MOLE CRICKET: CHARACTERISTICS, HABITAT, DISTRIBUTION, PESTS, CONTROL - BIOLOGY - 2025

The mole cricket (Gryllotalpa gryllotalpa) is a species of orthoptera that affects many horticultural crops, extensive crops and lawns. It is also known as the onion scorpion. Adult individuals are brown in color and approximately 5 cm long.

They are insects of underground habit with very strong digging front legs that serve to make tunnels or burrows from which they can hibernate, mate and hide from predators.

Mole cricket adults have wings. Source: pixabay.com

It produces serious damage to crops because it destroys roots, bulbs, tubers and the neck of the base of the stem of plant species such as carrots, potatoes, onions, among others.

Its presence is identified when the rain falls or irrigation is applied, since the galleries are flooded. Likewise, you can use a solution of water with liquid detergent (30 mL / 5 L of water) and apply it to the affected area of ​​the soil so that these crickets come to the surface.

characteristics

Larva

The size of this phase is less than 50 mm. Its morphology is similar to an adult but it does not have wings.

Adult

The adult individual of the mole cricket measures approximately 5 cm, its body is brown and it has an underground habit. Females are 40-46mm and males are slightly smaller, measuring 35-41mm.

The front legs are modified to dig into the ground and are covered in fine trichomes. Adults are the only ones with wings.

His flight is clumsy, disoriented, he does it few times and only during the night.

Adult males are distinguished from females by an open area on the wing, which is known as the harp. While, females lack the ovipositor apparatus that other cricket species present.

Reproduction

This animal begins living in underground galleries that can measure up to 1 m and occasionally makes its way to the surface. It spends part of its life cycle hibernating in the ground as a nymph, or as an adult.

Anterior view of the mole cricket. Source: H. Zell

The generation occurs every two years. Males usually produce a sound inside a chamber that they build in the burrow and it serves as an amplifier to attract females. This occurs in the hours between dusk and dawn on spring days.

The size of the different parts of the burrows depends on the size of the males. In Iran call burrows were observed, the shape of the entrance tunnel is similar to a horn.

The eggs are deposited in underground chambers since spring begins, and oviposition culminates in late July. The eggs hatch between two and four weeks.

Nymphs begin to mature from the beginning of the following spring and some individuals may even mature until the third spring. Nymphs and adults can be found throughout the year in the underground galleries.

Crop damage

The burrowing nature of this cricket affects the underground structures of the plant (roots, bulbs, tubers).

In addition, it can cause seedlings to fall by cutting the neck of newly emerged seedlings.

Due to the wounds it produces on plants, they become more susceptible to being attacked by diseases or other pests.

Plants that produce tubers, for example sweet potatoes and potatoes, suffer the depreciation of their harvest in commercial terms, which generates economic losses to farmers.

The presence of this pest can be identified when it rains or at the time of irrigation, since its galleries are flooded.

The front legs of the mole cricket are very strong and digging. Source: pixabay.com

Feeding

The mole cricket is a predator of insects, worms, roots, as well as some invertebrates.

Taxonomy

Animalia Kingdom

Phylum: Arthropoda

Class: Insecta

Order: Orthoptera

Superfamily: Gryllotalpidea

Family: Gryllotalpidae

Genus: Gryllotalpa

Species: Gryllotalpa gryllotalpa

Some synonyms for this species are Acheta grillotalpa, Gryllotalpa vulgaris and Gryllus talpa.

Its name derives from the word gryllus that means grilloy, "talpa" or mole, alluding to the resemblance of these animals to moles according to their underground habit.

Habitat and distribution

This species of cricket is distributed in sandy soils, also humid but with good drainage. Normally the soils it inhabits are rich in organic matter.

Its ideal habitat is grass or short grass, in sandy and peaty places, with fluctuating water tables and intervened or cultivated areas of soil.

The mole cricket makes underground tunnels. Source: wikimedia commons.

This cricket has been determined to build vertical and horizontal tunnels. The vertical ones are used for landing, hiding from predators, resting and for the molting process; while, horizontal tunnels are used for the mating process and also to escape predators.

The onion scorpion is distributed throughout Europe (except Norway and Finland), as well as in western Asia and North Africa. Likewise, this species and other species of the genus are distributed in America.

In Great Britain this cricket is registered in all its counties. However, from 1970 to 2001 only four settlements of this species were reported. It is considered in danger of extinction due to changes in agricultural practices and the use of pesticides, drainage of wetlands and conversion of wet grasslands to silage.

Conservation

Under the UK Biodiversity Action Plan (UKBAP), this species was identified as a priority for conservation. For this, as with other species, it has been considered to establish breeding colonies in captive conditions.

In fact, from the Natural History Museum of the United Kingdom, it is requested that people who see a mole cricket contact the relevant authorities and report the characteristics of the place where it is present, the time of year and the location, and if possible take a picture to confirm registration.

The mole cricket is also known as the onion scorpion. Source: Muséum de Toulouse

Pests

Some animals such as birds and rodents can attack the onion scorpion or mole cricket and control its population.

Control

Control can be done by chemicals such as methiocarb. This should be applied as a bait on the cultivated land.

This product can also be used to control the presence of snails, slugs and other insects on the ground.

References

1. Jafari, S., Kazemi, M., Lotfalizadeh, H. 2015. Acoustic burrow structures of European mole crickets, Gryllotalpa grillotalpa (Orth.: Gryllotalpidae) in Northwestern Iran. North-Western Journal of Zoology 11 (1): 58-61.
2. Bermejo, J. 2011. Information on Gryllotalpa gryllotalpa. Agroecological. Taken from: agrologica.es
3. Catalog of Life: 2019 Annual Checklist. Species details: Gryllotalpa gryllotalpa (Linnaeus, 1758). Taken from: catalogueoflife.org
4. Biopedia. 2009. Scorpion onion or mole cricket (Gryllotalpa grillotalpa). Taken from: biopedia.com
5. Infojardin. 2019. Mole cricket, Scorpion onion, Grillotalpa (Gryllotalpa gryllotalpa). Taken from: articulos.infojardin.com