These are clearly the larvae of the suborder Auchenorrhyncha, to whom cicadas, leafhoppers, treehoppers, planthoppers, and spittlebugs belong:
- the have an (usually) elongated body shape, often with a triangularish abdomen which is often bent up at the tail
- they have a well-developed, sclerotized pronotum
- they have characteristic piercing-sucking mouthparts located on the front of the head used for feeding on plant sap
- they usually have relatively short antennae
- their eyes are well-developed and positioned laterally on the head
- their legs are adapted for jumping, with hind legs being particularly muscular
- as hemimetabolous insects, their larvae lack wings and their segemented bodies are visible all around their abdomen
These characteristics can be seen here in this (german) labeled image of an adult Neophilaenus lineatus (image credits: Elke Freese | CC-BY-SA-2.5,2.0,1.0:
All these characteristics match well, therefore I conclude they must at least be Auchenorrhyncha. But even more, it is possible to identify them as leafhoppers (Cicadellidae):
- both adults and larvae, have a slender and elongated body shape
- usually, they are small insects (few mm to around 1.5 cm)
- they have each pair of compound eyes and of dot eyes (ocelli) on the top or front of the head
- the thickened part of the antennae is very short and ends with a bristle (the so-called arista)
- the femora are at front with, at most, weak spines.
- the (mostly squarish) hind tibiae have one or more distinct keels, with a row of movable spines on each (so-called setae)
- the tarsi have three segments
- the front wings not particularly thickened.
Here is a close-up of a leafhopper larvae (image credits: Patrick_K59 | CC-BY-2.0) depicting most of the named characteristics: