Also since the Argentine sugar ants invasion most moths and butterflies have disappeared.
I have just spent several hours searching my swan plant hedge for caterpillars and not one to be seen. As usual the Argentine sugar ants are methodically harvesting the Monarch eggs.
For the past three years Argentinian ants have eaten all the Monarch eggs on my and adjacent properties.
This is in Kuaotunu, on the Coromandel.
Yes, ants DO eat small caterpillars and eggs but do not kill the ants with a chemical spray because that may harm the cats.
Just read this in GET GROWING:
If you see a trail of ants heading up a stem it’s a sure sign that mealybugs, aphids, plant hoppers or whitefly are in residence. The ants are on the way to harvest the honeydew that the sap-suckers excrete.
Ants build their nests in dry, loose soil, so making sure potted plants are well watered to keep them away.
If pots are small enough to be lifted, soak them thoroughly in a bucket of water to drown any nests within.
Trays of seedlings and small pots can be placed above trays of water that act as moats, preventing ants from reaching the plants.
GET GROWING reader Maree Riordan sent this tip: “Getting rids of ants in the garden is easy. Mix equal amounts of icing sugar and baking soda and place in a plastic container with a few holes drilled in it. The ants are drawn to the sugar but can’t tell the sugar from the soda so ingest both. The soda builds up gas that can’t be expelled from their body, so the ant dies.”
Commercial products include Kiwicare’s NO Ants Gel Bait or NO Ants Liquid Bait, Yates’ Neverong or diatomaceous earth from DENZ Ltd.
Yes, people here have reported seeing ants taking eggs and small caterpillars before.
Below is some research date from the States regarding ants… In my experience ants have moved in when a chrysalis is damaged and not before.
http://www.ecology.info/monarch-butterfly-page-2.htm
She found that monarch eggs were less likely to survive on plants on which ants had been observed, suggesting that ants are important predators. This conclusion is supported by work in Texas by Calvert (1996, 2004), who found that monarchs inside enclosures were much more likely to survive than those outside the structures. Calvert found that invasive fire ants currently kill most of the monarch eggs and larvae present in many areas in Texas, but thinks that pre-fire ant mortality may have been similarly high, since these invasive ants displaced native ants that also preyed on monarchs. In addition to predators, insect parasitoids are important sources of monarch mortality in some locations. Prybsy (2004) and the Monarch Larva Monitoring Project have both documented mortality rates of from 10% to 90% in late instar monarchs due to tachinid fly (family Tachinidae) parasitoids, but these rates are variable from location to location and year to year.
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