Research Note

BACTERIA ASSOCIATED WITH THE WEST INDIAN OBLIQUA (MACQUART) (DÍPTERA: )* Current quarantine research with the room temperature greatly influenced bacte­ West Indian fruit fly, Anastrepha obliqua, rial growth. Hydrochloric acid (1M) concen­ by the University of -Agricul- trations of 15 ml per liter of -agar tural Experiment Station has required mass diet (pH 5.6) allowed unrestricted bacterial rearing of the for artificial infestation growth, whereas 30 ml and 40 ml HC1 per of fruit. Initially, bacterial contami­ liter (pH 4.9 and 4.4, respectively) reduced nation of larval-rearing media was a persis­ or inhibited bacterial growth. Analogously, tent fruit fly breeding problem. Since this little bacterial development was observed at situation has been previously reported temperatures at or below 27° C. Tempera­ about other members of this genus,2's we tures at or above 30° C largely worsened have isolated and characterized the most bacterial contamination problems. High lar­ common bacterial contaminants encoun­ val mortality was often associated with en­ tered while rearing the larvae, hanced bacterial growth under high temper­ Bacterial contaminants were isolated ature conditions (i.e., 30° C). Similar condi­ tions have been described by Greany et al. and purified from rearing media with stand­ 4 ard microbiological methods. Plate-count in for the close ally A. suspensa. agar was used as culture medium and incu­ Internal location of in adult bated at 35° C. Gram-negative bacteria from was determined after surface sterilization of pure colonies were subsequently charac­ the entire body in 0.15% NaOCl for 2 min­ terized with the API 20E system to identify utes. We dissected laboratory-reared and Enterobacteraceae and other gram-nega­ field-collected fruit flies and removed their tive bacteria (API Diagnostics, Div. Sher­ reproductive and digestive systems. Organs wood Medical, 200 Express St., Plainview, were surface-sterilized as described and New York 11803). placed on nutrient agar plates. Enterobacter Most prevalent bacteria isolated were cloacae, S. marcescens and Pseudomonas Enterobacter cloacae, followed by sp. were isolated from male and female di­ Pseudomonas sp. and Serratia marcescens. gestive tracts. Pseudomonas sp. was the Enterobacter cloacae and Pseudomonas sp. only bacteria isolated from testicles and have been isolated from A. suspensa and its ovaries. Bacteria appear to be transmitted Bwsteres longicaudatus.* We ob­ to offspring through surface contamination served that larval medium pH and rearing of from ovarial and proctodaeal

'Manuscript submitted to Editorial Board 9 November 1987. sMallory Boush, G., S. M. Saleh and R. M. Baranowski, 1972. Bacteria associated with the Caribbean fruit fly. Environ. Entomol. 1: 30-33. aRubio, R. E. P. and M. W. McFadden, 1966. Isolation and identification of bacteria in the digestive tract of the Mexican fruit fly, (Díptera: Tephritidae). Ann. Entomol. Soc. Am. 59: 1015-016. 4Greany, P. D., G. E. Allen, J. C. Webb, J. L. Sharp and D. L. Chambers, 1977. Stress-induced septicemia as an impediment to laboratory rearing of the fruit fly parasitoid Biosteres (Opius) longicaudatus (Hymenoptera: ) and the Caribbean fruit fly Anastrepha suspensa (Díptera: Tephritidae). J. Invert. Pathol. 29: 153-61. 489 490 SEGARRA-CARMONA ET AL./ANASTREPHA sources. Bacterial colonies failed to grow on larval crowding and temperature control at 0.15% NaOCl surface sterilized eggs. 27° ± 2° C. These measures have efficiently Sodium benzoate (0.03%) solutions routinely controlled most of the bacterial contamina­ used in rearing procedures did not seem to tion problems encountered in our colonies. affect bacterial growth. Most researchers Alejandro E. Segarra-Carmona recommend optimization of larval culture Carlos N. Torres-Rivera conditions as a preferred measure of bacte­ Jaime Escudero rial control.4'6 Cultural improvements in Department of Crop Protection rearing techniques of A. obliqua in our in­ Angel A. Ortiz vestigation have included proper sanitation, Juan Acevedo Alfaro regular sterilization of cages, keeping larval Winia Gonzalez Figueroa diet pH below 4.9, avoidance of adult and of Biology

5Kamasaki, H., 1970. Some pathogens and pests associated with tephritid flies in the laboratory. /. Econ. Entomol. 63: 1353-355.