Impacts of Antibiotic and Bacteriophage Treatments on the Gut-Symbiont-Associated Blissus insularis (Hemiptera: Blissidae).
The Southern chinch bug,Blissus insularis, possesses specialized midgut crypts that harbor dense populations of the exocellular symbiontBurkholderia. Oral administration of antibiotics suppressed the gut symbionts inB. insularisand negatively impacted insect host fitness, as reflected by retarded development, smaller body size, and higher susceptibility to an insecticide, bifenthrin. Considering that the antibiotics probably had non-lethal but toxic effects on host fitness, attempts were conducted to reduce gut symbionts using bacteriophage treatment. Soil-lytic phages active against the cultures of specificBurkholderiaribotypes were successfully isolated using a soil enrichment protocol. Characterization of the BiBurk16MC_R phage determined its specificity to the Bi16MC_R_vitro ribotype and placed it within the family Podoviridae. Oral administration of phages to fifth-instarB. insularis, inoculated with Bi16MC_R_vitro as neonates had no deleterious effects on host fitness. However, the ingested phages failed to impact the crypt-associatedBurkholderia. The observed inactivity of the phage was likely due to the blockage of the connection between the anterior and posterior midgut regions. These findings suggest that the initial colonization byBurkholderiaprograms the ontogeny of the midgut, providing a sheltered residence protected from microbial antagonists.
Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA. bigantbrl@hotmail.com.
Yao
Y
Xu
Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA. eabuss@ufl.edu.
Eileen A
EA
Buss
Department of Entomology and Nematology, University of Florida, Gainesville, FL 32611, USA. pathos@ufl.edu.
Drion G
DG
Boucias
Blissus insularis; Burkholderia; antibiotics; fitness; midgut crypts; podovirus