Influence of aquatic habitat quality on seasonal diapause induction in the West Nile Vector Culex pipiens

Hernandez, Erica; Mackay, Andrew

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https://hdl.handle.net/2142/100003 Copy

Description

Title

Influence of aquatic habitat quality on seasonal diapause induction in the West Nile Vector Culex pipiens

Author(s)

• Hernandez, Erica
• Mackay, Andrew

Contributor(s)

Allan, Brian

Issue Date

2018-04

Keyword(s)

• Entomology
• diapause
• culex
• stormwater
• westnilevirus
• green

Abstract

To overcome unfavorable seasonal periods, many insects will enter diapause - a state of suspended development and activity. In temperate regions, adult females of Cx.pipiens will emerge from aquatic habitats in the late summer and fall in a state of reproductive diapause. In this state, females divert energy resources to fat deposition and arrest their ovaries in an early stage of development to enhance overwintering survival. Previous research has demonstrated that day length and temperature experienced by early developmental stages are critical for inducing diapause in adult female Cx. pipiens. However, the degree to which other qualities of the larval habitat influence the response to these primary diapause cues requires further resolution. To examine whether aquatic habitat quality influences the induction of reproductive diapause, larvae of Cx. pipiens were collected during three successive weeks in September from two types of aquatic habitats with differing amounts of organic enrichment; conventional storm water catch basins (high nutrient availability), and rain garden overflow catch basins (low nutrient availability). Adult females were allowed to eclose under ambient field conditions before assessing their reproductive state at 7-9 days post-eclosion. Reproductive development was assessed by comparing the ratio of primary and secondary ovarian follicle lengths. Adult wing length was measured as a general indicator of exposure to stressors and conditions during development. Results showed that females emerging from the low-quality habitats were significantly smaller, and a greater proportion were found to be in reproductive diapause when compared with females from high quality habitats.

Type of Resource

image

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http://hdl.handle.net/2142/100003

Copyright and License Information

• Copyright 2018 Erica Hernandez
• Copyright 2018 Andrew Mackay

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