Phytophagous Groups Research Articles

Unveiled species diversity of moss-feeding mites (Stigmaeidae: Eustigmaeus): a research on their distribution, habitat, and host plant use in Japan.

The genus Eustigmaeus Berlese, 1910 represents the unique phytophagous group within the superfamily Raphignathoidea. Four species within this genus have been known to inhabit mosses and feed on them as larvae, nymphs, and adults. However, the interactions with mosses have remained poorly understood. In order to reveal the diversity and host-plant use of the moss-feeding species, we conducted an extensive field study in Japan. This study revealed an array of moss-feeding species inhabiting various moss species, with 10 morphologically distinctive species newly documented in Japan. Through DNA barcoding based on cytochrome c oxidase subunit I (COI) sequences, these morphospecies were recovered as distinct entities. Notably, the host-plant use of four species was elucidated. Among these, Eustigmaeus sp. 9 exhibited polyphagy, while three species (Eustigmaeus spp. 1-3) demonstrated varying degrees of host specificity, each using moss species from the Hypnales, Philonotis, and Dicranidae, respectively. While a few moss-feeding species were frequently found in the same geographic area, more than one species rarely co-occurred within the same moss colonies. Eustigmaeus offers a unique study system, with its diverse moss-feeding species and indications of specific host plant use. Consequently, the moss-feeding Eustigmaeus serves as a valuable model for exploring the macroevolutionary patterns underlying diversification in moss-feeding arthropods.

Variations in macrofaunal communities along sand physico-chemical gradient across the intertidal zones on island beaches

Island beaches, once mistakenly considered as 'ecological deserts', are actually unique ecosystems that support abundant macrofaunal communities. However, limited studies have examined the variations and determinants of macrofaunal communities across the intertidal zones on island beaches, which is crucial for shedding light on the underlying ecological processes and enhancing biodiversity conservation efforts. Here, we explored the variations in macrofaunal communities along sand physico-chemical gradient across four intertidal zones on nine representative beaches, within the largest land-bridge archipelago in eastern China. Our findings revealed that species richness, density, and Shannon-Wiener diversity of macrofaunal communities were notably higher in the lower intertidal zones, exhibiting a positive correlation with elevated levels of sand moisture (M), electrical conductivity (EC), available potassium (AK), and grain size (GS). Conversely, macrofaunal Simpson diversity displayed an inverse pattern, with heightened values observed in the vegetation zone. The Saprophagous, Predaceous, and Omnivorous groups of macrofaunal communities demonstrated an increase with higher levels of EC, AK, and M in the lower intertidal zones. Furthermore, Phytophagous group of macrofaunal communities tended to inhabit the vegetation zones characterized by elevated levels of sand total phosphorus (TP), total nitrogen (TN), and organic carbon (OC). Primarily, our findings indicate that sand nutrition, moisture, and salinity play pivotal roles in shaping the variations of macrofaunal communities on island beaches. These insights offer valuable perspectives into the holistic responses of macrofauna on island beaches to changes in sand physico-chemical properties, serving as a crucial theoretical foundation for the assessment, conservation, and restoration of island beaches.

Expression pattern and cellular localization of pepsinogen in early development and induced by different diets in the spotted knifejaw (Oplegnathus punctatus)

To solve the high mortality rate of early-stage larval feed conversion during aquaculture in Oplegnathus punctatus, the investigation of the structural and functional characteristics of the gastric tissue was conducted. Histological results showed that the gastric gland rudiment appeared at 17 dph. The basic structure of the stomach was fully developed between 26 and 35 dph. Two pepsinogen genes, named OpPGA1 and OpPGA2, were identified in the spotted knifejaw genome. qPCR results of developmental period showed that the two genes were low in expression during early development (5 and 15 dph). At 20 dph, the two genes started to show trace expression, and at 30 dph the mRNA expression levels of OpPGA1 and OpPGA2 reached the highest levels. Results of pepsin activity detection during the development period showed lower activity was detected 22 dph, followed by a peak at 30 dph. Under different feeding inductions, OpPGA1 showed the highest expression in the basic diet group and hard-shell group, while the expression level in the phytophagous group remained consistently low. The mRNA expression level of OpPGA2 in the phytophagous group was significantly higher than in other groups. Enzyme activity determination under different feeding inductions showed slightly higher enzyme activity in the basic diet group and crustacean group. The results of in situ hybridization showed that the mRNA of both OpPGA1 and OpPGA2 genes was both expressed in gastric gland cells. These information can contribute to the development of practical feeding methods in terms of digestive physiology for the development of larvae.

Evolutionary timescale of chalcidoid wasps inferred from over one hundred mitochondrial genomes.

Chalcidoidea is one of the most biologically diverse groups among Hymenoptera. Members are characterized by extraordinary parasitic lifestyles and extensive host ranges, among which several species attack plants or serve as pollinators. However, higher-level chalcidoid relationships remain controversial. Here, we performed mitochondrial phylogenomic analyses for major clades (18 out of 25 families) of Chalcidoidea based on 139 mitochondrial genomes. The compositional heterogeneity and conflicting backbone relationships in Chalcidoidea were assessed using various datasets and tree inferences. Our phylogenetic results supported the monophyly of 16 families and polyphyly of Aphelinidae and Pteromalidae. Our preferred topology recovered the relationship (Mymaridae+(Signiphoridae+Leucospidae)+(Chalcididae+((Perilampidae+Eucharitidae)+ remaining Chalcidoidea)))). The monophyly of Agaonidae and Sycophaginae was rejected, while the gall-associated ((Megastigmidae+Ormyridae)+(Ormocerinae+Eurytomidae)) relationship was supported in most results. A six-gene inversion may be a synapomorphy for most families, whereas other derived gene orders may introduce confusion in phylogenetic signals at deeper nodes. Dating estimates suggested that Chalcidoidea arose near the Jurassic/Cretaceous boundary and that two dynamic shifts in diversification occurred during the evolution of Chalcidoidea. We hypothesized that the potential codiversification between chalcidoids and their hosts may be crucial for accelerating the diversification of Chalcidoidea. Ancestral state reconstruction analyses supported the hypothesis that gall-inducers were mainly derived from parasitoids of gall-inducers, while other gall-inducers were derived from phytophagous groups. Taken together, these findings advance our understanding of mitochondrial genome evolution in the major interfamilial phylogeny of Chalcidoidea.

On a collection of (Insects, Acari) some insects and mites from medicinal plants of Ramakrishna mission, Narendrapur (India: West Bengal, Dist south 24 Paraganas)

A total 37 species of mites (under 22 genera, 9 family and 2 orders) and 17 species of insects (under 14 genera,11 family and 3 orders) has been recorded from 99 medicinal plants grown in three medicinal plant gardens of Ramakrishna Mission Ashrama, Narendrapur, collected during November 2021 - July 2022. Out of 37 species of mites, 23 species belonged to phytophagous group and 13 species predatory groups respectively. Among the phytophagous and predatory mites, Brevipalpus phoenicis, Petrobia harti, Steneotarsonemus spinki and Aceria guerreronis were found to be serious pests causing damage to their respective host plants, while Gynaneseius eharai, Amblyseius largoensis and Euseius finlandicus were found to be promising predatory mites feeding mostly upon Tetranychidae and Eriophyidae pest mites. In case of insects, 16 species was recorded as phytophagous and only 1 species (Scolothrips sexmaculatus) was predatory in nature. Among the phytophagous insects 3 species. Aphis nerii, Aspidiotus destructor, Kola vesta found to occur abundantly on the medicinal plants, causing serious damage symptoms to their respective host plants. The present study also recorded 25 mite species and 10 insect species shows new host records.

Assemblage of Ceutorhynchinae Weevils Associated With Brassicaceae in Quebec (Canada) Agroecosystems.

Ceutorhynchinae Gistel (Coleoptera: Curculionidae) are a highly diverse phytophagous group of weevils in which the most species rich genus, Ceutorhynchus Germar (Coleoptera: Curculionidae), is mainly associated with Brassicaceae. Some Ceutorhynchinae, such as the invasive cabbage seedpod weevil (CSW), Ceutorhynchus obstrictus (Marsham), are important pests of cultivated Brassicaceae, and others are natural enemies of weeds and potential biological control agents. This study aims to characterize Ceutorhynchinae assemblages in canola growing regions of Quebec. Ceutorhynchinae were sampled in areas adjacent to canola fields or other crops in six administrative regions of Quebec during the summers of 2019 and 2020. A total of 25 Ceutorhynchinae species were collected and identified. Canonical analysis and multivariate regression tree analysis revealed that the assemblage of Ceutorhynchinae varied regionally and was either dominated by the invasive canola pest CSW or by the native weevil Ceutorhynchus neglectus Blatchley. Our results also highlighted new biological associations between weevils and Brassicaceae like the CSW with the yellow rocket, Barbarea vulgaris R. Br., native Ceutorhynchus pauxillus Dietz with common pepper grass, Lepidium densiflorum, and native Ceutorhynchus semirufus LeConte with Pennsylvania bittercress, Cardamine pensylvanica Muhl. This study also provides a useful tool to find new biological control agents against Brassicaceae weeds and to monitor the abundance and diversity of this taxon and provide baseline data to assess future impacts of exotic parasitoids of CSW on native weevils.

Some mites and insects occurring on medicinal plants from medicinal plant gardens located in and around Kalyani, West Bengal

The present paper reports the occurrence of 22 species of mites belonging to 16 genera, 7 families and 3 orders as well as 11 species of insects under as many genera, 7 families and 3 orders, collected from medicinal plants from different medicinal plant gardens located in and around Kalyani during September 2021 to April 2022. Altogether 10 species of mites under 6 genera, 3 families belong to phytophagous group, 10 species of mites under 7 genera and 2 families belong to predatory group and 3 species of mites under as many genera and families belong to fungal feeding group. Out of these mite species, 2 species (Eotetranychus indicus and Oligonychus indicus) were found highly injurious causing damage to their respective host plants while 2 species, viz. Neoseiuslus longispinosus on Tetranychus neocaledonicus and Paraphytoseius orientalis on Polyphagotarsonemus latus were found as potential predators helping in biological control. Among the 11 species of insects, Aphis craccivora on Mentha arvensis, Aphis gossypii, Aphis nerii, both on Calotropis procera and Monanthia globulifera on Ocimum sanctum were important pests doing noteworthy damage on their respective host plants. All the species are listed with their hosts/habitat records, collection data and importance as pests/predators, if any.

Mites and insects occurring on some leafy ornamentals and floricultural plants in Howrah and Purba Medinipur districts of West Bengal, with their economic importance

The present paper deals with a total of 26 species of mites under 10 families, 17 genera and 3 orders as well as 10 species of insects under 5 families, 9 genera and 3 orders, collected from some floricultural and leafy ornamental plants in Howrah and Purba Medinipur districts of West Bengal. It may be mentioned here that these two districts are the largest producers of these plants. Among the mites, there are 14 species under 4 families and 8 genera which belong to phytophagous group, 10 species under 4 families and 7 genera belong to predatory group and remaining 2 species under as many families and genera belong to fungal feeding group. All the species of mites and insects are listed with their respective host/habitat plants, collection localities as well as their economic importance, if any. The most injurious species of mites which were observed in the field are Tetranychus urticae on Dahlia variabilis, Oligonychus biharensis on Rosa centifolia, Eutetranychus orientalis on Tabernaemontana divaricata and, Eotetranychus suginamensis on Nyctanthes arbor-tristis. Among the predatory mites, Amblyseius largoensis and Amblyseius herbicolus are important predators on phytophagous mites and the occurrence of the other predatory mites are only occasional. Among the insects, Ferrisia virgata, Aphis gossypii and Scirothrips sp. on Codiaeum variegatum, and Ferrisia virgata on Hibiscus rosa-sinensis, respectively were found abundantly.

A preliminary study of Mites and Insects occurring on plants used as Ethnomedicines collected from different medicinal plant gardens of Narendrapur Campus Ramakrishna Mission (South 24 Parganas, West Bengal)

The present study was conducted at Narendrapur Campus of Ramakrishna Mission during September 2021 to April 2022 for occurrence of Mites and Insects on plants used for ethnomedicinal purpose. The identification of the mites and insects reveals the occurrence of 20 spp. of mites belonging to 15 genera, 8 families and 3 orders as well as 11 species of insects under 11 genera, 9 families and 3 orders. Out of the collected mite species, 11 species belonging to 9 genera and 4 families are phytophagous in nature, 7 species belonging to 5 genera and 2 families are predatory in nature and 2 species which are fungal associates. In case of insects, all belong to phytophagous group. Among the mites only 3 species, viz. Panonychus citri, Polyphagotarsonemus latus and Tetranychus ludeni on Carica papaya, Ocimum tenuiflorum and Calotropis gigantea, respectively, were found abundantly, causing chlorosis of leaves. The occurrence of other mites and insects are only casual. In addition, a Host-Mites/Insects Table is also appended.

Assemblage Characteristics of Butterflies and Carabid Beetles as a Function of Soil Characteristics and Plant Diversity in Differently Managed Fields, Forests and Ecotones: A Case Study in Tuczno Forest District, Poland

A drastic decline in insect fauna on a large scale has been reported. We assume that this is a multifactorial problem involving biotope types and plant diversity, soil characteristics and human activity (management of areas). The aim of our study was to analyze diversity patterns of carabid beetles and butterflies as predatory and phytophagous arthropod groups in response to soil characteristics and plant diversity in different types of ecosystems and ecotones with diverse management situated in a heterogeneous landscape composed of different forests, agricultural and post-agricultural areas of different stages of succession and watercourses and mires in north-western Poland. Three different forests, three fallows, two meadows and two ecotones, differing with respect to the involved ecosystems, were included in the study. Our results showed that the study site types differed with respect to soil characteristics and plant diversity, but ecotones were not characterized by explicitly higher diversity in these parameters. For both carabid beetles and butterflies, characteristic assemblages for individual study sites could be demonstrated. We could also show differences in the most important factors between these two taxonomic groups. We assume that management type is important regarding ecosystem characteristics and biodiversity. Large-scale management strategies are necessary in order to maintain or create landscapes with high natural qualities.

Does fertilization with dehydrated sewage sludge affect Terminalia argentea (Combretaceae) and associated arthropods community in a degraded area?

Nutrients from dehydrated sewage sludge play an essential role in the development of many plants such as Terminalia argentea, in the recovery of degraded areas. The aims were to assess the abundance, diversity and species richness of phytophagous, pollinators and predators arthropods, as well as the percentage of defoliation of T. argentea trees, fertilized (or not) with dehydrated sewage sludge in a degraded area. The abundance, diversity and species richness of phytophagous Coleoptera and total predators (predator insects + protocooperating ants + spiders); abundance and species richness of Diptera, pollinator insects, spiders, and predators (predator insects + spiders) were higher on trees fertilized with dehydrated sewage sludge. The abundance of phytophagous Coleoptera declined with the presence of phytophagous Hemiptera and protocooperating ants; population of phytophagous Orthoptera declined in response to phytophagous Coleoptera and total predators; the numbers of the leafminer Lyriomyza sp. directly increased with the numbers of spiders. The ecological indices of phytophagous, pollinators, and predator arthopods increased on Terminalia argentea trees fertilized with dehydrated sewage sludge; such a better ecological indices in fertilized than in unfertilized trees, show it more suitable for the recovery of degraded areas. We discuss the competition between phytophagous insects groups as well as herbivory reduction by predators.

Revisiting diversity of coccinellid beetle in Mount Gede-Pangrango National Park: a preliminary observation

Declines in insect population and diversity particularly in the tropical forest region have stimulated wide interest among researchers worldwide. Loss of insect diversity and abundance is expected to provoke cascading effect on the ecosystem, but few data and documentation are available. So far, the coccinellid beetle study in Mount Gede-Pangrango National Park, Indonesia was conducted more than 40 years ago with last well-documented exploration by 2004. We aimed to update and deliver the newest data on the diversity of coccinellids of Mount Gede-Pangrango National Park. We tracked along the interpretation path and beetles were collected using hand method during observation between July 2018 to October 2019. A total of 17 species coccinellids were identified. Seven species belong to the phytophagous group of Diekeana, Epilachna, and Henosepilachna. Two mycophagous species from Psylloborini and Sticholotidini tribe, while others species (8 species) are a member of the predatory group, including Coccinellini and Chilocorini tribe. In this study, plenty of them are common species and widely distributed in the open area of the buffer zone. Our temporary findings indicate the possibility of species loss compared to past surveys that discover rare taxa, such as Ryszardia, and other specialist Epilachna group infesting wild host-plants.

Arthropod Diversity of Pomegranate Crop under High Density Planting in Tamil Nadu

Insects associated with pomegranate (Punica granatum L.), was observed from 2015 to 2016 in four major pomegranate growing districts of Tamil Nadu viz., Coimbatore, Erode, Tiruppur and Karurat monthly intervals. A total of 31 species under two genera and sixteen families of six orders was documented. In addition, seven natural enemies in association with pomegranate pests were also recorded. Among the different functional groups, phytophagous groups were dominated, followed by predators and parasitoids.

Leprosis mite and other mite species (Acari) associated to orange groves in Brazilian Central Amazon

The citrus leprosis mite, Brevipalpus yothersi Baker, is not considered to cause major damage to orange trees in the Brazilian Amazonas state. However, little is known about the diversity of plant mites and about mite damage to plants in this state of northern Brazil. The objective of the present study was to evaluate the level of occurrence of the leprosis mite in this region and the diversity and prevailing population levels of associated mites in unsprayed orange groves of the surroundings of Manaus, Amazonas state. In total, 1,614 mites were collected on citrus trees (616 of eminently predatory groups, 541 of eminently phytophagous groups and 457 of other groups). On plants growing spontaneously in orange groves, 514 mites were collected (270 of eminently predatory groups, 26 of eminently phytophagous groups and 218 of other groups). Most predators collected (638 specimens) belonged to Phytoseiidae, representing 14 species. The most abundant phytoseiids were Amblyseius aerialis Muma and Iphiseiodes zuluagai Denmark & Muma. Only 197 B. yothersi were collected, on leaves of orange, Lantana camara L. and Solanum paniculatum L.. Leprosis symptoms were not observed, and this may be related to the relatively low densities of the leprosis mite. The plant species Borreria verticillata (L.), Clidenia hirta (L.), L. camara, Paspalum virgatum L. and S. paniculatum are reservoirs of two abundant predatory mites of orange trees, A. aerialis and I. zuluagai.

Herbs as a source of nutrition for flower-visiting hoverflies (Diptera, Syrphidae)

Abstract During two seasons of observations, 244 specimens of hoverflies belonging to 16 species and four trophic groups were collected from herb flowers. Predatory species constituted about 50% of all the registered species and from 55% (2010) to 64% (2011) of all the specimens found. The most numerous flower-visiting species within this group were small, poor flyers, typical of communities with low plants - Sphaerophoria scripta (Linnaeus 1758) (19.6% in 2010 and 23.5% in 2011) and Eupeodes corollae (Fabricius 1794) (13.4% and 12.1%, respectively). Both species were classified to the eudominant group. Syrphus vitripennis (Meigen 1822) and Melanostoma mellinum (Linnaeus 1758) were classed as dominants. Non-predatory saprophagous species from the subfamily Eristalinae constituted about 25% of all collected species; the phytophagous group was scarce represented by Eumerus funeralis (Meigen 1822), E. strigatus (Fallen 1817) and Merodon rufus (Meigen 1838). Of the coprophagous species, only Syritta pipiens (Linnaeus 1758) was collected (6.8-8.0%). There were clear differences between flowers in terms of feeding visits by adult hoverflies. Matricaria chamomilla L. and Thymus vulgaris L. were the most attractive flowers, whereas Origanum vulgare L., Carum carvi L., Lavandula angustifolia L. and Hyssopus officinalis L. were of an intermediate visit status and Ocimum basilicum L. was relatively under-visited.

Effects of different forest stand types of Pinus sylvestris var. mongolica on insect community diversity in Saihanba Nature Reserve, North China

In order to study the effects of different stand types of Mongolian scots pine (Pinus sylvestris var. mongolica) on the diversity of insect community in the plantation under close-to-nature forest management, the structure of the insect community was studied in five stand types of the Mongolian scots pine pure forest and mixed forests in Saihanba Nature Reserve. The insects were collected by the sweep net method, and the diversity index, similarity, principal component, and stability of insect communities in different forest types were analyzed. In total, 9617 insects, belonging to 7 orders, 70 families, 195 species, were collected, and the Diptera, Hemipteran and Coleopteran were the dominant groups. The insect species in 5 stand types were all rich, and the insect community structure among the different stands reached a moderate dissimilar level. The species and individual number of mixed forest was more than those of pure forest. There was no significant difference among different stand types in insect community character indices. Principal component analysis indicated that phytophagous group, predatory group and parasitic group in each stand type were the main factors influencing the community structure, and predatory group and parasitic group had a stronger control effect on phytophagous group. The structure of insect community in the diffe-rent forest stand types had relatively high stability.

Determining Whether Exotic Cordgrass (Spartina alterniflora) Attracts Carnivorous Macrobenthic Fauna within a Zhanjiang (China) Mangrove Ecosystem

ABSTRACT Chen, Q. and Ma, K., 2018. Determining whether exotic cordgrass (Spartina alterniflora) attracts carnivorous macrobenthic fauna within a Zhanjiang (China) mangrove ecosystem. The last decade witnessed a paradigm shift concerning the impact of functional diversity on ecosystem functioning, and biological invasions have led to profound effects on functional diversity. However, a comprehensive understanding of the effects of exotic plants on macrobenthic functional diversity is not available for mangrove ecosystems. The macrobenthic functional feeding groups were compared in (1) a noninvaded stand vs. an Spartina alterniflora-invaded stand of the mangrove tree Avicennia marina (a mixture of A. marina and S. alterniflora) and (2) a noninvaded unvegetated shoal vs. an invaded shoal (a S. alterniflora monoculture) in Zhanjiang, China. The results indicated that the phytophagous group was the dominant functional feeding group regardless of habitat or macrobenthic parameter (species richness, abundance, ...

Soil Fauna Communities and Soil Attributes in the Agroforests of Paraty

ABSTRACT We conducted the present study in Paraty, southeastern Brazil, in areas under different management regimes and plant cover. The study comprised two different agroforestry systems (AFS-1 and AFS-2), a secondary forest, and a cassava monoculture. We aimed at assessing the effects of land use on the soil fauna and its relationship with soil chemical (pH, Al, Ca, Mg, P, K, carbon, and organic matter) and microbiological attributes (soil microbial biomass carbon - SMB-C, soil respiration – SR, metabolic quotient - qCO2, microbial biomass carbon - C-mic). During winter, AFS-2 showed higher abundance of microphagous, saprophagous, and total individuals than the other areas. AFS-1 and the forest showed an increased abundance of Formicidae and phytophagous groups from winter to summer. The soil fauna and community structure showed that the studied agroforests are under regeneration, becoming more similar to the native forest, where ecological processes are considered efficient.

Diet Evolution and Clade Richness in Hexapoda: A Phylogenetic Study of Higher Taxa.

Hexapoda, the insects and their relatives, includes over half of all described species. Because large proportions of this diversity cluster within a small set of phytophagous groups, dietary substrates have been proposed to shape patterns of richness within the clade through antagonistic coevolution and zones of ecological opportunity. Here we explore these processes in the context of a recent dated phylogeny of Hexapod families. Our results indicate phylogenetic clustering of specialized ecologies, such as phytophagy and parasitism, but reveal no consistent associations between the use of particular dietary substrates and clade richness. We also find no evidence that diets expected to promote antagonistic coevolution are consistently associated with elevated species richness or that sister clades differing in dietary state are associated with greater-than-expected differences in richness. We do, however, identify variation in the age of, and transition rates among, dietary states that are likely to play a role in the observed heterogeneity in richness among dietary classes. Based on these findings, we suggest remaining circumspect about the generality of adaptive zones based on broad dietary groupings as an explanation for hexapod richness and suggest that richness heterogeneity may be better explained by origination and transition rates as well as variation within dietary categories.

Arthropods Associated with Corn Planted in the Marginal Uplands of Inopacan, Leyte

A study was conducted to assess and identify the arthropods associated with corn planted in the marginal uplands of Inopacan, Leyte, using pan trap and sweep net methods, done biweekly during the two cropping periods. Two major groups of arthropods were recorded which included the Arachnids and the insect group, consisting of nine (11) orders of insects represented by 59 insects species and 20 spiders. These arthropods belonged to phytophagous groups (chewing and sucking arthropods); natural enemies (predators and parasitoids) and the innocuous groups or considered “others” (scavengers and saprophagous) The most abundant insect pest species in corn were the Chrysomelidae and Scarabaeidae beetles, while leafhoppers (Homoptera) were moderately abundant in the crop. The predators were mostly ants (Hymenoptera), the spiders (Arachnids), and coccinellid beetles. The parasitoids included the braconid, ichneumonid, and chalcid wasps. The most abundant non-pest and innocuous species are the Dipterans which are potential hosts or prey of the biotic agents in the corn ecosystem. The abundance of pest species in corn is not yet alarming, which indicates that the pests are not attracted to the crops which were marginal in growth. The natural enemies were also occurring in moderate numbers adequate to suppress abundance of pest species. However, from the results, the corn planted in the marginal upland with chicken dung was observed to have the higher number of insect associations than the other treatments.