A new approach to mark termites (Cornitermes cumulans (Kollar) Blattodea: Isoptera) for laboratory bioassays

Abstract

Behavioral lab bioassays involving termites must be promptly performed to allow intended observations prior to death from dissecation, typical of these soft-bodied insects. To this end, topic markers have been proposed as an alternative to histological stains which, while not always toxic are inevitably lengthy to apply. Among recommended topic markers, gouache is easy to apply, dries out quickly, but it is known affect termites in the long run, being suitable only to short-term bioassays. Its alternative, colored glue, is also easy to apply, but it takes long to dry and it is too dense and heavy, being thus prone to affect termite walking patterns. Here we tested a mix of gouache and colored glue aiming to combine the qualities of both into a suitable topical marker for Cornitermes cumulans termites. Similar patterns of survival presented by marked and unmarked termites ruled out concerns about toxicity of this mixture. Such results were consistent across distinct group densities evidencing that the mixture does not interfere with, nor it is affected by, crowding effects. Because crowding regulates interindividual interactions and these underlie most behaviors, the mixture can be thought to be suitable to behavioral studies. We argue that this 1:2 glue:gouache mixture is an excellent alternative to mark termites for lab bioassays. Being atoxic, cheap, easy to apply, and non-invasive, this mixture may happen to be useful not only for termites but also in bioassaying other similarly soft-bodied insects.

Cohabitation in termite nests: inquilines are habituated and attracted to hosts cues

“…In all cases, six workers were introduced into each Petri dish in interspeci c pairings (three inquilines + three hosts) or intraspeci c pairings (six inquilines or six hosts). The individuals used were previously marked in the pronotal region with a mixture of glue and gouache (see Marins et al 2023) to discriminate between intercolonial behavior. The individuals were acclimated for 1 min, and then the Petri dishes were lmed for 2 min to analyze their behavior.…”

Effect of food resource and carton nest material on laboratory group survival of Nasutitermes corniger (Motschulsky, 1855) (Termitidae: Nasutitermitinae)

“…It is important to know factors that can limit survival to ensure that laboratory tests will reflect the natural survival of these insects. While previous studies have been extensively tested the effect of markers (e.g., Loreto et al 2009;Marins et al 2023) and abiotic factors (e.g., Ferreira et al 2019;Zukowski & Su 2017) on the survival of termites to develop bioassays protocols; the effects of food resources and nest material on group survival of Nasutitermitinae are still poorly studied. Only one study has been conducted to investigate the better substrate to survival of Nasutitermes coxipoensis (Holmgren, 1910) (Termitidae: Nasutitermitinae) (Albuquerque et al 2008).…”