Litinsects

Litinsects #21: Complete vs. Incomplete Metamorphosis Welcome to METAMORPHOSIS PART 3: Let’s start with a recap of my last two posts... Within winged insects (or PTERYGOTES), there are two different developmental strategies: HOLOMETABOLOUS insects undergo complete metamorphosis with 4 stages: egg, larva, pupa, and adult. All stages look completely different from one another HEMIMETABOLOUS insects undergo incomplete metamorphosis with 3 stages: eggs, nymph, and adult. The nymphal stages physically resemble the adults Nymphs of hemimetabolous insects typically share the same food and habitat as adults and exhibit similar behaviors whereas holometabolous insects usually look different, display different behaviors, and occupy different habitats in each life stage. The takeaway here is that holometabolous insects are very good at compartmentalizing certain tasks into different life stages, in order to reduce or eliminate competition among life stages! Th...

(© Brandon Thorpe) (© Brandon Thorpe) Litinsects #20: Hemimetabola Welcome to METAMORPHOSIS PART 2: Yesterday I discussed complete metamorphosis, where an individual’s appearance changes pretty drastically through its life stages. But some insects undergo a different kind of transformation: INCOMPLETE METAMORPHOSIS. These insects are HEMIMETABOLOUS (hemi = half/part, metabola = change) because they go through gradual changes to their body layout. This includes 3 life stages: egg, nymph, and adult. 1) As usual it starts with an EGG 2) A NYMPH emerges, which generally resembles the adult form of the insect but WITHOUT WINGS. Nymphs molt several times, growing in the process, but never enter a pupal stage. These nymphal stages are called INSTARS 3) The ADULT insect emerges after the final molt, with WINGS and REPRODUCTIVE ORGANS. Nymphs may differ from adults in coloration or body proportions but hemimetabolous insects usually have similar diets in ...