Scanning electron microscopic studies on egg surface morphology and morphometrics of Culex tritaeniorhynchus and Culex quinquefasciatus (Diptera: Culicidae)

Abstract

Culex tritaeniorhynchus Giles, 1901 and Culex quinquefasciatus Say, 1823 is an important vector of Japanese encephalitis and Bancroftian filariasis, respectively in India and South East Asian countries. In this paper, we are describing the surface morphology and morphometrics of the egg of C. tritaeniorhynchus in comparison with C. quinquefasciatus for the first time. The results indicated that eggs of both the species appears to be similar to great extent in surface morphology, however, morphometrics provide 56.81% demarking attributes out of 44 attributes at various significant levels (p < 0.05-0.001), i.e., egg length, width and ratio of length/width, attributes of micropylar apparatus including corolla, disc, mound, tubercles size, and length of tubercular rows in micropylar region, size and density of tubercles, exochorionic pore in conical-shaped regions of eggs, and size of tubercular wheel units. Structurally, the additional presence of large tubercles strengthens the micropylar region to bear various collapsing forces in these species.

Systems Thinking: Prevention and Control of Japanese Encephalitis - "The Plague of the Orient"

“…The average life period of a mosquito is about 21 days and undergoes three gonotrophic cycle (WHO, 2006). Human infections are mainly transmitted by Culex tritaeniorrhynchus Giles, which is the principal vector of JE in India and South East Asian countries (Suman et al, 2008). The female specimens are infective 9-10 days after having taken the viraemic blood meal, having undergone three gonotropic cycles (Gajanana et al, 1997).…”

Structural characterization of the micropatterned egg plastron in the mosquito, Aedes albopictus

“…There are species‐specific micropatterns formed on the surface of mosquito eggs (Hinton ; Sahlen ; Suman et al . ). Female mosquitoes produce the eggs, but the chorion is deposited before the eggs are fertilized.…”

“…; Suman et al . , ). Such studies revealed that the chorionic ultrastructures such as micropyle and polygonal patterns can be used as strong taxonomic characters for differentiating between mosquito eggs (Suman et al .…”

Efficacy of botanical extracts against Japanese encephalitis vector, Culex tritaeniorhynchus

“…Culex tritaeniorhynchus Giles is an important vector of JE in India and South East Asian countries (Suman et al 2008). JE is endemic in few states of India and highly endemic in few districts of Tamil Nadu, Southern India (Reuben and Gajanana 1997;Sarkari et al 1984;Ravi et al 1989).…”