Biology and behaviour of Ephestiasula pictipes (Wood-Mason) (Hymenopodidae: Mantodea) under captive breeding

The biology and behaviour of a common predator in cashew plantations, Ephestiasula pictipes (Wood-Mason), were studied under captivity for three seasons using greater wax moth larvae as prey. During Feb–May, incubation and nymphal developmental period were shorter when compared with Jun–Sep and Oct–Jan. The female mantids laid ootheca once in every 3–4 days, for a period of 70–77 days. Adult longevity and oviposition period were significantly higher during Feb–May, while no significant difference was observed in sex ratio, oviposition interval and pre oviposition period during different seasons. Sexual behaviour consisted of preliminary courtship and copulation, involving 14 activities in sequence. Duration of mounting, copulation and riding around on the female by the male widely varied from 2 min to 28 h; 5.15 to 6.10 h; and 2 to 74 h, respectively. High fertility, high fecundity, shorter life cycle, multivoltinism and feasibility of laboratory rearing throughout the year are the advantageous features of E. pictipes that permits for its mass rearing and emergence as a viable biocontrol agent in future.     

The relation between phosphine sorption and terminal gas concentrations in successful fumigation of food commodities

Owing to increased tolerance and the development of resistance in stored product insects to the fumigant phosphine, in recent years there has been a shift in the target terminal concentration from 100 ppm (100 mL m(-3)) to a higher level of 1000 ppm to achieve 100% insect mortality in 7 day commodity treatments. Therefore, there is a need to investigate whether the revised target concentration could be achieved for food commodities fumigated with phosphine at the standard dose of 2 g m(-3) for 7 days under airtight conditions at > or = 25 degrees C. When different types of food commodity (total 74) were fumigated (300 g per replicate) with phosphine at 2 g m(-3) for 7 days, the terminal gas concentrations in the free space of the commodities varied from 0 to > 2000 ppm. In chambers containing no substrate, a 1417 ppm concentration was recorded. Paddy rice, most of the oilseeds, shelled tree nuts, butter beans, cardamom, green gram splits, coriander powder, rice bran and cocoa powder were more sorptive (> or =60%), such that the target concentration of 1000 ppm was not achieved at the end of 7 days. For these commodities, increased doses of 3-6 g m(-3) were required to attain 1000 ppm. In-shell almonds, green cardamom, in-shell peanuts, leaf tea, tamarind pulp and sunflower seeds were exceptionally sorptive (>90%), so that 0, 41, 112, 168, 203 and 217 ppm respectively were noted at the end of 7 days; the dose must exceed 6 g m(-3) for effective fumigation of these commodities.     

The influence of seed maturation on desiccation tolerance in Phalaenopsis amabilis hybrids

The Orchidaceae contains a large number of threatened species that could benefit from seed banking. However, successful seed storage requires a greater understanding of the enigmatic seed biology of orchids. In particular, there is little documentation of the presence or timing of the maturation drying that has been shown to be critical for longevity of agricultural seeds in storage. The aims of this work were to document seed water content, germinability and desiccation tolerance as a function of maturation in developing capsules of hand-pollinated flowers of Phalaenopsis hybrids. Lengthening of capsules was complete by 50 DAP, but capsule diameter continued to increase up to a maximum at 70 DAP. Relative water content rapidly declined from 75% moisture content (fresh weight basis) at 150 DAP to 50% moisture content at 165 DAP where it remained until dehiscence. Seed germinability remained high (75–99.5%) throughout the harvesting period (90–216 DAP), but desiccation tolerance only developed 165 days after pollination. Therefore, if Phalaenopsis seeds are to be stored, we propose that their harvest should be delayed until moisture content drops below 50%.