Field Guide     Pest Management     Southern Mole Cricket

Southern Mole Cricket

CROPS IMPACTED: turf grass

southern-mole-cricket-1

Family: Gryllotalpidae

southern-mole-cricket-2 southern-mole-cricket-3

About the Southern Mole Cricket

Reproduction and Life Cycle

The southern mole cricket has one generation annually. They mainly spend the winter as nymphs, or sometimes as developed adults, and will lay their eggs in the spring between April and May. The eggs are placed in a chamber neighboring to the burrows in the ground. The chamber is anywhere from 5 to 30cm below the surface and will be approximately 4cm in width, height, and length. There will be anywhere from 25 to 60 eggs placed inside. The eggs take 10 to 40 days to hatch; upon hatching, the nymphs will sometimes eat fellow nymphs or their eggshells before making their way to the soils surface. They go through 8 to 10 instars. The adult males tend to call from February to July, but with adults that live for long periods, calling can occur throughout the year.

Southern Mole Cricket Identification and Habitat

Identification

The southern mole cricket is slender and is very active. It can be distinguished from other mole crickets by its tarsal dactyls being separated by a gap that is approximately half as long as the claw. It also has a unique design on its thorax (dorsal side). They are a large sized cricket, reaching to be about 3cm long. They have lengthy hindwings, typically a greater length in comparison to the abdomen. The forewings are approximately two-thirds the size of the abdomen, and have rounded tops that are broad. The shape of their body has been tailored specifically for burrowing. Their colour ranges from pinkish to brown with a dark pattern on its thorax, or instead, has 4 lightly coloured spots. The males sing their call within 2 hours of the sun setting. The call is low-pitched with a 50 per second pulse rate. The eggs are either bean or oval shaped, about 3mm long and 1.3mm wide. The eggs will absorb water as they develop, increasing their size to almost 4mm long and 3mm wide. They tend to be gray or brown. The nymphs that first hatch are fairly white, but will turn much darker in colour within the same day.

Habitat

This insect originates from South America, but was introduced in the southern United States in the early 1900s. They prefer areas that are open such as gardens, lawns, and fields that have high moisture levels, are mucky or sandy. They will feed on material from plants and animals. On plants, they will eat any part, whether it is above ground or below. The southern mole cricket is especially a pest to turfgraass, and will create shallow tunnels that dry out the grass. They are also damaging to certain plants such as tomatoes and strawberries, mostly when they are seedlings. This mole cricket; however, is not as destructive as other mole crickets such as the short-winged mole cricket and the tawny mole cricket, as it is mainly carnivorous, feeding on other insects. When it tunnels in the ground in warm and moist soil, they will not burrow deeply. However, in cooler, drier weather, they will go much deeper. They emerge in the evenings to forage if the weather is bearable for them.

Southern Mole Cricket Management and Control Methods

Cultural Control

The southern mole cricket has a number of natural enemies that help to keep their population in check. Toads, sandhill cranes, armadillos, and tiger beetles are all predators of the mole cricket. However, often times they do not completely eliminate the problem. Other predators such as the larvae of the Ormia depleta tachinid fly, which is a parasitoid of the mole cricket, can be introduced into your soil to assist. You can also purchase Steinernema scapterisci nematode, which can be sprayed in the soil. This is effective when applied while the southern mole crickets are adults. The nematodes can make limited movements around the soils surface, and will mainly depend on host insects to move close to them so that they can survive. It is also important to maintain good turfgrass upkeep practices such as proper irrigation, fertilization, and mowing lengths to keep your grass healthy and less susceptible to damage. However, it is important to note that having satisfactory control is often dependent on using an integrated management system that includes the use of both cultural and chemical methods.

Chemical Control

Granular and liquid insecticides both have been found to be successful in controlling the southern mole cricket. The insecticides thiamethoxam, and dinotefuran can suppress the mole cricket. Insecticidal soaps and insecticides with bifenthrin, cyfluthrin, pyrethrins can also help. In many situations, treatment has the best results when applied in the middle of summer while the crickets are still small and vulnerable. This is also when the soil is warmer and more conductive to pesticides. If treatment is done when conditions are dry, it will not be particularly effective as the crickets will be deep below the ground. That being said, always make sure the soil is moist before application. Be sure to carefully read the insecticides label for cautions and proper application.

Latin / Alternative Southern Mole Cricket Names

  • - Scapteriscus borellii

Sources

http://content.ces.ncsu.edu/21240.pdf