Leaf Miner’s Leaves
Artist: Susan Hoenig
The Monmouth Museum in Lincroft, NJ has a current exhibit: Animal Architects. The exhibit features the work of New Jersey Artists that depict modification of the environment by animals including insects. Some modification are made by building such as mud dauber art. Others are made by subtraction, such as the work of leaf miners.
Are insects architects? By definition, an architect is someone than plans. However, the typical insect structure has no planning. How do insects know how to build complex nests or even a perfectly round ant mound? They don’t. The structures are built through a series of idiosyncratic behaviors in response to local stimuli.
Our leaf miner hatches from an egg and eats its way into the center of the leaf. If it senses the middle of the leaf, it will eat. If it contacts the upper or lower leaf surface, it will not eat. After it has consumed the material within reach of its mouthparts, the leaf miner moves forward. The mouthparts face forward extending the feeding site in the form of a linear tunnel. The width of its tunnel is determined by the size of its mouth parts and body.
A fully developed larva will chew an exit hole to the outside and drop to the ground to pupate. The leaf miner leaves its structure, its work of natural art in the leaf. at no point was the design planned or designed, however, the designs created by insects can inspire human architects and artists to incorporate insect designs into their own plans.
Rafting Fire Ants
Photo: AP/Chris O’Meara
The Weather Channel provides information on severe weather, storms, floods, earthquakes and other natural phenomena that may disrupt daily life. They have added a new warning: Fire Ants. Tropical Storm Cindy left flooding in its wake including many areas containing fire ant nests.
Fire ants are native to South America where flooding is common. Fire ants have adapted to flooding by linking legs and forming a raft. Not only do fire ant colonies survive, but they can disperse to new areas in this manner.
Fire ant rafts pose a hazard to those who contact them. If a raft is contacted, fire ants may move onto the person and begin biting and stinging. People moving through flood waters cannot retreat rapidly from the raft. Fire ant colonies may also drift into flooded homes or colonize furniture or other household items. Homeowners are warned to be careful when handling these items.
Oregon Silverspot Butterfly
The Oregon Silverspot Butterfly is a threatened species that lives in disturbed habitats along the coasts of California and Oregon. It has been sighted in Washington in the past but not recently. It has been reduced from 20 locations to only 5 primarily due to human induced loss of habitat.
The U.S. Fish and Wildlife Service (USFWS), in partnership with the State of Oregon Parks and Recreation Department plans to establish new populations of the butterfly at sites within its historic range. The new populations will be established by releases from a captive breeding program used to sustain the butterfly in its current habitat. Expanding populations to new areas will increase access to host plants such as hookedspur violet and serve as a buffer against catastrophic loss of existing habitats. Ongoing commercial activities that are not permitted in existing areas will be allowed in new locations.
Monarch Butterfly Feeding
Butterfly mouthparts are long tubes that can be inserted into the narrow channels formed by flowers to reach a nectar reward. Flying or walking while dragging an extended tube would be awkward. Packaging the mouthparts into a tightly coiled tube under the head makes movements less awkward. The mouthparts coil when at rest due to the resilin component. Resilin can be stretched under pressure, but when relaxed, will return to its original shape.
How does a butterfly extend its mouthparts? The butterfly lifts its mouthparts in an action that partially uncoils them. At the base of the mouthpart in the head, muscles repeatedly compress a tube called the stipes. The movement of the stipes pumps hemolymph into the mouthparts and the hydraulic pressure forces the mouthparts to extend. When the butterfly finishes feeding, the valve of the stipes opens and the resilin forces the hemolymph out of the mouthparts as they coil under the head.
Butterfly Cibarial Pump, Reconstructed from Micro-CT
Image: Lee & Colleagues*
Many butterflies visit flowers to obtain nectar, a fluid produced by flowers that contains sugars and other nutrients. Flowers often restrict access to nectar by their shape. A long tube such as the proboscis of a butterfly is necessary to reach the nectar. To ingest the nectar, a butterfly must pump the liquid such that it travels through the mouthparts and into the head.
Inside the head of the butterfly, the mouthparts are connected to a pump called a cibarium. The cibarium, is like a tube with a cavity in the center. When muscles pull upward on the top of the cibarium, the cavity opens allowing liquid to flow into the cavity and pulling liquid up the proboscis. Contraction of circular muscles surrounding the cibarium, close the cavity in a manner that pushes a bolus of liquid into the esophagus. The actions of the muscles pump liquid into the digestive system.
*Seung Chul Lee, Bo Heum Kim and Sang Joon Lee. Experimental analysis of the liquid-feeding mechanism of the butterfly Pieris rapae. The Journal of Experimental Biology (2014) 217, 2013-2019
Midges form a “bugnado” along Highway 30 in Council Bluffs, Iowa.
Photo: Mike Hollingshead
Firefighters in Hamburg, Germany were called to an historic church by reports of smoke rising from the building. Upon arrival, the firefighters found no smoke and no fire. What they did find was a swarm of gnats above the roof which the firefighters correctly identified.
Humans have been living on the continent of Antarctica for decades in bases heated to temperatures that support human life. Those conditions also support insects associated with human habitation. The house fly is now a permanent resident of Antarctica living primarily indoors at bases. The flies are stowaways in the kitchens of supply ships. As yet the house fly does not have a permanent presence outdoors. However, as the climate warms, ice melts and the plant biomass increases and flourishes the house fly may eventually invade the continent.