Aug 27, 2014

Red - August 25

Meadowhawks (Sympetrum) dragonflies are aptly named for their hunting habitat and speed. These are freshwater species that prefer open meadows for the darting forays after small flying insects. Adult males are striking ruby red.


The presence of this hunter wasn’t sufficient to deter a common denizen of the salt marsh from attack. The eastern salt marsh mosquito (Aedes sollicitans) can easily make any visitor to it haunts miserable. These mosquitoes are usually present in large number and attack in swarms, day or night. Although handsomely covered with stripped pattern, fully blooded mosquitoes look like little red gemstones ingesting approximately their own weight in blood (i.e. the equivalent of a full grown man drinking a 20 gallon smoothie).

In bug world, red can also mean “danger, poison!” Argus Tortoise Beetle (Chelymorpha cassidea) is cute looking lady beetles alike. However, it belongs to a different family, leaf beetles (Chrysomelidae). Similarly to lady bugs, the red color of Argus tortoise beetles warns potential predators, mostly birds, that this particular morsel is inedible. The beetles contain toxins derived from its host plants from the morning glory family (Convolvulaceae). The plants produce indole alkaloids toxic to animals. Hedge bindweed (Calystegia sepium) is found on the upper edge of the marsh and probably serves as food sources for Argus Tortoise Beetle. 


Familiar faces - August 20

Tis’ the time of the year when adult Seaside Lady Beetles (Naemia seriata) make their appearance on the marsh. 
Seaside lady beetle munching on pollen
These cheerfully colored ladybugs are running up and down the salt marsh grasses. Unlike other ladybugs, Naemia seriata adults eat Spartina pollen not aphids. This year salt marsh hay (Spartina patens) flowered weakly, and the ladybugs were mostly confined to saltmeadow cordgrass (Spartina alterniflora).

 Bluets are beautiful damselflies that tend to visit the salt marsh in our area. Their brilliant azure color peeks out among the drab vegetation like a glimpse of a blue sky on a cloudy day. Like other Odonata – dragonflies and damselflies, these delicate insects are predators feeding on small insects and spiders.

While dragonflies habits are commendable, there are other bugs on the marsh that do not behave in such a proper way. Deer and horse flies (family Tabanidae) are a constant nuisance during the summer months. These handsomely marked robust flies have rasping mouthparts that cut the skin of their victim like a miniature saw, and it hurts! Like mosquitoes, only female tabanids bite; male lack the saw-like mouthparts and feed on pollen.


The eggs are deposited on the vegetation in masses containing up to several hundred of individual eggs. 


The larvae slither their way through the muck, mud, and potholes of the salt marsh. They are predacious and will eat whatever they can catch – insects, snails, worms, and other little creatures. 






Aug 8, 2014

Dodders and roses - August 4, 2014

When one hears the word “parasite” most people think about worms, bacteria, or fungi. However, there are parasites in the plant kingdom as well. Dodders are parasitic vine-like plants that infest other plants as their hosts. In this case it is Common dodder (probably Cuscuta gronovii) on the salt marsh elder, Iva frutescens. While inhabiting mostly freshwater wetlands, common dodder can also sometimes make its way to the high salt marsh. After the dodder attaches to the host plant, it inserts a kind of false roots right into the host plant tissues and continues to feed off it. Dodder has no roots and no leaves (only small scales), and obviously, no chlorophyll either, hence the orange yellowing color. 

 

But, even dodders are not immune to insects. This dodder plant had a gall produced likely by dodder gall weevil (Smicronyx sculpticollis).This beetles spends almost their entire lives inside the protective walls of the gall, a kind of insect made habitat induced by the weevil larvae.


A much more showy (and tastier) plant makes its appearance on the salt marshes known this time of the year. Rose or marsh mallow (Hibiscus moscheutos) is one of the 3 species of marsh mallows found on New York salt marshes. As the name hints, the roots of the European species (Althaea officinalis) were used to make marshmallows in the past. Marsh mallows are also known for their medicinal properties.



Rose mallows have their share of specialized insects which are adapted to feeding off these plants. Hibiscus seed beetles (Althaeus hibisci) uses chemical cues from open petals to locate freshly open flowers. The beetles eat pollen and lay their eggs on the seeds. The beetles larvae are protected inside the see capsule, and have plenty of highly nutritious food for development. Thus, The entire life cycle of the beetles revolves around the lifecycle of the plant. 







Aug 1, 2014

Relatives – July 28

Salt marsh is a home to some interesting arthropods =”joint legs” referring to the movable appendages connected by joints. Insects, arachnids (spiders ticks…), and crustaceans (shrimp, crabs..) are all part of this big happy family. Amphipods are crustaceans with laterally compressed bodies. They are most numerous in the oceans, but are found in all aquatic and some semi-aquatic environments such as salt marshes.  Their color is normally olive brown when alive. Like crabs and lobsters, they molt, and the shed exuvia can acquire reddish color as seen on the photo. The can run and jump on the surface of the marsh, and generally resemble wolf spiders that occupy the same type of habitat. When in water amphipods are fast swimmers. The female amphipods carry their eggs and young in a pouch. This shed skin probably belongs to Gammarus species.


Jul 22, 2014

Not just insects - July 21

By midsummer, the resident fish populations on salt marshes are thriving. However, multitudes of killifish perish every time the marshes dry out at a low tide. In those times, larger pools and ponds provide refuge for fish, which then can migrate to the salt marsh quickly during high tides and eat away mosquito larvae and other aquatic invertebrates. Thus, the essence of biological mosquito control on the salt marshes is to create more and better killifish habitat.

Atlantic eel often found in salt marsh ponds



 Killifish (mostly mummichogs)   concentrated within the drying potholes at a low tide


 
 Ponds provide refuge for fish and good hunting for shorebirds


Tis’ the season for greenheads, horse and deer flies of the family Tabanidae. This monstrosity is one of the largest on the east coast. Mourning horse fly (Tabanus atratus) is over an inch long. The female mouthparts work like a saw to cut into the skin. Fortunately, this beast attacks large mammals such as deer, horses, and cows. The bite is described as excruciatingly painful.


Syrphid (aka hover or flower flies, family Syrphidae) are very common on the salt marsh. Adults feed on nectar, but the larvae of some species are predacious on aphids, while others eat fungi.



When I caught the glimpse of this “insect”, I couldn’t make heads or tails of what it was! Turns out, it was a mating pair of the yellow-collared scape moth (Cisseps fulvicollis) whose caterpillars feed on grasses and sedges

female
male









Coccinella septempunctata, the seven-spot ladybird, native to Europe and repeatedly introduced to North America for aphid control makes itself at home on the salt marsh. 


Jun 26, 2014

Aphids and their predators on marsh elder – June 23, 2014

Marsh elder aphids support one of the more diverse and easily observable salt marsh insect communities. Aphids on the marsh have no protection against predators or parasitoids. They are absolutely vulnerable. The only counter-measure available to them is high reproductive rate (by giving live births!) and overpowering by sheer numbers.
Female aphids giving birth to little nymphs
 One of the most conspicuous predators are the ladybugs, larvae and adults. They are strikingly beautiful animals. When it catches an aphid, the ladybug larva tears it apart with the powerful mandibles or jaws.


There are also some unusual creatures feeding on aphids. This is a flower fly larva (family Syrphidae). The larva looks like a greenish maggot. It actively searches for the aphid prey and when captured with a dart like mandibles, the larva sucks them dry. 


Aphids are practically sitting ducks for parasitoids, mostly tiny braconid wasps.  11 out of 33 or about 30% of the aphids on this leaf are mummies containing braconid wasp larvae. Aphid mummies look like dark inflated globules as opposed to the more normal reddish egg shape.