manure dry matter mass by 58%, whereas those fed 70 g daily reduced dry matter 33%. Black soldier fly larvae were able to reduce available P by 61-70% and N by 30-50% across treatments. Based on results from this study, the black soldier fly could be used to reduce wastes and associated nutrients in confined bovine facilities.     

黑水虻幼虫和预蛹的饲料价值研究进展

黑水虻Hermetia illucens L.是一种全世界广泛分布的资源昆虫,幼虫在自然界以动物粪便、腐烂的有机物,如腐肉、腐烂的水果、蔬菜和植物性垃圾为食,能够被用于畜禽粪便的无害化处理。黑水虻幼虫在将粪便转化成昆虫生物量的同时,减少了粪便的污染。利用畜禽粪便饲养的黑水虻幼虫干重达到42%～43%,其中粗蛋白含量占干重的42%～44%,脂肪含量占干重的31%～35%,灰份占干重的11%～15%,钙质占干重的4.8%～5.1%,磷占干重的0.60%～0.63%。使用粪便饲养的幼虫和预蛹,含有丰富的必需氨基酸和矿物质,是家禽、家畜和鱼类养殖的良好饲料来源。文章综述利用不同动物粪便饲养的黑水虻幼虫和预蛹的饲料价值及其幼虫和预蛹用于鸡、猪和鱼类饲料添加剂的研究进展。     

Positive and negative impacts of insect frass quality on soil nitrogen availability and plant growth

Frass deposition to soil is an important pathway by which herbivorous insects impact decomposition and soil nutrient availability. However, little is known about how frass quality influences ecosystem properties. Here, we examined the effects of frass quality on the decomposition process, soil nitrogen (N) availability, and plant growth, using frass of Mamestra brassicae (L.) that fed on fertilized or unfertilized Brassica rapa L. var. perviridis Bailey. The frass quality was largely dependent on the host plant quality. Frass excreted by larvae that fed on the fertilized plants had higher N than that of larvae that fed on the unfertilized plants. The decomposition rate of the frass did not differ between N-rich and N-poor frass, except during the early decomposition period. The inorganic N concentration decreased during decomposition in both frass types. However, difference in the initial inorganic N concentration led to different consequences regarding soil N availability. Furthermore, addition of frass to the soil differently influenced the growth of B. rapa plants depending on the frass quality: plant biomass was increased by N-rich frass addition but decreased by N-poor frass addition, compared to the biomass without frass addition. These results indicate that frass quality is an important factor in determining the impact of herbivorous insects on nutrient dynamics, and that frass positively or negatively influences soil N availability and plant growth, depending on its quality.     

Black soldier fly (Diptera: Stratiomyidae) larval heat generation and management

Mass production of black soldier fly, Hermetia illucens (L.) (Diptera: Stratiomyidae), larvae results in massive heat generation, which impacts facility management, waste conversion, and larval production. We tested daily substrate temperatures with different population densities (i.e., 0, 500, 1000, 5000, and 10 000 larvae/pan), different population sizes (i.e., 166, 1000, and 10 000 larvae at a fixed feed ratio) and air temperatures (i.e., 20 and 30 °C) on various production parameters. Impacts of shifting larvae from 30 to 20 °C on either day 9 or 11 were also determined. Larval activity increased substrate temperatures significantly (i.e., at least 10 °C above air temperatures). Low air temperature favored growth with the higher population sizes while high temperature favored growth with low population sizes. The greatest average individual larval weights (e.g., 0.126 and 0.124 g) and feed conversion ratios (e.g., 1.92 and 2.08 g/g) were recorded for either 10 000 larvae reared at 20 °C or 100 larvae reared at 30 °C. Shifting temperatures from high (30 °C) to low (20 °C) in between (∼10-d-old larvae) impacted larval production weights (16% increases) and feed conversion ratios (increased 14%). Facilities should consider the impact of larval density, population size, and air temperature during black soldier fly mass production as these factors impact overall larval production.     

Inoculating poultry manure with companion bacteria influences growth and development of black soldier fly (Diptera: Stratiomyidae) larvae

The growth and development of black soldier fly, Hermetia illucens (L.), larvae fed chicken manure inoculated with bacteria isolated from black soldier fly larvae and associated larval feed was evaluated. Four strains of Bacillus subtilis were evaluated. B. subtilis strains S15, S16, S19, were isolated from the gut of black soldier fly larvae. B. natto strain D1 was isolated from the diet fed to black soldier fly larvae. These bacteria were added individually into nonsterile 200 g fresh hen manure at 10(6) cfu/g and homogenized. Treated manure was then inoculated with 4-d old black soldier fly larvae. Prepupal weight ranged from 0.0606 g in the control to 0.0946 g in manure treated with the S15 strain. Larval survivorship to the prepupal stage in all treatments ranged from 98.00 ± 2.65% to 99.33 ± 1.15%. Prepupal survivorship to the pupal stage ranged from 91.92 ± 1.87% to 97.95 ± 1.03%. Adult emergence from the pupal stage did not significantly (P < 0.05) differ across treatments and ranged from 98.95 ± 1.82% to 100.00 ± 0.00%. Adult body length resulting from the larvae in each of the treatments was significantly greater than those from the control. Longevity of adults did not differ significantly between treatments. Time from hatching to the development of the first pupa did not differ significantly across treatments; however, development time from hatching to 90% reaching the prepupual stage was significantly different between treatments and ranged from 29.00 ± 1.00 d to 34.33 ± 3.51 d. Development time from hatching to 90% reaching the adult stages was significantly different between treatments. Our results demonstrate that inoculating poultry manure with bacteria from black soldier fly larvae influences the growth and development of conspecific larvae feeding on the manure.     

Effects of food substrates and moxidectin on development of black soldier fly,Hermetia illucens

Black soldier fly is a common and widely distributed saprophagous species that has an excellent potential for being used for biological conversion of organic wastes on an industrial scale. The main goal of the reported study was expanding the list of wastes suitable for utilization by this species. We compared larval growth on cull potatoes, horse manure and cafeteria food waste in 100‐L bins in a greenhouse. We also conducted laboratory experiments to investigate whether black soldier fly larvae are affected by the presence of moxidectin, a common endectocide used to treat an array of domestic animals and readily excreted in faeces, in their food substrates. Feeding on potatoes resulted in slower growth, and the final size of potato‐fed larvae was smaller compared to the larvae fed on cafeteria waste. Nevertheless, potatoes supported substantial biomass accumulation, and could be a valuable option for rearing fly larvae for commercial feed production. Larvae feeding on horse manure gained very little weight and eventually failed to pupate. Moxidectin had a strong negative effect on larval survivorship; however, ca. 30% of larvae reared in the substrate containing a realistic field concentration of moxidectin still survived to adulthood. Our findings confirm that using black soldier fly larvae is a promising technology for recycling organic wastes, including those of plant origin.     

进境小麦下脚料养殖黑水虻幼虫的饲料配比研究

黑水虻Hermetia illucens是一种备受关注的资源昆虫,主要用于处理粪便和餐厨余垃圾,虫体也可作为蛋白源进入下游的牲畜饲料。本研究以黑水虻幼虫为试验对象,设置5个不同配比的黑水虻饲料配方,探究进境小麦下脚料用于黑水虻饲养的可行性。研究发现,黑水虻幼虫抗逆性极好,不同饲料配方饲养的黑水虻幼虫存活率均超过95%。幼虫干虫的营养成分分析表明,进境小麦下脚料所养殖的幼虫蛋白成分可达45%,油脂含量可达30%,比常规蛋白饲料豆粕的44.2%蛋白含量稍高。综合黑水虻幼虫鲜重、干重、干重率以及饲料降解量的养殖结果,小麦下脚料含量为60%的饲料配方具有最佳的转化产出。     

A value added manure management system using the black soldier fly

A manure management system for laying hens using the black soldier fly, Hermetia illucens (L.) converted manure to a 42% protein, 35% fat feedstuff, reduced manure accumulation by at least 50% and eliminated house fly breeding. No extra facility or added energy was required. Mature larvae self-harvested producing a feedstuff as they attempted to pupate. Optimal feedstuff to manure dry matter yield was 7·8%. This insect occurs worldwide in tropical and warm-temperature regions and can digest many biological wastes.     

A caterpillar (Callopistria floridensis G. (Lepidoptera: Noctuidae)) accumulates arsenic from an arsenic‐hyperaccumulating fern (Pteris vittata L.).

1. The consumption of arsenic is toxic to most biota. However, a noctuid caterpillar was recently reported feeding on a plant known to hyperaccumulate arsenic. 2. The aim of this study was to investigate the effects of arsenic‐rich Pteris vittata L. consumption by Callopistria floridensis G., and measure differences in arsenic concentrations at various stages of development (larval and adult), and associated with exuviae and frass. 3. Callopistria floridensis accumulated extraordinary concentrations of arsenic. The relative accumulation of arsenic was highest in exuviae and larvae. Larvae invariably preferred P. vittata grown on low arsenic soil to P. vittata grown on higher soil arsenic concentrations, and appeared able to selectively forage on lower arsenic concentrations within each treatment. 4. These findings show that C. floridensis is tolerant of arsenic, and successfully develops to adulthood containing elevated concentrations of arsenic. Callopistria floridensis represents the only known terrestrial animal capable of accumulating arsenic, and may have developed novel physiological and behavioural adaptations to regulate the negative effects of arsenic.     

Effects of aeration rate and feed on growth,productivity and nutrient composition of black soldier fly (Hermetia illucens L.) larvae

Black soldier fly larvae (Hermetia illucens L.) are widely cultivated as bioconversion agents. These larvae are known to be highly sensitive to changes in the external environment, such as temperature and relative humidity. Therefore, a rearing hive equipped with an instrumentation system known as the Modular Fly Hive was designed to cultivate black soldier larvae. This study aimed to determine the effects of aeration rate (0 – 0.84 m³/s.) and feed type (coconut endosperm waste and soybean curd) on growth and productivity of black soldier fly cultivated in Modular Fly Hives as well as well as feed digestibility and nutrient composition of the larval biomass. Increasing aeration rate decreased the average temperature and relative humidity within the hives. The results showed that the larvae demonstrated a sigmoidal growth curve for all types of feed and the type of feed significantly affects the average wet weight and length of the larvae. The greatest dry biomass productivity (52.85 ± 3.85 g/m²/day) was observed when the larvae were cultivated using soybean curd residue with an aeration rate of 0.84 m³/s, while the lowest dry biomass productivity (35.27 ± 9.72 g/m²/day) was observed when the larvae were cultivated using coconut endosperm waste without aeration. Proximate analysis revealed that the larval biomass had total protein, lipid, ash and carbohydrate content in the range of 37.20 – 48.60%, 9.61 – 20.02%, 4.80 – 6.40%, 33.86 – 38.70%, respectively. Amino acid in the biomass were dominated by glutamic acid (11.11–12.30%), aspartic acid (8.25 – 10.35%), leucine (8.09 – 8.57%), and lysine (6.74 – 8.14%). Lipid isolated from the larval biomass were mainly composed of lauric acid (28.35–61.68%), linoleic acid (6.27 – 30.29%), palmitic acid (7.62 – 15.23%), and myristic acid (5.05 – 14.34%).     

A relationship between dry matter and damage by larvae of the turnip root flyDelia floralis in cultivars of the swedish turnipBrassica napus

A series of trials from 1981–85 investigating the amount of damage caused by larvae of the turnip root flyDelia floralis (Fallen) to cultivars of Swedish turnipBrassica Napus (L.) of varying percentages of dry matter indicated that those of high dry matter were damaged less than low dry matter cultivars. Pupal numbers of turnip root fly gave good correlations with damage but there was no relationship between damage and cabbage root fly pupae.     

Enhancement of fruit byproducts through bioconversion by Hermetia illucens (Diptera: Stratiomyidae)

Bioconversion is a biological process by which organic materials are converted into products with higher biological and commercial value. During its larval stage the black soldier fly Hermetia illucens is extremely voracious and can feed on a wide variety of organic materials. To study the impact of different fruit byproducts on the insect's growth, final larval biomass, substrate reduction, bioconversion parameters, and larval nutritional composition, 10 000 black soldier fly larvae (BSFL) were reared on 7.0 kg of one of three substrates (strawberry, tangerine, or orange) or on a standard diet as a control. The results highlight that BSFL can successfully feed and grow on each of these diets, though their development time, growth rate, and final biomass were differently impacted by the substrates, with strawberry being the most suitable. The lipid and protein contents of BSFL were similar among larvae fed on different substrates; however, major differences were detected in ash, micronutrient, fiber, fatty acid, and amino acid contents. Overall, the results indicate that fruit waste management through the BSFL bioconversion process represents a commercially promising resource for regional and national agrifood companies. Our study offers new perspectives for sustainable and environmentally friendly industrial development by which fruit byproducts or waste might be disposed of or unconventionally enhanced to create secondary products of high biological and economic value, including BSFL biomass as animal feed or, in perspective, as alternative protein source for human nutrition.     

Ethotypic Variation of Prey Recognition in Juvenile Anolis lineatopus (Reptilia: Iguanidae)

Among prey-naive Anolis lineatopus from Jamaica, individuals reject ants most commonly, crickets less commonly, and waxmoth larvae almost never. This study investigates the individual differences in the mechanism underlying prey perception in two of many ethotypes found, i.e., cricket-rejectors and cricket-acceptors. In one experiment artificially coloured live waxmoth larvae, crickets and ants were presented, in another experiment crickets and waxmoth larvae were moved passively with different speeds. Ethotypes differ in their evaluation of the interaction of prey key stimuli. Cricket-rejectors and cricket-acceptors differ in their responses to both crickets and waxmoth larvae that were either unicoloured yellow or black, but not in their responses to two types of ants of either colouration. Both ethotypes also differ in their preferences for artificially moved crickets and waxmoth larvae as a function of the interaction of prey type and velocity. In all but two prey items there is interaction in the perceptual pathways concerned. The first presentation in ontogeny of an ant inhibits attack on a cricket presented the next day. Some results suggest that ethotypes differ but gradually in their evaluation of stimuli presented, with cricket-rejectors having a higher threshold for attack. However, other results suggest that cricket-rejectors evaluate certain prey in a way qualitatively different from that of acceptors. At present there is little evidence for an understanding of the ethotypic differences of prey selection at a neural level, probably because neuroethologists have failed to look at individual differences of prey recognition; this failure is discussed in some detail.     

黑水虻幼虫及预蛹抗逆性的初步研究

本文初步研究了老熟和预蛹阶段的黑水虻Hermetiaillucens对于酒精毒性、氧胁迫和高渗透压条件下的耐受特性,结果显示黑水虻幼虫和预蛹在三种胁迫因子处于20%～60%(浓度)的较低水平时,其平均死亡率低于20%,表现出良好的抗逆性。高浓度的酒精、矿物油和氯化钠溶液对于黑水虻的生存都会产生负面影响,但是幼虫与预蛹由于其生理形态上的变化,致使其在抗逆性方面表现出显著差异,预蛹阶段的黑水虻对矿物油较为敏感,而幼虫则对高盐环境的耐受性表现较弱。     

The effect of a chemical deterrent, released from the frass of caterpillars of the garden pebble moth, on cabbage root fly oviposition

The cabbage root fly, Delia radicum (L.), was deterred from laying eggs on cauliflower plants that had been sprayed with a suspension of the frass of caterpillars of the garden pebble moth, Evergestis forficalis (L.). Polar extracts of the frass deterred oviposition irrespective of the cruciferous plant species on which the caterpillars had been feeding. Non-polar extracts of the frass had no effect. Spraying plants with macerates from Brassica leaves stimulated fly oviposition whereas spraying plants with macerates from garlic mustard leaves deterred fly oviposition. Macerates from the leaves of all other plants tested had no effect. In field experiments the deterrent effect persisted 2–3 days after leaves were sprayed with frass extracts. Plants infested with feeding caterpillars and contaminated with only a few discrete frass pellets were as deterrent to the fly as those sprayed with frass suspensions.

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Résumé D. radicum a évité de pondre sur des pieds de chou-fleur, qui avaient été pulvérisés avec une suspension d'excréments d'E. forficalis. Les extraits polaires de ces excréments empêchent la ponte quelle que soit l'espère de crucifère sur laquelle les chenilles se sont alimentées. Les extraits non polares sont sans effet. Dans la nature, l'action dissuadante persiste 2 à 3 jours après la pulvérisation des feuilles avec les extraits d'excréments. La pulvérisation tous les deux jours a maintenu l'action dissuadante. Des plantes contaminées par des chenilles en train de s'alimenter et souillées par quelques crottes sont aussi dissuadantes pour la mouche que celles pulvérisées avec une suspension d'excréments.