Phenology and Crypsis as Possible Determinants of Habitat Selection in Populations of Hemineura bigoti from Central Spain (Psocoptera: Elipsocidae)
Hemineura bigoti Badonnel 1970 belongs to a Psocid genus where species overwinter as adults. During an ecological study on the arboreal Psocoptera of Central Spain, it has been found that populations of H. bigoti are denser on Genista scorpius bushes than on both Rosmarinus officinalis and Cistus laurifolius. G. scorpius bushes lose their leaves during the winter and remain completely green during the summer. R. officinalis and C. laurifolius, which are also used as substrate plants by H. bigoti, remain green throughout the year. A field experiment conducted in April, when various foliage stages are recognizable in G. scorpius plants, demonstrates that populations of H. bigoti are significantly greater on dried than on green Genista bushes. Individuals of H. bigoti are notably homochromous with dried Genista bushes, both being variegate grey in colour. H. bigoti also shows a hiding behaviour, unique among Hemineura species, which consists in revolving round the Genista shoots and so keeping out of sight of possible predators. Colour and phenological pattern are common features of all species of Hemineura. The selection of G. scorpius as substrate plant by H. bigoti seems to be a phenomenon limited to the central regions of the Iberian Peninsula. This phenomenon may be presumably favoured by the close agreement between the phenology of H. bigoti and the time period in which G. scorpius remain dried.