Dr. Kassai Tibor szerk.: Parasitologia Hungarica 2. (Budapest, 1969)
vantage from the presence or absence of other flea species. The food requirements of the larvae and fully developed fleas hardly differ. And it would be unreasonable to suppose that some smaller-sized flea would have less food because of the presence of the large-sized Hystrichopsylla talpae orientális . There is no information to suggest that any one of the species could interfere with the feeding or reproduction of others. (One might presume disadvantages arising from the presence of certain species to coexisting species in only one case: viz, if some favourable circumstances enabled one species to overproliferate in a habitat /nest, burrow, litter/, though even then the members of the minority species might obtain less food only in proportion to the number of individuals of the species.) 3. A comparison of Tables 5 and 6 fully identifies those species which seldom or never associate with other species. The following were never found in specific associations: Chaetopsylla rothschildi , Ischnopsyllus octactenus , I. simplex mysticus , I. s. simplex , Leptopsylla segnis , Rhinolophopsylla u. unipectinata . .The species Archaeopsylla e. erinacei , Ischno psyllus variabilis , Nycteridopsylla eusarca , Rhadinopsylla pen- tacantha , and Rh.strouhali occurred together with other species in one case only. The majority of these species, having noTtendency to appear in the company of others, have been collected a few times only; most of them are probably truly rare, but there may be some which appear to be rare only because their hosts also occur infrequently in Hungary, or because of some aspect of collection. It should be emphasized again that the number of rare flea species is considerably less than we think and we are rather inclined to regard those which are seldom captured as rare whereas the cause of this phenomenon actually lies in faults of the collecting apparatus or techniques. If the species mentioned above are captured several times in future collections, they might also be found to coexist with other species. However, in the case of species which are frequent and still fail to occur in the company of others, the possibility remains that,for some unknown reason they have no „inclination"
