If there is one thing you have to know about pests, it is that they are everywhere. As long as there is human activity in a given location, you can almost guarantee that there will be a pest nearby — whether rodent, insect, or bird (yes, there are many species of bird that are considered pests). Even the most important food crop of the world, rice, has pests.
There are numerous kinds of pests that wreak havoc in rice farms. If you’re related to the farming industry, you would do well to know what these are. Meanwhile, the casual reader or insect enthusiast can still find this information interesting so continue reading to know five of the most destructive pests in rice farms.
The rice black bug (Scotinophara coarctata) has been the subject of many articles already, but it deserves a spot on this list because they are the blight of many farms across the Philippines. Not only are they pervasive, but they also attack rice crops at every stage of their growth — unlike some of the other pests on this list that have certain methods of attacking rice crops.
Next up is the rice stink bug (Oebalus pugnax). While the aforementioned rice black bug has also been known to produce a foul odor, the rice stink bug is much more popular, hence the name. The ‘stink’ is produced by scent glands found on their abdomen.
Rice stink bugs are also known as grain-sucking insects because that is how they damage rice crops. Their mouthparts penetrate the developing grain and suck the white fluid referred to as ‘milk’. This damages the rice in its early stages of development and prevents the grain from being ‘filled’. The resulting end-product is called “pecky rice.” It gets its name because it is sucked dry by stink bugs and stained by the bacteria or fungi that enter through the puncture wounds.
The rice water weevil (Lissorhoptrus oryzophilus Kuschel) belongs to a larger group of insects that mostly feed on rice leaves. While this may not be the most devastating in terms of damage, it can reach a point where the leaves’ photosynthetic capability is affected. This can mean a reduction in overall yield of crops — something that many farmers can’t afford to experience.
The only positive thing about this is that rice plants can usually recover from their leaves being defoliated. As long as the damage occurs early in the stages of the rice plant’s growth, they can still offset the damage done by producing new tillers. When this happens, yield loss is reduced if not fully avoided.
The brown planthopper (Nilaparvata lugens) is another destructive rice pest that attacks the basal portion, or the stems, of rice crops. Aside from the direct, physical damage that they cause, they are also vectors of damaging rice diseases like the grassy stunt virus and rice ragged stunt. The former reduces yield by inhibiting panicle production, while the latter reduces yield by producing unfilled grains and less plant density.
Both of the aforementioned viruses have no cure, which is why it is imperative you control any sort of brown planthopper infestation before it escalates. You can notice the presence of planthoppers by checking the color of the leaves. A high population causes the leaves of the crop to turn orange-yellow before becoming brown and dry. This condition is called ‘hopperburn’ and once plants are affected by it, it can already be too late.
The next rice farm pest is a type of stem-boring insect. The rice stalk borer moth (Chilo plejadellus) is a type of moth that lay eggs on rice leaves. The resulting larvae then bore into the stem. Larvae do this to feed on the stem during different parts of a plant’s life stages. When they feed during the vegetative growth stage of the plant, they cause damage to the central shoot, and prevents it from producing a panicle. No panicle means no grain.
Meanwhile, if the rice stalk borer moth larvae feeds during the plant’s reproductive stage then the resulting panicle is unfilled and pale or ‘whitish’ in color — instead of being filled with grain and brownish in color. For this reason, empty white panicles are called ‘whiteheads’.
Both outcomes mean a loss in crop yield, which is why you should stay alert and always check the stalks of your crops to see if there has been any sign of stem-boring insect activity.
Given the many different destructive rice pests that can potentially infest and terrorize rice fields around the world, knowing the enemy can be the first step in beating or even preventing these insects. If you observe any of the signs, symptoms, and behaviors in your rice field, contact your trusted pest control service providers. They can potentially save your precious harvest.