Insect Residues Research Articles

Laser cleaning of insect residue without surface alteration

AbstractInsect residues disturb and interrupt the laminar air flow on airplane wings after a while. These residues therefore need to be repeatedly removed. Shockwave‐based laser cleaning of insect residue on stainless steel (1.4544.9) is presented as a possible method to reduce insect residues in a single pass and without influencing the base material, as confocal laser‐scanning microscope images demonstrate.

Microbial community dynamics during decomposition of insect exuviae and frass in soil

With the expected growth of insect mass rearing industry, residual streams are set to become increasingly available. However, before these residues can be used as organic amendments, more knowledge of the decomposition dynamics and the associated microbial communities is needed. This study aimed to investigate the decomposition, N-mineralization, and fungal/bacterial community composition over a 16-week incubation period of exuviae and frass from BSF, mealworm, and house cricket in pots containing arable soil. The decomposition of insect residues in litterbags was rapid, with over 50% weight loss observed within two weeks. The release of mineral nitrogen from dispersed insect materials was highest during the initial two weeks, particularly evident in soils treated with exuviae compared to their frass counterparts. Moreover, soil amendment with insect residues enriched chitinolytic soil microbial inhabitants belonging to Gammaproteobacteria, Bacilli, Actinobacteria, and Mortierellomycetes. A comparison of soil amendments with sterilized and non-sterilized mealworm exuviae indicated minimal influence of microbial propagules on the composition of bacterial decomposers, though a notable impact on the fungal community was observed. These findings suggest that amendments with insect residues show promise in enhancing natural biocontrol by stimulating microbial antagonists of plant-pathogenic fungi, thereby presenting a potential tool for integration into soil-borne disease management strategies.

Insect residues as an alternative and promising source for the extraction of chitin and chitosan

This work aimed to obtain and characterize chitin and chitosan extracted from the rearing residues of Tenebrio molitor, Zophobas morio, and Blaptica dubia insects in different growth stages in the same rearing cycles chitin and chitosan yielded 11.21 %–20.89 % and 6.26 %–7.07 %, respectively. The deacetylation degrees of chitosan ranged from 75.75 %–89.21 %, and the solubilities from 69.88 %–94.39 %. Infrared spectroscopy corroborated the acquisition of chitin and chitosan and can be used as a semi-quantitative technique for determining the degree of chitosan deacetylation. The X-ray diffraction profiles revealed the presence of α-chitin, and the relative crystalline indices ranged from 65.9 %–89.2 %. Typical TG profiles with two thermal events are observed for chitin and chitosan samples with different residue contents from the extraction procedure. The chitosan solutions exhibited pseudoplastic behavior, with apparent viscosities ranging from 195.96 to 249.86 mPa.s. The characterization results of the biopolymers extracted from insect residues were similar to those obtained from conventional sources. The growth stage influenced the chitin yield and crystallinity index. The results of this study reinforce the feasibility of using alternative sources of chitin and chitosan, providing the use of waste from insect farms and contributing to sustainability and a circular economy.

Cytotoxicity and Genotoxicity Evaluation of Some Stored Grain Insects and Their Infested Flour Using the BHK-21 Cell Line in an In Vitro Experimental Model

Globally, stored grain is vulnerable to pest infestation, resulting in significant economic losses for some crops. Wheat is one of the most important crops in the world. Many sucking, piercing insects infect wheat in the form of grains or flour and may produce toxic residues that are harmful to human health. The current study aimed to estimate the safe use of four stored grain insects by evaluating the potential genotoxic effects and cytotoxicity of crushed insects (T. granarium, S. oryzae, R. dominica, and T. castaneum) and their flour residues. MTT and comet assays were conducted to assess the effects of six concentrations of insect flour residues (0, 6.5, 12.5, 25, 50, and 100%) on the baby hamster kidney cell line (BHK-21). The lowest BHK-21 cell viability was noted against T. granarium (LC50% 36.42 μg/ml) followed by T. castaneum flour (LC50% 46.73 μg/ml) compared to the control (LC50% 808.2 μg/ml). Significantly high DNA comet (%) was observed in the treatments of T. castaneum flour (18.8%), S. oryzae wheat (15.6%), T. granarium (15.4%), T. castaneum (13.6%), and T. granarium wheat (13.1%). FTIR spectra of stored grain insects and their flour residues identified various functional metabolite groups, including alkynes and phenols, which could enhance cell apoptosis and genotoxicity. T. granarium, T. castaneum, and their flour residues had the highest cytotoxic and genotoxic effects on the BHK-21 cell line. The current study concludes that insect residues in flour may have cytotoxic and genotoxic effects on living cells, potentially affecting public health, particularly after consuming T. granarium and T. castaneum-infested flour. Therefore, good storage of stored grains and their products is recommended.

Critical Protuberance Height for Transition of Leading Edge Boundary Layers

Leading edge contamination on aircraft wings can occur through the accumulation of insect residues, ice, or dirt or through existing surface defects. Such protuberances can increase skin friction drag by causing an earlier transition of the boundary layer from laminar to turbulent flow. To determine the likelihood of this effect, a simple and approximate model was developed for determining the critical height for boundary-layer transition on the airfoil leading edge. The model assumes an outer potential flow based on an effective leading edge radius coupled with an inner flow based on semi-empirical laminar boundary profiles. The effective leading edge radius was based on leading edge pressure distribution as related to flow over a cylinder and tends to the geometric leading edge radius for the limits of no camber and zero angle of attack. The model was compared with available experimental transition results, which showed that the predictions are reasonable but approximate. The potential susceptibility of various airfoils to transition was next considered using sample insect residues heights. The results indicate that laminar flow airfoils for large commercial aircraft would be significantly susceptible to transition due to insect contamination, whereas high-altitude low-speed UAVs would generally not have such susceptibility.

Fruit fly impact on an aerodynamic surface: Types of outcomes and residue components

Leading edge contamination on aircraft wings and wind turbine blades can occur through the accumulation of insect residues, which can then increase drag by causing an earlier transition of the boundary layer from laminar to turbulence. To investigate the mechanisms of residue adherence and composition, this study focuses on the impact dynamics of insects striking an airfoil with a circular leading edge placed in a wind tunnel at a wind speed of about 100 mph. To mimic in-flight conditions, live flightless fruit flies (Drosophila melanogaster) were injected into the wind tunnel sufficiently upstream such that they reached the test section air-flow speed prior to impact on the airfoil. The aerodynamic surface had a leading edge radius of 3.8 cm and was tested with coatings of various surface wettability, ranging from hydrophilic to superhydrophobic. Based on previous studies and present high-speed imaging and surface imaging, five types of insect outcomes were defined (roughly in order of increasing impact speed): 1) insect bounce without rupture and no residue, 2) insect burst with release of internal fluid with adherence of full exoskeleton, 3) insect burst with release of internal fluid with little or no exoskeleton adherence, 4) disintegration of insect yielding residue of many pieces of exoskeleton, and 5) insect burst with neither fluid nor exoskeleton residue. The fifth outcome generally occurred for a superhydrophobic surface developed in this study. When insect residue did occur on a surface, it included up to three distinct components (in order of decreasing residue heights): exoskeleton pieces, yellow hemolymph from the insect abdomen and thorax, and red fluid from the insect head. Surfaces with lower surface wettability generally yielded reduced insect hemolymph residue area per insect release. In particular, a superhydrophobic coating yielded the lowest residue area and no exoskeleton residue, while the aluminum surface resulted in the highest residue area and several exoskeletons.

Influence of hydrophobic and superhydrophobic surfaces on reducing aerodynamic insect residues

Insect fouling during takeoff, climb and landing can result in increased drag and fuel consumption for aircrafts with laminar-flow surfaces. This study investigates the effectiveness of various hydrophobic and superhydrophobic surfaces in reducing residue of insects on an aerodynamic surface at relatively high impact speeds (about 45m/s). An experimental setup consisting of a wind tunnel and a method to inject live flightless fruit flies was used to test the effectiveness of various surfaces against insect fouling. Insect fouling was analyzed based on residue area and height from multiple impacts. In general most of the residue area was due to the hemolymph spreading while most of the residue height was due to adhesion of exoskeleton parts. Hydrophobic and especially superhydrophobic surfaces performed better than a hydrophilic aluminum surface in terms of minimizing the residue area of various insect components (exoskeleton, hemolymph, and red fluid). Surfaces with reduced wettability and short lateral length scales tended to have the smallest residue area. Residue height was not as strongly influenced by surface wettability since even a single exoskeleton adhered to the surface upon impact was enough to produce a residue height of the order of one mm. In general, the results indicate that hemolymph spread needs to be avoided (e.g. by having reduced wettability and short lateral correlation lengths) in order to minimize the residue area, while exoskeleton adherence needs to be avoided (e.g. by having oleophobic properties and micro/nano roughness) in order to minimize the residue height. In particular, two of the superhydrophobic coatings produced substantial reduction in residue height and area, relative to the baseline surface of aluminum. However, the surfaces also showed poor mechanical durability on the high-speed insect impact location. This suggests that although low wettability materials show great insect anti-fouling behavior, their durability needs to be substantially improved in order to withstand harsh aerospace conditions.

In vitro digestibility and fermentability of selected insects for dog foods

Insects are considered as a sustainable protein source for future pet foods. Here we aimed to evaluate the protein quality of larvae of the black soldier fly (Hermetia illucens, BSF), housefly (Musca domestica, HF) and yellow mealworm (Tenebrio molitor, YMW) and to evaluate the fermentation characteristics of their indigestible fractions. Clean freeze-dried larvae were subjected to in vitro simulated canine gastric and small intestinal digestion. Undigested insect residues, shrimp chitin and fructooligosaccharides (positive control, FOS) were incubated for 48h with inoculum with fresh feces from three dogs simulating large intestinal fermentation. The AA profiles differed among the larvae with proteins from BSF and YMW larvae containing more Val and less Met and Lys than HF larvae. The in vitro N digestibility of the HF (93.3%) and YMW (92.5%) was higher than BSF larvae (87.7%). The BSF larvae also had lower in vitro digestibility values for essential AA (92.4%) and non-essential AA (90.5%) compared to the larvae of the HF (96.6 and 96.5%) and YMW (96.9 and 95.3%). Gas production for FOS increased rapidly during the first 6h. Low and similar amounts of gas were found for HF larvae and chitin whereas gas production slowly increased over 30h and was slightly higher at 48h for BSF than for chitin. Gas production for YMW increased considerably between 6 and 20h. At 48h, gas produced for undigested residues was comparable to shrimp chitin and lower than FOS (P<0.001). Incubation with insect residues resulted in more N-acetylglucosamine than with shrimp chitin (P<0.05), suggesting higher microbial degradation of insect chitin. Fecal microbiota from one dog appeared to be better able to ferment the undigested residue of YMW as gas production increased considerably between 6 and 20h of incubation and was higher than for the microbiota from the other two dogs. The associated metabolite profile indicated that acetate, propionate and butyrate were the main fermentation products. Furthermore, formate was produced in relatively high amounts. It is concluded that the protein quality, based on the amino acid profile and digestibility, of selected insect larvae was high with the undigested insect fractions being at least partly fermented by the dog fecal microbiota. As the microbiota from one dog was better capable of fermenting the undigested residue of YMW larvae, it is of interest to further study the selective growth of intestinal microbiota in dogs fed insect-based food.

Synthesis, Characterization and Evaluation of Urethane Co-Oligomers Containing Pendant Fluoroalkyl Ether Groups.

Coatings with the ability to minimize adhesion of insect residue and other debris are of great interest for future aircraft. These aircraft will exhibit increased fuel efficiency by maintaining natural laminar flow over greater wing chord distances. Successful coatings will mitigate the adhesion of debris on laminar flow surfaces that could cause a premature transition to turbulent flow. The use of surface modifying agents (SMA) that thermodynamically orient towards the air side of a coating can provide specific surface chemistry that may lead to a reduction of contaminate adhesion. Aluminum surfaces coated with urethane co-oligomers containing various amounts of pendant fluoroalky ether groups were prepared, characterized and tested for their abhesive properties. The coated surfaces were subjected to controlled impacts with wingless fruit flies (drosophila melanogaster) using both a benchtop wind tunnel and a larger-scaled wind tunnel test facility. Insect impacts were recorded and analyzed using high-speed digital photography and the remaining residues characterized using optical surface profilometry and compared to that of an aluminum control. It was determined that using fluorinated oligomers to chemically modify coating surfaces altered the adhesion properties relative to the adhesion of insect residues to the surface.

Influence of surface characteristics on insect residue adhesion to aircraft leading edge surfaces

Leading edge contamination caused by insects is problematic for modern aircraft utilizing laminar flow aerofoils. The residue of crushed insect bodies adhering to aircraft leading edge surfaces can cause transition of the boundary layer, from laminar to turbulent, resulting in a significant increase in drag and therefore causing an increase in fuel consumption. Consequently, current research is focused on the evaluation of novel low surface energy coatings that will reduce or prevent insect adhesion. Insect residue adhesion tests were conducted on a range of surfaces, from superhydrophobic to hydrophilic. Surface free energy of the investigated substrates was obtained from measured dynamic contact angle values and surface roughness was measured using profilometry. Live insect testing with Drosophila melanogaster and Drosophila hydei was conducted using an insect delivery device inserted into a medium-speed wind tunnel. Tests were conducted at speeds ranging from 90 to 100m/s (speeds representative of those on take-off and landing of a commercial passenger aircraft). Topography of insect residues was characterized using scanning electron microscopy and confocal laser scanning microscopy. Results obtained indicate that coatings with high surface roughness values and low wettability exhibit good anti-contamination properties.

AN INSIGHT INTO THE POST HARVEST HANDLING AND STORAGE OF PAPAYA (CARICA PAPAYA L.)

Papaya (Carica papaya L.) is one among the widely consumed fruits of the world and is grown throughout the tropics and subtropics. EU markets are highly conscious of fruit quality and all markets either big or small have a preference to hermaphrodite pear shaped fruits at 50-70% yellow on arrival at the market. Fruits absolutely free from latex stain, external debris, harvest wounds, handling punctures, scratches, bruises, scars, insect residues, spray damage, over or under yellowing and 'softness' are exclusively in demand. Imports into EU markets are showing a steady increase since the year 2001 and Netherlands, UK, Germany, Portugal, France, Spain and Italy are the top seven importers. Brazil is the major supplier of papaya to EU markets while India, Pakistan, Ghana, Thailand and Ecuador are the other suppliers of importance. The cultivation in India is spread over fifteen states and Karnataka, Uttar Pradesh, West Bengal, Assam and Gujarat are the major papaya growing states. The challenges faced by the industry are more towards post production phase than the production phase. India exports only 0.08% of its papaya production and the export destinations are mainly towards Bahrain, Kuwait, Qatar, Saudi Arabia, UAE and the Netherlands. New Delhi and Mumbai are the two principal papaya markets in India while Jaipur, Bangalore, Chennai, Kolkata and Hyderabad are the other markets. Sizeable arrivals have also been reported in Gauhati, Ahmedabad, Lucknow, Patna, Rajpur and Jammu Markets.

Health Hazards Among grain Storage Workers in Nigeria

Potential hazards to the health of grain storage workers have increased over the years basically because of the sophistication in storage systems, grain dust, biological contaminants and chemicals used in storage. To identify the hazards of grain storage in southwest and middle belt regions of Nigeria, analysis of medical records, interviews and questionnaires were used in eleven selected establishments from flour mills, the strategic grain reserves (SGRs) and breweries. Findings showed that the principal cause of hazards was the grain dust and other forms of dust like soil from harvest, insect and chemical preservative residues. The results obtained showed that 33.85% of workers were affected with catarrh, 21.54% with skin irritation, 18.46% headache, 4.62% high body temperature and 21.54% with cough. However, skin irritations were higher in SGRs, headache and cough were higher in breweries while flour mills were more associated with catarrh. Hazards in grain storage can be minimized or even eliminated if proper handling techniques are adopted and all necessary safety precautions strictly adhered to. Keywords : Grain, Storage, Workers, Health, Hazards, Dust Journal of Applied Science, Engineering and Technology Vol. 6 (1) 2006 pp. 1-7

A fundamental study of the sticking of insect residues to aircraft wings

The aircraft industry has long been concerned with the increase of drag on airplanes due to fouling of the wings by insects. The present research studied the effects of surface energy and surface roughness on the phenomenon of insect sticking. Aluminum plates of different roughnesses were coated with thin films of polymers with varying surface energies. The coated plates were attached to a custom jig and mounted on top of an automobile for insect collection. Contact angle measurements, X-ray photoelectron spectroscopy, and specular reflectance infrared spectroscopy were used to characterize the surfaces before and after the insect impact experiments. Scanning electron microscopy showed the topography of insect residues on the exposed plates. Moments were calculated in order to find a correlation between the parameters studied and the amount of bugs collected on the plates. It was demonstrated that surface energy has an effect on the sticking of insect residues.

Insect Control and Chemical Residues from Organophosphates and Synthetic Pyrethroids Applied Alone or in Tank Mixes on Flue-Cured Tobacco1

Tank mix sprays of fenvalerate or permethrin with acephate or encapsulated methyl parathion were compared with sprays of the compounds alone for control of the green peach aphid, Myzus persicae (Sulzer), tobacco budworm, Heliothis virescens (F.), and tobacco homworm, Manduca sexta (L.), on flue-cured tobacco in 1977 through 1980. The three insects were significantly controlled ( P = 0.05) with the tank mixes or organophosphates applied alone, except for encapsulated methyl parathion alone or mixed with permethrin against budwonns in 1979. The pyrethroids alone gave erratic control of aphids but significant ( P = 0.05) control of budworms, with the exception of fenvalerate in 1979 for budworm control. In 1979, samples of green and cured tobacco were analyzed for chemical residues at various intervals after applications of the compounds alone or in tank mixes. No detectable organophosphate residues were found on the green or cured tobacco. The pyrethroids were more persistent. Fenvalerate and permethrin applied alone left the largest residues on the cured tobacco of 20.1 and 50.7 ppm from rates of 0.13 and 0.18 kg of AI/ha, respectively. When the rate of fenvalerate and permethrin was reduced to 0.06 kg of AI/ha in the tank mixes, residues on the cured tobacco decreased to a range of 3.0 to 6.5 and 7.0 to 16.2 ppm, respectively, without loss of control efficacy. No synergism for insect control was noted from the tank mixes.

Insect Control and Residues in Sweet Corn Using Ground Equipment for Treating with Low-Volume Formulations12

Low-volume ground equipment was evaluated for its ellectiveness in insect control. The control of corn earworm, Heliothis zea (Boddie), using low-volume forumlations of endosulfan-malathion, DDT-malathion, and 50-8447 (2-chloro-I-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate) was equal to that obtained with 2 lb per acre of DDT emulsifiable concentrate. Corn earworm control with a pneumatic (F-l) nozzle with air plus charge and a flat fan (650017) nozzle was not significantly different when varying rates of malathion and SD-8447 were used, but both types of nozzles were significantly better than the DDT standard or the 1,-1 nozzle without air plus charge. Residues of low-volume DDT-malathion showed a 3-12 ppm DDT increase and a 4-24 ppm malathion increase from the first to the second application. with no additional increase shown for the remaining 3 applications. Seven days after the fifth application, residues declined to 6 and 0.8 ppm for DDT and malathion, respectively.

Effect of Insect Residues and Other Factors on Removal of Spray Residues From Apples*

Journal Article Effect of Insect Residues and Other Factors on Removal of Spray Residues From Apples Get access Harry C. Mclean, Harry C. Mclean New Jersey Agricultural Experiment Station, New Brunswick Search for other works by this author on: Oxford Academic PubMed Google Scholar Albert L. Weber Albert L. Weber New Jersey Agricultural Experiment Station, New Brunswick Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 32, Issue 3, 1 June 1939, Pages 357–360, https://doi.org/10.1093/jee/32.3.357 Published: 01 June 1939