Diel variation of aquatic insect drift in streams of Southern Brazil

Some organisms, such as aquatic insects, are transported from the upstream to downstream region of streams through a process called drift. This process occurs in passive and active ways and can be variable throughout the day, mainly between the nocturnal and diurnal periods. Here, we evaluate the periodicity of the drift of aquatic insects in two streams of the Middle Iguaçu basin, southern region of Brazil. We predicted that the drift of aquatic insects brings the highest richness, diversity and abundance during the nocturnal period, compared to the diurnal period. In addition, we expected that the composition of species is different between these periods. In each stream, aquatic insect sampling was carried out 10 times, for 24 hours, using drift nets. A total of 2,114 aquatic insect specimens were recorded, distributed in 26 families. Of these families, 20 were recorded during the diurnal period and 24 during the nocturnal period. Our results showed an increase in the diversity and abundance of aquatic insect drift in the nocturnal period. However, only abundance was significantly different between the periods. We attribute the higher abundance in nocturnal drift possibly to biological interactions. Thus, nocturnal drift can be a strategy of some aquatic insects to avoid visual predation by other invertebrates and/or vertebrates, in Neotropical streams. We highlight the importance of our study, because it can be used for comparison in surveys of lotic environments that have been impacted by human activity (e.g. by dam construction), which can alter the water flow, and consequently the pattern of insect drift.

Tebang Pilih Mengubah Keanekaragaman Semut Tanah Hutan di Kalimantan Timur, Indonesia

This study assesses the short-term effects of selective cutting on the diversity of ground ants (Hymenoptera: Formicidae) in the secondary rainforest. Ground ants were collected using a pitfall trap in a circular sample plot of 0.5 ha. A total of nine sample plots were randomly placed in a 98-ha cutting compartment. Fifteen pitfall traps were planted in each circular plot. A total of 135 pitfall traps were established in the cutting compartment. The average cutting intensity of 8 trees/haas applied in the cutting compartment. Insect sampling and measurement of environmental factors were carried before cutting and two days after cutting. In this study, the abundance, diversity, species richness, and evenness index of ground ants before cutting compared to after cutting. The results of this study indicated that the short-term impact of selective cutting on ground ants was varied. Selective cutting may increase or decrease the abundance and morphospecies composition of ground ants. The abundance of forager and ground-dwelling omnivores increased after selective cutting, whereas for the predator, scavenger, and seed disperser ants were decreased after selective cutting. Keywords: biodiversity, forest conservation, ground ant, selective cutting

TYPES AND ACTIVITIES OF DAILY INSECT POLINATORS IN ORDER GARDEN AND GARDEN FRUIT LIWA

Pollinator insects are insects that play a role in pollinating plants. This research was conducted in December-January 2020 at the Liwa Botanical Garden which aims to determine the types and daily activities of pollinator insects in the Liwa Botanical Garden Ornamental and Fruit Parks. The research used observation methods in 2 locations, namely Ornamental Gardens and Fruit Gardens. Pollinator insect sampling using a sweap net. The data obtained were analyzed descriptively. The results found that including pollinator insects in the Ornamental Park were 11 species and 165 individuals, namely (Junonia orithya, Hypolimnas bolina bolina, Neptis clinioides gunongensis, Oriens gola, Euploea mulciber, Elymnias panthera, Apis cerana, Apis florea, Xilocopa confuse, Lucilia sericerata, Coccinella septempuncata), in the Fruit Garden there were 6 species and 276 individuals, namely (Bactrocera dorsalis, Eurema blanda, Zizina otis, Ypthima baldus newboldi, Apis cerana, and Apis florea). Observation of Junonia orithya's daily activities starts in the morning at 08: 00-11: 00 WIB. Flying activities are initiated by the butterfly around the flower plant then perching on the leaves to sunbathe, suck nectar, suck minerals, suck nectar repeatedly, and look for a partner to carry out mating activities. Observation of daily afternoon activities was carried out at 14: 00-16: 00 WIB Junonia orithya was seen carrying out her activities such as in the morning. When the brightness starts to decrease for example due to rain, the butterflies will rest and take shelter under the leaves or bush environment.

Use of 3-Dimensional Videography as a Non-Lethal Way to Improve Visual Insect Sampling

Insects, the most diverse and abundant animal species on the planet, are critical in providing numerous ecosystem services which are significant to the United Nation’s Sustainable Development Goals (UN-SDGs). In addition to the UN-SDGs, the UN has declared the period 2021–2030 as the “Decade on Ecosystem Restoration.” Insects, because of the ecosystem services they provide, are critical indicators of restoration success. While the importance of insects in providing ecosystem services and their role in helping fulfil the UN-SDGs is recognized, traditional techniques to monitor insects may result in observer bias, high rates of type-I and type-II statistical error, and, perhaps most alarmingly, are often lethal. Since insects are critical in maintaining global food security, contribute to biological control and are a key food source for higher trophic levels, lethal sampling techniques which may harm insect populations are undesirable. In this study, we propose a method to visually sample insects which involves non-lethal 3-dimensional video cameras and virtual reality headsets. A total of eight observers viewed video captured insects visiting floral resources in a landscaped area on a university campus. While interobserver variability existed among individuals who partook in this study, the findings are similar to previous visual sampling studies. We demonstrate a combination of 3D video and virtual reality technology with a traditional insect count methodology, report monitoring results, and discuss benefits and future directions to improve insect sampling using these technologies. While improving quantitative monitoring techniques to study insects and other forms of life should always be strived for, it is a fitting time to introduce non-lethal sampling techniques as preservation and restoration of biodiversity are essential components of the UN-SDGs and the “Decade on Ecosystem Restoration”.

‘Drone-Netting’ for Sampling Live Insects

Drones have become valuable tools for biodiversity studies by providing aerial photographs; however, for most entomological studies, images, in particular those taken remotely, are usually insufficient; rather sampling of specimens is required. We equipped a cheap off-the-shelf drone with a net bag, flew it over the ground, sweeping the vegetation, and sampled adult and larval insects as well as spiders. ‘Drone-netting’ proved to be a versatile method for general insect sampling, particularly in inaccessible terrains. It is time- and cost-effective, minimally invasive, and adaptable for many research tasks in entomofaunistics; it shows a degree of representativeness similar to hand-netting, and caught specimens stay alive and can be released if not needed.

Keanekaragaman dan komposisi kumbang elaterid (Coleoptera: Elateridae) di kawasan hutan hujan tropis Taman Nasional Bukit Duabelas dan Hutan Harapan, Jambi

<p>Jambi province is one of the regions in Indonesia that has tropical rainforests with different landscape characteristics in each region. Tropical rainforests contain the highest biodiversity in the world and as a habitat for various types of flora and fauna, including elaterid beetles. Elaterid beetles have an important role as ecological bioindicators. The aim of this research was to study the diversity and species composition of elaterid beetle in two different landscape types. Insect sampling was carried out in Jambi Province on two tropical rainforest landscape, i.e. Bukit Duabelas National Park (TNBD) and Harapan Rainforest. Elaterid beetles were collected by canopy fogging method in the morning. Each landscape consists of four core plots and each core plot consist of three as subplot, total subplots observed in both landscape were 24 subplots. A total of 2069 individuals of elaterid beetles were collected, belonging to 6 subfamilies, 23 genera, and 59 morphospecies. The abundance of elaterid beetles was higher in Harapan Rainforest, while species richness was higher in TNBD landscape. Species dominant in two landscape consist to subfamily Agrypninae, belonging to genera <em>Adelocera </em>with morphospecies <em>Adelocera </em>sp.01. The result of this research showed that landscape differences influencing the composition and abundance of elaterid beetles, but it does not influence in species richness of elaterid beetles.</p>

KEANEKARAGAMAN HAMA DAN MUSUH ALAMI PADA TANAMAN PALA (Myristica fragrans HOUTT.) DI ACEH SELATAN

The diversity of insects, both pests and natural enemies in each place differently is influenced by environmental factors and technical culture of cultivation. This study aims to determine the diversity of pests and natural enemies in nutmeg plants in South Aceh. Insect sampling was carried out at nutmeg plantations in South Aceh, followed by identification in the Faculty of Agriculture laboratory, Teuku Umar University. Methods of data collection using purposive sampling, using light traps, pit fall traps, yellow traps. The Parameters of this study are number of individuals, families, and insect diversity obtained. The results showed that the abundance of pests and natural enemies in Meukek was higher compared to Samadua. The Shannon-Wiener index shows a variety of pests in Meukek high (H'=3.029) and moderate in Samadua (H'=2,788). While the diversity of natural enemies in both Meukek and Samadua is relatively low, namely H'= 1.230 and H' = 1.049. Planting patterns and crop management affect the abundance and diversity of both pests and natural enemies in both locations. Plantations in Meukek tend to be heterogeneous which are planted with a variety of plantation crops (polyculture) while nutmeg plants in the same two are relatively homogeneous (monoculture of nutmeg). Keywords: diversity, pests, parasitoids, predators, nutmeg

Tipe penggunaan lahan memengaruhi keanekaragaman dan komposisi hymenopteran parasitoid di Jambi

<p>Hymenoptera is one of the four largest insect orders in the world, one of which is its role as a natural enemy (parasitoids, predators). Land conversion can affect the diversity and composition of the parasitoid Hymenoptera and its ecological role. This study aims to examine the effect of land use types on the diversity and composition of hymenopterans parasitoid in Jambi. The study was conducted on various types of land use in the Harapan Forest landscape and Bukit Duabelas National Park (TNBD), Jambi Province including forests, rubber forests, oil palm plantations, and rubber plantations. Insect sampling was conducted from March to September 2013, using fogging techniques. A total of 14,258 hymenopteran parasitoid individuals consisting of 30 families were obtained from all study sites. Encyrtidae, Braconidae, Aphelinidae, Eulophidae, Scelionidae, Ceraphronidae, and Platigasteridae families are found in high abundance. Oil palm land use types are found to have different parasitoid compositions compared to other land use types, while forest and rubber forest land use types have high species composition. The results of this study indicate that the type of land use affects the diversity and composition of hymenopteran parasitoid species.</p>

A Novel CO2-Based Insect Sampling Device and Associated Field Method Evaluated in a Strawberry Agroecosystem

There is high demand for accurate insect sampling methods to inform integrated pest management strategies. Despite widespread application, existing sampling methods, such as portable aspirating and sweep netting, can result in overrepresentation of prominent pests, underrepresentation of natural enemies, and damage to plants. In this study, we test a novel device for insect sampling via anesthetization. Specifically, we test the effect of CO2 (application pressure and duration of exposure) on Lygus hesperus Knight (Hemiptera: Miridae) anesthetization in the laboratory and on insect community density in a strawberry agroecosystem. Carbon dioxide application proves an effective means of anesthetization compared to negative controls, and an increase in net CO2 exposure results in a decrease in time until L. hesperus anesthetization. Field results indicate the CO2 method collects more parasitoids and thrips than a portable aspirator, and at the 50 PSI application pressure and 15-s exposure, the CO2 method results in a comparable number of pests collected as the research standard, a portable aspirator with 8-s aspiration time. Benefits of the CO2 method include minimal plant damage, highly explicit spatial and temporal data, and scalability.