Diet experiments
It was found that if newlv hatched larvae were fed the natural host scale for at least
2 days, before being fed artificial diet, their survival and subsequent development was
enhanced, compared with completely artificially fed larvae. Summaries are given for 1
test with C. bipmtulatm larvae first fed on scale for 2 days before being fed the wasp and
bee brood diets; and 1 test with C. cacti larvae first fed on scale up to 2nd and 3rd instar
before being fed the 3 artificial diets (Tables 2 & 3). The percentage of adults obtained
from the larvae in each treatment is given as the % yield, and the mean larval plus pupal
period combined is given as MLP ( f standard error) in days, from hatching of larvae
to emergence of adults from pupae.
In an experiment to test the effects of larval diet on adult weight (Table 4), 3 groups
of C. cacti larvae were fed different proportions of artificial diet and/or natural host scale.
One group was reared entirely on scale, 1 group was reared entirely on artificial diet
(the wasp brood diet), and the third group was fed on scale from hatching until second,
third or early 4th instar, then transferred to artificial wasp brood diet and reared to
pupation. The adults obtained from these larvae were weighed after emergence from their
pupae and as soon as they had hardened.
Adult C. infernalis reared on scale insects as larvae, were fed the wasp brood diet when
first imported and held in quarantine. Between 25 and 44 adults were kept in each of
3 boxes containing a water wick, the wasp brood diet sprinkled on the floor, and double
muslin gauze egg laying strips. Eggs were collected every second or third day over a
2 week oviposition period.