Untrustworthy and sensational news about insects and arthropods are constantly shared through social networks, spreading tergiversated data and confusing amateur users. As a result, this usually leads to misidentifications and unnecessary alarmism toward harmless organisms.
Here we bring you a brief list of some insects and other arthropods that are usually confused and how to tell them apart. Don’t get tricked!
Spiders VS ‘Anything resembling them’
Spiders (Order Araneae) probably are some of the most feared arthropods among users for two main reasons: they are venomous and there are a lot of other arachnids that resemble them. So, it is quite understandable some people have serious doubts when finding an organism with eight long legs and a grim face.
However, most of these spider-like organisms are harmless and unable to weave webs:
Harvestmen: unlike other arachnids, harvestmen or daddy longlegs (Order Opiliones) don’t have their body divided into two parts (prosoma and opisthosoma) by a thin waist, so they remind off a ‘ball with legs’. Also, they only have a pair of central eyes very close to each other. They neither have venom glands nor silk glands, so they can’t bite nor weave webs. They live in moist places, caves and near to streams and harvests. They are usually confused with spiders of the Pholcidae family because of their long legs.
Solifugae: also known as camel spiders, Solifugae is an order of tropical arachnids characterized for having a segmented body and a pair of conspicuously large chelicerae forwardly projected. However, and despite their menacing appearance, they aren’t venomous (even though they bite can be very painful) nor weave webs. They inhabit desert and arid places, some of them are nocturnal and the diurnal ones move quickly looking for shadows to escape from sunlight.
Amblypygi: also known as whip spiders or tailless whip scorpions, Amblypygi is an order of tropical arachnids that are neither spiders nor scorpions. Despite their menacing appearance, as it happens with camel spiders, whip scorpions don’t have venom glands. They have a pair of big thorny pedipalps ended in a pincer for grabbing preys, while the first pair of legs, which are filiform and segmented, act as sensory organs (not for walk). They don’t weave webs and have nocturnal habits.
Pill bugs VS Pill millipedes
When playing in a park or in some natural place as a kid, you some time probably found a small animal, full of legs that rolled up when being touched.
These organisms are commonly known as woodlice. Woodlice belong to the suborder Oniscidea, a group of terrestrial crustaceans within the order Isopoda. They have a tough, calcarean and segmented exoskeleton, and inhabit moist places.
Woodlice of the family Armadillidae, also known as pill bugs, are usually confused with pill millipedes (Subphylum Myriapoda, Class Diplopoda, Superorder Oniscomorpha), both groups with a similar external appearance and able to roll up into an almost perfect sphere as a defensive mechanism (convergent evolution).
To tell them apart, you have to count the total number of legs per segment: if it has only a pair of legs per segment (one at each side of the segment), it is a pill bug; if it has two pairs, it is a pill millipede.
Bees and wasps VS Hoverflies
We talked widely about the main differences between bees and wasps (Order Hymenoptera) in this post. This time, we introduce you the hoverflies or syrphid flies (Order Diptera, Suborder Brachycera, Family Syrphidae), which resemble a lot to bees and wasps.
Resemblance of hoverflies to bees, wasps and bumblebees is a clear example of Batesian mimicry, which we explained widely in this post about animal mimicry. Moreover, hoverflies mimicry goes even further, since some of them also imitate the flight and the hum of these hymenopterans.
To tell them apart, you have to pay attention to their eyes, antennae and wings: since they are flies, hoverflies have a pair of big compound eyes that occupy almost all their head, very short antennae with eight or less segments and a single pair of wings (the second pair has evolved into small equilibrium organs, the halteres), while wasps, bees and bumblebees have smaller compound eyes that occupy only the sides of the head, longer antennae with ten or more segments and two pairs of functional wings. Moreover, female hoverflies don’t have the abdomen ended in a stinger, so they are completely harmless.
Ladybugs VS Pyrrhocoris apterus
If you look for ladybugs pictures on Internet, you’d probably find a picture of this insect:
This is Pyrrhocoris apterus, a very common insect in the Palearctic area (from Europe to China) and recorded to the USA, Central America and India. You can find it on common mallows (Malva sylvestris), from which they eat seeds and sap, and they usually congregate in big groups because of their gregarious behavior.
Ladybugs are coleopterans (Order Coleoptera) with a more or less globular shape; they are carnivorous (with a diet based mainly on the intake of aphids) and can fly. Their first pair of wings are hard (elytra) and form a kind of shield that encloses the second pair of membranous wings.
On the other hand, Pyrrhocoris apterus is a bug (Order Heteroptera) with a depressed body, phytophagous habits and, unlike ladybugs and other bugs, it is unable to fly. Moreover, it doesn’t have a hardened shield.
Mantises VS Mantidflies
Mantises (Order Dyctioptera), which were widely addressed in this post, are very alike to this insect:
This insect belongs to the family Mantispidae (Order Neuroptera), also known as mantidflies or mantispids. This group is very well represented in tropical and subtropical countries, and just a few species are known from Europe. They have a pair of raptorial legs like those of Mantodea which they use for grabbing their preys.
Neuropterans, like mantidflies, green lacewings and antlions, have two pairs of similar sized wings with a very complex and branched venation. In Mantodea, the first pair of wings are smaller and harder than the second one, which are membranous and functional for flying; also, this second pair doesn’t have such a complex venation like that of neuropterans.
Mantidflies of the genera Climaciella and Entanoneura have a body coloration like that of some wasps, but they are totally harmless.
Mosquitoes VS Crane flies
Have you ever seen a giant mosquito and dreaded its bite? Well, you can stop being afraid of it.
These giant ‘mosquitoes’ (Order Diptera), which are commonly known as crane flies or daddy longlegs (Family Tipulidae), are totally inoffensive (and somewhat clumsy). They are distributed all over the world and inhabit moist places, like meadows and streams. Adults feed on nectar or don’t feed; in any case, they don’t suck blood!
Females have the abdomen ended in a kind of stinger; however, it is only their sharp ovipositor (not a stinger like those of bees or wasps).
Dragonflies VS Damselflies
Both groups belong to the Order Odonata and have very similar appearance and behavior, being very common near sitting waters and lakes.
Two thirds of the Odonata are dragonflies (suborder Anisoptera), while the other third are damselflies (suborder Zygoptera). An easy way to tell them apart is by paying attention to their wings at rest: in dragonflies, wings are held flat and away from the body, while in damselflies they are held folded, along or above the abdomen.
On the other hand, eyes of dragonflies are large and touch in the vertex of the head, of which they occupy most of its surface, while those of dragonflies are smaller and are usually located on the sides of the head.
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If you know about any other insect or arthropod that can be confused, let us know it by leaving a comment!
References
- Capinera, J. L. (Ed.). 2008. Encyclopedia of entomology. Springer Science & Business Media.
- Resh, V. H. & Cardé, R. T. (Eds.). 2009. Encyclopedia of insects. Academic Press.
- Cooke, F. 2004. The encyclopedia of animals: a complete visual guide. University of California Press.
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