Spermathecal Filling inAedes aegyptiandAedes albopictus: Effects of Female and Male Body Sizes and Species

Abstract

The mosquitoes Aedes aegypti (L.) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) are ecologically similar species that have evolved independently in their native ranges, Ae. aegypti in Africa and Ae. albopictus in Asia. Where their invasive ranges overlap, interspecific mating is facilitated by both species swarming to mate around bloodmeal hosts during daylight. Here, we test hypotheses to account for variation in spermathecal filling in females of Ae. aegypti and Ae. albopictus, particularly, the effect of mosquito size on the number of spermathecae containing sperm after intraspecific and interspecifc matings of these two species. Results show that significantly more spermathecae contained sperm in large than in small Ae. albopictus females, but there was no effect of Ae. aegypti female body size on the average number of spermathecae filled. Among inseminated females, there was no effect of male size or cross-type on number of spermathecae with sperm. Differences in the effect of female size on the number of spermathecae that store sperm in Ae. aegypti and Ae. albopictus imply differences in the mating biology of these two species.

Differentiation of Multiple Fluorescent Powders, Powder Transfer, and Effect on Mating in Aedes aegypti (Diptera: Culicidae)

“…Likewise, the high percentage of visualization of sperm in the three spermathecae in inseminated marked or unmarked females, agrees with other reports that allowed unmarked Ae. aegypti to copulate freely [ 20 , 34 ], but differs with others that report that usually one of the three spermathecae remains empty [ 16 , 44 ]. All experiments agreed that usually, the medial spermatheca is the first in being filled [ 16 , 20 , 34 , 44 ].…”

“…aegypti to copulate freely [ 20 , 34 ], but differs with others that report that usually one of the three spermathecae remains empty [ 16 , 44 ]. All experiments agreed that usually, the medial spermatheca is the first in being filled [ 16 , 20 , 34 , 44 ]. Discrepancies in results may be related to different methodologies, mainly at the moment of manipulating the spermathecae and observing the sperm using an optical device.…”

“…A high percentage of insemination success in all marked or unmarked copulated females, as when analyzed in first, second, or third in the sequence, is consistent with reports of insemination rates in laboratory conditions of 74–100% using Ae. aegypti mosquitoes of different ages [ 11 , 34 , 43 ] and Ae. aegypti male capacity of inseminating 4–6 females consecutively [ 20 , 23 , 24 ].…”

“…The movement of the sperm was immediately checked in each of their three spermathecae, by placing them in between a glass slide and a coverslip (a thin piece of cotton was used on one of the edges, to prevent the spermatheca from bursting), and using 4× and 10× objective lens of a compound microscope (Olympus BH2 Series) (Olympus Corporation of the Americas, Center Valley, PA, USA). The number and position (central, and/or one or two of the lateral) of spermatheca with sperm was registered [ 34 ], and a filled spermatheca was recorded even if a low quantity of sperm was visualized.…”

No impact of biocontrol agent’s predation cues on development time or size of surviving Aedes albopictus under optimal nutritional availability

“…albopictus , larger adults have greater reproductive success [33, 34]. Larger males have been shown to produce more sperm [34], and in larger females, more spermathecae have been observed to contain sperm [35]. Larger female body size consistently correlates with higher fecundity, when measured as the number of mature follicles in the ovaries [36], or as the number of eggs laid [33].…”