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Fulltext Field evaluations of the granular fly bait, Quick Bayt and the paint-on fly bait, Agita against synanthropic flies

Nurita AT, Abu Hassan A, Nur Aida H, Norasmah B

Trop Biomed, 2008 Aug;25(2):126-33.
PMID: 18948883

The efficacy and residual efficacy of commercial baits, Quick Bayt (0.5% w/w imidacloprid) and Agita (10.0% w/w thiamethoxam) against synanthropic flies were evaluated under field conditions. Efficacy was evaluated based on knockdown percentage (KD %). The bait efficacy and residual efficacy evaluation were conducted for a period of 3 weeks and 6 weeks respectively. Baits were applied onto bait targets and placed on fly-count targets to facilitate the counting of flies. All baits were applied according to the manufacturer's recommended application rate. Three replicate treatments for each type of bait were placed at the study site each week. The number of flies feeding on baits and the knocked down flies were counted and collected. The efficacy of Agita and Quick Bayt did not differ significantly (t-test, P>0.05) over the 3-week period, even though Quick Bayt had a slightly higher KD% than Agita. In the residual efficacy evaluation, the (knockdown) KD% of Quick Bayt was consistent at around 36% for the first five weeks but dropped to 33.8 +/- 0.4% on the sixth week. The KD% for Agita on the first week was 33.6 +/- 12.2% and remained relatively consistent for the first 4 weeks at around 31%. KD% dropped to 16.7 +/- 3.3% on week 5 and to 15.7 +/- 1.2% on week 6. The difference in residual efficacy of the two baits was significant (t-test, p < 0.05).

Matched MeSH terms: Diptera/drug effects*
Influence of paraquat on Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) infesting minced-beef substrates in Kelantan, Malaysia

Mahat NA, Yin CL, Jayaprakash PT

J Forensic Sci, 2014 Mar;59(2):529-32.
PMID: 24745083

This study investigated the influence of paraquat, a prevalent poison used by suicides, on initial oviposition and development of Chrysomya megacephala (Fabricius) using minced-beef substrates. Paraquat in lethal dose for human (40 mg/kg), two times the lethal dose (80 mg/kg) and five times the lethal dose (200 mg/kg) were mixed thoroughly with respective minced-beef substrates (1 kg each) that were decomposed in a shaded habitat fully protected from rain. Results of four replications of the above experiment revealed that the presence of paraquat neither delayed initial oviposition nor prolonged the developmental stages of C. megacephala. Therefore, estimation of postmortem interval (PMI) based on empirical baseline data obtained using animal models devoid of any poisons would still be appropriate for estimating PMI in paraquat-related deaths.

Matched MeSH terms: Diptera/drug effects
Fulltext Effects of preservatives and killing methods on morphological features of a forensic fly, Chrysomya megacephala (Fabricius, 1794) larva

Rosilawati R, Baharudin O, Syamsa RA, Lee HL, Nazni WA

Trop Biomed, 2014 Dec;31(4):785-91.
PMID: 25776605 MyJurnal

Preservation of larvae retrieved from cadavers is important in ensuring the quality and integrity of entomological specimens used for the estimation of post-mortem interval (PMI). The process of killing and preserving larvae could distort the larvae leading to inaccurate estimation of PMI. In this study, the effects of killing Chrysomya megacephala larvae with hot water at different temperatures and subsequent maintenance in various preservatives were determined. Larvae not killed by hot water but preserved directly were used as control. The types of preservative used were 10% formalin, 70% ethanol and Kahle's solution. The morphological features examined were length, turgidity, curvature and coloration of larvae. Larvae killed in 80ºC hot water have shorter mean length (12.47 ± 2.86 mm) compared to those in 60ºC hot water (12.95 ± 2.69 mm). Increasing the duration of preservation in all types of preservative caused elongations of larvae treated or untreated with hot water. There were no significant changes in larval turgidity preserved in Kahle's solution compared to other two preservatives and were unaffected by the duration of storage. Larvae preserved in Kahle's solution experienced the least changes in coloration and shape compared to other preserved larvae in 70% ethanol or 10% formalin. Larvae directly immersed alive in 70% ethanol experienced the most changes in curvature, coloration and turgidity. This study suggested that killing larvae with hot water at 80ºC and preservation in Kahle's solution is the optimum method resulting in least changes in morphological features of Ch. megacephala larvae.

Matched MeSH terms: Diptera/drug effects*
Fulltext Malathion extraction from larvae of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae) for determining death due to malathion

Mahat NA, Jayaprakash PT, Zafarina Z

Trop Biomed, 2012 Mar;29(1):9-17.
PMID: 22543598 MyJurnal

The use of Chrysomya megacephala larvae for detecting malathion for diagnosing the cause of death was investigated. This could prove useful when the visceral organs have become liquefied during decomposition and therefore cannot be sampled. A field experiment was conducted in which C. megacephala were allowed to colonise naturally the corpses of rabbits that had died of malathion poisoning. The concentration of malathion increased gradually during the larval stages of C. megacephala reaching the maximum concentration in the third instar larvae. The concentration of malathion declined during prepupal stage and reached its lowest level among tenerals. The average malathion concentrations in C. megacephala growing in poisoned rabbit corpses left in a sunlit habitat were significantly higher (p<0.05) than those growing on poisoned rabbits left in a shaded habitat. The concentrations of malathion in the different stages of development of C. megacephala were moderately correlated (r = 0.51-0.69) with the administered doses as well as with those estimated in visceral organs. Thus, it would not be reliable to suggest the formulation of mathematical algorithms for relating the concentration of malathion found in the different stages of development of C. megacephala with those found in the visceral organs. However, in the context of forensic investigation, the qualitative detection of malathion in C. megacephala may prove useful in diagnosing the cause of death, since malathion is a common cause of accidental and suicidal deaths.

Matched MeSH terms: Diptera/drug effects
Fulltext Comparative performance of two commercial neonicotinoid baits against filth flies under field conditions

Nurita AT, Abu Hassan A

Trop Biomed, 2010 Dec;27(3):559-65.
PMID: 21399598 MyJurnal

Two performance (efficacy and attractiveness) comparisons of neonicotinoid baits QuickBayt® (imidacloprid) and Agita® (thiamethoxam) against filth flies were conducted under field conditions to determine suitability for use outdoors. The first experiment compared bait performance and the second compared effects of different applications on QuickBayt® performance. Applications compared were: (i) scattered in petri dish (SPD); (ii) wet-down in petri dish (WPD); (iii) scattered on cardboard (SCB) and (iv) painted on cardboards (PCB). Efficacy and attractiveness were assessed based on knockdown percentage (KD%) and number of flies feeding on baits, respectively. The KD% of QuickBayt® (34% ± 3.0%) was not significantly higher than Agita® (29% ± 1.3%) (t-test, P>0.05). Agita® (101 ± 5.7 flies) was significantly more attractive to flies than QuickBayt® (76 ± 4.8 flies) and the sugar solution (49 ± 7.2) (one-way ANOVA, P<0.05). The PCB and SCB applications were significantly more attractive to filth flies than WPD and SPD (One-way ANOVA, P<0.05), however differences in KD% were not significantly different (One-way ANOVA, P>0.05). The two baits provided the same level of efficacy in a wide-open area against filth flies of various species. QuickBayt® was more versatile; efficacy was not significantly affected by different applications. Surface area and moisture affects attractiveness of the bait.

Matched MeSH terms: Diptera/drug effects*
Fulltext Determination of malathion levels and the effect of malathion on the growth of Chrysomya megacephala (Fibricius) in malathion-exposed rat carcass

Rumiza Abd R, Osman K, Mohd Iswadi I, Raja Muhammad Z, Rogaya Abu H

Trop Biomed, 2008 Dec;25(3):184-90.
PMID: 19287355

This study was conducted to examine the effect of malathion on the development of Chrysomya megacephala. A total of 12 adult Sprague-Dawley rats was divided into 4 groups. Each animal in the 4 groups was given orally 0 (control), 10, 25 and 50ml/kg body weight of malathion, respectively. Chrysomya megacephala larvae were then allowed to grow on the liver of carcass. Larvae development was estimated by means of weight and length, time of adult emergence and survival rate. Results indicated that for the first 6 to 30 hours, larvae from control group developed more rapidly than larvae feeding on tissue containing malathion. However, the 3 doses of malathion did not exhibit significant impact on larvae length and weight. The time required for adult emergence was significantly greater for malathion-treated colony which was 10 days compared to 7 days in control colony. Control larvae of C. megacephala had higher survival rate compared to larvae exposed to the three different doses of malathion. Analysis of the tissues indicated that all rats and fly samples were positive for malathion. Malathion concentration was highest in liver. It was concluded that the presence of malathion altered the development rate of C. megacephala and thus disrupted normal postmortem interval estimation.

Matched MeSH terms: Diptera/drug effects*
Field assessment of synthetic attractants and traps for the Old World screw-worm fly, Chrysomya bezziana

Urech R, Green PE, Brown GW, Spradbery JP, Tozer RS, Mayer DG, et al.

Vet Parasitol, 2012 Jul 6;187(3-4):486-90.
PMID: 22575279 DOI: 10.1016/j.vetpar.2012.03.046

The performance of newly developed trapping systems for the Old World screw-worm fly, Chrysomya bezziana has been determined in field trials on cattle farms in Malaysia. The efficacy of non-sticky traps and new attractants to trap C. bezziana and non-target flies was compared with the standard sticky trap and Swormlure. The optimal trap was a modified LuciTrap(®) with a new attractant mixture, Bezzilure-2. The LuciTrap/Bezzilure-2 caught on average 3.1 times more C. bezziana than the sticky trap with Swormlure (P<0.05) and provided selectivity for C. bezziana against Chrysomya megacephala and Chrysomya rufifacies with factors of 5.9 and 6.4, respectively. The LuciTrap also discriminates with factors of 90 and 3.6 against Hemipyrellia sp. and sarcophagid flesh flies respectively, compared to the sticky trap. The LuciTrap/Bezzilure-2 system is recommended for screwworm fly surveillance as it is more attractive and selective towards C. bezziana and provides flies of better quality for identification than the sticky trap.

Matched MeSH terms: Diptera/drug effects*
Chrysomya bezziana (Diptera: Calliphoridae) infestation: case report of three dogs in Malaysia treated with spinosad/milbemycin

Han HS, Sharma R, Jeffery J, Noli C

Vet Dermatol, 2017 Apr;28(2):239-e62.
PMID: 27918123 DOI: 10.1111/vde.12403

BACKGROUND: Infestation of wounds with the larvae of Callophorid flies is relatively common in countries where these parasites are found. The most common species associated with infections in Southeast Asia is Chrysomya bezziana (Ch. bezziana), the Old World screw worm. Treatment consists of either subcutaneous injection of ivermectin or oral administration of nitenpyram combined with aggressive tissue debridement under general anaesthesia.
OBJECTIVES: To describe the treatment of cutaneous myiasis in three dogs caused by the larvae of Ch. bezziana in Malaysia and their treatment with spinosad plus milbemycin.
RESULTS: In all dogs, a single oral dose of spinosad plus milbemycin at the recommended dosage of 31-62 mg/kg and 0.5-1.0 mg/kg, respectively, was able to kill all larvae within 8 h. Most dead larvae fell off the host and those remaining on the host were dead and easily removed with simple saline flushing and gentle debridement. Neither general anaesthesia nor aggressive mechanical debridement were needed in any patient.
CONCLUSIONS AND CLINICAL IMPORTANCE: Oral spinosad plus milbemycin is a safe, licensed and effective treatment at the recommended dose for the rapid elimination of Ch. bezziana myiasis, with no need for sedation or anaesthesia.

Matched MeSH terms: Diptera/drug effects