Nymphal development and lerp construction of Glycaspis sp. (Hemiptera: Psylloidea) on Eucalyptus sideroxylon (Myrtaceae) in central-west New South Wales, Australia.

The ability to form lerps is common in Australian Psylloidea. Various species of Glycaspis Taylor (Aphalaridae) form conical lerps on different species of Eucalyptus. Lerps, being a rich sugar source, are preferentially fed by bell miners (Aves: Meliphagidae). In this paper we report the process of lerp construction by a purported new species of Glycaspis living on Eucalyptus sideroxylon. This taxon constructs lerps with anal sugary exudates first building the ribs of the lerps and later filling the space between the polymerized ribs with horizontal tractions of the same sugary substance. Developmental events in this taxon do not follow Dyar's rule strictly. Oviposition induces a non-lethal hypersensitive response in the host leaf. Population trends assessed in 2011-2012 and 2012-2013 showed distinct variations, which have been related to environmental factors. In the 2012-2013 sampling, oviposition occurred preferentially proximally to leaf cracks (possibly induced by intense frost events); we infer that this could be a strategy of this taxon to establish an 'easier' access to moisture. Sensillar designs vary between the nymphal instars and adults. The trichoid sensilla and sensillar cavities on the antennae perform mechanosensory and olfactory functions. The mouthpart complex includes a relatively long stylet bundle.