A Hairy Entanglement

hairs

Camponotus larvae have hairs that interlock & cause them to clump

The larvae of the ant Camponotus floridanus, have bodies that are covered with curly hairs. When larvae contact each other, their hairs interlock causing the larvae to clump. The hairs also allow the larvae to avoid drowning.  Camponotus larvae will float in a droplet of water that would drown larvae such as a Drosophila that lack dense hairs. Locking hairs improve the ability of larvae to float by maintaining a clumped unit. Clumping may also facilitate feeding and care by adult workers.

Wang, Y., et al., Cuticular body hairs mediate clumping of small Camponotus floridanus larvae, Arthropod Structure & Development (2016)
http://dx.doi.org/10.1016/j.asd.2016.12.003

Posted in behavior, by jjneal, Environment, Taxonomy | 1 Comment

Living With Ants

The Ant Store

The Ant Store Photo:
DW.com

Pets are a hobby enjoyed by many people that occasionally turns into a business. Martin Sebesta enjoys ants and has made a business of selling ants from his AntStore in Berlin, Germany. His shop, in business for over a decade, provides terrariums, habitat materials and instructions to the ant enthusiasts. He has a selection of over 300 species of ants, native and exotic. Each ant species has its own characteristics and habitat needs.  The habitats must be managed to keep the ants from escaping and to exclude parasites such as mites and pathogens such as molds that could harm the ants. Mr Sebesta has written a popular guide to keeping ants, Principals of Keeping Ants.

Among the popular species are carpenter ants that are easier to observe because of the larger size.  They will make elaborate tunnels in wood. Leaf cutter ants do well in captivity making elaborate fungus gardens.  Ants exhibit more complex behaviors than most tropical fish.  As they build their nests, the ants offer something new to see every day.

Posted in by jjneal, Education | 1 Comment

Navigating While Walking Backward

Pavement Ants

Pavement Ants

The Spanish Desert Ant, Cataglyphis velox is a good model for studying orientation. They live in the desert where the landscape is flat and relatively uncluttered. Ant colonies have many individuals that can provide a pool of test subjects.

Ants that locate food will orient back to their nest using landmarks and the position of the sun. A group of scientists* placed an arena next to an ant nest and placed cookie crumbs in the arena some distance from the nests. After an ant picked up a cookie, they placed a barrier in the ant’s path so that it could not follow the straight path leading from the nest to the cookie crumb.  The ants were forced on a detour.  When the ants were forced to follow a path 90 degrees from the straight route to the nest, ants would carry the cookie crumbs to the edge of the barrier, make the appropriate turn and return to the nest. The scientists concluded that the ants could see as they walked and used landscape scale cues to navigate.

Navigation was successful if the ants carried small cookie crumbs and walked forward. Slightly larger crumbs cannot be carried forward by the ants. Instead, the ants must drag the larger crumbs while walking backward. When backward walking ants were blocked by the barrier, many of the ants failed to navigate the turn at the end of the barrier and headed off into the desert. Some backward walking ants did negotiate the turn by using a different behavior. These ants walked backward with the large crumbs for a short distance, dropped the crumb and looked around. They repeated this behavior when forced to detour.  These ants were able to recognize the nest location when they reached the end of the barrier because within a short distance, they would drop the cookie crumb and look around facing forward.  Apparently, ant navigation does not work as well in reverse.

Sebastian Schwarz, Michael Mangan, Jochen Zeil, Barbara Webb & Antoine Wystrach. How Ants Use Vision When Homing Backward. Current Biology. Volume 27, Issue 3, p401–407, 6 February 2017
DOI: http://dx.doi.org/10.1016/j.cub.2016.12.019

Posted in behavior, by jjneal | 1 Comment

Rusty Patch Bumblebee Update

Bumblebee

Rusty Patch Bumblebee Photo: Sarina Jepsen

The USFWS published a revised decision on the Rusty Patch Bumblebee. The rule placing it on the Endangered Species List was scheduled to be in effect today, February 10, 2017. However, that rule along with all other rules published but not yet in effect on January 20, 2017 were delayed by the new administration. According to the FWS, the rule will now go into effect on March 21, 2017 barring further action. This is great news for the bumblebee and those who want to preserve it.

Posted in by jjneal, Endangered Species, Policy | Leave a comment

Living With Asian Hornets

Asian Hornet

Asian Hornet
Photo: Charlesjsharp

The Asian or “Yellow Legged” Hornet, Vespa velutina, is spreading in Europe and in 2016, reached the UK. First found in France in 2004, perhaps imported in a shipment of pottery from Asia, the Asian Hornet has adapted to European climate. This hornet, like all wasps, is a predator. Most worrisome is the ability of the Asian Hornets to enter bee hives, attack and kill bees. Hornets have been known kill sufficient bees to eliminate colonies.

Beekeepers in the UK have been put on alert as Asian Hornets are expected to spread throughout the UK. Where possible measures to slow the spread or manage this invasive pest will intensify.

Posted in by jjneal, Invasive Species | 1 Comment

Paper Wasps in Winter

Paper wasps

Left: Paper wasps feed their larvae (look in the open cells) and guard their nest. The cells closed with silk caps contain pupae.
Right: An adult wasp rolls a caterpillar into a ball to take back to the nest and feed to the hungry larvae.

Paper Wasps build nests in sheltered areas and expand their colonies in the summer. In fall, the colony will disband. All the males and unmated females will die. Mated females (queens) will seek shelter from the elements, resting under leaves or underneath bark. In spring, the wasps will begin new colonies. A queen (foundress) will usually build a new nest from masticated wood mixed with saliva.

In some species, old nests may be utilized but only by a low percentage of foundresses. Using old nests would save energy, but the nest might contain pathogens detrimental to the colony. In some species, a new colony can be initiated by multiple foundresses. Multiple foundresses are all sisters who were in the same colony the previous fall. Paper wasps can recognize their sisters, but how they do this is not clear.

Jerry Lynn Allen, Kate Schulze-Kellman and George J. Gamboa. Clumping Patterns during Overwintering in the Paper Wasp, Polistes exclamans: Effects of Relatedness. Journal of the Kansas Entomological Society, Vol. 55, No. 1 (Jan., 1982), pp. 97-100.

Posted in behavior, by jjneal, Environment | 1 Comment

Fooling the Flower Visitors

Nice Flowers Give Butterflies Nectar Rewards

Flowers can increase their pollination efficiency by attracting insects that carry their pollen to a nearby flower of the same species. Most flowers act in “good faith”. They reward the insect pollinators with nutrient-containing nectar. One South African orchid, Disa ferruginea, has a single butterfly pollinator, Meneris tulbaghia, but does not reward it for its effort. Instead it mimics another flower, Tritoniopsis triticea, which rewards its pollinators with nectar.  S.D. Johnson* noted that Disa ferruginea, has high levels of pollination and fruit production in locations where Tritoniopsis triticea, grows nearby. In locations where Tritoniopsis triticea, is not present, the orchid bears much less fruit. Disa ferruginea can get by “on the cheap by mimicry. Butterflies used to getting rewards from flowers will inadvertently visit these mimics. However, that strategy also limits the range of the orchid mimic to that of its flower model. In areas where Disa ferruginea, grows without its model flower present, butterflies rarely visit to pollinate them because the butterflies are not rewarded for their effort. Incentives matter.

*S.D. Johnson. 1994. Evidence for Batesian mimicry in a butterfly-pollinated orchid. The Biological Journal of the Linnean Society. 53: 91–104
DOI: 10.1111/j.1095-8312.1994.tb01003

Posted in behavior, by jjneal, Environment | 1 Comment