Bug Splat Decline


Have you ever observed or given thought that maybe, just maybe, there are fewer insects about than you remember?

Wasps can be abundant seasonally, but what about other insects?

Hmmm… Butterflies? Moths? What about the bug splats on your car after a drive?

These shifts in populations are difficult to determine without any actual scientific evidence. They are just observations, perhaps vague memories of how things used to be. Changes happen incrementally and are difficult to detect over long periods. We adjust to what we are used to experiencing. After all, insects are often small and insignificant in the scale of the world. Right?

Studies overseas have revealed evidence of some long term declines in insect populations. Yet little work has been conducted here in New Zealand.

Insect abundance (with several exceptions, such as wasps) and diversity are signs of good environmental health. They are also crucial to our economy and wider biodiversity.

The link above to a RNZ interview discusses the "bug splat" indicator and issues around insect diversity and declines in insect abundance.

DOC information on wasps

The Department of Conservation (DoC) also provides very good information around wasp identification and control.

"New Zealand has several kinds of native wasps which have evolved here and have never become a nuisance.
But five social species of wasps have been accidentally introduced since the 1940s and are classed as pests (German and common wasps, and three species of paper wasp).
How to identify wasps
Introduced wasps are a significant pest which harm our native birds and insects, and are a threat to human health and recreation."

Or view via this link:


Identifying wasps

Sometimes people are not sure which wasps they have present. Here is a really good link from Landcare showing the difference between different wasps species found in New Zealand. The main thing to learn is the difference between Asian Paper Wasps (pictured here) and german/common wasp. It's important to distinguish between these wasps because control measures vary according to what species are present. All these wasps are bad introduced species that we could do without.


Asian paper wasps (Polistes chinensis antennalis): which are distinguishable from Vespula by have a different pattern of colouration on the abdomen. Paper wasps do not hold their legs close to their body, so when they fly they have "long dangly legs". Paper wasp nests are found above the ground and are not enclosed, so you can see into the cells (unlike Vespula nests where the layers of cells are enclosed in an envelope).

© This image by Landcare Research is published under the
CC-BY 4.0 international licence unless otherwise specified.