Scientific name: Gryllotalpa orientalis (= africana) Burmeister
Common name: Mole cricket
Mole crickets are polyphagous. They feed on the underground parts of almost all upland crops. They occasionally cause heavy damage to the roots and basal parts of rice plants growing in raised nursery beds or upland conditions. In wetland rice, infestation occurs when there is no standing water. No recorded outbreak of this pest is known.
Afghanistan, Australia, Bangladesh, Bhutan, Cambodia, India, Indonesia, Japan, Lao PDR, Malaysia, Myanmar, Nepal, Pakistan, Papua New Guinea Philippines, Thailand, and Vietnam.
Feeding on seeds and roots results in loss of plant stand in upland rice. In older plants, tillers are also fed upon.
Biology and ecology
The eggs are laid in hardened cells constructed in the soil by the females. One cell usually contains 30-50 eggs. Egg incubation varies from 15 to 40 days. The hatching nymphs feed on roots and damage the crops in patches. The nymphs have limited migrating ability and generally suffer heavy mortality. Nymphal development takes 3-4 months. The insect has only one generation per year in the temperate region.
In flooded rice fields, mole crickets are usually seen swimming on the water. Their low population density is due to cannibalism.
The host range of G. orientalis includes the following: Allium cepa L. (onion), Brassica oleraceae L. (cabbage), Camellia sinensis (L.) O. Ktze. (tea), Helianthus annuus L. (sunflower), Hordeum sp. (barley), Nicotiana tabacum L. (tobacco), Oryza sativa L. (rice), Solanum tuberosum L. (white potato), and Triticum aestivum L. em. Thell. (wheat).
Detection and inspection
The rice field can be checked for damage symptoms by using a light trap. Cut seedlings are indicative of the insectís feeding damage.
Hahn HE. 1958. Investigation on the habits and development of Gryllotalpa africana in Braudenberg. Berr. Entomol. 8:334-365.
Pathak MD, Khan ZR. 1994. Insect pests of rice. Manila (Philippines): International Rice Research Institute. 89 p.
Reissig WH, Heinrichs EA, Litsinger JA, Moody K, Fiedler L, Mew TW, Barrion AT. 1986. Illustrated guide to integrated pest management in rice in tropical Asia. Manila (Philippines): International Rice Research Institute. 411 p.
Shepard BM, Barrion AT, Litsinger JA. 1995. Rice-feeding insects of tropical Asia. Manila (Philippines): International Rice Research Institute. 228 p.