M. Castagnoli et S. Simoni, Effect of long-term feeding history on functional and numerical response of Neoseiulus californicus (Acari : Phytoseiidae), EXP APPL AC, 23(3), 1999, pp. 217-234
The functional and numerical responses of the predatory mite Neoseiulus cal
ifornicus to eggs and protonymphs of Tetranychus urticae were studied on ex
cised strawberry leaflet discs under laboratory conditions (25 +/- 1 degree
s C, 75-85% RH and 16L:8D). Four strains of the phytoseiid were compared: t
hree originated from a long-term mass-rearing with different food (T. urtic
ae, Dermatophagoides farinae and Quercus spp, pollen) and under controlled
conditions, while the fourth was directly collected from a natural environm
ent and therefore considered a wild strain. The different nutritional histo
ries affected the responses of N, californicus on tetranychids. On the whol
e, the wild strain gave better performance. When egg prey was administered
this strain and the one mass-reared on two-spotted spider mites showed simi
lar functional as well as numerical responses; on the contrary, when proton
ymphs were furnished, the wild strain did not differ from that mass-reared
on pollen. The strain previously fed on house dust mites gave the worst per
formance and also showed the lowest percentages of females in the progeny.
The functional responses obtained were predominantly type II curves. In all
cases considered, no stored energy was allocated for reproduction and, wit
h the exception of the wild strain on eggs, the prey was exploited less eff
iciently as the consumption increased. In spite of the differences evidence
d in this experiment all strains were characterized by high predation and o
viposition rates. Thus the results obtained suggest no drawbacks in the use
of mass-reared N. californicus as biocontrol agents. Exp Appl Acarol 23: 2
17-234 (C) 1999 Kluwer Academic Publishers.