Objective To apply DNA barcoding in species identification of exotic vectors. Methods Morphology and DNA barcoding based identification was performed on two blowflies from Australia that were intercepted at the Shenwan port (Zhongshan, Guangdong) in September 2013. The identification results were confirmed with specialists in Australia and compared to data of a similar species, Calliphora augur. Results The two blowflies were identified as C. dubia, which represents exotic species in China based on sci-tech novelty search. Conclusion DNA barcoding is a strong supplementary tool for conventional taxonomy, which plays an important role in frontier health and quarantine inspection by timely identifying vector insects, reducing the spread of vector insects and the carried pathogens, and mitigating threats to public health.

Objective To investigate the insecticide resistance of Musca domestica in recent years and the resistance of Chrysomya megacephala to several common insecticides in Shenzhen, China, and to provide a scientific basis for the control of flies. Methods M. domestica and C. megacephala were collected in the urban area of Shenzhen and raised in the laboratory for 1-2 generations. Topical application was used to determine the median lethal doses (LD₅₀) (μg/insect) of deltamethrin, beta-cypermethrin, permethrin, tetramethrin, DDVP, and fenobucarb for M. domestica and C. megacephala. Results For M. domestica, the LD₅₀ of deltamethrin, permethrin, tetramethrin, DDVP, and fenobucarb were 0.024 819, 0.092 076, 0.649 075, 0.065 610, and 5.008 337 μg/insect, respectively, increased by 8.27, 7.25, 3.45, 0.11, and 0.54 times compared with the resistance monitoring data in 1998. For C. megacephala, the LD₅₀ of deltamethrin, beta-cypermethrin, permethrin, tetramethrin, DDVP, and fenobucarb were 0.271 852, 0.318 642, 0.174 697, 0.657 885, 0.086 490, and 1.743 459 μg/insect, respectively. Conclusion The resistance of M. domestica to deltamethrin, permethrin, and tetramethrin increases slowly, while its resistance to DDVP and fenobucarb exhibits a declining trend. The results of resistance test for C. megacephala are different from those for M. domestica, and it is necessary to improve experimental methods and establish the standard for resistance levels.

Objective To compare the efficacy of three kinds of baits (rotten fish, rotten eggs and brown sugar-vinegar) against flies to offer the ideal option for vector monitoring. Methods Fly traps with different baits were deployed simultaneously in five experimental sites. The captured flies were identified in the laboratory. Results No significant differences in the captured species was found between the baits. Flies captured by the rotten fish, rotten eggs and brown sugar-vinegar accounted for 66.99%, 32.07% and 0.94%, respectively. Chrysomya megacephala and Musca domestica were the dominant species in the rotten fish group. Lucilia cuprina was more easily attracted by sugar-vinegar baits. Rotten eggs were more attractive to C. megacephala and Hemipyrellia ligurriens. Calliphoridae and Muscidae were more easily attracted by rotten fish, while Sarcophagidae, Calliphoridae and Anthomyiidae preferred rotten eggs. Conclusion Sugar-vinegar baits did not reflect seasonal changes as they attracted a very small number of flies. Rotten fish attracted a large number of flies from only a few species. Rotten eggs could attract a proper number of flies from a balanced collection of species, and thus could be used for fly monitoring.

Objective To describe the invasion of exotic species into the composition of fly fauna in China and the significance of human-induced invasion of fly vectors. Methods The disaggregated data on Muscidae, Calliphoridae and Sarcophagidae in China were analyzed. Results Among all the fly vectors of Fanniidae, Muscidae, Calliphoridae and Sarcophagidae in China, 78 species were distributed in the China-North America, China-Africa, China-Australia, China-Europe-South America, China-Australia-Africa, China-North America-South America, China-Europe-Australia and China-Africa-America ecozones as well as the worldwide ecozone, accounting for about 5.0% of all known species in China. A total of 84 species of 4 families were distributed in China-Europe-North America, accounting for 5.3% of the known species. Those distributed in China-Europe, China-Asia-Australia and China-Europe-Africa amounted up to 233 species, accounting for 15.0% of all known species. The larvae of these cosmopolitan species were either coprophilous or saprophytic, and most of the adult flies lived in the same living environment as human beings or domestic animals. Of the 35 major polluting fly species living in residential or semi-residential areas settlements in China, 22 showed disjunctive or global distributions in the worldwide ecozone, and the other 4 were widely distributed in the Palaearctic, Oriental and Australia regions. Conclusion Many a species of the fly vectors in China was introduced from abroad through human activities. Human activities constituted a leading cause for the invasion of flies.

A total of 57 species, 34 genera of Sarcophagidae in Guangdong and Hainan were identified, including 44 species in Guangdong and 25 in Hainan. Robineauella walayari (Senior-White) was a newly recorded species in China, in addition to other thirteen newly recorded species from Guangdong and two from Hainan. Sinonipponia hainanensis (Ho) was first recorded in Hong Kong. The flesh flies in Guangdong and Hainan were mostly of the subfamily Sarcophagidae.