Journal of Entomological and Acarological Research

Distributions of agrobiont lady beetles (Coleoptera: Coccinellidae) among crop and non-crop habitats within an agricultural landscape in east-central South Dakota, USA

Louis Hesler — 2024-11-28

Alternative habitats to predominant corn and soybean fields may help to stem declines of native lady beetles in central North America, but their relative values to native lady beetles have not been directly compared. The goal of this 2-year study was to compare the abundance and species composition of native agrobiont lady beetles among habitats such as corn, winter grains, prairie, and arboreal tracts across three seasons (late spring, summer, and autumn) in eastern South Dakota, USA. Yellow sticky traps were used to sample a total of 797 individuals and 13 species of lady beetles. Coleomegilla maculata lengi Timberlake was the most abundant species and found predominantly in corn and arboreal habitats. Hippodamia convergens Guérin-Méneville was the second-most abundant species and found mainly in prairie and crop habitats. Harmonia axyridis (Pallas) was sampled only in 2023 in low numbers but preferred arboreal habitat to other habitats. Hippodamia parenthesis (Say) preferred winter grain and prairie habitats over corn and arboreal habitats. Cycloneda munda (Say) preferred corn to other habitats. This study was designed to include habitats that would optimize detection of Hip. tredecimpunctata tibialis Timberlake, which has declined in recent years, but it was not sampled from any of the habitats. Prospects are discussed for conserving native agrobiont lady beetles that prey on crop pests among habitats within agricultural landscapes in eastern South Dakota.

Fruit flies (Diptera: Teprithidae) and their parasitoid (Hymenoptera: Braconidae) species from registered snake fruit production during early rainy and dry seasons in the Special Region of Yogyakarta, Indonesia

Oka Dwi Handaru — 2024-11-26

Exportation of snake fruit from Indonesia to China, Australia, and New Zealand has been hindered due to fruit fly infestations (Diptera: Teprithidae). The goal of this study was to identify fruit flies and their parasitoid species from registered snake fruit productions in Turi, Sleman, that have reached packaging houses during early rainy and dry seasons. Fruit fly species were morphologically identified from collected rejected or damaged snake fruit. Parasitization was calculated by dividing the number of emerging parasitoid species by the total number of parasitoid and fruit fly individuals. The population of fruit flies and parasitoids was then compared to climatic data. Female fruit flies that emerged from snake fruit possessed spots on their front preapical femur, concluding that these species were Bactrocera carambolae. The average fruit fly that emerged per fruit was 16.5 individuals. Only one parasitoid species emerged and possessed notauli on mesonotum that elongated to the center and petiole and longitudinal metasomal tergum 2, implying that this parasitoid species was Fopius arisanus with an average population of 5.71 individuals with a parasitization percentage of 26.86%. Results from this research concluded that the fruit fly species collected from registered snake fruit productions in Turi, Sleman, during the early rainy season and dry season was Bactrocera carambolae with a low parasitization level by Fopius arisanus. This parasitization level may be affected by fruit fly density and climatic factors, such as humidity and rainfall.

Infestation level of banana fruit fly (Bactrocera musae, Tryon) on Kalapua banana (Musa sp.) in Gazelle Peninsula, Papua New Guinea

Kari Iamba — 2024-07-11

The banana fruit fly (Bactrocera musae Tryon), belonging to the family Tephritidae and subfamily Dacinae, is the main pest of bananas responsible for significant crop losses. In order to monitor the B. musae infestation, we collected banana fruit samples from four locations on the Gazelle Peninsula: Burit, Kereba, Vudal, and Vunapalading. On each field collection date, twelve banana bunches were chosen at random from the corresponding study sites. Following the removal of 100 individual fruits (fingers) from each fresh bunch at each study site, the fruits were weighed, thoroughly cleaned with rainwater three times, and then incubated in containers until the larval developmental stages were finished. When compared to the other three sites, the number of adults in the Kalapua bananas sampled from Burit was the highest. The banana fruits were divided into three main groups: “mature green”, “mature ripe”, and “immature green”. Mature green fruits produced a higher adult abundance than mature ripe fruits. Compared to the other two stages, immature green had the fewest adults. By fruit weight, Burit had the highest infestation (20.9%), while Vunapalading had the lowest (11.9%). After Kereba (14.7%), Vudal had the second-highest infestation (16.8%). Mature ripe fruit had the highest infestation (37.1%) by fruit weight, while immature green fruits had the lowest infestation (2.04%). A moderate level of infestation was observed in mature green fruits (17.1%). Regarding fruit count, the least infected fruits were immature green fruits (1.8%), moderately infected mature green fruits (17.0%), and highly infected mature ripe fruits (26.9%). Geographically, the Gazelle Peninsula has a Kalapua infestation level ranging from 11.9 to 20.9%, and a different maturity stage infestation level ranging from 2.04 to 26.9%. In general, the degree of infestation has escalated, and B. musae has established itself in the Gazelle Peninsula.

Hyperparasitic showdown: Sclerodermus cereicollis, a non-aggressive but surprisingly secondary hyperparasitoid

Serena Malabusini — 2024-05-29

This study investigates the dynamics of hyperparasitism within the Bethylidae family, focusing on the interaction between Sclerodermus cereicollis and Goniozus legneri, two parasitoid wasp species characterized by different sociality and aggressivity towards conspecifics. Experimental trials were conducted using Corcyra cephalonica larvae as hosts, with different setups to stimulate competition. The results revealed unexpected behaviors, especially by S. cereicollis, including aggressive interactions, cannibalism, and hyperparasitism. In contrast, despite the typically aggressive nature of G. legneri, no particular hostility was observed toward S. cereicollis. The study highlights the complex dynamics of competition for resources among parasitoids, shedding light on the adaptive strategies and fitness costs associated with hyperparasitism. These findings contribute to a deeper understanding of the ecological interactions within parasitoid wasp communities.