A. Carpenter

The rise and fall of manuka blight scale: a review of the distribution of Eriococcus orariensis (Hemiptera: Eriococcidae) in New Zealand

The decline in abundance and distribution of the manuka blight scale insect, Eriococcus orariensis Hoy, between the 1950s and 1997/99 is described. Manuka blight was discovered about 1937 in the Orari Gorge, Mid-Canterbury, and by 1958 had become widespread throughout New Zealand. Despite intensive searches in 1997/99, the scale was found on only five out of 27 samples of manuka (Leptospermum scoparium) from 23 sites around New Zealand. A dramatic decline of manuka blight scale, and its displacement by the less noxious species, Eriococcus leptospermi Maskell, in a period of little more than 40 years has occurred. This survey shows that in recent years sooty mould is mainly caused by E. leptospermi rather than E. orariensis.

Effect of day length on development and reproductive diapause in Nysius huttoni White (Heteroptera, Lygaeidae)

Abstract:  Nysius huttoni White is endemic to New Zealand and an important pest of wheat and brassica crops. To provide critical information for pest forecast, management and quarantine inspection, we investigated the effect of day length on the growth, development and reproductive diapause of this pest under a series of photoperiodic regimes: 16 : 8, 14 : 10, 12 : 12 and 10 : 14 h [light : dark (L : D)]. Long day lengths [16 : 8 and 14 : 10 h (L : D)] promote a continuous lifecycle while short day lengths [12 : 12 and 10 : 14 h (L : D)] slow up the growth and development, prolong the pre‐mating period, and induce the reproductive diapause. The absence of oviposition for approximately 30 days is recognized as the criterion for N. huttoni reproductive diapause definition. When all life stages are kept under the short day length conditions, only 60–73% of females enter reproductive diapause; if the exposure to short day lengths starts in late instar nymphs, 100% of females enter reproductive diapause. If only adults experience short day lengths, does diapause incidence fall in between, with up to 26% of females laying a few eggs before entering diapause. The critical photoperiod for the induction of reproductive diapause falls between 13.3 : 10.7 and 13.5 : 10.5 h.

Effects of treatment with elevated carbon dioxide levels on the sensory quality of asparagus

Abstract Asparagus spears (Asparagus officinalis L. cv. Limbras 10) were stored for 3–5 days in atmospheres containing between 40 and 90% carbon dioxide (CO2) to evaluate the effect of insecticidal CO2 atmospheres on sensory quality based on sensory panel ratings of characteristic asparagus flavour, off‐flavours, flavour acceptability, andoverall acceptability. Sensory quality of spears after 4 days storage in 60% CO2 was similar to air‐stored spears but 5 days storage caused deterioration in the CO2‐stored spears relative to the air‐stored spears. Using higher CO2 levels than this for shorter storage times resulted in spears with CO2 injury and poor sensory quality. Spear quality deteriorated with shelf period but previous CO2 treatment did not affect the rate of deterioration. Storing spears at 5°C in 60% CO2 or 0°C in air gave consistently higher (lower for off‐flavours) sensory quality ratings for all characteristics assessed than vice versa. Thick spears had more flavour and were more acceptable than...

Chemical treatment of porina eggs to prevent loss of viability in culture

Treatment of porina (Wiseana spp.) (Lepidoptera: Hepialidae) eggs with copper oxychloride enhanced the viability of the eggs in laboratory cultures. A commercially available wettable powder fungicidal formulation of copper oxychloride was more effective than formalin, asulam, captan, chlorthal-dimethyl, or maldison.