Journal of Applied Entomology最新文献

Mould detection in stored grain remains an important issue. This can be solved by using insects, including the pest Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), which develop and live in stored grain. The objectives of this study were to determine whether P. interpunctella females discriminate between fungus-infected and non-infected grain, and to determine whether there are any insect species with more sensitive olfactory receptors than those of P. interpunctella to 3-methyl-1-butanol, a biomarker of fungus infection. An egg-laying test demonstrated that P. interpunctella females can distinguish between Aspergillus flavus Link (Eurotiales: Trichocomaceae) infected and non-infected wheat grains. The females avoided laying eggs directly on grain infected with the fungus already on the first day after infection. Meanwhile, parameters such as weight loss and moisture content of the fungus-infected sample differed from the uninfected sample significantly starting the second day. On the third day after infection, the total number of eggs laid by the females decreased significantly. From this date, 3-methyl-1-butanol, the only volatile compound of infected grain that induces the electroantennographic response in P. interpunctella females, became detectable by gas chromatography. EAG recordings revealed that 0.1 μg of 3-methyl-1-butanol was the threshold dose for P. interpunctella. A comparative sensitivity study of 8 species from different taxonomic groups indicated that the sensitivity of P. interpunctella to 3-methyl-1-butanol is comparable to that of the honeybee Apis mellifera Linnaeus (Hymenoptera: Apidae), while the highest sensitivity was recorded in the fruit fly Drosophila melanogaster Meigen (Diptera: Drosophilidae). The other insect species studied were significantly less sensitive to this compound. In this context, D. melanogaster antennae are the most suitable biosensor for the detection of 3-methyl-1-butanol, a volatile marker indicating grain contamination.

Since insect pollinators are essential for their ecological and agricultural roles, their conservation should be a priority, particularly in the remnant green spaces within highly urbanised cities. To gain insight into the occurrence of interactions between plants and often overlooked pollinators, and into their requirements for persistence over time in urban green spaces, we studied flower visitor diversity associated with a remnant of native vegetation in Cordoba (Argentina), one of the largest cities in South America. We recorded 198 insect species from six orders (Hymenoptera, Diptera, Lepidoptera, Coleoptera, Thysanoptera and Hemiptera) interacting with the flowers of 94 plant species. The plant–pollinator interaction network was significantly modular, with 178 pollinators playing a peripheral role (i.e., it has a few links inside its own module and rarely any to other modules). We focused on the life history traits of these peripheral pollinators, which are often neglected in ecological studies. We classified their requirements to complete the life cycle and to persist over time into three broad categories: floral rewards, places to reproduce and additional resources for food and nests. The life cycle requirements of peripheral pollinators differ significantly across insect orders. Hymenoptera and Lepidoptera have distinct life history requirements while Diptera and Coleoptera overlap in resource use. The three life history categories highlight how pollinators display different foraging behaviour, reproductive strategies of immature and adult stages, and the requirement of additional food resources used by larvae and adults beyond flower rewards to complete their life cycles. Knowledge about the requirements of neglected pollinators is a benchmark that can help to identify where efforts need to be made to conserve and maintain their biodiversity, even in small urban green spaces.

Comparisons of insect pollinator–plant interactions through time have identified shifts in community structure for bees and flies. However, trends for the majority of other insect pollinators remain understudied due to a lack of available data. Historical collections are uniquely positioned to fill this data gap due to their extensive holdings of diverse pollinating taxa. This study uses the Canterbury Museum's natural history collection in Christchurch, New Zealand, to investigate insect pollinator–plant interactions among five insect orders: Coleoptera, Lepidoptera, Hemiptera, Hymenoptera (excluding bees) and Diptera (excluding syrphid flies). By comparing field collection labels and metadata with data from the Global Biotic Interactions (GloBI) database, we identified that 86% of recorded interactions in the museum data for insects identified at the genus and species level were not previously identified in GloBI. This analysis underscores that valuable data, archived in historical collections highlights the importance of digitising and sharing not only specimen data, but also detailed metadata to enhance scientific understanding of insect pollinator–plant interactions.

Foraging in leafcutter ants alternates between periods of inactivity and activity that extend over several days or weeks. Many factors could influence this alternation, with a preponderance of environmental factors, such as temperature, humidity, and rain. Moreover, ant colony size and the management practices used for their control could also modify the cycles of activity/inactivity. We surveyed the foraging activity of the nests of the leaf-cutting ant Atta sexdens (Linnaeus) in Eucalyptus plantations and evaluated the relative importance on foraging activity of temperature, past possible immediate experience in foraging, and use of machinery. Twenty transects with an average of 6 colonies in each were selected. Each nest was checked for foraging activity once in different months of the year and we investigated whether foraging inactivity was influenced by nest size, temperature, number of favourable hours for foraging on the day preceding the evaluation, and the use of agricultural machinery. The management practices of A. sexdens nests in Eucalyptus plantations had no influence on the occurrence of foraging inactivity, contrary to nest size and possible past immediate experience in foraging. The probability of foraging inactivity decreased by about 23% for each 10 m² increment in the nest size. A nest was also more likely to be active on a certain day if the conditions for foraging activity had been favourable on the preceding day. Leaf-cutting ants are one of the main herbivores in Brazil, often reaching pest status in several crops. Our results indicate that the efficiency of their control in Eucalyptus plantations could be increased by implementing control strategies several times a year and by increasing the number of bait applications in areas with a high density of small nests (less than 20 m²), as these areas are more prone to inactivity and thus may lead to increased control failures.

Floral foragers' pollination performance varies by taxon, and many crops rely on insect pollinators to produce fruit. Although honey bees are the primary pollinators for most crops, wild pollinators can sometimes be more effective and efficient. This study evaluated the pollination efficiency of several bee species: Apis mellifera, Megachile spp., and Bombus terrestris (queens and workers) on alfalfa. The research was conducted in the Wilaya of Mila, at Djebel Aougeb, Commune of Oued El Athmania (36°31′48.6″N, 6°39′49.1″ E), during the flowering seasons of 2021 and 2022. The experiments compared the pollination efficiency of the four groups based on pollen deposition per visit, foraging behaviour, and foraging speed. In terms of pollination efficiency, B. terrestris queens deposited the most pollen, visited more flowers per minute, and spent the least time per visit. This was followed by Megachile spp., while A. mellifera deposited the least pollen, visited fewer flowers per minute, and spent more time per flower. Whereas B. terrestris workers primarily collected nectar, contributing less to effective pollination. A significant increase in alfalfa grain yield was observed when comparing insect-pollinated and unpollinated plants. The findings highlight the economic value of wild bees, particularly Bombus terrestris queens and Megachile species (M. leachella and M. pilidens), in agroecosystems. Insect pollination resulted in a substantial increase in fruit and seed production, with pollinated flowers producing up to 17 times more seeds in 2021 and 14 times more in 2022 compared to unpollinated flowers. Open pollination had a significantly greater impact than self-pollination. To optimise pollination in Algerian alfalfa fields, synchronising the flowering period with the emergence of B. terrestris queens to avoid the dominance of workers and providing nesting habitats for Megachile species, in addition to using Apis mellifera, is recommended.

Nezara viridula (L.) (Hemiptera: Pentatomidae) is a significant pest affecting crops in both outdoor and greenhouse environments. To improve pest management strategies, we validated and compared two degree-day models predicting N. viridula development using citizen science occurrence records, greenhouse observations, and laboratory trials. Model 1, based on literature data from high-protein diets, was tested against Model 2, which accounts for slower development in nutrient-limited conditions. Citizen science records, collected via biodiversity platforms, provided insights into N. viridula's natural occurrence, while laboratory trials investigated its development on different food sources, including beans, peppers, and nuts. In natural conditions, Model 1 accurately predicted first appearance dates and population dynamics. However, in greenhouse environments, where nutrient availability is more limited, Model 2 performed better, correctly predicting two observed generations, while Model 1 overestimated the number of generations. Although RMSE and MAE metrics quantified model accuracy, visual inspection highlighted developmental trends that were not fully captured by these metrics alone. Greenhouse environments are suboptimal for N. viridula, primarily due to limited protein availability in monocultures like peppers, restricting the population to two generations per year. This finding suggests that new biocontrol strategies could exploit these suboptimal conditions to effectively manage pest populations. Further refinement of these models is needed to better account for all factors influencing development rates, especially in controlled environments.

The selection of suitable food resources for parasitoids plays an important role in their effectiveness as biological control agents. We investigated how different diets influence resource allocation in two Tephritidae fruit fly parasitoids, Fopius arisanus and F. caudatus. The diets consisted of pollen from cotton Gossypium hirsutum, coatbutton Tridax procumbens and maize Zea mays, a mixture of pollen with honey, and honey alone. Longevity, parasitism, lifetime fertility and life table parameters such as net reproductive rate (R_ο), intrinsic rate of increase (r_m), finite rate of increase (λ) and mean generation time (T_c) were assessed. Our findings show that the two Braconidae species consumed pollen with a preference of coatbotton and cotton pollen. Host-deprived F. arisanus with access to cotton and maize pollen mixed with honey exhibited increased longevity by 14% and 27%, respectively, compared to honey alone. However, when host eggs were available, the addition of pollen did not affect F. arisanus longevity, mortality risk, as well as parasitoids emergence compared to honey alone. The addition of coatbutton and maize pollen to honey resulted in higher fecundity, parasitism and superparasitism in F. arisanus. Furthermore, maize pollen mixed with honey led to a higher proportion of female offspring and an increased net reproductive rate (R₀) in F. arisanus compared to other diet treatments. In F. caudatus, adding maize pollen to honey decreased longevity compared to honey alone, while other pollen types showed no significant effect. Our findings highlight the importance of assessing plant pollen suitability before implementing plant-derived nutritional supplements in mass-rearing or conservation biological control.

Under field conditions, almost all organisms are exposed to a variety of threats including predators, heterospecific, and conspecific competitors, leading to disruptions in feeding as well as mating. Such disruptions may negatively impact reproduction, development, and in extreme cases even survival. Ladybirds are no exception to such disruptions. Ladybirds function as a biocontrol agent and as such, are an economically important insect. Disruptions in the duration of copulation may negatively impact the reproductive output of ladybird beetles; thus, affecting their long-term efficacy as biocontrol agents. In the present study, we examined the effect of copulation duration on the reproductive parameters of ladybird beetle Propylea dissecta Mulsant (Coleoptera Coccinellidae). We hypothesised that increased copulation duration in ladybird beetles may lead to enhanced reproductive performance. It was tested by rearing first instars of P. dissecta on an ad libitum supply of Aphis craccivora Koch until they reached adulthood and were 10 days old. We allowed them to copulate for different durations (i.e., 30, 60, 90, 120, 150, 180 min and complete mating (211 ± 8.1 min). We observed and recorded average fecundity, percent egg viability, and sperm count. Average fecundity and percent egg viability increased with copulation duration; lowest fecundity was observed at 30 min and highest at complete mating. Inviable eggs were obtained if interruptions occurred at 90 min and beyond. Highest percent egg viability was observed at complete mating and it declined with interrupted mating. Lowest sperm count was observed after 30 min of copulation, and highest count was observed after complete mating. This study of sperm quantification about different copulation durations is the first attempt in ladybird beetles. In conclusion, our study suggests that mating interruption in P. dissecta leads to poor reproductive performance, which is unlike that reported for other ladybirds. Hence, optimising copulation duration enhances the reproductive efficiency of Propylea dissecta, leading to increased population growth. As a beneficial insect, this improved reproductive performance strengthens its effectiveness as a sustainable biological control agent for managing agricultural pest populations.