pesky little hoppers

With the new house came a long drive lined with agapanthus. My mother would have said, "the dreaded agapanthus", & she wouldn’t have been far wrong. I don’t like the things very much; they spread very vigorously & I tend to view them as a weed. (I see from Te Ara that Biosecurity New Zealand was looking at calling for a nationwide ban on the plants, back in 2007. I wonder what happened with that? Where we live now, every second house has agapanthus in the garden.) Still, we haven’t really given any thought to what we might replace them with, so the agapanthuses (agapanthi?) have had a reprieve for the moment. And this means that I have to cut back all the spent flowerheads – a bit before they’ve finished flowering, actually, so as to minimise the chances of them setting (& spreading) seed.

This is a bit of a back-breaking job, as it happens, bending down to cut the stems off low. (The Significant Other suggested going hell-for-leather with the pruning shears but that would make an awful mess.) But it’s given me a good view of what’s living in the leaf clumps – & as far as I can tell, it’s mostly passion-vine hoppers (Scolypopa australis. The pesky little things keep flying up & landing on the inside of my glasses & it’s a bit unnerving, I can tell you, to have blurry brown things creeping round in front of your eyes! (For those not familiar with these little beasties, there are some lovely images by Phil Bendle here.)

The adults are about 10mm long, with dark grey-brown bodies & transparent wings supported by a lattice of dark brown veins. The nymphs (juvenile form) are quite different, with creamy white bodies marked with brown spots, and the most wonderful collection of bristles sticking out of their rear ends – reminiscent of an arthropodan shaving brush. Both nymphs & adults feed by inserting long pointed mouthparts (rather like hypodermic needles) into the phloem of plant stems, an efficient if rather vampiric way of getting nutrients as they don’t even have to suck: because phloem is moved around the plant under positive pressure, the animals just have to sit there & breakfast, lunch & dinner simply flow into their guts.

This is quite a cool trick, actually, because the layer of phloem tissue in a stem is very thin, just a few cells thick, & before modern technology came along it was very difficult for an enquiring botanist to insert a needle into the phloem for purposes of measuring flow & nutrient content. This problem was overcome by using aphids, which are also little plant-suckers. Once an aphid had got its mouthparts nicely into the phloem, the scientists wouldcut the insect’s body off just behind its head. The disembodied head remained attached to the plant by its embedded mouthparts, & phloem sap would continue to flow through it for several days.

Because aphids, hoppers & the like are tapping directly into a plant’s nutrient transport system, a heavy infestation can be quite debilitating for the plant. (Not that this seems to be the case for our dreaded agapanthi; their growth is revoltingly vigorous.) The female hoppers cut little slits in the stem in which to lay their eggs, thus creating an opening for infection which can result in die-off of the affected parts. And, as with human drug addicts who share needles, as the hoppers move from plant to plant they can spread disease from one feeding station to the next. In other things, they’re not something you want in large numbers in your garden.

I suspect it’s a vain hope that they’ll stay on the agapanthuses & leave our nice new passionfruit vines alone…


In other news: the goldfish must like their new pond 🙂 There was a lot of piscine hanky-panky going on when I went out to feed them this morning.


One thought on “pesky little hoppers”

  • We used to call these ‘flick moths’ because of the way they flick away when you touch them 🙂 Good luck with the agapanthuses/si – can’t say I much like them either, but they are rather prolific.

Leave a Reply

Your email address will not be published. Required fields are marked *