Modelling winter survival mating and trapping of Queensland fruit fly in Auckland New Zealand

In February 2015 an established population of the Queensland fruit fly (Qfly Bactrocera tryoni) was detected in Grey Lynn Auckland It was questionable whether Qfly might successfully overwinter in Auckland and how trap efficacy and mating behaviour would be affected by winter conditions During the official biosecurity response to eradicate Qfly these questions were addressed using published Qfly models that had been developed and parameterised from biological data from its native range A model for cold acclimatisation suggested that Auckland winters would not be sufficiently cold to cause significant mortality of adult Qfly but substantial cold mortality might occur in more southern locations The temperature requirement for mating suggested mating would be relatively rare from June to October and two models for relative trap efficacy suggested that traps would be relatively ineffective until late spring (OctoberNovember) The Ministry for Primary Industrys biosecurity response was successful with no detection of Qfly after March 2015 and eradication formally declared in December 2015

β-1,3-glucanase and chitinase activities in winter triticales during cold hardening and subsequent infection by Microdochium nivale

The accumulation of pathogenesis-related proteins such as β-1,3-glucanases and chitinases was studied in cold induced snow mould resistance in two Polish cultivars of winter triticale, cv. Hewo and cv. Magnat that substantially differ in resistance to Microdochium nivale. The plants were pre-hardened at 12°C for 10 days and hardened at 4°C for 28 days. Subsequently, cold hardened plants were inoculated with fungal mycelium (M. nivale) and incubated at 4°C for 7 days in dark. Cold acclimatisation resulted in suppression of the total glucanase and chitinases activities in the resistant Hewo as well as sensitive Magnat cultivars that possibly coincides with altered metabolism. However, upon infection with M. nivale the chitinases were markedly induced in the cv. Hewo. At the same time, total β-1,3 glucanases activities did not seem to be affected by fungus in any of the tested triticale cultivars. The pattern and/or the activity of chitinases in plants might be indicative for the resistance/susceptibility against M. nivale.

The ultrastructure of quiescent buds of Tilia europaea

Shoot apices from quiescent axillary buds of the European linden tree were collected at three periods during the winter and prepared for electron microscopy by freeze-fracturing without pretreatment (i.e., no chemical fixation or glycerol infiltration). Cell structures were well preserved and not damaged by ice crystal formation. Tissue fine structure was comparable with other winter-quiescent tissues (particularly cambia) and showed the following characteristics: plentiful oil droplets, smaller quantities of other storage materials (protein, starch), inactive dictyosomes, and unusual arrangements of endoplasmic reticula (particularly a peripheral reticulum). Oil droplets were not bounded by a membrane. The quantity of oil (by cytoplasmic volume) declined steadily through the winter, presumably fuelling metabolic activity. The relatively flaccid condition of plasma membranes indicated that osmotic pressure was similar inside and outside the cells. Membrane-particle partition coefficients (Kp) between plasma membrane fracture moieties was unusual (< 1), and the significance of this observation in relation to cold acclimatisation is discussed. The appearance of the mouths (neck constrictions) of plasmodesmata changed between midwinter (closed) and early spring (open) and the observations are interpreted to indicate dynamic changes in a sphincter controlling intercellular exchange.