Patricia Holden MD|

Time for another insect post. I’m not sure why I love writing about insects especially since I’m an internist, not a parasitologist. Anyway, after writing about dangerous insects and largest insects, I’ve decided to write about the smallest this time. Well, I doubt you’ll be able to see these without a microscope so I doubt you even know they exist. However, they do. So be afraid…be very afraid. (Just kidding.)

It’s amazing how some of the smallest insects in the world would be smaller than a protozoa (single-celled organism) and still have every part an insect should have. How they have functional cells of that size are astounding. These insects may be small but they can be very quick, too. As if they’re not already difficult enough to spot. One second they’re there, you blink and they’re gone. Here are five of the smallest insects in the world.

Dicopomorpha echmepterygis - Quite possibly the smallest insect in existence, the Dicopomorpha echmepterygis is a species of fairyflies found in Costa Rica. Fairyflies are not flies but parasitic wasps. The male of the species is blind and flightless can be considered the smallest insect in the world (talk about useless).

Megaphragma Caribea - A hymenopteran (insects having two pairs of membranous wings and an ovipositor specialized for stinging or piercing) parasite from Guadeloupe. It measures only 0.17 - 0.2 mm (around 0.007 in) long.

Feather-Winged Beetle - There are a lot of small beetles that are less than a millimeter in length. The Nanosella fungi, for example,  measures only 0.25mm and is one of the smallest insects in the world. Like other Nanosellinae, the feather-winged beetle inhabits spore tunes of polypore fungi. They can be found mostly in Southern and Eastern United States.

Grease Ants - Quite possibly the smallest ants, they are found in homes in Iowa. Like it’s namesake, they usually prefer greasy foods like fats or meat. They create nests in cracks of walls and cabinets and can be difficult to control. Insecticides may be effective but reappearance after a few days is quite common. A good strategy in catching them would be to use greasy foods (of course) along with baits. Lure them into strips of masking tape to catch them.

Nepticulid Moths - The Nepticulid Moth has a wingspan of only 0.1 inch and is the smallest known species of moth. Most moths have an average of 1 inch in wingspan so these are definitely small. They are not as small as most of the smallest insects but I wouldn’t want to fill this post with only fairyflies.

I was reorganizing and redesigning my daughter’s room this weekend when I found a widow spider in one of the boxes that were left in her room. My daughter, scared of insects, held on to me while I tried to capture the spider and throw it outside. Anyway, if you read my earlier post, you would know that widow spiders are venomous so I tried to avoid hurting it in fear of being bitten. Good thing it was pretty small so I had a rather easy time putting it in a small plastic bag.

They can be quite scary, even with their size. You might have seen people scramble just to kill one cockroach, or a spider. Now imagine some of them being as large as your palm. Here are 7 of the largest insects and spiders that still exists.

Giant Burrowing Cockroach - These can be found in Australia. They can reach up to 3 inches in length and weigh 35 g. They don’t have wings and they usually feed on leaves. They can also burrow 1 meter below the ground and set up a home of their own. Some people actually keep them as pets.

Giant Cockroach - These can be found in Panama and Northern South America. Their length can reach up to 3.5 inches but not as heavy as the giant burrowing cockroach.

Goliath Bird Eater - The largest spider in the world and can be found in Northern South America. It got its name when explorers found one eating a humming bird. They can reach up to 1 ft and can weigh up to over 100 grams. The females generally have a longer life span than the males. They feed mostly on smaller insects, mice, lizards, and amphibians.

Giant Indian Black Scorpion - The currently known largest scorpion. Like it’s namesake, it can be found in India. It can reach to almost 1 ft in length and can weigh to as much as 57 grams.

Amazonian Giant Centipede - Can be found in North and West South America, these can reach up to 13 inches in length. They are known to prey on bats, lizards, birds, and mice. Their venom can cause chills, fever, and sever swelling on humans but is unlikely to be fatal.

Titan Beetle - One of the largest insects in the world and can be found in South America. They can reach a length of up to 6.5 inches or 8 inches with the antenna. They are reported to be able to snap pencils in half using their mandibles.

Stick Insect - The largest known stick insect according to body length is the Phobaeticus kirbyi, which can be found in Borneo. It’s body reaches up to 13 inches but when extended, it can reach up to 21 inches in length. The longest when extended is the Pharnacia serratipes, which can reach a length of 555 mm or 21.9 inches.

BONUS

I just read an article about a beetle that had survived a a two-week journey from Britain to Costa Rica. The Elephant Beetle had a length of around 5 inches (smaller than the titan beetle) and weighed around 35 grams. Read the article here.