Neotropical Entomology最新文献

Mocis latipes (Guenée, 1852) (Lepidoptera: Erebidae) is the main pest of graminaceous plants in the American Continent, especially in warm areas. Under normal conditions, M. latipes populations have their densities maintained at equilibrium by different natural enemies, including microorganisms (viruses, bacteria, and fungi), nematodes, insects, arachnids, birds, and mammals. In the megadiverse insect order Diptera, the families Tachinidae and Sarcophagidae are important natural enemies of various invertebrates, including pests, since several species parasitize insects and other arthropods. In the present work, we report the fly species Chetogena scutellaris (Wulp, 1890) (Tachinidae: Exoristinae: Exoristini); Atacta brasiliensis Schiner, 1868 (Tachinidae: Exoristinae: Goniini); and Peckia (Sarcodexia) lambens (Wiedemann, 1830) (Sarcophagidae: Sarcophaginae) parasitizing caterpillars of M. latipes collected on pasture, in Alagoas state, Northeast Brazil. This is the first record of C. scutellaris parasitizing M. latipes in Alagoas, the first report of the occurrence of P. (S.) lambens in Alagoas, and the first report of P. (S.) lambens parasitizing M. latipes in Brazil. Additionally, we reviewed the records of Tachinidae and Sarcophagidae parasitizing M. latipes, as well as all other hosts reported for them, and discussed the importance of parasitic flies for natural biological control of this and other lepidopteran pests in agrosystems, based on the distribution and host specificity of parasitic flies reported so far.

The fruit fly causes yield losses of 40 to 80% in various fruit crops, resulting in an approximate annual loss of USD 100 million in Colombia. Anastrepha obliqua is a significant pest for the mango production sector. Although biopesticides are promising alternatives for its control, there are currently no registered biopesticides derived from biomass or extracts of entomopathogenic fungi with the Colombian Agricultural Institute (ICA) for this purpose. This study demonstrates for the first time the potential of biomass and extracts from a native entomopathogenic fungus, Metarhizium robertsii MT008, cultivated through a liquid fermentation process, to effectively control both adult and preimaginal stages of A. obliqua. The optimal fermentation time was determined to be 5 days, producing the highest concentration of viable biomass (5.3 × 10⁵ CFU mL^-1), along with 75.89 ppm of destruxin A and 147.58 ppm of destruxin B. The fungal extract caused 100% mortality in A. obliqua adults within 48 h. While the biomass without formulation achieved 100% mortality, a biomass prototype achieved nearly 90% mortality at doses of 0.10 and 0.20 mg of dry biomass per gram of vermiculite against the preimaginal stages of the fruit fly by 24 days post-inoculation under laboratory conditions. The results demonstrate strong potential for advancing biopesticides, as combining these bioactive agents could allow more effective control of A. obliqua populations in field conditions by causing mortality at two different stages of its life cycle.

The sweetpotato weevil, Cylas formicarius (Fabricius, 1798) (Coleoptera: Brentidae), is a serious pest of sweet potatoes, damaging crops in the field and  during storage. Its cryptic nature limits chemical control. Entomopathogenic fungi (EPF) like Metarhizium anisopliae sensu lato (s.l.) (Metschnikoff) Sorokin, 1883 (Ascomycota: Hypocreales) offer eco-friendly alternatives. This study aimed to isolate and characterize a native M. anisopliae s.l. strain from infected C. formicarius using morphological and molecular methods and to evaluate its biocontrol potential against the weevil under in vitro conditions. Morphological characteristics and molecular analyses were used to confirm the identity of the isolate. Virulence was tested at three spore concentrations and compared with the commercial M. anisopliae s.l. strain ARSEF5369. Scanning electron microscopy (SEM) was employed to visualize the infection process. Enzyme activities (chitinase, protease) were quantified to compare virulence between strains. The effects of culture media and temperature on fungal growth and sporulation were investigated to optimize mass production conditions. The native isolate caused higher adult mortality (96.7, 93.3, and 50%) than the commercial strain at 1.2 × 10⁸, 5.5 × 10⁷, and 6.2 × 10⁶ conidia/mL after 7 days. The median lethal concentrations 30 (LC₃₀) and LC₅₀ of M. anisopliae s.l. strain Pm04 against C. formicarius were 2.15 × 10⁷ and 3.7 × 10⁷ conidia/mL, respectively, while at 1.2 × 10⁸ conidia/mL, the lethal times 30 (LT₃₀) and LT₅₀ were 2.33 and 2.4 days. Fungal infection stages were evident under SEM, and native strain exhibited elevated enzymatic activities relative to the commercial strain. Optimal growth and spore yield occurred at 25 ± 1°C on sabouraud dextrose agar (SDA) medium. These results highlight the potential of the native M. anisopliae s.l. strain as a promising biocontrol agent against C. formicarius, warranting further evaluation under field conditions.

Alphitobius diaperinus Panzer, 1797 (Coleoptera: Tenebrionidae), a common insect in poultry farms, poses a significant threat to poultry production. However, this insect also shows potential as a nutritional source due to its high protein and fat content. Studying its biological cycle and metabolic profile is essential for understanding its biology and biochemistry, enabling the development of more effective control strategies based on biochemical targets. This study aimed to investigate the biological and metabolic aspects of A. diaperinus at different developmental stages, providing relevant information for future research. Insect samples, maintained in colonies, were analyzed morphologically and metabolically. Morphological measurements were performed using digitized images, while metabolic profiles were obtained through gas chromatography coupled with mass spectrometry. The average biological cycle was 54 days, from egg to adult. Morphological parameters revealed distinct patterns of larval growth, with a positive correlation between length and age. Significant biochemical transformations were observed in the levels of amino acids, sugars, and organic acids throughout development, reflecting the specific metabolic needs of each stage. These findings expand the knowledge of the biological and biochemical aspects of A. diaperinus, providing a foundation for more effective and sustainable management strategies for controlling this pest.

Reproductive behavior and the use of stridulatory signals are well-documented in Curculionidae. Euscepes postfasciatus is an agricultural pest of sweet potato for which effective control strategies are still lacking. In this context, the objective of the present study was to investigate the reproductive behavior and the associated acoustic and vibrational signals of this species. To analyze reproductive behavior, 100 mating pairs were observed; data were compiled in an ethogram. To study the stridulatory signals emitted in stressful and reproductive contexts, 20 and 50 pairs, respectively, were recorded using systems equipped with microphones and piezoelectric accelerometers for capturing airborne and vibratory components of stridulatory signals. Morphological analysis of the stridulatory apparatus was conducted in 30 specimens dissected and examined using scanning electron microscopy. During mating, variation was observed in the male's mounting behavior and in the female's responses. Females were found to emit a specific rejection signal, while males produced a copulatory signal, potentially to enhance female receptivity, along with a distinct behavioral display. Stress-induced signals did not differ between sexes and showed clear temporal differences with female rejection and male courtship signals. The morphology of the stridulatory apparatus conformed to the pattern described for Curculionidae, with no observed sexual dimorphism.

Thrips (Thysanoptera: Thripidae) are sucking pests that damage a wide range of crops worldwide. Chemical insecticides are the main strategy for their control, but species can vary in susceptibility or develop resistance. Here, we developed and validated a bioassay method (dip test) using soybean (Glycine max [L.] Merr.) leaf discs to evaluate the susceptibility of thrips to insecticides. We compared the susceptibility of Caliothrips phaseoli (Hood, 1912) to acephate and spinetoram assessed using this method with results of the IRAC Susceptibility Test Method 010, in which bean pod sections are dipped into an insecticide solution. Concentration-mortality data from both methods fit the probit model, with mortality lines showing similar parameters (intercepts and slopes) and mortality increasing with the increase of insecticide concentrations. The lethal concentrations (LCs) of acephate were similar for both methods, whereas spinetoram showed higher LCs in the proposed method. Nonetheless, mortality at field label doses of both insecticides was consistently high (96.5-100%) in both methods. In conclusion, acephate and spinetoram exhibited high lethality against C. phaseoli, and the proposed bioassay method, due to its simplicity, reliability, and statistical robustness, represents a reliable alternative to the IRAC method for assessing susceptibility of thrips species to insecticides.

Entomopathogenic fungi (EPF) are promising eco-friendly alternatives to chemical insecticides against various insect pests. We assessed the efficacy of different Beauveria bassiana (Bals.-Criv.) Vuill. strains against Brevicoryne brassicae (L.), a major pest of Brassica crops under both laboratory and field conditions. The virulence and endophytic properties of three strains of B. bassiana, the commercial strain GHA, the endemic one KA14 from the Democratic Republic of Congo (DRC), and GxABT-1 from Belgium, were assessed under laboratory conditions. Under field conditions in eastern DRC, the efficacy of the B. bassiana GHA was evaluated compared to that of a conventional insecticide. In vitro, the lethal time 50 (LT₅₀) values ranged from 3 days for B. bassiana GxABT-1 to 4 days for both GHA and KA14 following direct application of fungi. Aphid exposure to fungus-treated leaves at 7 and 14 days after inoculation (DAI) resulted in LT₅₀ values of 4 to 5 days for GHA and KA14. Regarding the endophytic potential, B. bassiana KA14 showed higher performance in colonizing plant tissues and improving plant height growth. In the dual-choice tests, aphids were initially attracted to fungus-treated plants at 7 DAI but showed no preference between treated and control plants at 14 DAI. Field trials indicated no significant difference between fungal and chemical insecticide treatments, but both significantly reduced B. brassicae infestation compared to the Control. Our results support the interest of exploring the potential of the endemic B. bassiana KA14 strain against various insect pests and applying different methods.

Aedes (Fredwardsius) vittatus (Bigot) has a native geographical distribution that encompasses tropical areas of Asia, Africa, and the Mediterranean region of Europe. In its native range, this mosquito species is a potential vector of the dengue, chikungunya, Zika, and yellow fever viruses. Currently, Ae. vittatus is reported in the Caribbean countries of Cuba, Jamaica, and the Dominican Republic. We report the discovery of one female Ae. vittatus captured on September 11, 2024, in X-Calakoop, located near a major tourist site in Yucatán. Additionally, 11 mosquito species were found: Aedes aegypti (Linnaeus), Aedes albopictus (Skuse), Aedes bimaculatus Coquillett, Aedes cozumelensis Díaz Nájera, Aedes podographicus Dyar & Knab, Aedes taeniorhynchus (Wiedemann), Culex coronator Dyar & Knab, Culex nigripalpus Theobald, Haemagogus mesodentatus Komp & Kumm, Limatus durhamii Theobald, and Toxorhynchites moctezuma (Dyar & Knab). Notably, Ae. albopictus was the most abundant mosquito in the collection, accounting for 77.5% of the adults and 78.66% of the immature stages. The identification of Ae. vittatus in Mexico represents the first record of this species for continental America. The discovery represents the 252nd species in the country and 49th in Yucatán. The increase in the distribution pattern may have implications for public health in tropical America.

Tympanoterpes merganota sp. nov. is described and illustrated. Notes on natural history and adult behavior are presented including the description of the acoustic repertoire. This new species is currently endemic to Brazil, occurring in shrublands in the Atlantic Forest and Pampa regions. Adults have been observed in association with Asteraceae shrubs, using these plants as calling, copula, and oviposition sites. These results were achieved with the contribution of citizen science, proving its importance as an auxiliary tool for researchers.

The aim of this study was to evaluate how climatic seasonality affects the defense mechanisms of plants and how this is reflected in the richness and abundance of different guilds of herbivorous insects, using the species Ipomoea carnea subs. fistulosa as a model. Herbivore collections were carried out over 12 months, during this same period the phenology and herbivory was monitored in 30 marked plants, in addition to the analysis of the herbivory index in the dry and rainy season, in addition to collection and analysis of soil nutrients. Phenology showed strong seasonality, showing pivot of leaves and fruits emission during the dry season, and the reproductive phases of emission of buds and flowers peaked in the rainy season. A total of 10,199 herbivores were registered, distributed in 6 orders, and in four guilds. The total abundance of herbivores was greater during the dry season and the richness was greater during the rainy season. As for herbivore guilds, the abundance of leaf chewers-crushers was higher during the dry season, while flower and bud chewers-crushers were more abundant in the rainy season, whereas the suckers showed greater wealth and abundance in the rainy season. The results show a strong influence of climatic seasonality on the phenological patterns of the plant species. However this influence is very conspicuous in Seasonally Dry Tropical Forests, therefore, there are several biotic and abiotic factors responsible for these results. Factors such as interspecific competition and the distribution of food resources at a certain time of the season, can act in conjunction with climatic factors to shape insect abundance patterns.