Salt marsh waking up in May

Finally, the temperatures are in the balmy 80s. Whereas last week the marsh looked brown and dead, with few signs of 6- or 8- legged life besides the ubiquitous Pardosa littoralis, the thin legged wolf spider, this week was very different. Planthoppers and flies happily cavorted around in the grass or on the mud flats. Water boatmen and mosquito larvae frolicked in the little pools. A rare guest visited from the woods nearby. 

Hister beetles (Histeridae) love decaying matter- carrion, dung, and rotting plants. They are not scavengers but predators searching for a snack of maggots or other arthropods found in those habitats. Perhaps this beetle was attracted by a dead animal; it also got a little hitchhiker or maybe a transitory companion, a tiny red mite running up and down the much larger beetle.

The thin legged wolf spiders (Pardosa littoralis) were as numerous as ever scattering in all directions. These spiders are semi-aquatic and run on water as if it were dry land. They can reach densities of up to several hundred per square meter, and are voracious predators of planthoppers and other invertebrates. This spider is a particularly good candidate for an indicator species of healthy salt marsh environment. 

While the spiders may snatch a mosquito larva out of the water, the salt marsh mosquitoes have evolved to avoid predation by unpredictable and irregular emergence, and to overcome any generalist predators by sheer numbers. The “balling” behavior is typical of the late instar or stages of the eastern salt marsh mosquito, Aedes sollicitans. Hundreds or thousands of larvae pack closely together to form tight larval “balls” in some potholes. The advantages of this behavior are not very clear, but it is still very impressive.

A damsel bug

Damsel bugs (family Nabidae) are slender creatures resembling miniature praying mantids in having raptorial front legs. Like praying mantids, their front legs are used to capture small prey, likely plant hoppers on the salt marsh. Damsel bugs have a long beak with which they suck out juices from insects they capture. The beak can also delivery a painful bite, if handled carelessly. These individuals are possibly nymphs, i.e immature true bugs since they don't have fully developed wings.

August - the battle of two predators 2

Praying or European mantis (Mantis religiosa) is the most common mantid on the salt marsh. As the name suggests, it is an introduced species that came to the US in the late 1800s. It is still popular for "pest control", a notion totally opposed to the non-specialized nature of the mantid hunting, in which both pests and beneficial insects are captured and consumed. Case in point is this photo, where European mantis has eaten several Seaside dragonlets, a very beneficial dragonfly.

Although Seaside dragonlets are fierce predators in their own right tirelessly patrolling the marsh for flies, mosquitoes, and other small flying insects, they are no match for the fearsome pincers of a large praying mantis female.

Parasitoids - the truely tiny

 Parasitoids, or insect consuming other insect but in moderation (usually just one) are frequently overlooked due to their small size, like a flying spec of dust. These tiny wasps search for eggs or small insects as a food source for their larvae.

End of July - The battle of two predators 1

Seaside dragonlet is among the most beautiful insects on the salt marsh. It is also among its deadliest. As an immature, which is called naiad for dragonflies, it is the top invertebrate predator in the potholes and on the mudflats, a hunter of other creatures.

   As an adult, seaside dragonlet eats whatever it can catch, mostly flies - mosquitoes, midges, syrphids and similar. But, the marsh surface is also a home to another deadly creature, the spider. Spiders are mostly generalist predators and take whatever comes their way, which usually means the most abundant insects at the moment. This year it's been dragonflies buzzing around in enormous swarms. Sadly, many ended up in the spider nets protruding from the salt marsh vegetation...   

More July plant eaters - and predators

This gem of a true bug (Trigonotylus uhleri) from the family Miridae or aptly named Plant Bugs is a common denizen of the salt marsh. It apparently really likes the saltmarsh cordgrass (Spartina alterniflora) sucking out the juice with the stylet like mouth. The young look like miniature adults with reduced wings.The striped coloration resembles some of the planthoppers, distant cousins of these plant bugs.

Yet to be identified beetles were happily munching on the salt marsh threesquare (Schoenoplectus robustus) leaves. Interestingly, there were two color forms, one with mostly brown elytra (wing cover) color, and another with almost black, with some intermediate forms present as well, perhaps sexual dimorphism or even two different species?

 This beauty is only visiting the salt marsh from nearby freshwater ponds. A slender and fragile dragonfly relative, the Bluet damselflies (genus Enallagma) are also predators. This particular individual seemed to hover around salt marsh hay grass and pick out tiny bugs possibly planthoppers (?). The immature Bluets, called naiads, live in ponds and feed on small water creatures.

July is for plant munching

July is a good month for herbivores. The marsh vegetation is vigorous but not yet toughened and scorched by the heat. It is also tall and dense, with many nooks and crannies to hide and be invisible. Grasshoppers have chewing mouthparts, and love to munch on the threesquare (Schoenoplectus pungens). Despite their relatively large size, the salt marsh grasshoppers are a wary bunch always preferring to keep a leaf blade between them and a potential danger jumping off or dropping to the ground at the slightest movement.

Salt marsh lacks large mammalian herbivores, there are no herds of buffalo or antelopes. Even grasshopper sized insects are not the plant eaters dominating Spartina prairie. The main herbivores are tiny sapsuckers, leafhoppers and planthoppers swarming the grasses this time of the year. More on those later on.....

The aphid eaters

The larvae of a green lacewing (Neuroptera) are voracious predators. Often, they go after prey twice their size. On salt marsh, these little fierce creatures with outsized scythe like jaws are common on the marsh elder (Iva frutescens).



 

The green lacewing larvae run busily up and down the branches inspecting the leaves for aphids. When found, an aphid is grabbed forcefully without hesitation and no resistance.

For the night, they appear to produce a cocoon of sorts, where the whole body is hidden head first making it difficult to extricate those long jaws.

Curious wasp mimic fly

A curious little fly was searching among the marsh elder leaves. Its front legs had white “feet”, which the fly frequently rubbed producing an eerie resemblance with an ichneumonoid wasps. The body coloring was also similar to its hymenopteran models, and banded wing patterns made the fly appear to have a

narrow wasp-like waist. Very little is known of the biology of Stilt-legged Flies (Micropezidae) other than the larvae are mostly excrement or rotted plant material eaters and that the North American species live near water. These flies are mostly tropical, and not very common further north.

The adult diet is mostly unknown.  Some species have elaborate courtship rituals such as “dancing”, direct feeding of the female, or placement of fluids on the eye of the female to wipe off and consume. This particular species is probably Taeniaptera trivittata.