Welcome to our comprehensive guide on managing pests in wheat crops. Wheat, a vital staple crop, is susceptible to various pests that can cause significant damage if left unchecked. In this blog, we will explore the common signs of pest infestation in wheat, delve into preventative measures to safeguard your crop and discuss effective treatment options.
How to Manage Pests in Wheat
Overview of Wheat Pests
Wheat, a widely cultivated grass, is a staple food worldwide. Belonging to the genus Triticum, the most commonly grown species is common wheat (T. aestivum). Evidence from archaeology suggests that wheat cultivation dates back to around 9600 BCE in the Fertile Crescent regions. Botanically, the wheat kernel is classified as a caryopsis, a type of fruit. Wheat surpassed all other food crops with a staggering land area of 220.4 million hectares (545 million acres) in 2014.
Additionally, the global wheat trade exceeds that of all other crops combined.is crucial in feeding approximately 35% of the global population. Although it hosts nearly twenty-four different insect species, only six of them—aphids, termites, armyworms, pink stem borers, pod borers, and Ghujhia weevils—attain the status of major pests. These pests pose a significant threat to wheat crops throughout their growth stages, from sowing to maturity. This chapter focuses on the distribution, host plants, identification, biology, and damaging symptoms caused by these insect pests.
Major and Common Damaging Pests in Wheat
- Termite: The two species of termites that pose a threat to wheat crops are Odontotermis obesus Rambur and Microtermes obesi Holmgren. These insects can cause major damage to the plants.
- Wheat Aphid: Sitobian avenae, commonly known as wheat aphid, is a major pest of wheat. These small insects feed on the sap of wheat plants, leading to stunted growth, yellowing leaves, and reduced yield.
- Armyworm/Cutworm: Mythimna separata Walker, also known as armyworm or cutworm, is a destructive pest that can quickly devastate wheat fields. Their voracious appetite results in defoliation and severe crop damage.
- American Pod Borer: Helicoverpa armigera Hubner, commonly called the American pod borer, is a serious threat to wheat crops. The larvae of this moth feed on developing pods, causing yield losses.
- Brown Mite: Petrobia latens Mull is a brown mite species that can infest wheat plants. These mites feed on the leaves, leading to discoloration, necrosis, and reduced photosynthesis.
- Pink Stem Borer: Sesamia inferens Walker is a major pest that attacks the stem of wheat plants. Infested stems exhibit characteristic pink discoloration, weakened structure, and reduced nutrient transport.
- Shootfly: Atherigona naqvii Steyskal and A. oryzae Mall are two species of shootflies that affect wheat crops. They lay eggs in the leaf sheaths, and the emerging larvae bore into the stem, causing “dead hearts” and yield loss.
Aphid Pests of Wheat and Their Management
Aphids Sitobion avenae, Rhopalosiphum padi, and other species are common aphids affecting wheat crops. They are found in wheat-growing areas, especially in the North-Western Plain Zone and Peninsular India. Infestation occurs from the second half of January until crop maturity.
In case you missed it: How to Manage Common Diseases in Wheat: Damage Symptoms, Treatment, Spread, and Prevention
Chemical pesticides can be used if aphid levels exceed 10 per tiller during the vegetative phase or 5 per tiller during the reproductive phase. Imidacloprid is a recommended insecticide, applied initially on border rows and then, if necessary, in the entire field. Natural enemies present in the field also help control aphid populations.
Brown Wheat Mite Pest of Wheat and Their Management
Brown wheat mites are prevalent in rainfed areas, particularly in Rajasthan, Haryana, and Madhya Pradesh. They cause damage by infesting leaves and sucking plant sap, resulting in silvery flecking on leaves. Individual mites are too small to be seen without effort but can be observed by shaking infested leaves on white paper. Mites usually do not pose significant production constraints, and management practices are optional. However, monitoring is essential to prevent them from becoming a major pest in changing cropping sequences.