Species: Gryllotalpa gryllotalpa; european mole cricket (gryllus– cricket, talpa– mole)

Taxonomy: Insecta→ Orthoptera→ Ensifera→ Gryllotalpidae→ Gryllotalpa→ Gryllotalpa gryllotalpa (Linnaeus, 1758)

Appearance and size: Adult males are about 50mm, females about 70mm but size may vary. 100% sex determination is done by looking at veins on their wings, as both adult sexes are winged and male have ,,harph“- one of the veins on each wing is modified with a line of tiny teeth to form a stridulatory file. Their longitudinal body is brown with velvet and shimmery hairs. Head is pointing out from saddle-shaped thorax. Insect got it´s name by typical massive mole-like/ showel-like forelegs.

Origin: This polyphagous insect is notorious world-vide introduced pest. Recent research now shows up that G. gryllotalpa is complex of several very similiar subspecies, which can be satisfactory distinguished mostly by their song patterns. European mole cricket is distributed within the Western Palaearctic and shares same area with other similiar species on it´s borders.

Habitat: Besides adult insects, mole crickets are strictly underground, living in their galleries of tunels. So they preffer sandy, damp rich soils and reservoir edges. Mole crickets can be also found in gardens and in crop fields. When occuring synantropic, they are considered as major pests, damaging crop´s roots and mainly tuberous vegetable (digging holes trough).

Housing: Young nymphs up to 5cm showed to be quite tolerant among each other, so holding 3-4 (or even 10 animals) in 1L box seems to be possible (on your own try, in my experience it worked…). Subadult nymphs and adults should be housed separately as mainly adults show high territorial behaviour and will kill each other if not separated in time! For each animal, 250ml to 1L box fullfilled with sandy soil should be used. The soil should be more wet than dry, with about 65-75% humidity. There is also possibility to create cca 2cm space between two plates of glass for better behavioral observations. Don´t forget to provide ventilation holes.

Diet: They seem to be facultatively predatorous (soil fauna like worms, beetle grubs etc), but besides this, animals will feast on tuberous vegetables and crops regulary. In captivity, chunks of potato, carrot (or any other tuberous vegetable), pieces of apple and half-cut slices of bread can be provided once a week. As protein, worms, beetle grubs od dead crickets (1-3 exemplars) are served 1-2 times a week. Remove remains of food routinely so the soil should not get infected with entomophagous fungi, moulds or mites.

Reproduction and growth: There is little if any evidence on long-lasting or continual reproduction in captivity. I did not found any yet but there exist some experiences of sucesfull incubations while keeping a gravid female from nature. In the spring, gravid female create space which can be recognized as ,,maternal chamber“ and here she lays down 100-350 eggs. Larvae hatch within 10-20 days and she continuously protect them for next 2-3 weeks. Development takes 1-3 years and nymphs will undergo from 6 to 8 moults into adults, all according to conditions and region/ clima. In slovakian nature (gardens and near lakes) you can find little nymphs during spring and early summer, while sub-adults occurs around August-October and adults will overwinter to the next season.

Sources:

http://entnemdept.ufl.edu/molecrickets/mcri0201.htm

https://en.wikipedia.org/wiki/Gryllotalpa_gryllotalpa

 

Filip Repta, 31.08.´20 a 03.02.´22