Application Of Larvae Research Articles

Exploitation of Tenebrio molitor larvae as biological factories for human probiotics, an exploratory study

Abstract The exploitation of yellow mealworm (Tenebrio molitor) larvae for the bioaugmentation of probiotic Bacillus clausii strains was evaluated during a 7-day rearing period. qPCR was applied to evaluate the persistence and growth of B. clausii in the rearing substrate and larvae (washed and non-washed). Moreover, the effect of freeze-drying of larvae on B. clausii viability was evaluated. The results demonstrated the suitability of yellow mealworm as biological factories for the multiplication of B. clausii through a simple and inexpensive procedure, in view of the further application of larvae as foods and food ingredients. In more detail, an increase in the load of B. clausii was observed during the 7-day rearing of larvae fed wheat middlings spiked with 1 Log cells g−1. Further research is needed to evaluate the most suitable technologies and processing parameters for obtaining yellow mealworm-based ingredients with a stable and active population of probiotic B. clausii.

A randomized controlled trial of larval therapy for the debridement of leg ulcers: Results of a multicenter, randomized, controlled, open, observer blind, parallel group study

It has been known for centuries that the application of larvae is useful to heal certain wounds by facilitating debridement of necrotic tissue,(1) yet the efficacy of larval therapy continues to be debatable. This study compared the clinical effectiveness of a larval therapy dressing (BioFOAM) with a standard debridement technique (Purilon gel; hydrogel) in terms of time to debridement of venous (VLU) or mixed arterial/venous (MLU) leg ulcers. Data analyses were conducted on 88 subjects. Sixty-four subjects completed the full study. Of these, 31 of the 32 (96.9%) patients who completed treatment in the larvae arm debrided fully, compared with 11 of the 32 (34.4%) patients who completed the hydrogel arm. In addition, 42 (48%) ulcers fully debrided within the 21-day intervention phase, 31 (67.4%) from the larvae arm (n = 46), and 11 (26.2%) from the hydrogel arm (n = 42), which was statistically significant (p = 0.001) in support of larvae. A statistically significant difference was also observed between treatment arms with regard to numbers of dressing changes during the intervention phase of the study (p < 0.001) in that subjects in the larvae arm required significantly fewer dressing changes(mean = 2.83) than those in the hydrogel arm (mean = 5.40). There were no statistically significant differences in the clinical condition of the wound bed and surrounding skin by intervention. Subjects in the larvae arm experienced more ulcer-related pain or discomfort than subjects in the hydrogel arm (p < 0.001). This study provided good evidence to show that larval therapy, in the form of a BioFOAM dressing, debrided VLU and MLU considerably more quickly than a hydrogel, although the possibility of resloughing should be closely monitored.

INTRODUCTION OF CHRONICAL WOUNDS HEALING WITH LUCILIA SERICATALARVAE IN SLOVENIA

BACKGROUND Due to infection of chronic wounds with antibiotic resistant bacterial strains, their healingcan be very difficult. The main purpose of the presented research study was the introductionof a new method for chronic wounds healing, using Lucilia sericata fly larvae intoSlovenia. METHODS For chronic wound healing sterile larvae of L. sericata fly were prepared from a continuousfly culture, maintained at the Department of Biology, Biotechnical Faculty, Universityof Ljubljana. In this way 32 wounds of 30 patients were treated. Larvae were appliedon the wounds for two to three days. Than they were washed off and replaced, if necessary.Microbiological smears were collected before and after the application of the larvae on thewounds. Microorganisms were then isolated and identified. During larval therapy healingimprovement, patient’s general state, potential presence of pain, mobility, patient’s independenceand psychological reaction to the therapy were monitored. RESULTS Using biosurgical therapy 24 (75 %) out of 32 wounds were cleaned and healed. In thecase of combined arterio-venous leg ulcers one wound was completely healed and eight ofthem were cleaned of necrosis and infection. In the case of a venous leg ulcer, six diabeticulcers, eight cases of chronic postoperative wounds and pressure ulcers, wounds were completelycleaned after the treatment. 16 patients reported unpleasant feeling during larvaltreatment and two patients felt pain which diminished after the treatment with analgesics.17 (57 %) patients had to use crutches during biosurgical treatment and the same numberof patients felt uncomfortable, frightened and depressed during the application oflarvae. CONCLUSIONS The method of healing chronic wounds with L. sericata larvae was successfully introducedinto Slovenia. Due to its simplicity and effectiveness biosurgery should be accepted as astandard method in Slovene clinical practice. With the help of biosurgical method chronicwounds heal faster, further inflammation and tissue decomposition are prevented andpatients can integrate faster into normal everyday life

Experiencia de terapia larval en pacientes con úlceras crónicas

MAGGOT THERAPY IN PATIENTS WITH CHRONIC SKIN ULCERS The technique of maggot therapy was applied for the first time in Chile in an attempt to duplicate beneficial results of this method as reported in the literature. Microbiologically sterile fly larvae were used to clean five ulcerative lesions (three sacral, one trocantral, and one diabetic foot) in four patients in the Surgical Service of the Valdivia Regional Hospital. The selected patients signed informed consent release papers permitting the therapy. The sterile larvae were obtained from the eggs of Lucilia sericata flies which had been treated with 0.5% sodium hypochlorite followed by 10% formalin, with sterility proved by negative results of inoculations of eggs onto blood agar and into tryptose broth. The larvae were deposited onto ulcers at 5-10 larvae per cm 2 of surface, protecting adjacent healthy skin with an adhesive tape shield. Escape of the larvae was prevented by overlaying the preparation with fine nylon screen. The exudate from the preparation was absorbed by gauze pads which were changed 2-3 times a day. The ulcers treated were totally cleaned after 1-6 applications of larvae, and odors disappeared after the first larval application in all patients. There was some escape of larvae in all patients in the initial stages of the treatment. Only one patient experienced a tickling sensation due to the larvae. The method proposed here may be of great use for the cleaning of chronic ulcers in patients who show no improvement from routine daily treatment of the ulcers.

Larva therapy in wound management

The use of maggots for wound debridement has a long history and has lately gained ground in several countries. We collected prospective data to examine the current use of larva therapy (LT) in the UK. Quantitative information was collected on 70 patients treated in nine hospitals. LT is used primarily to treat leg ulcers and generally involves three applications of larvae at two to three day intervals. This method is judged effective in wound debridement and promotes the growth of granulation tissue. Wound exudate, odour, infection and pain are all reduced by the treatment. Adverse reactions are infrequent but include pain, bleeding, pyrexia and influenza-like symptoms. Prevention of hospital admission and surgery, reduced need for antibiotics and reduced hospital stay are all identified as outcomes of LT. The nurse practitioners who used LT believed it to have an important role in wound management. A randomized clinical trial, comparing LT with other debriding agents, is required for evaluation of cost effectiveness.

Larvicidal Actmty of 2 Pyrethroids from Different Spray Droplet Attributes, 1991

Abstract Asana-XL and Karate applied to cotton with 2 flat fan nozzles, Spraying Systems Co. 8002E and 650033, were evaluated for mortality of TBW larvae and fruit damage. The 2 nozzles, which were selected to give different spray droplet spectrums, also delivered different spray rates. AI rates used in the study were 0.0168 and 0.014 kg/ha for Asana-XL and Karate, respectively. These rates, which are half of the lowest recommended rate for each pyrethroid, were used in the study to better-detect treatment differences and because preliminary studies indicated extended persistence of these pyrethroids in the greenhouse. Plants were grown in the greenhouse, 2 plants/pot, to average heights of 0.5 m. A susceptible strain of laboratory-reared TBW moths deposited eggs on paper towel strips. These strips, with emerging larvae, were placed on untreated cotton plants, and larvae were allowed to feed for 2 days before being used in the tests. The 2 spray treatments were applied in a spray table to a series of plants for subsequent application of larvae on selected DAT. The treated plants were then returned to the greenhouse. Characteristics of the spray plumes from the 2 nozzles in the test sections where the plants were placed for treatment were:

Yield Response of Two Cotton Cultivars to Tobacco Budworm Infestation1

Two cotton, Gossypium hirsutum L., cultivars were artifically infested with tobacco budworm, Heliothis virescens (F.), larvae for different time intervals during the first 8 weeks of fruiting to determine impact on yield reduction and maturity delay. The cultivars tested were ‘Stoneville 213’ (full‐season) and ‘Tamcot CAMD‐E’ (short‐season) grown in 1 ✕ 13.7 m long single row plots in a two‐planted one‐skip row pattern during the 1982 and 1983 growing seasons on a Leeper silty clay loam (fine, montmorillonitic, nonacid, thermic Vertic Haplaquepts). Treatments consisted of applying 12 first instar larvae in the terminal area of each plant, once per week for the following combination of weeks after fruiting had begun: none (control), Weeks 1 to 2, to 4, 1 to 6,1 to 8, 7 to 8, 5 to 8, 3 to 8, 3 to 4, to 6, and 3 to 6. When larvae were not applied in a given week, plots were protected with an insecticide. Plots were machine harvested three times for yield determinations and delays in maturity. All treatments involving larval applications the first 2 weeks of fruiting resulted in significant reductions in yield, compared with the control, for both cultivars at first harvest. Tamcot CAMD‐E with larval treatments produced a larger percentage of its total yield at first harvest than did Stoneville 213. When first and second harvest were accumulated, the same trends were apparent. Total yield of Stoneville 213 was significantly reduced only when larvae were applied for at least a 4‐week time period. The same trend was apparent with Tamcot CAMD‐E: timing of applications (rather than length of time) had the greatest effects; however, reduction in yield was not significant. Subclass regression analysis of yield as a function of larval application indicated that yield reduction trends averaged over years were significant and the responses of the two cultivars were found to be significantly different from each other as tested by homogeneity of slopes. The yield of Tamcot CAMD‐E was not reduced or delayed as much as that of Stoneville 213 when tobacco budworm larvae were applied during early‐, mid‐, and full‐season. The application of larvae during the early stage of fruiting had a greater impact on reducing yield and delaying maturity than when larvae were applied during mid‐ and late‐season.

Impact of Extrafloral Cotton Nectaries on Feeding Behavior of Young Heliothis virescens (Lepidoptera: Noctuidae) Larvae

The allelochemical concentrations in extrafloral nectary tissues are similar to those in corresponding tissues of nectariless cottons. Variation exists among nectaried cotton lines in size of extra floral nectaries. Heliothis virescens (F.) larvae are not attracted to extrafloral nectar, but this nectar does appear to be a feeding stimulant. Extrafloral nectarines are important routes of entry by larvae damaging ovaries of cotton squares; however, larvae damaged equal numbers of pistils regardless of presence or absence of extrafloral nectaries. The artificial infestation of cotton terminals allowed for more natural feeding behavior of larvae than application of larvae directly to squares.

Insecticide Resistance in the Light Brown Apple Moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae): Larval Response to Azinphosnlethyl

Azinphosmethyl resistance in the light brown apple moth Epiphyas postvittana (Walker) was confirmed with four methods: topical application of larvae, a Potter tower direct-spray method, and two residue exposure methods using middle instars and newly hatched larvae. The Mariri population exhibited a 140-fold resistance factor, using topical application of larvae. A 20-fold resistance factor was obtained by using a Potter tower to spray the insects directly. The first residue exposure method, using a Potter tower to treat apple leaf discs with the 50 WP formulation, produced a 13-fold resistance factor when third- and fourth-instar larvae were caged on the discs for 48 h. In the second residue exposure method, when first-instar larvae were caged onto leaf discs for 16 h, the resistance factor was 5-fold. The Potter tower, acetone-spray method was found to be the most satisfactory technique for evaluation of azinphosmethyl resistance in larvae. The application of this technique for monitoring resistance in the field is suggested.