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April 2017. Aphids, ants and interestingly, maggots were found on potted capsicum plants in a garden in Fiji. These were reared. They have one pair of wings, about 1 cm in length and wingspan of about 2 cm. Some of the maggots jumped off the plants. They do not seem to be doing damage. Are these maggots after the honey dew from the aphids or the aphids themselves.
It was thought to be a hoverfly, Ischiodon scutellaris (Syrphidae). They are aphid predators. This species has been recorded from Fiji along with several other species. Most of these predate aphids or other Homoptera. During their larval stage they feed voraciously on aphids and can be valuable natural enemies.
A member also wrote, “your description of them “jumping off” probably made people think that they might be Tephritid fruit fly larvae that do literally jump. But Tephritid larvae look completely different and do not dwell on leaves. Hoverfly larvae do not jump like fruit fly larvae.
“FYI, we have done a lot studies on hoverfly larvae recently because they are so common on Solanum crops in New Zealand, and are particularly important predators of the new pest, tomato potato psyllid, also aphids and small caterpillars on outdoor potatoes. They become the dominant foliage-dwelling predator on many vegetable crops in New Zealand in early summer, and will predate on everything they come across on leaves, including other predators and small brothers and sisters. So, they are the “”lion”” of the vegetable crop, being the top predator. They displace our common brown lacewing on potato plants and will even eat ladybird beetle larvae.
“Our behaviour studies show that the female normally lays more than 1 egg on a leaf, often a small batch of 2 to 3 eggs. When they hatch and cannot find other food (small insects) they sustain themselves on their siblings, while they wait for other insects to arrive on their plant! So, you often find a variety of different insects on a plant, and come back a few days later and only find one big fat hoverfly larva. It has eaten everything else. So, it’s a great crop protector, living on the plant and pupating there as well.
“A flower source for the females will increase their local abundance a lot (3-4 times the number per plant). So, flower sources close to crops are good reservoirs for non-flowering vegetable crops, such as cabbage and lettuce”.
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