caa a22 4500 469096039 CHVBK 20180323133031.0 cr unu---uuuuu 170328e19921201xx s 000 0 eng 10.1007/BF00317462 doi (NATIONALLICENCE)springer-10.1007/BF00317462 Coexistence of ecologically similar colonising species III. Drosophila aldrichi and D. buzzatii: larval performance on, and adult preference for, three Opuntia cactus species [Elektronische Daten] [Robert Krebs, J.S.F. Barker, Tim Armstrong] Two Drosophila species, D. buzzatti and D. aldrichi, coexist on several species of Opuntia cacti in Australia, primarily on O. tomentosa and O. streptacantha in the northern part of the cactus distribution, and on O. stricta in the south. Thorax length of field-collected adults was less, and the variance in length greater, than that for flies reared on simulated rots in the laboratory, indicating that these species are affected by crowding in nature. A larval performance index, measured on simulated cactus rots at low, moderate and high densities in single-species cultures, and at moderate and high densities in mixed-species cultures, was used to compare the relative intensity of intra- and interspecific competition at the same total larval density per 5 g necrotic cactus. Larval performance of both fly species was greatest on O. streptacantha, intermediate on O. tomentosa, and least on O. stricta in both single-species and mixed-species cultures. On O. stricta, the performances of D. aldrichi and D. buzzatii were not different when in single-species cultures, but that of D. aldrichi decreased significantly in mixed-species cultures. On the other two cactus species, the performances of D. aldrichi and D. buzzattii were not different in mixed-species cultures. The order of preferences by adult females for the cacti differed from that for larval performance, with females of both species prefering O. stricta. Analysis of microbial numbers growing on the cacti showed little difference among cacti at the rot age used for testing adult preference, but later growth was greater on O. tomentosa and O. streptacantha, the cacti that best supported larvae. Differential larval performance on O. stricta may contribute to the rare presence of D. aldrichi in the southern part of the cactus distribution, while the superior quality of O. tomentosa and O. streptacantha (larger rot size and higher microbial concentration) may reduce competition and facilitate cocxistence of the fly species in the north. Springer-Verlag, 1992 Larval competition nationallicence Microbial ecology nationallicence Olfactometer nationallicence Host plant preference nationallicence Krebs Robert Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut Barker J.S.F. Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut Armstrong Tim Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut Oecologia Springer-Verlag 92/3(1992-12-01), 362-372 0029-8549 92:3<362 1992 92 442 https://doi.org/10.1007/BF00317462 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00317462 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Krebs Robert Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut NATIONALLICENCE 700 1- Barker J.S.F. Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut NATIONALLICENCE 700 1- Armstrong Tim Department of Animal Science, University of New England, 2351, Armidale, NSW, Australia aut NATIONALLICENCE 773 0- Oecologia Springer-Verlag 92/3(1992-12-01), 362-372 0029-8549 92:3<362 1992 92 442 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer