The feeding behaviour, activity and trappability of wild female Glossina pallidipe in relation to their pregnancy cycle

Female Glossina pallidipes Austen trapped with baited NG2B traps were subjected both to detailed ovarian dissection and to nutritional analysis. Using a calibration curve derived from dissected wild-caught, laboratory-held flies, the field females were assigned by discriminant analysis to each day of the pregnancy cycle. Field females were most available to NG2B traps while carrying the first instar larva. The nutritional characteristics of trapped field females over the pregnancy cycle lead to the following main conclusions. (i) Fat levels increase most rapidly during the egg in utero stage, while CRDW increases significantly only during the larval stages, culminating in a 4 mg increase during the last day of the third larval instar. (ii) The haematin content of the flies indicates that females feed at approximately 3-day intervals and may feed on any day of the pregnancy cycle. (iii) The estimated time of feeding during the day corresponds with the observed time of peak activity, both of which are earlier in the day later in the pregnancy cycle. (iv) The rate of fat usage reveals significantly greater flight activity on day 5 of the cycle than on other days, agreeing with the high trappability on this day, and overall females appear to use fat at twice the rate of males. Reproductive data provide a much more accurate picture of the relative sampling efficiency than do nutritional data, although the latter reveal the general trends correctly.     

Investigations on fungicides.

Uninoculated roots of pea (Pisum sativum) and French bean (Phaseolus vulgaris) have been shown to exude a number of antifungal compounds when grown in a non-sterile aqueous aerated medium. These have been identified and their possible importance in relation to disease resistance is discussed.     

Seed dispersal effectiveness increases with body size in New Zealand alpine scree weta (Deinacrida connectens)

Weta are giant, flightless orthopterans that are endemic to New Zealand. Although they are known to consume fleshy fruits and disperse seeds after gut passage, which is unusual among insects, their effectiveness as seed dispersal mutualists is debated. We conducted a series of laboratory experiments on alpine scree weta (Deinacrida connectens) and mountain snowberries (Gaultheria depressa) to investigate how fruit consumption rates, the proportion of ingested seeds dispersed intact and weta movement patterns vary with weta body sizes. On average weta dispersed 252 snowberry seeds nightly and travelled at a rate of 4 m min^?1. However, seed dispersal effectiveness varied over three orders of magnitude and was strongly associated with body sizes. Smaller weta consumed few snowberry seeds and acted primarily as seed predators. On the other hand, the largest weta consumed and dispersed thousands of seeds each night and appear to be capable of transporting seeds over large distances. Overall results indicate that scree weta shift from being weakly interacting seed predators to strongly interacting, effective seed dispersers as they increase in size.