Category: Leopard’s Echo

Many organisms manage fine, or better, without eyesight, but nevertheless eyes are extremely useful. Eyes have evolved on at least 40 separate occasions, in different branches of the animal family tree. On one of those occasions, around 500 million years ago, the early insect/crustacean branch gained their eyesight.

Today, please join me on a quick tour of insect eyes. Insects as a group have two types of eyes: simple and compound.

Simple eyes

Simple eyes, or ‘ocelli’, only detect light intensity, they do not form an image. Gradual changes in light helps insects tell the time – both hours and seasons. Springtails (close insect relatives) have up to six ocelli, but in modern insects, ocelli are usually found in triplets – unless of course they are absent.

Those bulging fisheye lenses must be exceptionally sensitive. One simple eye (seemingly with a faint pink filter) points forward, two simple eyes (with yellow filter) point left and right. One can only guess what sort of visual cues this flower mantis is recording as it picks the perfect perch. It also has two large, grey-green compound eyes.

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.

In the last article I started presenting the contents of a temporary exhibition that sadly fell victim to the pandemic. We covered the first four roles of insects in nature: pollination, seed dispersal, recycling and improving soil quality. In this article we continue the series, and look at roles 5: pest control, 6: weed control, and another role ‘X’ that goes beyond the content of exhibition – population control.

Role 5. Pest control – insects eat each other

What is a pest? A pest is something that directly harms our crops or livestock, or even us, something that is so numerous that we notice it and that does measurable damage. A lonesome caterpillar in the garden is not a pest.

Many insects that could become pests, never do, because enough of them get killed by their natural enemies. Natural enemies of insects include birds, lizards and other animals, but the most important natural enemies of potential pest insects are other insects. About a quarter of insect species eat other insects, thus keeping them in control.

Predators, such as the praying mantis, ladybird and assassin bug (header), catch their prey, then eat it up whole or suck it dry, depending on their mouth parts.

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.

Back in 2018 and 2019 Andrew Carter of the Durban Natural Science Museum and I put together a temporary exhibition on the roles of insects in nature. In January 2020 Andrew was still putting on the finishing touches when Covid-19 struck. Sadly, visits to the museum stopped or came at a slow trickle.

I would hereby like to present the contents of the exhibition to the readers of Leopard’s Echo, per chance to reach a new audience. The information came largely from the book What Insect Are You? and from educational events offered under its banner. Those who know me may have seen me talk about this topic at local conservation events.

The exhibition also featured specimens that came from the museums’ wonderful insect collection, see the first picture in this article (and it so happens that one of the entomologists who reviewed the book What Insect are You? was the curator of this collection at that time, Kirstin Williams.)

Insects are disappearing at alarming rates. But is this a problem? You probably already know the answer. Insects are not just pests – they also play important roles in nature. Sure, most people can think of a few good uses for insects (they pollinate flowers, they make honey), but for many people that is where the good opinion ends.

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.

Having just returned from an international trip, exhausted from sitting around on aeroplanes and airports for many hours, I couldn’t help marvelling again how small creatures like godwits fly for 11 days non-stop on their own wings. Insects, which are even smaller, are capable of similar feats.

Following a previous article on insect migrations, here we look at some of the fascinating ways in which insects get around, and special adaptations that help them get there.

So let’s go!

Walk before you run

Let’s start at the beginning: Ants, Beetles, Cockroaches, all these and more have six standard-issue walking legs. Even for creatures this small, walking can be pretty efficient, make no mistake. Ants just walk and walk and keep on walking, and don’t they just end up everywhere? By way of pheromone trail markers they find their way home, but now I’m wondering: how many end up getting lost anyway? I couldn’t immediately find an answer to this question on the Internet.

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.

For me personally, the diversity of insects is a wonderful expression of the creativity of the Creator: the vast and seemingly unnecessary variety, the sheer ingenuity, the visual beauty that has no discernible purpose or evolutionary advantage. ‘It must have’ some would say. Maybe.

I appreciate the evolutionary process, but don’t think everything can be so easily labelled as ‘blind, random chance’ and ‘survival of the fittest’ or even ‘runaway selection’. It is much easier to believe that a divine artist had a lot of fun.

Either way, there is something divine about insects.

Dung divine

The scarab was the symbol of Khepri, the ancient Egyptian god of rebirth and the rising sun. Like the beetle rolls a ball of dung, from which a new beetle will hatch in time, Khepri was thought to roll the sun across the sky, where it hatched anew every morning.

There is definitely something divine about insects, both in their benefits, and their deadly powers.

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.

Smaller, vaster, better, faster

Insects migrate. In a GRAND way. Forget the migration of the wildebeest across the Serengeti. The painted lady butterfly, found all over the world, migrates from as far North as the arctic circle to the tropics and back – a 14 000 round trip. Individuals fly several thousand kilometres! Dragonflies migrate between India and Africa, flying several kilometres up in the air, over open ocean. How is this even possible? The mind boggles.

In my opinion humans always underestimate insects. Because they are small we don’t take them seriously, we don’t appreciate them, we don’t give them the respect they deserve. Even when we are finally made aware of some amazing feat, we are still missing something even more amazing.

The vagrant emperor dragonfly, also featured in the header, is a known migrant. It is a spectacular animal, one of the largest dragonflies that exists. It occurs in Durban – this individual strayed into our house.

The painted lady butterfly completes its migration over the course of a few generations. The offspring can’t learn the route from their parents. So how do they know to stop flying South, but turn around and head back North? This is a mystery worth solving!

Read the whole article in Leopard’s Echo, a bi-annual online magazine of Kloof Conservancy.