Forest litter crickets prefer higher substrate moisture for oviposition: Evidence from field and lab experiments

Abstract

For insects, choosing a favorable oviposition site is a type of parental care, as far as it increases the fitness of its offspring. Niche theory predicts that crickets should show a bell-shaped oviposition response to substrate moisture. However, lab experiments with mole crickets showed a linear oviposition response to substrate moisture. Studies with the house cricket Acheta domesticus also showed a linear juvenile body growth response to water availability, thus adult ovipositing females should respond positively to substrate moisture. We used a field experiment to evaluate the relationship between oviposition preference and substrate moisture in forest litter-dwelling cricket species. We also evaluated oviposition responses to substrate moisture level in Ubiquepuella telytokous, the most abundant litter cricket species in our study area, using a laboratory study. We offered cotton substrate for oviposition which varied in substrate moisture level from zero (i.e., dry) to maximum water absorption capacity. We used two complementary metrics to evaluate oviposition preference: (i) presence or absence of eggs in each sampling unit as binary response variable, and (ii) number of eggs oviposited per sampling unit as count response variable. To test for non-linear responses, we adjusted generalized additive models (GAMM) with mixed effects. We found that both cricket oviposition probability and effort (i.e., number of eggs laid) increased linearly with substrate moisture in the field experiment, and for U. telytokous in the lab experiment. We discarded any non-linear responses. Our results demonstrate the importance of substrate moisture as an ecological niche dimension for litter crickets. This work bolsters knowledge of litter cricket life history association with moisture, and suggests that litter crickets may be particularly threatened by changes in climate that favor habitat drying.

Alkaline water as a potential agent for biting midge control: Managing effectiveness and non-target organism impact evaluation

“…Our laboratory experiments showed that the number of eggs laid by female crickets in soil moistened with either alkaline or regular water was similar, indicating that long term spraying of alkaline water to control biting midge population would not affect egg laying site selection of ground arthropods such as crickets. Congruent with the finding of this present study, results of previous studies showed that compared to pH value, soil moisture was a more critical factor in affecting oviposition site choice of crickets [ 21 , 33 ]. Female crickets would lay small number of eggs when soil moisture was low and would lay no eggs when the soil moisture was too high [ 33 ].…”

“…This experiment aimed to study whether pH of substrate surface influenced the oviposition site choice of ground arthropods. Crickets were chosen as the model organisms, and we followed the method of de Farias-Martins et al [ 21 ] to set up the oviposition sites. A single gravid female cricket was placed into each of 20 rectangular transparent boxes (L = 28 cm; H = 21 cm; W = 15 cm).…”

Persisting while changing over time: modelling the historical biogeographic of cave crickets (Orthoptera, Grylloidea) in Neotropics

“…The spatial rearrangements (21 ka, 6 ka, 0 ka and RCP8.5) indicated that the most stable occurrence areas of Endecous are associated with the Atlantic Forest. This highlights moisture as a threshold condition for these crickets, since they depend on substrate moisture for oviposition (De Farias-Martins et al 2017). Considering that caves frequently present high moisture content and climatic stability (Mejía-Ortíz et al 2021, Moldovan et al 2018, Sánchez-Fernández et al 2018, the frequent observations of the genus associated with climatically stable regions within caves also coincide to what is exposed by the models.…”

Ethology of the cricket Endecous (Endecous) chape Souza-Dias & de Mello, 2017 (Orthoptera: Grylloidea: Phalangopsidae) I: Agonistic and reproductive behavior

“…All oviposition behaviors presented by E. chape have been reported in other Gryllidae species (Destephano et al 1982, Evans 1983, Sugawara 1993. Some behaviors, like females combing the substrate, may be interpreted as a search for an oviposition site that offers adequate temperature (Destephano et al 1982) and moisture, as indicated by Boake (1984) with N. maya, and tested by Farias-Martins et al (2017) with Ubiquepuella telytokous Fernandes, 2015 (Phalangopsidae), among other qualities that are important choices for offspring success. Similarly, numerous insertions of the ovipositor into the oviposition site may be a method for preparing the oviposition site or a way to lay more eggs, which both ensure greater reproductive success.…”