Energetic underpinnings of yellow dung fly mating success in the field

Foraging provides the basis for animal reproduction, but requires energy and time to be sustained, entailing a trade-off. Whereas females should maximize their time foraging for resources, males should minimize their foraging time by optimizing time budgets to maximize their access to mating partners. Mark-resight field studies are difficult and hence uncommon for small insects. Yellow dung flies (Scathophaga stercoraria L.) abound on pastures in cold-temperate regions across the northern hemisphere. Adult flies lick nectar from flowers for energy, but require small insect prey to produce eggs and sperm. Males wait for females around fresh cow dung, but at one point also need to replenish their energy and/or sperm reserves in the surrounding vegetation. Their foraging time budgets should depend on their body size, nutritional energy reserves, availability of sperm, competitor and female density. Marked male dung flies whose nutritional status was experimentally manipulated – water only (null control); water + sugar (energy replenishment); or water, sugar + Drosophila prey (energy and sperm replenishment) – were repeatedly observed on an experimental pasture for an entire day. Both nutrient types were expected to increase the mating success of especially large males. The total number of resighted males seen copulating was lowest for water-treated flies. Mating success was positively related to body size. The distance travelled between dung pats was greater for males fed sugar or prey and also increased with body size, while pat residence times decreased with size. No differences were found between the sugar- and prey-fed groups. Crucially however, there was no evidence in the field for a time budget or mating advantage of small males when nutrients were limited.

Bruchus pisorum (pea weevil).

The pea weevil is a small insect (up to 5 mm long) with good flight possibilities. The adults may fly up to 5 km in search of pea flowers. The larvae develop within a single pea seed; the pupae and newly emerged adults also remain there, so the pest is easily spread all over the world in seed (grain) trade. This is the reason why the pest can be found everywhere that pea is cultivated. It may be invasive in tropical, subtropical and warmer parts of temperate zones. It only has one generation per year, but is a prevalent pest on pea in many countries, causing considerable damage. Infestation by the pest causes economic losses, partly due to the direct loss of seed contents consumed by the pest and partly due to the fact that weevil-damaged seed has a lower germination rate and fetches a lower unit price.

First records of the Palaestes abruptus Sharp, 1899 and P. nicaraguae Sharp, 1899 (Coleoptera: Cucujidae) from South America, with a checklist of flat bark beetles from the continent

The flat bark beetles (Coleoptera: Cucujidae) is a small insect family with only about 70 species. Most of the species are distributed in Holarctic, Oriental and/or Australasian realms, while in South America, only six species have been recorded, including a single one known from Peru. Two cucujid beetle species, Palaestes abruptus Sharp, 1899 and P. nicaraguae Sharp, 1899, are recorded from South America for the first time. The species are recorded from the Pasco (P. abruptus) and Cusco and Junín (P. nicaraguae) Regions of Peru, based, in part, on data collected through the iNaturalist citizen science database. Habitats of both species are presented in photographs for the first time. A country-level checklist to Cucujidae species currently known from South America is provided.

Resonance-Driven Passive Folding/Unfolding Flapping Wing Actuator

The wings of flapping-wing micro aerial vehicles (MAVs) face the risk of breakage. To solve this issue, we propose the use of a biomimetic foldable wing. In this study, a resonant-driven piezoelectric flapping-wing actuator with a passive folding/unfolding mechanism was designed and fabricated, in which the folding/unfolding motion is passively realized by the centrifugal and lift forces due to the stroke motion of the wings. Although the passive folding/unfolding is a known concept, its feasibility and characteristics in combination with a resonant system have not yet been reported. Because the resonant actuation is necessary for extremely small, insect-scale MAVs, research is required to realize such MAVs with a foldable-wing mechanism. Therefore, we first examine and report the performance of the resonant-driven passive folding/unfolding mechanism. We also present a simplified theoretical model demonstrating an interaction between the resonant actuation system and folding/unfolding mechanism. We successfully demonstrate the folding/unfolding motion by the fabricated actuator. In addition, the theoretical model showed good agreement with the experiment.

Generate (Non-Software) Bugs to Fool Classifiers

In adversarial attacks intended to confound deep learning models, most studies have focused on limiting the magnitude of the modification so that humans do not notice the attack. On the other hand, during an attack against autonomous cars, for example, most drivers would not find it strange if a small insect image were placed on a stop sign, or they may overlook it. In this paper, we present a systematic approach to generate natural adversarial examples against classification models by employing such natural-appearing perturbations that imitate a certain object or signal. We first show the feasibility of this approach in an attack against an image classifier by employing generative adversarial networks that produce image patches that have the appearance of a natural object to fool the target model. We also introduce an algorithm to optimize placement of the perturbation in accordance with the input image, which makes the generation of adversarial examples fast and likely to succeed. Moreover, we experimentally show that the proposed approach can be extended to the audio domain, for example, to generate perturbations that sound like the chirping of birds to fool a speech classifier.

The odonate phenotypic database, a new open data resource for comparative studies of an old insect order

We present The Odonate Phenotypic Database (OPD): an online data resource of dragonfly and damselfly phenotypes (Insecta: Odonata). Odonata is a relatively small insect order that currently consists of about 6400 species belonging to 32 families. The database consists of multiple morphological, life-history and behavioral traits, and biogeographical information collected from literature sources. We see taxon-specific phenotypic databases from Odonata and other organismal groups as becoming an increasing valuable resource in comparative studies. Our database has phenotypic records for 1011 of all 6400 known odonate species. The database is accessible at http://www.odonatephenotypicdatabase.org/, and a static version with an information file about the variables in the database is archived at Dryad.