Malaria vector Anopheles culicifacies sibling species differentiation using egg morphometry and morphology

Area of Science:

• Medical Entomology
• Molecular Biology
• Parasitology

Background:

• Anopheles culicifacies is a key malaria vector in Southeast Asia, with five sibling species (A-E).
• Only certain sibling species are significant malaria vectors, necessitating accurate identification.
• Previous identification relied on methods like PCR, with limited use of morphological traits.

Purpose of the Study:

• To investigate the potential of egg morphometry and morphology for differentiating Anopheles culicifacies sibling species.
• To compare egg characteristics of sibling species A, D, and E from malaria-endemic regions of India.

Main Methods:

• Adult Anopheles culicifacies were collected from five districts in Madhya Pradesh, India.
• Allele-specific polymerase chain reaction (AS-PCR) identified sibling species.
• Scanning electron microscopy (SEM) analyzed egg morphology and morphometrics of sibling species A, D, and E.

Main Results:

• AS-PCR identified sibling species B, C, D, and E in the study area.
• Significant differences in egg surface morphology and morphometric attributes were observed among sibling species A, D, and E.
• Distinct features included deck width, micropyle size and sectors, float size, and rib number.

Conclusions:

• Egg morphology and morphometrics provide a viable method for differentiating Anopheles culicifacies sibling species, complementing PCR.
• Sibling species A, D, and E exhibit distinct morphological characteristics at the egg stage.
• Advanced microscopy techniques can effectively resolve morphological dissimilarities among Anopheles culicifacies sibling species.