Bukbók – Beyond Entomology and Pest Management Science

After the cocolisap (Aspidiotus rigidus Reyne) outbreak a few years ago, another insect species now captures the limelight. Initially, a few netizens were quick in putting the blame on government entomologists, understandably so, as the problem centers on an insect, a beetle – a weevil or snout beetle to be exact. In the midst of multi-media releases and posts from all corners, all focusing the spotlight on the lowly 2-mm long “culprit”, the picture of a top-ranking government official, no less than the Secretary of Agriculture himself, demonstrating how to cook rice infested with rice weevil (https://www.facebook.com/MindaKnow2017/videos/421346601721949/) and then showing the public that he can, and he did, eat them, presents mixed feelings and thoughts to me. Maybe the Honorable Secretary did achieve in pointing out what he wanted to – that it is safe to eat weevil-infested rice. What was or were missed were the main points that sparked and continue to kindle the public outrage. With all due respect to the DA Secretary, I am putting into writing my thoughts – as an entomologist, and as an ordinary rice-eating Filipino.

Bukbók or Rice Weevil, Sitophilus oryzae – The Star of the Moment

Unlike most other insect pests, grain or stored product weevils, collectively called bukbók in the Tagalog and other Philippine languages, have been with humans in Southeast Asia since time immemorial. In general, these insects belong to any of the families under the taxonomic superfamily of weevils or snout beetles (the Curculionoidea) (All beetles are classified under the insect order Coleoptera). However, the vernacular term as a general or collective name also includes a few species that belong to the subfamily of bean weevils (Bruchinae of the leaf beetle family (the Chrysomelidae, which is under superfamily Chrysomeloidea). My mentioning of these group names is intended to emphasize the diversity of the “bukbóks” as a large group and as a small group of species allied to that infesting our staple food – rice.

The Rice Weevil (Bukbók ng Bigas), is known to science as Sitophilus oryzae (Linnaeus). [see picture here – above – that I grabbed from Wikipedia: by Olaf Leillinger – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=1550147%5D.  Its closest relative in the Philippines is the corn weevil (Bukbók ng Mais), Sitophilus zeamais (Motschulky). The corn weevil is also known to occasionally attack rice and the two differ in at least seven minute characteristics, that are often difficult to discern by unfamiliar eyes. The adult rice weevils have well-developed hindwings beneath their hardened forewing and, hence, can fly. Impressively, they can live for up to two years and during its relatively long life, a mother rice weevil can lay 2-6 eggs each day, with a cumulative record (in the laboratory) of up to 300 per female. An egg is deposited singly in each rice grain within a hole drawn by the mother rice weevil using its strong mandibles. After an egg is deposited, the mother weevil plugs the hole with substances secreted from her ovipositor. The grub (C-shaped larva) develops within the grain, hollowing it out while feeding. When full-grown, the grub proceeds to the resting stage (pupa) within the rice grain. The pupal stage lasts for 4-6 days and a new adult weevil emerges, coming out of the grain within 2–4 days. Male rice weevils produce an aggregation pheromone that attracts both males and females to come closer together. The female, on the other hand, produces its sex pheromone solely to attract male weevils.

Entomologists know and have shown the solution to the rice weevil problem

The brief account in the previous section summarizes that we know the problem as far as the biological-ecological side is concerned. We have pinpointed which among the species should be the target. Entomologists have studied how the species lives and how it damages our grains. Far above these basic knowledge, pest management entomologists have recommended control strategies, from having a well dried rice after harvesting and before storage, to eliminating sources of infestation, and treating stored rice grains in every shipment and with a chemical (e.g. phosphine) that is both effective against the stored pests of rice grains and safe to humans when applied properly. In this case, Science, as physically embodied by scientists who deal with basic studies of insects (entomologists) and entomologists who have searched for solutions to this and other pest problems (pest management scientists), both in government and private sectors, has again shown that it has not been reneged on nor negligent of its responsibilities to the consuming public.

The Bukbók Problem – Beyond Science

The solution, fumigation, is available, fairly simple, and relatively economical, considering the economic costs entailed by losses due to infestation by the rice weevil and other stored product pests. Safeguarding farm produce from pests, from harvest to warehouse storage, and strict quality control of grain shipments from abroad are routine measures. The problem, therefore, although highlighted by the infestation by an insect pest species, is beyond entomology, and far above, what pest management scientists can prescribe. Only good governance, can prevent immense problems such as the present rice shortage and the infestations of our rice grains. In relation to this, the eminent Dr. Emil Q. Javier has outlined five complementary strategies for the future of our rice sector (https://business.mb.com.ph/2018/07/28/wanted-a-new-rice-industry-road-map-after-lifting-of-quantitative-restrictions/).

Lastly, while I, like most Filipino entomologists, agree that insects are generally (or mostly) edible, and that entomophagy (consuming insects for food) is something to explore not only for the thrill (in the Philippines mainly, because many other Southeast Asians have insects in their diet) but also for the nutritional quality, I believe that we deserve rice with quality much, much better and more pleasant than bukbók-“enriched”. Nobody deserves to eat food that is considered low quality, if not altogether rotten; and all the more, when that food is staple and has become quite costly. Filipinos deserve much better, or rather, the best.

I know, because I am an entomologist. I am a scientist. I am Filipino.

–  Ireneo L. Lit, Jr., Ph.D.