Biological control of Phlebotomus papatasi larvae by using entomopathogenic nematodes and its symbiotic bacterial toxins.

The sand fly Phlebotomus papatasi is an important disease-bearing vector. Five entomopathogenic nematodes (EPNs) - Steinernema carpocapsae DD136, Steinernema sp. (SII), S. carpocapsae all, S. abbasi, and Heterorhabditis bacteriophora HP88 - were applied as biocontrol agents against the late third instar larvae of P. papatasi. In addition, the effect of toxin complexes (TCs) of Xenorhabdus nematophila and Photorhabdus luminescens laumondii bacteria was evaluated. Results revealed that S. carpocapsae DD136 was the most virulent species followed by Steinernema sp. (SII) and S. carpocapsae all where LC50 were 472, 565, 962 IJs/ml, respectively. Also, the crude TCs were slightly more active and toxic than their fractionated protein. Histopathological examination of infected larvae with H. bacteriophora HP88 showed negative effect on their midgut cells. In conclusion, EPNs with their symbiotic bacteria are more effective as biocontrol agents than the crude or fractionated TCs against sand fly larvae.

Biological control of Phlebotomus papatasi larvae by using entomopathogenic nematodes and its symbiotic bacterial toxins

@# The sand fly Phlebotomus papatasi is an important disease-bearing vector. Five entomopathogenic nematodes (EPNs) – Steinernema carpocapsae DD136, Steinernema sp. (SII), S. carpocapsae all, S. abbasi, and Heterorhabditis bacteriophora HP88 – were applied as biocontrol agents against the late third instar larvae of P. papatasi. In addition, the effect of toxin complexes (TCs) of Xenorhabdus nematophila and Photorhabdus luminescens laumondii bacteria was evaluated. Results revealed that S. carpocapsae DD136 was the most virulent species followed by Steinernema sp. (SII) and S. carpocapsae all where LC50 were 472, 565, 962 IJs/ml, respectively. Also, the crude TCs were slightly more active and toxic than their fractionated protein. Histopathological examination of infected larvae with H. bacteriophora HP88 showed negative effect on their midgut cells. In conclusion, EPNs with their symbiotic bacteria are more effective as biocontrol agents than the crude or fractionated TCs against sand fly larvae.

Prevalence and pathogenesis of some filarial nematodes infecting donkeys in Egypt.

AIM: The primary objective of the present study is to determine the commonness of filarial parasites in donkeys in Egypt, identification of the filarial species tainting them and the delivered pathogenic impact connected with the infestation. MATERIALS AND METHODS: A total of 188 donkeys were examined for filarial infection. The blood samples and scraping of the cutaneous bleeding lesions were collected, stained, and inspected for microfilariae all through the period from March 2011 to October 2013. The adult worms were perceived in tissue samples acquired from skin scraping, testes, eyes, tendons, peritoneal and pleural cavities, and the ligamentum nuchae. RESULTS: On the basis of morphological identification, 163 of 188 donkeys (86.70%) were infected with Onchocerca cervicalis (82.98%), Setaria equina (31.11%), Parafilaria multipapillosa (5.32%), and Onchocerca reticulata (4.26%). There was no significant effect of the sex on the incidence of all the encounteredfilarial worms except for S. equina, where the infection rate prevailed in males versus females (40.82% vs. 35.90%). In addition, age group of 5-15 years old exhibited a fundamentally higher predominance (p< 0.05) of the recognized filarial worms versus those of < 5 years old and >15 years old. CONCLUSION: The preliminary results add to our comprehension of filarial species infecting donkeys in Egypt, their impact on animal execution and production. Accentuation must be taken for avoidance, control of filarial disease, and improvement of the management system of donkeys.