温度对家蝇广州种群成虫繁殖力及卵黄蛋白发生的影响

研究了不同温度对家蝇(Musca domestica L.)广州种群繁殖力及卵黄蛋白发生的影响,旨在为利用家蝇广州种群大规模高效养殖提供技术支持。选同一天刚羽化的健康雌、雄蝇,分别置于20、24、28、32和36℃环境下单对饲养,重复6次。每天测定成虫日产卵量、卵孵化率及死亡数等,统计家蝇单雌产卵量、卵孵化率、成虫寿命、产卵前期和产卵期;同时自雌蝇羽化第一日起,连续15 d,每天每个温度处理下取雌蝇3头,采用间接酶联免疫(indirect enzyme-linked immunosorbentassay,ID-ELISA)法测定5种温度下雌蝇每日卵黄蛋白合成量及羽化后前15 d卵黄蛋白合成总量。结果表明,温度对家蝇成虫繁殖力影响显著。产卵量以24℃环境下最高(1 921.17粒/雌),24～28℃时产卵量显著下降。28℃时卵孵化率最高(93.48%),高或低于此温度,卵孵化率显著下降,当温度达36℃时,孵化率仅为60.78%。雌蝇在20～28℃范围内产卵期差异不显著,32℃及以上温度下,雌蝇产卵期显著缩短。产卵前期以20℃最长(9.83 d),28℃最短(3.00 d),高于28℃产卵前期又显著延长。雌、雄蝇寿命均随着温度升高而显著缩短。温度对广州种群雌蝇羽化后前15 d的卵黄蛋白合成影响显著,24℃下前15 d合成的总卵黄蛋白最高(1 683.15μg/雌),其次为28℃(1 591.95μg/雌),20℃最低(232.81μg/雌)。家蝇广州种群在24～28℃繁殖效率最高。     

家蝇巨螯螨的生活史及其养殖方法

本文报告家蝇巨螯螨的发育历期与人工养殖方法。每只雌螨每天可产卵约20个,一生可产100个左右。从卵到成虫需3～4天,完成一个世代需10天左右。用牛粪加蝇卵饲养的螨发育历期比单纯用牛粪或加线虫的历期为短,并且产卵历期长,产卵量也大。文中并比较了两种养螨方法,提出优选方法与注意事项。     

家蝇卵巢中的信息化学物质引诱雌蝇产卵的研究

产卵期家蝇MuscadomesticaL .卵巢中的信息化学物质诱引家蝇产卵。行为试验表明 ,雌蝇产卵时优先选择被成熟卵巢污染过的发酵麦麸 ,诱集的产卵百分率依次为 :发酵麦麸 + 1对卵巢 >湿麦麸+ 1对卵巢 >发酵麦麸 >湿麦麸 ;卵巢提取物同样对产卵雌蝇有诱集活力。产卵雌蝇卵巢正己烷、二氯甲烷以及乙酸乙酯的提取物均能诱集雌蝇产卵 ,诱集的产卵百分率依次为 :雌蝇卵巢正己烷提取物 >乙酸乙酯提取物 >二氯甲烷提取物。推测家蝇卵巢中的信息化学物质可能含有家蝇产卵聚集信息素的组分。     

家蝇抗菌肽基因MAF-1的表达模式及响应微生物刺激分析

Musca domestica antifungal peptide-1(MAF-1)是家蝇体(Musca domestica)内组成型表达的一种独特且具有良好抑菌效果的抗真菌肽.本研究利用实时荧光定量PCR技术分析MAF-1在家蝇不同发育时期、不同组织器官及家蝇3龄幼虫经微生物(大肠杆菌、金黄色葡萄球菌和白色念珠菌)刺激后的表达特征.结果显示,MAF-1在家蝇各个发育时期的相对表达量依次为:2龄幼虫＞1龄幼虫＞3龄幼虫＞雄蝇成虫＞卵＞雌蝇成虫＞蛹;MAF-1在家蝇3龄幼虫各组织器官的相对表达量依次为:脂肪体＞唾液腺＞气管＞肠道＞体壁.通过超微量显微注射法向家蝇3龄幼虫体内注入病原微生物,其中金黄色葡萄球菌刺激后MAF-1的表达量呈下降趋势;大肠杆菌刺激后MAF-1的表达量先降低后升高再降低;白色念珠菌刺激后MAF-1的表达量先升高然后逐渐下降.本研究从RNA水平上说明了MAF-1的表达随着家蝇幼虫的生长发育阶段变化,对不同微生物刺激的响应具有不同的特征.同时MAF-1还是家蝇抵抗病原微生物感染的重要天然免疫分子,这为进一步研究其参与家蝇天然免疫防御过程提供了基础.     

家蝇抗菌肽基因MAF-1的表达模式及响应微生物刺激分析

Musca domestica antifungal peptide-1(MAF-1)是家蝇体(Musca domestica)内组成型表达的一种独特且具有良好抑菌效果的抗真菌肽.本研究利用实时荧光定量PCR技术分析MAF-1在家蝇不同发育时期、不同组织器官及家蝇3龄幼虫经微生物(大肠杆菌、金黄色葡萄球菌和白色念珠菌)刺激后的表达特征.结果显示,MAF-1在家蝇各个发育时期的相对表达量依次为:2龄幼虫＞1龄幼虫＞3龄幼虫＞雄蝇成虫＞卵＞雌蝇成虫＞蛹;MAF-1在家蝇3龄幼虫各组织器官的相对表达量依次为:脂肪体＞唾液腺＞气管＞肠道＞体壁.通过超微量显微注射法向家蝇3龄幼虫体内注入病原微生物,其中金黄色葡萄球菌刺激后MAF-1的表达量呈下降趋势;大肠杆菌刺激后MAF-1的表达量先降低后升高再降低;白色念珠菌刺激后MAF-1的表达量先升高然后逐渐下降.本研究从RNA水平上说明了MAF-1的表达随着家蝇幼虫的生长发育阶段变化,对不同微生物刺激的响应具有不同的特征.同时MAF-1还是家蝇抵抗病原微生物感染的重要天然免疫分子,这为进一步研究其参与家蝇天然免疫防御过程提供了基础.     

家蝇抗菌肽基因MAF-1的表达模式及响应微生物刺激分析

Musca domestica antifungal peptide-1(MAF-1)是家蝇体(Musca domestica)内组成型表达的一种独特且具有良好抑菌效果的抗真菌肽.本研究利用实时荧光定量PCR技术分析MAF-1在家蝇不同发育时期、不同组织器官及家蝇3龄幼虫经微生物(大肠杆菌、金黄色葡萄球菌和白色念珠菌)刺激后的表达特征.结果显示,MAF-1在家蝇各个发育时期的相对表达量依次为:2龄幼虫＞1龄幼虫＞3龄幼虫＞雄蝇成虫＞卵＞雌蝇成虫＞蛹;MAF-1在家蝇3龄幼虫各组织器官的相对表达量依次为:脂肪体＞唾液腺＞气管＞肠道＞体壁.通过超微量显微注射法向家蝇3龄幼虫体内注入病原微生物,其中金黄色葡萄球菌刺激后MAF-1的表达量呈下降趋势;大肠杆菌刺激后MAF-1的表达量先降低后升高再降低;白色念珠菌刺激后MAF-1的表达量先升高然后逐渐下降.本研究从RNA水平上说明了MAF-1的表达随着家蝇幼虫的生长发育阶段变化,对不同微生物刺激的响应具有不同的特征.同时MAF-1还是家蝇抵抗病原微生物感染的重要天然免疫分子,这为进一步研究其参与家蝇天然免疫防御过程提供了基础.     

家蝇幼虫集约化生产的初步研究

对家蝇幼虫在人工条件下的集约化饲养进行了研究．结果表明,在２４０ｍ２场地（日生产单元６０ｍ２）上得到鲜蛆日产量最高超过２００ｋｇ,平均约１５０ｋｇ;蝇蛆自卵孵出的第２天是蝇蛆生长的最关键阶段,此时要严格控制环境条件和饲料质量;同日龄的成蝇群体开始产卵后,约３ｄ便进入产卵高峰期并维持３～４ｄ;雌蝇一生产卵１０～１４次,每产１００～２００粒,最多９００多粒;蝇卵约１ｄ即孵化成幼蛆,由卵到成品蛆的时间需５～６ｄ;蝇蛆体重的增长过程符合Ｌｏｇｉｓｔｉｃ曲线;蛆料比０．４～０．５,产投比２．１～３．３;试验条件下,家蝇经过一个世代后个体数的实际倍增为理论倍增的２５．５％．利用农业生产中的各种副产品和废弃物进行蝇蛆的集约化生产,以获得高质量的动物蛋白和精饲料是可行的途径     

成虫饲料中糖与奶粉不同配比对家蝇繁殖力及卵黄蛋白发生的影响

本文研究了成蝇饲料中糖与奶粉不同配比对家蝇繁殖力及卵黄蛋白发生的影响,旨在为家蝇Musca domestica大规模高效养殖提供技术支持。结果表明,随着成蝇饲料中奶粉比例提高,单雌产卵量逐渐提高,且差异显著,但当饲料中奶粉比例达到和超过80%以后,单雌产卵量又显著减少,其中以60%奶粉+40%白糖饲养雌蝇产卵量最高(1935.83粒/雌),用100%白糖饲养产卵量最低(328.17粒/雌)。当成蝇饲料中白糖的添加比例为20%~60%时,雌虫寿命和产卵期差异均不显著,但用100%奶粉或80%以上的白糖饲养,雌虫寿命和产卵期显著缩短;雄虫寿命则随饲料中白糖比例的增加而延长;奶粉与白糖配比的变化对雌蝇产卵前期无显著影响。卵孵化率随饲料中白糖比例的增加而下降,尤其当饲料中白糖比例超过60%以后,卵孵化率下降更为明显。进一步测定卵黄蛋白的结果表明,雌蝇取食含糖量越高的饲料,其每日合成的卵黄蛋白及羽化后15 d内合成的总卵黄蛋白也越少,尤其是雌蝇完全摄取白糖,其每日合成的卵黄蛋白均维持在一个较低的水平,而蛋白质补充过多(如奶粉在饲料中的比例超过60%),雌蝇每日合成的卵黄蛋白及羽化后15 d内合成的总卵黄蛋白,基本不随饲料中奶粉的增加而增加。综合以上结果,作者认为用60%奶粉+40%白糖作为家蝇成虫的营养补充料,其不仅能保持雌蝇良好的繁殖力,同时也能有效降低成蝇养殖成本。     

家蝇和大头金蝇在麦麸和猪瘦肉上的产卵选择和发育差异

在中国许多地区, 大头金蝇Chrysomya megacephala F.已侵入过去由家蝇Musca domestica L.占绝对优势的垃圾生态位, 逐渐成为城市蝇类的优势种. 为了解单独和混合饲养时食物种类对家蝇和大头金蝇幼虫生长发育的影响, 在室内观察了野外大头金蝇和家蝇F1代在湿麦麸、猪瘦肉以及两者混合物上的产卵选择和生活史. 结果显示: (1)大头金蝇嗜在含有猪瘦肉的基质上产卵, 而家蝇嗜在含有麦麸的基质上产卵;(2)初孵家蝇和大头金蝇幼虫都能在含有瘦肉的食物上发育至成虫. 在麦麸上, 初孵家蝇幼虫能发育至成虫, 而初孵和2龄大头金蝇幼虫在进入下一龄期前全部死亡, 但少数3龄大头金蝇幼虫能发育至成虫;(3)等量初孵家蝇与大头金蝇在含有猪瘦肉的食物上共同生长时, 与家蝇相比, 大头金蝇的发育历期较短、存活率较高. 与家蝇在麦麸上共同生长时, 与在麦麸上独立生长的同龄大头金蝇相比, 大头金蝇的发育历期较短、存活率较高. 这些结果表明, 共生时家蝇可促进大头金蝇对植物质营养的利用, 这也许是大头金蝇能成功侵入家蝇占绝对优势的垃圾生态位的一个重要原因.     

黄瓜钝绥螨对茶黄螨雌成螨和腐食酪卵的功能反应

研究黄瓜钝绥螨Amblyseius cucumeris 对茶黄螨Polyphagotarsonemus latus (Banks)雌成螨和腐食酪螨Tyrophagus putrescentiae卵的功能反应。结果表明,黄瓜钝绥螨的第1若螨,第2若螨,雌成螨捕食茶黄螨雌成螨和腐食酪螨卵的功能反应均属于Holling II型,其中,雌成螨的捕食能力最强,对腐食酪螨卵和对茶黄螨雌成螨的攻击系数a大,处理时间th短,第2若螨也具有较强的捕食能力,对静态的腐食酪螨卵比对动态的茶黄螨捕食能力强,黄瓜钝绥螨对茶黄螨雌成螨具有很强的捕食能力。     

Euseiusfinlandicus (Acari: Phytoseiidae) as a potential biocontrol agent against Tetranychus urticae (Acari: Tetranychidae): life history and feeding habits on three different types of food

Life history and reproductive parameters of the generalist predatory mite Euseius (Amblyseius) finlandicus (Oudemans) were studied in the laboratory at 25 +/- 1 degrees C, with a 16L:8D photoperiod and 60 +/- 15% RH, to investigate its response to different food sources: an eriophyid mite Aceria sp., tulip pollen Tulipa gesnerana L., and two-spotted spider mite Tetranychus urticae Koch. Total developmental time of the immature stages was the shortest on eriophyid mites, followed by pollen, and then spider mites. Fecundity was highest on pollen (43.69 eggs; 1.63 eggs/female/day), then eriophyid mites (39.73 eggs; 1.37 eggs/female/day) and lowest on spider mites (18.16 eggs; 0.80 eggs/female/day). Intrinsic rate of increase (Rm), net reproductive rate (Ro) and finite rate of increase (lambda) followed the same pattern [pollen (0.168, 27.96 and 1.183, respectively), eriophyid mites (0.153, 20.81 and 1.167), spider mites (0.110, 9.44 and 1.119)]. Mean generation time (days) was the shortest on pollen (19.90), followed by eriophyid mites (20.02), and then spider mites (20.59). Average spider mite larvae consumed by E. finlandicus during immature stages were 9.18 for males and 11.85 for females. Adult E. finlandicus females consumed an average of 166.38 spider mite protonymphs during adult stage compared to an average of 66.55 by males. The number of prey protonymphs consumed per day by females was highest in the oviposition period, lower in the pre-oviposition period and the lowest in the post-oviposition period. The eriophyid mite as a prey recorded the shortest developmental time, while pollen as food recorded the highest oviposition rate in E. finlandicus. The potential of this predator as a biocontrol agent against T. urticae is discussed.     

EFFECT OF ECTOPARASITIC MITES ON SEXUAL SELECTION IN A SONORAN DESERT FRUIT FLY

We conducted a field study and a laboratory experiment to test whether ectoparasitic mites, Macrocheles subbadius, generate parasite-mediated sexual selection in the Sonoran desert endemic fruit fly, Drosophila nigrospiracula. Male flies gather on the outer surfaces of necrotic saguaro cacti where they engage in male–male competitive interactions and vigorous female-directed courtship. At these sites, operational sex ratios were significantly skewed toward males. The degree to which mites were aggregated among flies varied across the 25 fly populations sampled. The degree of mite aggregation across fly populations was strongly positively related to the mean number of mites per fly (intensity of infestation). Both the intensity and prevalence of infestation (fraction of flies infested) increased with the age of the cactus necrosis. Infested flies of both sexes were significantly less likely to be found in copula than uninfested flies, and mean intensity of infestation was significantly more pronounced in noncopulating than in copulating flies. The effect of attached mites on copulatory success exhibited dose-dependency, and this effect was more stringent in males: males or females with more than two and four mites, respectively, were never found in copula. The magnitude of parasite-mediated sexual selection was estimated for 12 fly populations by calculating selection differentials for each sex separately. The relation between intensity of infestation and magnitude of parasite-mediated sexual selection was stronger in males but significant for both sexes. We also assayed copulatory success of field-caught males in the laboratory, both during infestation and after experimental removal of mites. Males infested with two mites copulated less frequently than uninfested individuals, and in mating trials after mites had been removed, previously infested males copulated as many times as flies with no history of infestation. These findings, and the lack of difference in the number of mite-induced scars on copulating and single individuals in nature, strongly suggest that the reduced copulatory success of infested flies is attributable to an effect of mites per se, rather than to a character correlated with parasitism or previous parasite infestation.     

Assessment of mite numbers: New methods and results

The determination of mite numbers in dust samples depends on the effectiveness of the sampling procedure. We report on mite isolation from dust samples by flotation distinguishing between living and dead mites. The results are varied and unreproducible; ageing processes are of relevance in the case of dead mites. Living mites can be determined more reliably when using mite mobility. Two methods based on this principle, the mobility test and the heat escape method, are described and discussed. In the case of a natural analogous mite development on carpets, mite numbers ranging from 80 000 to 200 000 mites per m² are found after approx. 3 months. It is shown that the mobility of different mite species varies. The mobility test allows the detection of mites in textile objects, and shows how mites are distributed over these objects. It is demonstrated how the infestation of clothes by mites can be determined.     

Phoretic relationship between the myceliophagous mite Microdispus lambi (Acari: Microdispidae) and mushroom flies in Spanish crops

We studied the role played by the phorid Megaselia halterata (Wood) and the sciarid Lycoriella auripila (Winnertz) in the phoretic dispersion of the myceliophagous mite Microdispus lambi (Acari: Pygmephoridae). Twenty‐four crops were monitored during 18 months in commercial mushroom farms in Castilla‐La Mancha (Spain). Adults of both species were collected weekly and the mites they carried were counted and identified. Both phorids (19.6%) and sciarids (4.4%) carried the mite M. lambi. The calculated load of each was 3.4 M. lambi mites per phorid and 1.9 per sciarid. The same percentage of male and female phorid was used as vector, but the load was slightly higher for females (1.86 mites per female compared with1.48 mites per male). A mean of 7.2% of the phorids examined in winter were vectors of M. lambi, while in spring and autumn of the first year the average was more than 22%. The mean load did not vary significantly between seasons. Inside the mushroom farms, less than 10% of a small initial population of phorids carried mites (less than two mites per phorid). As the cycle progressed, more than 35% of a larger population of emerging flies did so (average 3.5 mites per phorid vector). At the end of the growth cycle, the flies may fly off to colonise nearby farms, favouring the propagation of M. lambi from infested to uninfested crops. Megaselia halterata is the principal vector of M. lambi in the mushroom farms of Castilla‐La Mancha due to their high numbers, the high percentage carrying mites and the number of M. lambi they carry.     

Monitoring northern fowl mites (Acari: Macronyssidae) in caged laying hens: feasibility of an egg-based sampling system

Northern fowl mites were monitored on a caged-layer operation in southern California for 22 mo. Three experienced observers underestimated actual numbers of mites in the vent region approximately 80% of the time. Errors were higher for heavy infestations. Observer estimates were highly correlated with each other (r > 0.89, P < 0.01) and with mite numbers estimated by vent feather removal (r > 0.82, P < 0.01). Mites on hens varied between houses and over time. Molting consistently reduced mite numbers, but did not eliminate then in a flock. Long-term monitoring of individual sentinel hens demonstrated that some hens would support high numbers of mites for several months or more. Use of a new sequential hen sampling plan required approximately 1 min per hen, if mite numbers were estimated. At this site, treatment decisions often could be reached in < 20 min per house. Mite scores (index of estimated mites per hen) were well correlated with percentage of hens infested in both test houses. In a chronically infested house, prevalence of mites on eggs averaged 8.5%, with a range of 0-55%. Applications of tetrachlorvinphos-dichlorvos by the producer appeared to be based on mites on > about 20% of eggs. The chemical was marginal for controlling mites on hens (25% reduction in percentage of hens infested), but effectively reduced mites on eggs (95% fewer mites on eggs at 1 wk and 90% at 2 wk). When data were grouped by mite index score on hens, there was a strong relationship (r2 = 0.83, P < 0.01) between mite prevalence on eggs and the scores of the hens which laid them. Sampling 100 eggs evenly spaced in a house required < 7 min, and adult mites were easily seen. Sampling mites on eggs appears to be useful to localize at least high-level infestations, and egg-based sampling for mites merits further investigation.     

Ecology of yellowstone thermal effluent systems: Intersects of blue-green algae,grazing flies (Paracoenia,Ephydridae) and water mites (Partnuniella,Hydrachnellae)

Summary As subjects for ecosystem studies, thermal spring effluents offer the advantages of trophic diversity with taxonomic simplicity, ease of sampling, replicability, world-wide distribution and manipulability. The dominant primary producers (filamentous blue-green algae) are grazed by ephydrid flies. These in turn harbor larvae of the water mite Partnuniella. The high instrinic rate of increase of the fly enables it to exploit temporary cool spots in the mat. The lower fecundity and longer life cycle of the mite restrict its ability to exploit temporarily suitable habitat. Thus the intersect of mites with flies is a sensitive measure of stability in the algal mat. Springs with a variable-flow pattern and consequent mat instability had both a lower mean incidence of parasitism and a lower mean larval load per fly. The data support our hypothesis that the abundance and relative densities of organisms in higher trophic levels can be predicted from knowledge of the growth and stability patterns of the filamentous blue-green algal mat in thermal spring effluents.     

Phoretic association betweenMacrocheles muscaedomesticae (Acari: Macrochelidae) and flies inhabiting poultry manure in Peninsular Malaysia

The phoretic association betweenMacrocheles muscaedomesticae and flies that inhabited poultry manure in a poultry farm in Sungai Buloh, Selangor, Malaysia was studied. The effects of temperature, relative humidity and fly abundance on phoretic rates also were in vestigated.The most abundant fly species found wasMusca domestica; Musca sorbens, Chrysomyia megacephala andOphyra chalcogaster were present in relatively large numbers.Representatives of ten families of mites were found on collectedMu. domestica. The most common mite wasMa. muscaedomesticae (Macrochelidae), found on all four species of flies mentioned above. The highest infestation (2.0%) occurred onO. chalcogaster butMu. domestica had the highest average number infested (5.7).The ventral part of the housefly's abdomen was the most common site of mite attachment. Usually only one mite was found attached per fly.The highest phoretic rate recorded was 64.4Ma. muscaedomesticae per 1000Mu. domestica. There was no correlation between phoretic rates andMa. muscaedomesticae abundance, nor was relative humidity a factor. However, a positive correlation was recorded in this host species between phoretic rates and temperature.This paper forms part of the Ph. D. thesis of the author submitted to the Universiti Sains Malaysia, Malaysia, in March 1988.     

家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对果蝇蛹的寄生比较

【目的】蝇蛹金小蜂Pachycrepoideus vindemmiae(Rondani)是杨梅园等果园果蝇类害虫蛹期常见寄生蜂种类,在对果蝇类害虫的生物防治上具有重要价值。本文旨在探讨使用家蝇蝇蛹为替代寄主繁育蝇蛹金小蜂的方法。【方法】探讨分别以家蝇蛹和果蝇蛹繁育的蝇蛹金小蜂对家蝇和果蝇蝇蛹的选择性,并比较了在两种寄主上繁育的蝇蛹金小蜂在大小、寿命、产卵期、后代产量和性比等方面的差异。【结果】结果表明与果蝇蛹相比,家蝇蛹明显较大,在家蝇蛹上发育的蝇蛹金小蜂后代个体也明显较大;家蝇蛹和果蝇蛹发育的寄生蜂雌蜂寿命为(13.4±4.11)和(3.94±2.49)d、产卵期分别为(11.4±4.11)和(3.13±2.42)d、单头雌蜂后代雌蜂数量分别为(34.31±31.83)和(7.88±3.58)头,在家蝇蛹上繁育的寄生蜂明显具有较长的寿命和产卵期、更多的雌雄蜂后代数量;在对家蝇蛹和果蝇蛹的选择上,繁育自家蝇和果蝇的蝇蛹金小蜂雌蜂选择频率的差异不大。【结论】利用家蝇蛹繁殖的蝇蛹金小蜂在寄生果蝇蛹时具有更大优势,在繁殖蝇蛹金小蜂控制杨梅园等果蝇的为害时,可以选择家蝇蛹作为替代寄主。     

The role of some cyclorrhaphan flies as carriers of human helminths in Malaysia

The role of some adult flies (Diptera: Cyclorrhapha) as carriers of helminth parasites of man was studied at four sites in Malaysia: a refuse dump, where no helminth-positive flies were detected, and in three peri-domestic situations where four species of flies carried up to three types of nematodes. The dominant fly species Chrysomya megacephala (Fabricius) carried eggs of the roundworm Ascaris lumbricoides L., the pinworm Trichuris trichiura (L.) and hookworm on the adult external body surface and in the gut lumen, in association with Bukit Lanjan aborigines. Chrysomya rufifacies (Macquart) and Sarcophaga spp. also had Ascaris lumbricoides and Trichurus trichiura eggs in their gut contents. Human helminths were not recovered from Lispe leucospila (Wiedemann), Lucilia cuprina (Wiedemann) or the housefly Musca domestica L. In an urban slum area of Kuala Lumpur city, filariform larvae identified as the hookworm Necator americanus (Stiles) occurred in the intestines of the face-fly Musca sorbens Wiedemann (22 larvae per 100 flies) and of Chrysomya megacephala (4.5 larvae per 100 flies). This concentration of apparently infective N. americanus in M. sorbens, a fly which often breeds in faeces and browses on human skin, could have transmission potential.     

Experimental evidence that the mite Poecilochirus davydovae (Mesostigmata: Parasitidae) eats the eggs of its beetle host

The relationship between the mite Poecilochirus davydovae Hyatt and its burying beetle carrier ( Nicrophorus vespilloides ) was investigated. Beetles experimentally stripped of deuteronymphs of Poecilochirus had larger apparent clutch sizes than beetles carrying mites. Furthermore, apparent clutch sizes were not affected by the presence or absence of carrion flies (Diptera: Calliphoridae). These results support the hypothesis that P. davydovae is a specialist predator feeding on the eggs of N. vespiloides.