Neotropical Entomology最新文献

Aphis craccivora Koch and Planococcus lilacinus Cockerell are phloem feeders and act as vectors for transmitting plant viruses to agricultural and horticultural crops thereby damaging them. The persistent and widespread use of synthetic, wide-spectrum pesticides has resulted in resistance development that is detrimental to the environment, human health, and natural enemies of pests. The present investigation uses various extraction mediums to examine the insecticidal efficacy of essential oils (EOs) isolated from Murraya koenigii (L.) leaves. Increase in yield was observed in the EO extracted using NADES-AHD [0.16% (obtained with hydro-distillation)] to 0.30% [obtained with N-1 (glycerol:lactic acid)]. EO obtained with water was found more effective against A. craccivora (LD₅₀ = 0.89 µL/insect) and followed by N-1 (glycerol:lactic acid), and N-3 (choline chloride:citric acid) (LD₅₀ = 1.29-1.38 µL/insect). Similarly, EO isolated by water and N-4 (choline chloride:oxalic acid) was effective against P. lilacinus (LD₅₀ = 2.63-3.06 µL/insect). Additionally, the EO prepared by water substantially reduced glutathione S-transferase (GST) and acetylcholinesterase (AChE) in target pests, suggesting that these enzymes may be the EOs' site of action. NADES-AHD has enhanced the EO yield as compared to the conventional method. The EO obtained with water showed promising toxicity against target pests and target site of action. Therefore, based on field and greenhouse bio-efficacy experiments, EOs/biopesticides/botanicals can be proposed for controlling the spread of mealy bugs and aphids.

Bedellia somnulentella Zeller, 1847 (Lepidoptera: Bedelliidae), a global pest of the sweet potato Ipomoea batatas, was recorded in Brazil, but morphological information on the sexual dimorphism of this insect is scarce. The objective was to evaluate morphological characters of sexual dimorphism of B. somnulentella pupae and adults. External structures with sexual dimorphism were not detected in the last abdominal segments of B. somnulentella pupae. The females of this insect are heavier, which could be a distinctive sex characteristic. A pair of frenulum on the hind wings of females and only one on those of males, in addition to elongated cerci and bipartite genitalia in the latter and smaller cerci involving the last abdominal segment and an ovipositor in females, differentiate sexes of B. somnulentella.

The sugarcane weevil (Sphenophorus levis Vaurie, 1978) is currently considered the most important sugarcane pest in Brazil, causing significant yield losses. Application methods of insecticides for S. levis control have not been effective, mostly due to the insect's cryptic behavior below the soil surface which suppresses the correct placement of insecticide active ingredients on target. Two experiments were conducted using an innovative bioassay methodology that simulates sugarcane field conditions to effectively evaluate S. levis adult mortality and insecticide residues in the soil under different treatments. The first experiment aimed to assess the efficacy of two liquid- and solid-applied insecticides, while the second aimed to examine the effect of increasing the dose of lambda-cyhalothrin + thiamethoxam on S. levis adult control. The novel bioassays simulated liquid and solid insecticide applications on sugarcane by exposing S. levis adults to chemical residuals on rhizomes and in soil after insecticide application. In the first experiment, low S. levis adult control was detected (< 53% mortality) across all treatments, where both solid and liquid applications of lambda-cyhalothrin + thiamethoxam provided greater efficacy levels than imidacloprid and control treatments, respectively. Solid applications maintained higher insecticide concentrations in the soil for longer periods than liquid insecticide applications, providing maximum insect control levels 7 days after application. The second experiment revealed that solid applications at higher insecticide doses significantly improved control of S. levis adult (76.7% mortality) and resulted in greater insecticide concentrations in the soil compared to the recommended label rate (58.8% mortality).

The Equatorial Pacific Region (EPR) in Ecuador is characterized by high rates of vegetation diversity, and rapid loss of vegetation cover due to anthropogenic pressures. In this study, general ecological aspects of the Tabanidae family, including richness, endemism, and seasonality, were evaluated. Analyses reveal that approximately 42% of the species recorded for Ecuador are present in the EPR, and out of the 84 species cataloged in the EPR, 6 are endemic, representing an endemism of 7.14%. Furthermore, it was established that tabanid populations in a coastal dry forest significantly increased their population density during the dry season, while decreasing during the wet season.

The bethylid genus Solepyris Azevedo (Scleroderminae) is studied and revised. Five species are recognized, including three previously described ones: †S. electromexicanus Brazidec and Perrichot, S. montuosus Azevedo, and S. unicus Azevedo. Additionally, two new species are described and illustrated: S. maleku sp. nov. from Costa Rica and S. pataxo sp. nov. from Brazil. An emended diagnosis and a detailed discussion regarding the morphological diagnostic characters of this genus are also presented. A taxonomic key for all species is provided.

The genus Nealiolus Mason, 1974 (Hymenoptera: Braconidae, Brachistinae) is recorded for the first time in the Atlantic forest remnants and traditional cocoa agroforests, Theobroma cacao (Malvaceae) in the northeastern Brazilian region. A new species Nealiolus seb Silva, Shimbori & Fernandes sp. n. is described and named in honor of the "Sociedade Entomológica do Brasil - SEB", on the occasion of its fiftieth anniversary (golden jubilee). Digital images, map and an identification key for all Brazilian species of Nealiolus are provided.

Neonicotinoid insecticides are used against agricultural, forest, and urban insect pests. Evaluation of dry neonicotinoid residues on treated filter paper is a commonly used method to determine the toxicity of active ingredients towards target and non-target organisms. Dry residues of four neonicotinoids, acetamiprid, dinotefuran, imidacloprid, and thiamethoxam, on filter paper did not cause significant levels of mortality in Hippodamia convergens (Guérin-Méneville) (Coleoptera: Coccinellidae) and Nezara viridula (L.) (Hemiptera: Pentatomidae) when compared to paired untreated groups. Conversely, nearly 100% mortality was observed when test insects were exposed to dry neonicotinoid residues on leaf discs and glass plate surfaces. On the other hand, dry residues of the pyrethroid bifenthrin on filter paper, leaf disks, and glass plates killed significantly more test insects when compared to untreated groups. Additional bioassays tested the toxicity of acetamiprid and thiamethoxam by evaluating the toxicity of dry residues on (1) the upper and (2) lower surfaces of treated filter paper, (3) on a glass plate underneath treated filter paper, (4) on the upper surface of treated filter paper treated with insecticide and adjuvant, and (5) dried residues on a glass plate after dipping treated filter paper in water and letting the solvent dry on the inert test surface. The results indicated that neonicotinoid insecticides applied to filter paper were adsorbed. Toxic compounds possibly move in between and binding to paper fibers so that no toxic residues were left on treated surfaces. However, adsorbed insecticides were still biologically active when washed out of filter paper and dried on an inert glass surface. The results reported here clearly demonstrate that the toxicity of neonicotinoid insecticides should not be evaluated using filter paper as a test surface.

We report for the first time that larvae of the genus Bothynus Hope (Coleoptera: Melolonthidae) caused economic damage to lucerne (Medicago sativa L., Fabaceae) crops in General Acha, province of La Pampa, Argentina. In two consecutive years (2021 and 2022), this insect infested 150 ha of lucerne, causing seedling losses of 80 ha. Based on soil sampling and laboratory insect rearing, the species was identified as Bothynus striatellus (Faimaire) (Coleoptera: Melolonthidae). Information is given here on the damage recorded in this forage crop, the density of the larvae observed at the time of damage assessment and the morphological characteristics of the third instar larvae reported in this crop in Argentina.

Studies on the diversity of Anastrepha species have been conducted mainly in agricultural orchards due to the economic importance of this insect group, consequently, research on fruit flies in undisturbed environments is scarce. Moreover, very few studies have investigated the diversity of fruit flies in urban areas, where fruit flies survive under native or exotic hosts. Thus, to understand the diversity of Anastrepha species in an environment with different anthropization degrees, surveys were carried out in four areas of the "Luiz de Queiroz" campus, in Piracicaba, São Paulo State (Brazil), using Multilure traps with putrescine and ammonium acetate for 12 months. The software R 3.6.3 was used to characterize the fruit fly community and the faunistic analysis was carried out using the ANAFAU program. The analysis of species richness and total abundance of fruit flies among the sites was carried out using the rarefaction method and adjustment to the generalized linear model (GLM) using the Poisson distribution, respectively. We collected 1,080 females and 14 species of Anastrepha in the four sampled sites. Anastrepha fraterculus and A. obliqua were the predominant species (behavioral patterns). Similar to agricultural sites, A. fraterculus and A. obliqua also show a predominant occurrence in urban environments.

Dichotomius Hope, 1838 (Coleoptera: Scarabaeidae: Scarabaeinae) is a very abundant and diverse genus of dung beetles of the New World ecosystems, with about 190 species, distributed in four subgenera. Luederwaldt (Separata Rev Mus Paul 14: 3-13 1929) proposed the division of subgenera into sections (now species groups) based mainly on characters of external morphology. Based on Luederwaldt's proposal, progress has been made in recent years in the taxonomic revision of the genus; however, inconsistencies have been found in the subgeneric division and species groups proposed by this author. Based on the external morphology and the male genital organ of the all type material and other material deposited in fifteen entomological collections, in this paper, the redefinition and taxonomic revision of the Dichotomius mormon species group is carried out. The new definition of the group and the species key are presented. Five species are included in the group: Dichotomius conicollis (Blanchard, 1846) (Bolivia), Dichotomius larseni sp. nov. (Bolivia), Dichotomius mormon (Ljungh, 1799) (Argentina, Brazil, and Paraguay), Dichotomius ohausi (Luederwaldt, 1923) (Brazil, Colombia, Ecuador, and Peru), and Dichotomius talaus (Erichson, 1847) stat. rev. (Bolivia, and Peru). The lectotypes for D. conicollis, Copris ephialtes Mannerheim, 1829, Copris nasuta Castelnau, 1840, Copris protensus Perty, 1830, D. ohausi, and D. talaus were designated. For each of the species that are included in the group, the following information is presented: taxonomic history, species' citation in published literature, description or redescription of males and females, list of material examined, photographs of the external morphology, illustrations of male genital organ and its endophallites, and distribution map.