Studies onRhodnius prolixus: growth and development of normal and sterile bugs, and the symbiotic relationship

The growth and development of normal and sterile (i.e. symbiont-free)Rhodnius prolixusare compared. The last three instars of sterile bugs weigh less than normal ones. Sterile insects completed the first three stages of their life-histories in less time than normal insects, and at the fourth stage, nutritional deficiencies had profound effects on their further development. 2. The sensitivity of theRhodniussymbionts,Nocardia rhodnii,to five antibiotic substances is determined. Terramycin, aureomycin and chloramphenicol are effective inhibitors. 3. The symbiotic condition inRhodniusand the related bug,Triatoma infestans,is discussed.