Beetle Abundance Research Articles

Dung beetles prefer used land over natural greenspace in urban landscape

Urbanization drives land-use and patterns of biodiversity. Yet, very little is known about how biodiversity of structurally different habitats is responded to urbanization. We surveyed coprophagous dung beetles and their ecological functional groups—tunnellers, dwellers, and rollers—in shaded natural semi-evergreen forests of sacred groves and the neighbouring relatively open home gardens of sites that represent three levels of urbanization to address the following questions: (1) Do sacred groves have higher abundance, richness, and diversity of dung beetles than home gardens? (2) Is urbanization a key driver of dung beetle abundance, richness, diversity, and community? (3) Is dung beetle assemblage of sacred groves immune to urbanization? and (4) Which ecological functional groups of dung beetles are affected by urbanization? We hypothesized that the sacred groves have a distinct community, resulting in higher abundance, richness, and diversity of dung beetles than home gardens, and the dung beetle assemblage of sacred groves may be immune to urbanization. We sampled the beetles during wet and dry periods using cow dung as a bait. Against our predictions, dung beetle abundance, richness, and diversity were higher in used lands than sacred groves, particularly in urban landscapes. The two habitats had distinct compositions of dung beetles. Tunnellers and rollers were affected by urbanization, but not dwellers. Heliophilic and synanthropic species characterized by smaller species dominated overall catches in the used lands of urban areas. Results downplay sacred grove as a potential refuge for dung beetles and suggest that the biodiversity of native forests may be affected more by urbanization than the manipulated anthropogenic habitats.

Omnivorous Notoxus trinotatus Pic (Coleoptera: Anthicidae) is a newly recognized vector of northern leaf blight in maize.

The adaptations of omnivorous insects to food are manifested in a multifaceted manner, and the availability of food resources directly determines insect feeding tendencies, which contribute to a complex insect-food relationship and impact insect functionality in the environment. Stable isotope analysis was applied to test the feeding preference and further define the functional role of omnivorous beetles in cropland. Our results confirmed that as an omnivorous beetle, the fungivorous nature of Notoxus trinotatus accounted for a prominent proportion food selection at the adult stage, and more importantly, this dietary feature contributed to the dispersal of the northern corn leaf blight in maize (NLB) during the feeding trials. In addition to the preference for fungi, water supplementation was an essential element extending adult longevity, which directly prolonged the contact time of adults with pathogenic fungi in agricultural fields. Consistent with the herbivorous characteristics of beetles, before the emergence of NLB fungal pathogens, corn tissues served as the main food, which provided the beetles with more opportunities to transmit fungal pathogen propagules. We conclude that the role of N. trinotatus in carrying NLB pathogen is due to its feeding on this plant mycopathogen, and an increased abundance of beetles carrying the pathogen may increase the rate of NLB disease infestation. More focus should be concentrated on the functions of fungivorous beetles, not only as pathogen-transmitting pests, but also as an element among the balanced biotic factors in farmland.

Xylophagous insects associated with the mangrove forest of the Ramsar wildlife refuge protected area, Bahía de Panamá wetland

In Panama, terrestrial forests and mangrove ecosystems are very susceptible to insect damage, due to the increase in exotic species. The objective of this study was to determine the relative abundance of xylophagous beetles in mangrove forest of the Wildlife Refuge RAMSAR protected area, Bay de Panamá wetland. The research was carried out in the mangrove forests located in the areas of El Embarcadero, Costa Sur and Don Bosco, where 5033 individuals, corresponding to 6 families (Kalotermitidae, Termitidae, Cerambycidae, Curculionidae, Elateridae and Scarabaeidae), associated with the mangrove forest were captured. The El Embarcadero was the site with the highest number of xylophagous insects with 3,803 individuals. Of the three areas sampled, the areas closest to the coast (Zone 1) El Embarcadero and Costa Sur showed the greatest number of xylophagous insects, while Don Bosco showed the least number. The beetle family Curculionidae was the most commonly observed family, with the subfamilies Scolitinae and Platypodinae being the most important. 91% of all captured xylophagous insects belonged to the Scolytinae subfamily, while 6% belonged to the Platypodinae subfamily; one particular species, Euplatypus parallelus, was observed to affect many Avicennia germinans. Xylophagous beetle families that presented lower abundances were: Elateridae with 45 individuals, Scarabaeidae with 5 individuals, and Cerambycidae with 2 individuals. Two termite families were observed, Kalotermitidae with 50 nests, and Termitidae with 5 nests. Termites in mangrove ecosystems are important due to their ability to modify soil properties by decomposing organic matter, mainly the wood of mangrove trees that are already very old or dead. They also contribute to protecting nutrients, factors key to maintaining tropical ecosystem stability.

Diversity of Auger Beetles (Coleoptera: Bostrichidae) in the Mid-Cretaceous Forests with Description of Seven New Species

The diversity and abundance of auger beetles were compared with ecologically similar families of other beetles. It was shown that the ecological niche in dead wood, which in the Paleogene belonged to bark and ambrosia beetles, was occupied by Bostrichidae in the Mesozoic. Seven new species, Poinarinius aristovi sp. nov., P. antonkozlovi sp. nov., P. lesnei sp. nov., P. perkovskyi sp. nov., P. zahradniki sp. nov., P. borowskii sp. nov., and P. cretaceus sp. nov. from the subfamily Alitrepaninae of the family Bostrichidae are described from mid-Cretaceous Burmese amber. The key to the species of the genus Poinarinius Legalov, 2018 is given. The new synonym, Alitrepanum Peng, Jiang, Engel & Wang, 2022, syn. nov. to Poinarinius, was established. A list of the fossil Bostrichidae was compiled.

Multi-phase recovery of carabid assemblages during 19 years of secondary succession in forest stands disturbed by windstorm without salvage logging in northern Poland

Windstorms impact the functioning and structure of forests and cause economic losses. For this reason, various potential methods of regenerating windthrown stands are investigated. Some of these studies use invertebrates, such as carabid beetles (Col., Carabidae). Salvage logging is used to recoup some of the economic ecosystem losses but increases the environmental impact of windthrow. I sampled ground beetles annually over 19 years (2003–2021y) in stands without salvage logging to test the effect of three varying levels of disturbance (severely, moderately and least disturbed stands with canopy cover of 10–30 %, 40–60 % and 70–90 %, respectively) on the regeneration of carabid assemblages and to determine its association with changes in the soil environment and in the recovering stands.Increased disturbance severity increased the abundance (up to 0.4 ind/trap/day) and species richness of ground beetles (up to 16.4) and proportion of beetles associated with early successional habitats (up to 53.5 %). Recovery of carabid assemblages and the environment was slowest in the severely disturbed stands, where at high soil pH nitrification initially increased the pool of nitrogen in the soil (up to 0.3), which was exploited by nitrophilous grasses taking over the space (up to 37,5 %), limiting the occurrence of forest species (decrease from 82.2 % to 51.4 %) and delaying the development of natural regeneration. Carabid recovery and ecosystem regeneration were associated with forest mosses surviving (84.1 % coverage) in patches with a high leaf area index (up to 1.9) and with the presence of Vaccinium vitis-idaea (up to 53.3 % coverage) in the moderately and least disturbed stands. The study indicated advanced successional development of carabid assemblages in less disturbed stands which can regenerate naturally. Natural recovery of carabids and regeneration of the most disturbed stands, rapidly taken over by nitrophilous grasses, was impeded; therefore, such stands should be regenerated traditionally.

Partitioning of Ambrosia Beetle Diversity on Teak Plantations in Java, Sumbawa, and Sulawesi Islands

Ambrosia beetles are the largest group of beetles living mutualistically with ambrosia fungi. Increased global shipments of forest and agricultural products have expanded the distribution of some species of ambrosia beetle. We investigated the partitioning diversity of the ambrosia beetle community on teak plantations in Indonesia’s Java, Sumbawa, and Sulawesi Islands. The ambrosia beetles were collected on the twelve sites of teak plantations with different managements (un-thinned and thinned) in Java, Sulawesi, and Sumbawa Islands. Ambrosia beetles were collected ten times at 7-day intervals. The diversity of ambrosia beetles recorded in teak plantations across twelve sites in Java, Sumbawa, and Sulawesi Islands were 17 species and 6154 individuals. Xyleborus affinis (47.17%), Xylosandrus crassiusculus (27.64%), and Hypothenemus sp. (12.33%) were the three dominant species. The highest and lowest species richness were found in the teak plantations in Java and Sumbawa Islands, respectively. The highest and lowest populations of ambrosia beetles were in Sulawesi and Sumbawa islands, respectively. Three factors contribute to the species richness of ambrosia beetles, i.e., temperature, rainfall, and altitude. Stand age, temperature, rainfall, altitude, and teak management contribute to ambrosia beetle abundance. Ambrosia beetle communities among islands show differences between each group, as confirmed by analysis of variance based on homogeneity of multivariate dispersion (sig. 0.001) and permutation test for homogeneity of multivariate dispersions (sign. 0.001). For the group of teak managements, there are differences between both teak managements, as confirmed by analysis of variance based on homogeneity of multivariate dispersion (sig. 0.001) and permutation test for homogeneity of multivariate dispersions (sign. 0.01). Based on the eigenvalues for PCoA axes by the Bray–Curtis method, Sulawesi Island is separate from both Java, and Sumbawa islands. However, Java and Sumbawa islands overlap each other. For groups of teak managements (thinning and non-thinning), there are overlap with each other based on the eigenvalues for PCoA axes by the Bray–Curtis method. The β-1 (Within bottle trap/local scale) contributes the highest to γ-diversity (42.46%). The relative contribution of species replacement (β-sim) in multiple sites across Java, Sumbawa, and Sulawesi Islands (regional scale) provides a high contribution (85%) to overall beta diversity, and the relative contribution of β-nes to the β-sor among sites is 14.03%.

Response of the dung beetle community to different climatic zones: Does the land use system matter?

AbstractThe conversion of Brazilian savanna into exotic pastures leads to the loss of dung beetles and a decrease in their contribution to ecological functions. We hypothesized that the dung beetle communities from exotic pastures would show greater significant differences between climatic zones, when contrasted to communities from Brazilian savanna in the same region, since dung beetle assemblages in pastures are more simplified. We assessed which variables (purpose of production, type of management, percentage the habitat per buffer, soil penetration resistance, pasture area and herd size) affect more the dung beetle community in exotic pastures. We carried out this study in 48 areas of native Brazilian savannas and exotic pastures distributed across four bioclimatic zones: BZ1, hot with three dry months; BZ2, hot with 4–5 dry months; BZ3, sub‐hot with 4–5 dry months and BZ4, meso‐thermal with 4–5 dry months of Minas Gerais State, Brazil. In each BZ, six areas of Brazilian savannas and six areas of exotic pasture were selected. In the Brazilian savanna areas, the species richness, abundance and biomass of dung beetles did not differ between the bioclimatic zones, unlike the exotic pastures. The composition of the dung beetle community was different between land use systems and between bioclimatic zones; the interaction between the two factors was also significant. Our results provide evidence that dung beetle communities active in exotic pastures are more susceptible to climatic environmental variations than communities from more complex and stable habitats, such as savannas. Finally, the best model suggested that all the six variables combined explained about 91% of the total variability in species composition observed between sampling sites.

Effects of different tree harvesting intensities on saproxylic beetle diversity in coniferous and broad‐leaved mixed forest in the Changbai Mountain, Northeast, China

Effects of different tree harvesting intensities on saproxylic beetle diversity in coniferous and broad‐leaved mixed forest in the Changbai Mountain, Northeast, China

Earlier flowering of winter oilseed rape compensates for higher pest pressure in warmer climates

Abstract Global warming can increase insect pest pressure by enhancing reproductive rates. Whether this translates into yield losses depends on phenological synchronisation of pests with their host plants and natural enemies. Simultaneously, landscape composition may mitigate climate effects by shaping the resource availability for pests and their antagonists. Here, we study the combined effects of temperature and landscape composition on pest abundances, larval parasitism, crop damage and yield, while also considering crop phenology, to identify strategies for sustainable management of oilseed rape (OSR) pests under warming climates. In all, 29 winter OSR crop fields were investigated in different climates (defined by multi‐annual mean temperature, MAT) and landscape contexts in Bavaria, Germany. We measured abundances of adult pollen beetles and stem weevil larvae, pollen beetle larval parasitism, bud loss, stem damage and seed yield, and calculated the flowering date from growth stage observations. Landscape parameters (proportion of non‐crop and OSR area, change in OSR area relative to the previous year) were calculated at six spatial scales (0.6–5 km). Pollen beetle abundance increased with MAT but to different degrees depending on the landscape context, that is, increased less strongly when OSR proportions were high (1‐km scale), interannually constant (5‐km scale) or both. In contrast, stem weevil abundance and stem damage did not respond to landscape composition nor MAT. Pollen beetle larval parasitism was overall low, but occasionally exceeded 30% under both low and high MAT and with reduced OSR area (0.6‐km scale). Despite high pollen beetle abundance in warm climates, yields were high when OSR flowered early. Thereby, higher temperatures favoured early flowering. Only among late‐flowering OSR crop fields yield was higher in cooler than warmer climates. Bud loss responded analogously. Landscape composition did not substantially affect bud loss and yield. Synthesis and applications: Earlier flowering of winter OSR compensates for higher pollen beetle abundance in warmer climates, while interannual continuity of OSR area prevents high pollen beetle abundance in the first place. Thus, regional coordination of crop rotation and crop management promoting early flowering may contribute to sustainable pest management in OSR under current and future climatic conditions.

Struktur umur dan kelimpahan kumbang badak dan kumbang tanduk (Coleoptera: Scarabaeidae) pada perkebunan kelapa sawit di PTPN VIII Unit Parakan Salak, Kabupaten Sukabumi

Kumbang badak (Oryctes rhinoceros L.) dan kumbang tanduk (Xylotrupes gideon L.) (Coleoptera: Scarabaeidae) merupakan dua spesies serangga hama yang biasa ditemukan di perkebunan kelapa sawit di Indonesia. Ketersediaan tempat perkembangbiakan merupakan salah satu faktor yang dapat meningkatkan populasi kedua jenis kumbang tersebut. Penelitian ini bertujuan untuk mengetahui kelimpahan dan struktur umur populasi kumbang badak dan kumbang tanduk pada tempat perkembangbiakan yang ada di perkebunan kelapa sawit. Penelitian dilakukan pada perkebunan kelapa sawit belum menghasilkan dan yang sudah menghasilkan. Hasil penelitian menunjukkan bahwa di perkebunan kelapa sawit PTPN VIII Parakan Salak, Kabupaten Sukabumi, kelimpahan kumbang badak lebih rendah dibandingkan dengan kumbang tanduk (4,47 ± 13,56 berbanding 25,23 ± 16,48 individu/plot). Struktur umur populasi kumbang badak pada breeding site yang berada di lokasi dengan tanaman kelapa sawit yang sudah menghasilkan didominasi oleh larva instar I dan instar II, sedangkan pada lokasi dengan tanaman yang belum menghasilkan tidak ditemukan individu kumbang badak. Sementara, struktur umur populasi kumbang tanduk pada breeding site didominasi oleh fase larva, baik larva instar I, instar II, dan instar III pada kedua lokasi pengamatan. Hasil analisis korelasi menunjukkan rendahnya keterkaitan antara sifat kimia tanah pada breeding site dan kelimpahan kumbang. Karakter kimia tanah yang relatif sama pada breeding site yang ada pada kedua lokasi pengamatan menyebabkan kelimpahan dan struktur umur populasi kumbang badak dan kumbang tanduk pada kedua lokasi pengamatan tersebut tidak jauh berbeda.

Influence of afforestation on coleopterans abundance and diversity at the University of Dodoma, Tanzania

Afforestation transforms the structure and functioning ability of an ecosystem. Converting a bare landscape through afforestation may have positive and negative consequences to the biodiversity. The study assessed the abundance and diversity of beetles in different selected habitats at the University of Dodoma, Tanzania. The habitats involved afforested areas with exotic trees of five years, three years, and eight months, as well as shrubland and grassland. Pitfall traps were established along the 10 transects of 100 meters each in the sampled plots to collect beetles. About 1031 beetles of 19 species were collected. Species richness was high in shrubland [Margalef's index (D) = 1.75, 10 species] and in afforested plots of five years (D = 1.62, 9 species), implying that areas with high vegetation cover might be suitable for beetles. Kruskal–Wallis showed a statistically significant difference among the five plots (H = 57.33, p = 0.03), with the highest abundance in shrubland (303 individuals). An afforested area was occupied by 608 beetles, equivalent to 59% of total abundance. According to the Shannon-Wiener index, shrubland had the most species diversity (H′ = 3.17) and an 8-month plantation had the least (0.61). The study also found that the species abundance, richness, and diversity were high in the 5-year old afforested plot. The difference in abundance was statistically significant in afforested areas (Kruskal-Wallis, H = 31.21, p = 0.01). The study recommends more research on the influence of plant species on beetle abundance and diversity to gain a better understanding of beetle functional diversity. • Increase in vegetation cover influenced coleopterans abundance and diversity. • Afforested area harbors high abundance of coleopterans. • Aging of plantation increased species abundance, richness and diversity of beetles.

Multiphase processes of seed dispersals via masked palm civets as a non-native species in cool-temperate forests of northern Japan

The disappearance of large seed dispersers such as primates increases the dependence of endozoochorous plants bearing large fruits on frugivorous mesocarnivores for seed dispersal. Ecosystems in northern Japan are typical examples wherein the distribution and abundance of large-sized dispersers (i.e., Macaca fuscata and Ursus thibetanus) have been constrained mainly owing to past anthropogenic disturbances. Moreover, the distribution of several native mesocarnivores has been fragmented, although masked palm civet, Paguma larvata, a non-native frugivorous mesocarnivore, has expanded its distribution over the past quarter-century. Here, we evaluated the roles of this non-native species in defaunated cool-temperate forests by assessing primary and secondary seed dispersal via civets. To assess the primary dispersal process, we identified their possible latrines, where seeds were initially dispersed, by tracking radio-tagged civets. We then compiled an inventory of seeds transported by civets combining the results of the fecal analysis performed in this study and a literature survey for seeds known to be transported by civets. To explore secondary seed dispersals, we first determined the ability of civet feces to attract dung beetles using pitfall traps and then compared this ability of civet feces with that of the feces of raccoon dog, Nyctereutes procyonoides, a native mesocarnivore. Our findings showed that (1) over 90% of the civet latrines confirmed within forested areas with flat terrain, safe sites for germination and establishment of common plant seeds, and carried seeds of 20 plant species; (2) the civet feces were more strongly preferred by dung beetles than raccoon dog feces; and (3) the abundance of large tunneler beetles with superior seed burial ability using the civet feces was 3.7 times as high as that of raccoon dog feces. Thus, these findings suggest that this non-native mesocarnivore could recover functional redundancy by offsetting injured endozoochorous processes.

Effect of environmental factors on the abundance of riffle beetles (Coleoptera: Elmidae) and co-inhabiting aquatic insects within a reach scale, in Japan

Effect of environmental factors on the abundance of riffle beetles (Coleoptera: Elmidae) and co-inhabiting aquatic insects within a reach scale, in Japan

Rainforest conversion to smallholder cash crops leads to varying declines of beetles (Coleoptera) on Sumatra

AbstractSoutheast Asian arthropod biodiversity is in rapid decline, but the variability of responses within taxa has received little attention. Using canopy fogging, we collected ~50,000 beetles (Coleoptera) in (1) lowland rainforest, (2) jungle rubber (rubber agroforest), and smallholder monoculture plantations of (3) rubber and (4) oil palm in Sumatra, across two landscapes and seasons. On average, beetle abundance was more than 50%, and biomass over 75%, lower in rubber and oil palm plantations than in rainforest and jungle rubber. This pattern was influenced by landscape and season. Abundance and biomass declines were similar in Chrysomelidae, Elateridae, and Staphylinidae, but differed in Curculionidae, which were most abundant in oil palm due to the introduced oil palm pollinator Elaeidobius kamerunicus. Across beetle families, species richness in monocultures was reduced by at least 70% compared to rainforest, with beetle richness in jungle rubber being similar to rainforest. Community composition in oil palm plantations differed markedly from the other land‐use systems for Chrysomelidae and Curculionidae, but less for Elateridae and Staphylinidae. Turnover contributed more to overall beta diversity than nestedness for all families and land‐use systems. Likely undersampling of the beetle community in rainforest suggests that declines of beetle density and diversity are much more severe than reported here, especially for beetle families with many concealed species, such as Staphylinidae. This study provides first evidence that negative responses of beetles to tropical land‐use change vary among families, and is the first report of its kind from heavily understudied Sumatra.Abstract in Indonesia is available with online material.

Dung-visiting beetle diversity is mainly affected by land use, while community specialization is driven by climate.

Dung beetles are important actors in the self‐regulation of ecosystems by driving nutrient cycling, bioturbation, and pest suppression. Urbanization and the sprawl of agricultural areas, however, destroy natural habitats and may threaten dung beetle diversity. In addition, climate change may cause shifts in geographical distribution and community composition. We used a space‐for‐time approach to test the effects of land use and climate on α‐diversity, local community specialization (H 2′) on dung resources, and γ‐diversity of dung‐visiting beetles. For this, we used pitfall traps baited with four different dung types at 115 study sites, distributed over a spatial extent of 300 km × 300 km and 1000 m in elevation. Study sites were established in four local land‐use types: forests, grasslands, arable sites, and settlements, embedded in near‐natural, agricultural, or urban landscapes. Our results show that abundance and species density of dung‐visiting beetles were negatively affected by agricultural land use at both spatial scales, whereas γ‐diversity at the local scale was negatively affected by settlements and on a landscape scale equally by agricultural and urban land use. Increasing precipitation diminished dung‐visiting beetle abundance, and higher temperatures reduced community specialization on dung types and γ‐diversity. These results indicate that intensive land use and high temperatures may cause a loss in dung‐visiting beetle diversity and alter community networks. A decrease in dung‐visiting beetle diversity may disturb decomposition processes at both local and landscape scales and alter ecosystem functioning, which may lead to drastic ecological and economic damage.

Host and Seasonal Effects on the Abundance of Bean Leaf Beetles (Ootheca spp.) (Coleoptera: Chrysomelidae) in Northern Uganda.

Simple SummaryBean leaf beetles (Ootheca spp.) (Coleoptera: Chrysomelidae) are endemic in Africa and are pests of cropped legumes (Fabales: Fabaceae). On common beans (Phaseolus vulgaris L.), the beetles cause leaf and root damages, leading to losses sometimes exceeding 50% in northern Uganda. Additionally, legumes are often grown in neighboring plots or in rotation season after season. This promotes the multiplication of pests and thus complicate their management. We conducted field trials to assess the seasonal variations in the abundance of the Bean Leaf beetles on common beans, cowpea (Vigna sp. Walp) and soybean (Glycine max L.), which are major legumes grown in northern Uganda. The beetles were most abundant during the long rainy season of 2018 and on cowpea, but also present during short rainy seasons of 2017 and 2018. Pupae remained in the soil after the harvest of the first season’s crops and were detected during the second season as well. Ootheca spp. preferred cowpea for foraging and development. Our study indicates that management strategies should be designed to target the above- and below-ground stages of Ootheca spp. in both seasons. Bean leaf beetles (BLBs) (Ootheca spp.) are serious legume pests in Uganda and sub-Saharan Africa, but their ecology is not well understood. We planted host plants, viz., common bean, cowpea, and soybean, in an experiment in the hotspot areas of Arua and Lira districts in Northern Uganda in order to assess their influence on the density of adults and immature stages of BLBs in different seasons. Overall, the number of adults, larvae, and pupae were higher in cowpea than common bean and soybean plots. The number of adults were highest in cowpea (29.5 adults/15 plants) in Arua during the long rainy season (2018A). The number of adults did not differ significantly during short rains (season B) in 2017 and 2018. Similarly, in Lira district, the highest number of adult BLBs was in cowpea (4.6 beetles) compared to the common bean (2.7 beetles) and soybean plots, with a peak at four weeks after planting (WAP). During 2018A, larvae of BLBs first appeared at five WAP and seven WAP and peaked at 13 WAP and 11 WAP in Arua and Lira, respectively. The pupae were present in the soil after the harvesting of crops during 2018A, but peaked at seven WAP and eight WAP in 2018B season in Arua and Lira, respectively. The occurrence of below-ground adults in 2018B followed the peak abundance of pupae, although this was delayed until six WAP in Arua compared to Lira. We conclude that cowpea is the most preferred by adults and larvae compared to common bean and soybean. Similarly, the first rain season (2018A) attracted higher abundance and damage than the second rain season. Management of the BLBs should thus take into consideration avoidance of host crop rotation and dealing with the below-ground stages.

​Diversity, Abundance and Composition of Ground Beetles (Coleoptera: Carabidae) in Jhunjhunu District of Rajasthan, India

Background: Jhunjhunu district has semi-arid climatic condition which is favorable to flourish ground beetles. Diversity of ground beetles are beneficial to agricultural ecosystem as carabid beetles are prominent decomposers and reduce population of insect pest specially, caterpillars. The present study aimed to document diversity of ground beetles which will provide first even preliminary information needed for their conservation and use in integrated pest management program. Methods: Sampling was carried out in Jhunjhunu district from January 2021 to December 2021. Four sampling sites viz., Site-A (agriculture land), Site-B (Plains are relatively flat land which is dominated by grasses, herbs and shrubs), Site-C (rocky area) and Site-D (blanks of water bodies) were selected based on different habitats situation. Carabid beetles were collected using pitfall trap, hand picking and light trap and identified by valid taxonomic keys. Result: Diversity indices authenticated a good diversity and abundance of ground beetles in the district. A total of 956 individuals of carabid beetles, representing 28 species and 19 genera belonging to 11 subfamilies viz. Harpalinae (7 species), Trechinae (7 species), Brachininae (3 species), Scaritinae (3 species), Lebiinae (2 species), Paussinae (1 species), Anthiinae (1 species), Carabinae (1 species), Pterostichinae (1 species), Platyninae (1 species), Cicindelinae (1 species) under Carabidae family were collected and identified from various habitats of study area. On the basis of total number of individuals Dromius quadrimaculatus is the most dominant species and constituted 18.62% of total beetles followed by Chlaenius bimaculatus (8.05%), Tetragonoderus intermedius (7.64%) Lophyra differens (6.80%) and Bembidion ambiguum (5.02%). The highest diversity was observed at Site-B (H=2.72, J=0.83, M=4.43) followed by Site-A (H=2.72, J=0.83, M=4.08), Site-C (H=2.52, J=0.90, M=3.48) and Site-D (H=2.25, J=0.87, M=2.25).

Body size, richness, and abundance of Staphylinidae unaffected by landscape composition and cropping system in a push–pull maize system in Kenya

The change from predominantly natural to agricultural landscapes has been shown to reduce pollination and biological control services and also affect the functional traits of the insects that provide such services. Research shows that increasing agricultural area at the landscape scale can have variable effects on functional traits such as body size in predators. Moreover, local factors such as farm management strategies have also been shown to affect functional traits in insects. Studies of local or landscape effects on functional traits are often contradictory in temperate regions, and absent from tropical regions. In Kenya, local pest management technologies, e.g. push–pull systems have been shown to increase biological control, but data is lacking on how local management could affect body size of natural enemies. We investigated how the proportion of natural areas in the landscape and local management (push–pull) affected the body size of rove beetles (Staphylinidae) in Kenyan maize fields. Elytral and pronotal measurements were used to quantify body size, and a mixed-effects model was used to test the effect of landscape complexity and local management on the body size, richness, and abundance of rove beetles. We found no effect of landscape composition or local management on body size, richness, or abundance of rove beetles. We hypothesize that the lack of landscape effects could be caused by less plasticity in functional traits in tropical versus temperate zones. Our results demonstrate that changes in land use and local management do not always lead to changes in the diversity and functional traits of predator communities.

Community Composition of Beetles (Insecta: Coleoptera) along Elevational Gradients in Phulchowki Hill, Lalitpur, Nepal

Beetles are recognized as important bio-indicators of the ecosystem that can be used to determine species diversity, genetic diversity and ecosystem diversity. We investigated the species composition and diversity of beetles in four seasons along elevational gradients in Phulchowki hill from June 2018 to May 2019. Sampling was done using pitfall traps in five sites located at 1500 m, 1800 m, 2100 m, 2400 m and 2700 m altitude respectively. Overall, we documented 43 morphospecies under 37 genera and 12 families from the study area. Scarabaeidae was the most dominant family whereas Onthophagus sp.2 being the most abundant species in our study. The Shannon-Weiner diversity index, species richness and abundance were highest at 1500 m. Furthermore, diversity and species richness were highest in the spring, whereas peak beetle abundance was observed in summer. Principal component analysis (PCA) was performed to analyze the distribution patterns of the beetle families along the elevational gradients. PCA revealed a strong association of the Carabidae family with 1500 m, 1800 m and 2100 m altitude whereas the Scarabaeidae family were mostly associated with human-influenced areas such as 1500 m and 2700 m altitude. The generalized linear model (GLM) revealed that temperature had a major impact on the overall beetle composition.

Bean Leaf Beetle (Ootheca spp.) (Coleoptera: Chrysomelidae) Management via Planting Timing and Insecticides.

Simple SummaryBean leaf beetles (Ootheca spp.) (Coleoptera: Chrysomelidae) are a major pest of the common bean (Phaseolus vulgaris L.) in Africa, attacking the roots, leaves, floral parts, and young pods, and reducing grain yields significantly. However, there is no comprehensive program for managing bean leaf beetles. In Uganda, farmers typically try to reduce pest impacts by delaying bean crop sowing, and to a lesser extent, using insecticides, but there is no information on the impact of delayed planting and insecticide application on bean leaf beetles. We conducted a study to assess the effects of planting timing and insecticide spray regimes on bean leaf beetle abundance, foliar damage, and common bean grain yield in three agro-ecological zones. Bean leaf beetle abundance was highest in mid-planting compared to late and early planting, while foliar damage was highest in late planting in two of the three agro-ecological zones. However, marketable grain yield was highest in early-planted plots in all three agro-ecological zones. Insecticide application reduced foliar damage and increased marketable grain yield, with a combination of soil drench and foliar spray resulting in significantly less foliar damage and higher grain yield. Marketable grain yield was higher when insecticides were combined with early planting in all agro-ecological zones.Bean leaf beetles (Ootheca spp.) (Coleoptera: Chrysomelidae) are one of Africa’s most important pests of the common bean (Phaseolus vulgaris L.). Roots, leaves, floral parts, and young pods are all attacked, leading to a considerable loss in grain yield. In Uganda, there are no comprehensive prescribed management strategies for bean leaf beetles, but farmers typically try to control the pest by delaying bean crop sowing, and to a lesser extent, using insecticides. Although farmers have consistently implemented the two approaches, there is no information on the effects of the approaches in Uganda. To assess the impact of planting timing and insecticide spray regimes on bean leaf beetle populations, concomitant foliar damage, and grain yield, we set up trials in three agro-ecological zones with known presence of the beetles during the second rainy season of 2016 (2016) and the first rainy season of 2017 (2017). The first planting, coinciding with early planting, was conducted within one week after the onset of rains. The second planting, coinciding with mid planting, followed two weeks later, while the third planting, considered late planting in this study, was conducted one month after the second planting. A foliar application of cypermethrin commencing at 7 days after emergence (DAE), 14 DAE, 21 DAE, 28 DAE, and 35 DAE; a soil drench of imidacloprid at planting combined with a foliar spray starting at 7 DAE; and an untreated control were among the insecticide spray regimes evaluated. Higher bean leaf beetle abundance was recorded from mid-planting, while higher foliar damage was recorded from late planting in two of the three agro-ecological zones. However, higher marketable grain yield was recorded from early planting in all agro-ecological zones, suggesting that delayed planting may not be beneficial. Insecticide application reduced foliar damage and increased marketable grain yield, with a combination of soil drench and foliar spray resulting in much less foliar damage and, as a result, higher grain yield. However, this did not result in economic benefits. Furthermore, marketable grain yield was higher when insecticide spray regimes were combined with early planting in all agro-ecological zones during both seasons. Our findings suggest that the common bean should be planted early and that the control of the bean leaf beetle should target both the adults and the juvenile stages in the soil. Therefore, there is a need for farmers to be able to access less-expensive soil treatments.