Chill tolerance (time of survival at -5?C) increased in non-diapausing (reproducing) adults of Pyrrhocoris apterus after a gradual, 4-week-long decrease in ambient temperature from 25? to 0?C. The level of chill tolerance attained after cold-acclimation was considerably lower than that in similarly cold-acclimated diapausing adults. Some physiological changes accompanied the cold-acclimation, irrespective of developmental state (diapause vs. reproduction). They were: A decreased oxygen consumption, loss of body water, an increased haemolymph osmolality, an increased proportion of phosphatidylethanolamines vs. a decreased proportion of phosphatidylcholines in membrane phospholipids, and an increased proportion of linoleic vs. a decreased proportion of oleic acid in phosphatidylethanolamines. Such changes could contribute to the limited potential for cold-acclimation found in non-diapausing insects. Other physiological changes appeared to require the induction of diapause prior to cold-acclimation. They were: Down regulation of ice nucleators resulting in a lowering of the individual supercooling point, synthesis and accumulation of specific "winter" polyols, an increased proportion of palmitic acid in membrane phospholipids; and regulation of the concentrations of Na⁺ and K⁺ in the haemolymph. The potential contributions of these changes to the cold hardiness of P. apterus are discussed.

Domestic gardens supply pollinators with valuable habitats, but the risk of exposure to pesticides has been little investigated. Artificial nesting shelters of a red mason bee species (Osmia bicornis) were placed in two suburban gardens and two commercial fruit orchards to determine the contamination of forage sources by pesticides. Larval pollen provisions were collected from a total of 14 nests. They consisted mainly of pollen from oaks (65–100% weight/sample), Brassicaceae (≤34% w/s) and fruit trees (≤1.6% w/s). Overall, 30 pesticides were detected and each sample contained a mixture of 11–21 pesticide residues. The pesticide residues were significantly lower in garden samples than in orchard samples. The difference was attributed mainly to the abundant fungicides pyrimethanil and boscalid, which were sprayed in fruit orchards and were present on average at 1004 ppb and 648 ppb in orchard samples, respectively. The results suggested that pollinators can benefit from domestic gardens by foraging from floral sources less contaminated by pesticides than in adjacent croplands.

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