How Butterfly wing patterns confuse predators

Amazing stuff!

"... That’s because the dazzling stripes and spots on their wings create powerful visual illusions as they flap, tricking predators into missing them, researchers report today in Nature.

Scientists have long suspected that high-contrast animal markings—such as the zebra’s iconic stripes—confuse predators via “motion dazzle” effects. Yet attempts to investigate the theory have produced mixed results. ..."

From the abstract:

"The dazzling stripes found on zebras and snakes have long been thought to interfere with predator motion perception, but this hypothesis has received little empirical support so far.

Butterflies show enormously diverse and high-contrast wing patterns, the function of which has inspired intense theoretical debate and research.

Here we suggest that butterfly wing patterns work in tandem with flight dynamics to create visual illusions that confuse predators.

We use multiple lines of enquiry with biologically inspired modelling to support this hypothesis:

free-flight butterfly take-offs filmed at high speed demonstrate the creation of misleading motion cues;

phylogenetically controlled analyses demonstrate that this is an evolutionarily widespread strategy;

in silico evolution experiments independently converge on high-contrast butterfly-like wing patterns; and behavioural experiments validate model predictions.

Our results show that butterfly wing patterns and flight dynamics create powerful illusory motion effects, potentially representing one of the most successful visual defence strategies in moving animals."

Butterfly wing patterns give predators the old razzle-dazzle | Science | AAAS

Butterflies use optical illusions to dodge predators (original news release)

Butterfly wing patterns in flight create powerful illusory motion cues (open access)

European swallowtail

Fig. 2: Motion confusion across European butterflies.

CRISPR-based genetic technique eradicates malaria mosquitoes with over 99% efficiency

Good news!

Why don't we try to completely eradicate bloodsuckers? What are bloodsuckers good for?

From the significance and abstract:

"Significance

Controlling the primary African malaria vector, Anopheles gambiae mosquitoes, is crucial for reducing malaria transmission. Conventional methods relying on insecticides are losing effectiveness. The sterile insect technique (SIT) has successfully eradicated pests, but implementing it for A. gambiae is hindered by technological gaps. Our precision-guided SIT (pgSIT) uses CRISPR to induce male sterilization and female elimination for use in SIT. Through engineered Cas9 and gRNA strains, we achieve over 99.5% male sterility and over 99.9% female lethality. Genetically sterilized males display longevity, induce population suppression, and, according to models, can eliminate wild A. gambiae populations. This finding enhances the malaria genetic biocontrol toolkit, allowing scalable, confined suppression in the species.

Abstract

Controlling the principal African malaria vector, the mosquito Anopheles gambiae, is considered essential to curtail malaria transmission. However, existing vector control technologies rely on insecticides, which are becoming increasingly ineffective. Sterile insect technique (SIT) is a powerful suppression approach that has successfully eradicated a number of insect pests, yet the A. gambiae toolkit lacks the requisite technologies for its implementation. SIT relies on iterative mass releases of nonbiting, nondriving, sterile males which seek out and mate with monandrous wild females. Once mated, females are permanently sterilized due to mating-induced refractoriness, which results in population suppression of the subsequent generation. However, sterilization by traditional methods renders males unfit, making the creation of precise genetic sterilization methods imperative. Here, we introduce a vector control technology termed precision-guided sterile insect technique (pgSIT), in A. gambiae for inducible, programmed male sterilization and female elimination for wide-scale use in SIT campaigns. Using a binary CRISPR strategy, we cross separate engineered Cas9 and gRNA strains to disrupt male-fertility and female-essential genes, yielding >99.5% male sterility and >99.9% female lethality in hybrid progeny. We demonstrate that these genetically sterilized males have good longevity, are able to induce sustained population suppression in cage trials, and are predicted to eliminate wild A. gambiae populations using mathematical models, making them ideal candidates for release. This work provides a valuable addition to the malaria genetic biocontrol toolkit, enabling scalable SIT-like confinable, species-specific, and safe suppression in the species."

CRISPR-based genetic technique eradicates malaria mosquitoes with over 99% efficiency Scientists at the University of California, USA, have developed a precision-guided sterile insect technique to eliminate the primary African malaria vector, Anopheles gambiae mosquitoes, and subsequently reduce malaria transmission.

Eliminating malaria vectors with precision-guided sterile males (open access)

Credits: Johns Hopkins Bloomberg School of Public Health: Global Health NOW

Fig. 1 Homozygous pgSIT gRNA females crossed to Cas9 males produce nearly exclusively sterile male F1 offspring.

Houston has the most cockroach infestations of any U.S. city, study says

Maybe Houston needs a clean up a la San Francisco? Houston, we have a problem!

"The largest city in Texas is leading the Top 25 Roachiest Cities in America list with more infestations than other metro areas, according to a Pest Gnome study.
The online marketplace for pest control services has named the country's fourth largest city, Houston, as No. 1 partially due to 37% of homes showing signs of pests in the past 12 months. ..."

Houston ranked the highest for roach infestations by study