The headword is an actually a present participle (from the verb diatre/xw), literally meaning 'darting-across' or 'rushing-across'; i.e. 'shooting [stars]'. The glossing is from the scholia to Aristophanes, Peace 838 (web address 1), where one character asks what oi( diatre/xontes a)/steres are (and another replies that they are "rich folks on their way home from the feast with a lantern"). "Spark-emitters" (cf. Aristotle, Meteorologica 341b30) may suggest specifically "fireballs," very bright meteors with a visual magnitude brighter than -3, similar to that of the planet Venus (web address 2), as LSJ indicates that spinqhrobole/w is used of that planet in a papyrus (P.Mag.Par.I). If so, this would lend further humor to Aristophanes' characterization, as fireballs are very conspicuous, and very transitory.
[1] cf. delta 786 for this headword and gloss in reverse.