We have published two papers on the occurrence of viruses in crickets that are reared for food and feed. They show that there a several viruses present, where some can have serious impacts on individual health and reproduction.
We have recently published two publications in Journal of Insects as food and feed on the effects of removing feed prior to harvest. The analyses show that starvation is not an effective method for reducing microbial loads in edible crickets (microbial load has impact on food safety) and that starvation for 24 h decreased fat content, indicating potential production losses. We also observed changes in the behaviour of the crickets. We conclude that, in the absence of a microbial lowering effect of fasting and considering the finding that fasting induces behavioural responses in crickets, there is currently no scientific support for using fasting in cricket production.
This week we have participated in the 71st Annual Meeting of European Federation of Animal Science (EAAP). It was impressive to see all the reseach efforts that are made all around Europe to support this new industry! We presented results from our studies on the use of flowering plants as feed for crickets and also studies on the effects of salt supplementation and feed deprivation.
In that study we conclude that white nettle has some potential as feed for house crickets, and that red clover supplementation increase cricket maturation. Using feeds including these plants may support wild biodiversity.
We have a new publication by Fernandez-Cassi et al. on food safety aspects; “Microbial communities and food safety aspects of crickets (Acheta domesticus) reared under controlled conditions”. In this study we investigated the effect of feeding forages preserved in different ways and also the effect of rinsing. We describe the dominant bacterial communities and also that all batches tested negative for the food-borne bacteria Salmonella, Listeria monocytogenes, Bacillus cereus and Clostridium perfringens. However, crickets fed some diets had Aspergillus flavus. Rinsing in water had no effect. It was concluded that more work is needed to identify specific food-borne pathogens and establish bacterial quality reference values.
We are excited that it is now legal to sell house crickets as food throughout the EU!
In one of our ongoing projects we study the possibility to use late cut red clover as feed for house crickets. If the clover crop is harvested at late botanical stage it is likely that it benefits pollinators. Below you can read a short report from Post Doc Laura Riggi about this project:
There are indication of positive effects of late season red clover mass-flowering crops on bumblebee reproduction. Clover is also known to be a good pollen resource for less widespread bumblebees. Despite the increasing interest in the effects of mass-flowering crop resources on pollinators, it remains unclear how late season flowering crop affect the abundance and community composition of bumblebees in non-crop habitats during and after mass-flowering crop bloom. In the summer of 2019 we carried out a large field scale study across Skåne to test whether landscapes with clover crops harbor higher abundances and more diverse bumblebee communities in non-crop habitats compared to landscapes without clover resources. We expected clover landscapes to benefit rarer bumblebee species, specifically, we expect more long-tongued bumblebees in clover landscapes. Preliminary results indicate positive effects of clover on bumblebee richness and diversity.
We have recently also published a study about the function of the gastrointestinal tract of the house cricket. In that study we investigated the presence of an enzyme (carbonic anhydrase, CA) involved in pH regulation. The findings support the suggestion that CA contributes to digestive tract pH gradient, by driving acidic secretions from the salivary glands and alkaline secretions from the midgut. Neither starvation nor sex had any effect on CA activity or localisation.
We are happy to announce that we just had a paper published in Journal of Insects as Food and feed! In this study we wanted to investigate if house crickets can thrive and growth on a red clover-only diet. We have earlier shown that field crickets can do well on a cassava-only diet and also on a diet including only one weed. Red clover is a plant that provides important ecosystem services while growing on the fields. The conclusion from the study is that red clover cannot be recommended as a sole feedstuff for these crickets. The possibility to partly include late cut red clover in cricket diets is however interesting. The flowering crop will provide feed for declining populations of bees and other pollinators.
Fernandez-Cassi X, Supeanu A, Vaga M, Jansson A, Boqvist S and Vagsholm I. 2019. The house cricket (Acheta domesticus) as a novel food: a risk profile (Review). Journal of Insects as Food and Feed. https://doi.org/10.3920/JIFF2018.0021