Insect mouthparts show a huge range of adaptations. Fossil evidence indicates that the ancestral form was the chewing type shown in A. This is the form of mouthparts currently seen in grasshoppers. As insects diversified over time, some of the parts became modified to piercing, sucking, lapping or siphoning structures. B shows the lapping mouthparts of a bee, C shows the piercing and sucking mouthparts of a mosquito, and D shows the proboscis (elongated sucking tube) of a moth or butterfly. These insects have no chewing mouthparts but siphon the liquid nectar from flowers, as shown in the main photograph.
The hummingbird hawk moth (Macroglossum stellatarum) has several additional adaptations. The first is its ability to hover. Its wings beat at approximately 80 beats per second — just below the maximum limit for synchronous flight. Synchronous flight means that each wing beat is triggered individually by nerve impulses coming from the central nervous system, in the same way as hummingbirds beat their wings, and we move our limbs. Secondly this moth is diurnal, which means it is most active in daylight. Its eyes are adapted from the usual compound eye of insects in a way that allows vision more like that of vertebrates. This means the moth can focus clearly on close moving objects such as the lavender flowers it is feeding from, and keep itself in position while feeding.
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