Meconial peritrophic membranes and the fate of midgut bacteria during mosquito (Diptera : culicidae) metamorphosis

Citation
Rm. Moll et al., Meconial peritrophic membranes and the fate of midgut bacteria during mosquito (Diptera : culicidae) metamorphosis, J MED ENT, 38(1), 2001, pp. 29-32
Citations number
13
Categorie Soggetti
Entomology/Pest Control
Journal title
JOURNAL OF MEDICAL ENTOMOLOGY
ISSN journal
00222585 → ACNP
Volume
38
Issue
1
Year of publication
2001
Pages
29 - 32
Database
ISI
SICI code
0022-2585(200101)38:1<29:MPMATF>2.0.ZU;2-Z
Abstract
The location of midgut bacteria relative to meconial peritrophic membranes (MPMs) and changes in bacterial numbers during midgut metamorphosis were st udied in Anopheles punctipennis (Say), Culex pipiens (L.), and Aedes aegypt i (L.) pupae and newly emerged adults. After adult emergence in Aedes, Anop heles, and most Culex, there were few to no bacteria in the midgut. In most newly emerged adult mosquitoes, few bacteria were found in either the lume n or within the MPMs/meconia. In a few Culex specimens, high numbers of bac teria were found in the MPMs/meconia and low numbers in the lumen. In all t hree species bacterial counts were high in fourth instars, decreased after final larval defecation, increased in young pupae, and increased further in old pupae. A very effective gut sterilization mechanism is operating durin g mosquito metamorphosis and adult emergence. This mechanism appears to inv olve the sequestration of remaining larval gut bacteria within the confines of the meconium and one or two MPMs and the possible bactericidal effect o f the exuvial (molting) fluid, which is ingested during the process of adul t emergence.