The parasitic impact of Romanomermis iyengari Welch (Nematoda: Mermithidae) on the survival and biology of the common mosquito, Culex pipiens L. (Diptera: Culicidae)


  • Hanaa Elbrense Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt
  • Muhammad Shamseldean Department of Zoology and Agricultural Nematology, Faculty of Agriculture, Cairo University, Cairo, Egypt
  • Wesam Meshrif Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt
  • Amal Seif Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt



Romanomermis iyengari. Culex pipiens, biological control, biology & Mermithids.


The extensive use of chemical insecticides to control mosquitoes led to the development of insecticide resistance and environmental health hazards. This caused a surge in interest in eco-friendly biocontrol agents. The present study aimed to explore the susceptibility of different instar larvae of the common mosquito, Culex pipiens Linnaeus, 1758, to the mermithid nematode, Romanomermis iyengari Welch, 1964. Moreover, the effects of R. iyengari on the mosquito pupal developmental time, adult emergence, longevity, female fecundity, as well as egg-hatching rate were determined after larval treatment with an LC50 quantity of the nematode pre-parasites. Different instars of Cx. pipiens (1st–4th) were exposed separately to R. iyengari at concentrations of 1–6 pre-parasites/mosquito larva. Mortality rates of mosquito larvae were observed and the LC50 values were calculated. The estimated LC50 values for the 1st–4th larval instars were 3.18, 2.73, 3.79 and 4 pre-parasites/larva, respectively. Mean percent mortality of the 1st–4th larval instars ranged from 10–94%, 16–100%, 4–100% and 0–52%, respectively. The results indicated that exposure of 4th larval instar to the LC50 of R. iyengari pre-parasites significantly prolonged the duration of pupal development, reduced the percentage of emerged adults and reduced mosquito female fecundity compared with the control. In contrast, adult longevity and the egg-hatching rate did not differ between the control and the exposed group. In conclusion, this isolate of R. iyengari could be a promising biocontrol agent for Egyptian Cx. pipiens. Other trials are required to assess the biocontrol potential of this parasite in field conditions.


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Author Biography

Wesam Meshrif, Department of Zoology, Faculty of Science, Tanta University, Tanta, Egypt

I had my Master degree at Ain Shams University on insect immunity under supervision of Prof. Magdi G. Shehata and my Ph D study was at Tanta University under the supervision of Prof. Amal I. Seif. Part of this study was performed under the supervision of Prof. Marko Rohlfs at Christian-Albrechts University of Kiel, Germany. Thereafter, I started my post-doc with Prof. Rohlfs on the nutritional effect on the fitness of Drosophila melanogaster. When I return to Tanta University, I started work on fungal infection of caterpillars as well as the evolution of resistance to bacterial infection in collaboration with Prof. Thomas Roeder, Kiel University. Currently i work on different topics related to vector biology, the effects of environmental changes, insecticides, plant extracts on insects and Drosophila as model of diseases.


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How to Cite

Elbrense H, Shamseldean M, Meshrif W, Seif A. The parasitic impact of Romanomermis iyengari Welch (Nematoda: Mermithidae) on the survival and biology of the common mosquito, Culex pipiens L. (Diptera: Culicidae). Afr. Entomol. [Internet]. 2022 Aug. 2 [cited 2022 Aug. 8];30. Available from: