ISSN 2808-3229
Journal of Biodiversity and Biotechnology.
, 65Ae70, 2025 URL: https://jurnal.
id/jbb/article/view/113966 doi: http://dx.
org/10.
20961/jbb.
Effects of Rice Varieties on Attractiveness.
Population Development, and Weight Loss Caused by Sitophilus oryzae During Storage Dicky Marsadi1*.
Ketut Ayu Yuliadhi1 Department of Agroecotechnology.
Faculty of Agriculture.
Udayana University.
Bali *Corresponding author: dicky.
marsadi@unud.
Abstract Sitophilus oryzae is one of the main pests that attack rice and cause quantitative and qualitative losses during storage.
This study aims to analyze the effect of several rice varieties on attractiveness, population development, and weight loss of rice due to S.
oryzae infestation.
The study was conducted using a free choice test to measure attractiveness, population development observation, and weight loss measurement on four rice varieties, namely red rice, white rice, black rice, and brown rice.
The results showed that brown rice had the highest palatability and the highest population growth rate, black rice was the second best, followed by husked rice.
In contrast, white rice had the lowest palatability, population growth rate, and weight loss.
The pattern of rice weight loss was consistent with the pest population level, where varieties with higher S.
oryzae populations experienced a greater percentage of weight loss.
The differences in S.
oryzae response between rice varieties are thought to be related to the physical and chemical characteristics of the rice varieties, including nutrient content and grain structure, which affect pest preference and development success.
This study shows that rice varieties have the potential to be used as an essential component in post-harvest pest management strategies, particularly in efforts to reduce losses during storage through the selection of varieties that are relatively more resistant to S.
oryzae infestation and the use of rice varieties to develop attractants for trapping S.
Keywords: pest attractiveness.
pest population.
rice varieties.
Sitophilus oryzae.
weight loss.
Cite this as: Marsadi.
Yuliadhi.
Effects of Rice Varieties on Attractiveness.
Population Development, and Weight Loss Caused by Sitophilus oryzae During Storage.
, 65Ae70.
http://dx.
org/10.
20961/jbb.
Introduction Rice plants (Oryza sativa L.
) are the primary source of rice, which is a staple food for more than half of the world's population.
Rice also plays a vital role in supporting food security, social and economic stability, and agricultural sustainability in developing countries, especially in Indonesia .
Rice, as the main product of rice plants, not only serves as a source of energy but also as an essential source of nutrition for the community.
Currently, more and more people are realizing the importance of healthy food, so public interest in functional rice such as brown rice, brown rice, and black rice is increasing.
This is because these types of rice come from rice varieties that have special nutritional content, such as fiber, vitamins, minerals, and bioactive compounds that are higher than those of regular white rice.
Rice production continues to be increased by improving seed types and farming methods, but the problem of post-harvest losses remains a significant threat to ensuring the availability and quality of rice.
One of the leading causes of post-harvest yield loss is rice weevil (Sitophilus oryzae L.
) infestation.
oryzae is a cosmopolitan pest with a high infestation rate and significant destructive oryzae is capable of attacking whole rice grains and completing its entire life cycle inside the grain, causing structural damage to the endosperm, increased weight loss, and a noticeable decline in the physical and nutritional quality of rice .
Attacks by S.
oryzae on rice are greatly influenced by the characteristics of the rice variety and type, such as nutritional content, endosperm hardness, grain size and shape, and the thickness of the aleurone layer and bran, which are known to development success, and pest population growth rate.
Doherti et al.
reported significant differences in attractiveness, number of offspring, and damage levels between rice types and varieties.
The results of a study by Syahrullah et al.
also showed that the population density of S.
oryzae was positively correlated with an increase in weight loss and physical damage in various local rice varieties.
Damage caused by warehouse pests such as S.
oryzae not only results in quantitative losses in the form of weight loss but also reduces the physical quality and commercial value of rice through contamination with powder, frass, and potential biological contamination that poses a risk to food safety .
Until now, warehouse pest control has generally used synthetic insecticides that have the potential to leave harmful residues and accelerate the development of pest resistance, thereby posing risks to human health and the sustainability of storage systems.
To overcome these problems, a sustainable control approach is needed through the selection of rice types and varieties that produce rice that is relatively resistant to storage as a safer and more environmentally friendly alternative.
To date, research that simultaneously examines the attractiveness, population dynamics, and weight loss rate of S.
oryzae in four commercial rice types .
hite rice, red rice, brown rice, and black ric.
under uniform storage conditions is still However, these four rice types have different morphological characteristics and nutritional compositions that have the potential to affect their susceptibility to storage pests.
Based on this description, this study was conducted to analyze the differences in dynamics, and weight loss rates of S.
oryzae in white rice, brown rice, brown rice, and black rice during storage.
The results of this study are expected to provide a scientific basis for determining the type of rice that is more resistant to storage and to support the development of a safe, effective, and sustainable rice storage system.
Materials and Equipment The materials used included white rice, brown rice, red rice, black rice, and test insects (S.
The equipment used included analytical scales, plastic jars, gauze, and statistical software.
Material and Methods Time and Place of Research This research was conducted at the Integrated Pest Management Laboratory.
Faculty of Agriculture.
Udayana University.
Bali.
Indonesia, from October to December Weight loss (%):
Experimental Design The study used a completely randomized design (CRD) because it was conducted in a homogeneous environment .
There were four treatments .
hite rice, brown rice, brown rice, black ric.
with five replicates, resulting in a total of 20 experimental units.
Media Preparation Each jar was filled with approximately 75 g of rice and inoculated with 5 pairs of S.
oryzae imagoes, then covered with gauze for air Attractiveness Test (Preferenc.
The preference test was conducted using the free choice test method, where the four rice types were placed together in one test arena, and 20 S.
oryzae imagoes were released in the center of the test area.
The number of insects that chose each type was recorded after 24 hours as an indicator of attractiveness .
Population Development Observation The first generation (F.
population was counted after 45 days of incubation to reflect the reproduction rate and population development of S.
oryzae in each rice type.
The population development rate was calculated using the formula from Zhang .
Population growth rate (%):
yaycnycuycayco ycyycuycyycycoycaycycnycuycu Oe yaycuycnycycnycayco ycyycuycyycycoycaycycnycuycu ycu100 yaycuycnycycnycayco ycyycuycyycycoycaycycnycuycu Weight Loss Measurement Weight loss observation of rice was conducted after all S.
oryzae imagoes emerged.
Rice weight loss is defined as the decrease in rice mass during the storage period caused by pest attacks.
The percentage of rice weight loss was calculated using the formula according to Susanti .
initial rice weight Oe final rice weight ycu100 initial rice weight Data Analysis The data on the attractiveness of S.
oryzae were analyzed using analysis of variance (ANOVA) at a significance level of 5% ( = 0.
to determine the effect of rice varieties on the number of insects attracted.
the ANOVA results showed significant differences between treatments, the analysis was continued with Duncan's Multiple Range Test (DMRT) at a significance level of 5% to compare the mean values and identify statistically different treatment groups.
Data on population development and rice weight loss were presented descriptively in tabular form to illustrate trends and differences between rice varieties during the observation period.
Results and Discussion Attractiveness (Preferenc.
Test The S.
oryzae preference test showed that rice varieties had a significant effect on the number of S.
oryzae individuals attracted to each treatment (Table .
The results of the analysis of variance showed significant differences between rice varieties, as indicated by a p-value < 0.
05, which was further tested using Duncan's 5% test.
Duncan's multiple range test showed that brown rice had the highest average number of individuals attracted, 2 individuals, and was significantly different from all other varieties.
Black rice showed a medium level of attractiveness with an average of 6.
4 individuals.
White rice and brown rice had an average of 3.
0 and 1.
individuals, respectively, and were not significantly different from each other, indicating a relatively low level of attractiveness to S.
Overall, there was a gradation in the level of attraction of S.
oryzae to rice varieties, with the order of preference being red rice > black rice > white rice OO brown rice, as reflected in the separation of groups in Duncan's test.
Table 1.
Mean number of S.
oryzae individuals attracted to different rice varieties.
Experimental Replicates Treatment (Rice Variet.
Red rice White rice Black rice Brown rice Note: Different letters indicate significant differences at p < 0.
The high level of attractiveness of S.
oryzae to red rice indicates that this variety possesses characteristics that are more attractive to stored product pests compared to other rice This preference is presumably associated with differences in the physical and chemical properties of the grains, particularly the composition of volatile compounds and nutrient content, which function as olfactory and gustatory stimuli for insects.
Cao reported that S.
oryzae exhibits significant attractive responses to specific volatile compounds, such as nonanal, hexanal, and 1-octen-3-ol, which are commonly found in rice varieties with intact aleurone layers and bran .
These compounds play a crucial role in guiding pest orientation during host and food source searching.
In addition to volatile compounds, grain nutritional characteristics also contribute to host preference by S.
Salman stated that carbohydrate and protein contents, as well as grain moisture levels, influence feeding behavior and oviposition decisions of the pest .
Rice varieties with relatively higher nutritional content tend to be more preferred because they can better support the energy requirements and reproductive success of This is consistent with the results of the Mean 9,2a 6,4b 1,4c present study, in which red rice and black rice, which are generally recognized as having higher nutritional value than white rice, exhibited higher levels of attractiveness.
The preference pattern observed in this study is also consistent with the findings of Sharma et al.
, who reported that S.
oryzae is capable of distinguishing and selecting hosts based on differences in the physical and chemical characteristics of the substrate .
Therefore, the variation in attractiveness among rice varieties observed in this study confirms that the phytochemical profile and physical properties of rice grains are key factors influencing host selection by S.
From a practical perspective, this information is essential for postharvest pest management, as rice varieties with lower attractiveness may present a reduced risk of infestation and can be prioritized in sustainable storage systems.
Observation of Population Development The population development of S.
oryzae differed significantly among rice varieties during the observation period (Table All treatments were initiated with the same initial population .
adult individual.
Population growth rate (%) was calculated based on the increase in the total number of insects per replicate at the end of the observation period relative to the initial The final population size included all emerged individuals, regardless of life stage, and was expressed as the mean number of insects per replicate.
The highest population growth rate was recorded on red rice .
954%), followed by black rice .
720%), brown rice .
968%), and white rice .
%), indicating marked differences in the suitability of rice varieties for population development of S.
Table 2.
Percentage of population growth of S.
oryzae on different rice varieties Population S.
oryzae Population Treatment Initial Final rate (%) Red rice White rice Black rice Brown rice The differences in population growth rates indicate that rice varietal characteristics play an essential role in supporting the reproductive success and development of S.
Abedi et al.
reported that starch content and macronutrient levels in cereal grains are positively correlated with the population growth rate of stored product insects, as these nutrients serve as the primary energy sources for larval development and egg Rice varieties with higher nutritional content tend to provide more favorable conditions for the population development of S.
Zhang et al.
also demonstrated that different rice varieties offer varying levels of developmental duration and metabolic More digestible varieties allow the insect to complete its life cycle more rapidly, resulting in higher population growth rates.
the present study, the high population growth observed on red and black rice is likely associated with the preservation of nutrients in the bran and aleurone layers, which support oviposition, larval development, and adult In contrast, the low population growth rate observed in white rice can be attributed to the removal of most bran layers during polishing, leading to a reduction in essential nutrients required by the insect.
Meanwhile, the more moderate population growth on brown rice may be influenced by its more complex grain structure and relatively thicker outer layers, which can restrict larval penetration and slow individual development.
Abedi et al.
reported that grain physical structure may act as a mechanical barrier to oviposition and nutrient utilization by stored-product insects.
Overall, the variation in S.
population development among rice varieties suggests that varietal susceptibility to storedproduct insect infestation can serve as an essential indicator in the design of postharvest pest management strategies.
Rice varieties with lower population growth rates have the potential to reduce infestation risk and minimize losses during storage.
Weight Loss Assessment The results of the weight loss assessment revealed significant differences among rice varieties after the storage period under S.
oryzae infestation (Table .
The highest percentage of weight loss was recorded in red rice .
68%), followed by black rice .
61%), brown rice .
04%), and white rice .
57%).
This pattern indicates that each rice variety exhibits a different level of susceptibility to quantitative damage caused by feeding activity and population development of oryzae during storage.
Table 3.
Percentage of Rice Grain Weight Loss Caused by S.
oryzae Infestation During Storage Initial rice Final rice Weight
Treatment
loss (%) Red rice
White rice
Black rice
6,61
Brown rice Weight loss is an essential parameter for describing the level of physical damage and mass loss in rice caused by S.
oryzae infestation during storage.
High weight loss values reflect the intensity of grain consumption by S.
the formation of feeding tunnels, and the accumulation of powdery debris resulting from larval feeding and development.
Hendrival and Rika .
reported a robust positive correlation between S.
oryzae population density and the percentage of rice weight loss during storage .
= 0.
p < 0.
, indicating that an increase in pest population directly causes greater quantitative losses.
The differences in weight loss among the rice varieties observed in this study can be explained by variations in the physical and chemical properties of rice grains, such as starch and protein content, moisture level, and husk Das et al.
showed that these parameters were significantly positively correlated with the amount of rice weight loss due to S.
oryzae infestation.
Rice varieties with higher nutritional content and a more permeable grain structure tended to experience greater weight loss.
The highest weight loss in rice was observed in red rice, indicating that this variety is not only more attractive to S.
oryzae but also provides more favorable conditions for pest population development, resulting in greater damage intensity.
In contrast, white rice showed the lowest weight loss.
The low weight loss of rice is due to S.
oryzae being less attracted to white rice compared to other rice varieties.
oryzae low interest in white rice is thought to be due to white rice's relatively higher resistance or lower nutritional content to support the development of S.
oryzae pests.
The evaluation of weight loss among rice varieties provides an essential scientific basis for selecting more storage-resistant varieties and developing effective post-harvest pest control strategies to minimize losses during Conclusion The results of the study indicate that rice varieties have a significant effect on attractiveness, population development, and the level of damage to rice caused by S.
infestation during storage.
Red rice showed the highest levels of attractiveness, population growth rate, and weight loss, while white rice showed the lowest values for all parameters The differences in S.
response to each rice variety indicate that the physical characteristics and nutritional composition of the grains play an important role in determining S.
oryzae's preference and development success.
Acknowledgments The author would like to express his deepest gratitude to the institution for the facilities provided, as well as to all those who took the time to discuss, provide valuable feedback, and offer suggestions so that this research could be carried out correctly.
Conflict of Interest The authors declare that there are no conflicts of interest, either financial or nonfinancial, that could have influenced the conduct of the research, the data analysis, or the preparation of this manuscript.
References