Size of Openings in Water-Holding Containers: Impact on Oviposition by <i>Culex (Culex)</i> Mosquitoes

• Main Authors: Dongyoung Shin, George F. O’Meara, Ayse Civana
• Format: Article
• Language: English
• Published: MDPI AG 2019-08-01
• Series: Insects
• Subjects: <i>Culex nigripalpus</i> 1; <i>Culex quinquefasciatus</i> 2; <i>Culex coronator</i> 3; oviposition 4; oviposition site selection 5
• Online Access: https://www.mdpi.com/2075-4450/10/9/257

To assess how a grate covering a catch basin impacts oviposition by <i>Culex</i> mosquitoes, a field study was conducted in south Florida using containers with two types of covers, with openings of equal area, but different configurations. One opening mimicked a catch basin grate with 16 small openings, while the other cover had just one large opening. The number and presence of egg rafts in six of each container and cover combination was recorded over 18 nights at two field sites, consisting of a wastewater management facility area and residential subdivision. Three mosquito species, all belonging to the subgenus <i>Culex</i> accounted for more than 99% of total egg rafts collected: <i>Culex</i> <i>nigripalpus</i> (<i>n</i> = 1766), <i>Culex</i> <i>quinquefasciatus</i> (<i>n</i> = 754) and <i>Culex</i> <i>coronator</i> (<i>n</i> = 526). Approximately 90% of <i>Cx. nigripalpus</i> and Cx. <i>coronator</i> egg rafts were deposited in the containers with the large opening cover; whereas more <i>Cx.</i> <i>quinquefasciatus</i> egg rafts were laid in the containers with small opening covers than those of <i>Culex</i> <i>nigripalpus</i> and <i>Culex</i> <i>coronator</i> combined. Similar patterns of egg laying activity were noted at each sampling stations. These results suggest that for locating oviposition sites <i>Culex</i> <i>quinquefasciatus</i> may rely more on olfactory clues, while other <i>Culex</i> species depend more on visual clues.