Aspectos da associação entre ácaros foréticos e Pseudolynchia canariensis (Macquart, 1839) (Diptera, Hippoboscidae)

Abstract

With the objective of evaluating the ecological aspects of the populations and component communities of mites on the pigeon fly Pseudolynchia canariensis, an ectoparasite of the common pigeon, Columba lívia, 156 specimens of P. canariensis were collected from pigeons captured in Juiz de For a municipality, Minas Gerais, Brazil. The birds were examined manually and the P. canariensis specimens were placed in 70ºGL alcohol. All the mites and eggs were counted and some were removed for clarifying and mounting on slides. The population and spatial aggregation indices were calculated. In the 156 specimens of P. canariensis analyzed, 236 phoretic mites were found, with a prevalence of 47.44% (n = 74). The prevalence for Myialges anchora was 23.72% (n = 37), with 54 individuals, mean intensity of 1.46 ± 0.90 and mean abundance of 0.35 ± 0.76. In 94.44% of the infested flies, M. anchora was found on the abdomen (n = 51), 3.70% on the head (n = 2) and 1.85% on the leg (n = 1), and 75.93% (n = 41) were surrounded by ovigerous masses, giving an average of 16.43 ± 14.44 eggs per female and 21.63 ± 12.46 eggs per ovigerous female. For Myialges lophortyx, the prevalence was 13.46% (n = 21), with 62 individuals, mean intensity of 2.95 ± 2.75 and mean abundance of 0.397 ± 1.41. Of these, 41.94% of the specimens were found on the right wing (n = 26) and 58.06% on the left wing (n = 36). The majority of the exemplars (46.77%; n = 29) were adhering to the base M1+2, 19.35% (n = 12) at the M3+Cu1, 12.90% (n = 8) at the R3, 11.29% (n = 7) at the R1 and 4.84% (n = 3) at the Cu2. Of the M. lophortyx observed, 72.58% (n = 45) presented xv ovigerous masses, with an average of 4.56 ± 3.42 eggs per female and 6.29 ± 3.04 eggs per ovigerous female. The prevalence of Ornithocheyletia hallae was 23.72% (n = 37), with 120 individuals, mean intensity of 3.24 ± 4.47 and mean abundance of 0.77 ± 2.56. There were simultaneous infestations on 28.38% (n = 21) of the flies: 66.67% (n = 14) by M. anchora and O. hallae; 19.05% (n = 4) by M. lophortyx and M. anchora; the same value for M. lophortyx and O. hallae. One fly (4.76%) was infested by all three species. The component communities showed an aggregate distribution with a dispersion index (di) > 1. The species O. hallae was the most highly aggregated (K = 0,145), M. anchora and M. lophortyx had the same value of K (0.552). These are the first reports of spatial aggregation of phoretics of this species of mites on P. canariensis or any other species of Hippoboscidae.