What’s that in my spinach?

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A speck on the spinach leaf…

One morning as I was preparing my lunch before school, I noticed something attached to a spinach leaf. It looked like a small tan rounded egg of some sort. Closer inspection revealed something very funny–an aphid mummy! These are the hollowed out exoskeletons of aphids, created by the larva of a parasite that had devoured the aphid’s internal organs. I was familiar with aphid mummies, having seen them many a time on aphid-infested plants outdoors, but to find one on a piece of spinach from the market was worth a good laugh. I tossed it in a vial and headed off to school.

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Aphid mummy on spinach. The only locality information I have is from the packaging, which simply stated “Product of USA”. So this aphid and its associated parasite could be from almost anywhere in the country.

Later that day I decided to get a few shots of the aphid mummy. As I was photographing it I noticed that there was no hole in it, and there was a suspicious-looking dark area inside. What if, despite all odds, there was still life inside? I decided to keep it on the off chance that the parasite might still be inside. Turns out I didn’t have long to wait. The very next day I was excited to spot a 2-mm long wasp walking around in the container. As expected, the aphid mummy now had a large circular hole cut in it where the wasp had emerged. I photographed the wasp and posted it to BugGuide, where Ross Hill quickly determined it as a member of the subfamily Aphidiinae (Hymenoptera: Braconidae), which specialize in parasitizing aphids.

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The resulting aphidiine wasp.

Never doubt that insects are all around us, even in your food!

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Nepa – a plain-colored but rare hemipteran gem

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Two nymphs of Nepa apiculata (Kennebunk, ME)

I gently scooped the small brown shape out of the water. At first I thought I had grabbed the wrong object–wasn’t this just a bit of decaying leaf? But then slender legs extended, eyes became visible, and I could make out its true colors. This “bit of old muck” was in fact one of North America’s rarest species in the family Nepidae, the water scorpions. The name is a bit inaccurate, as these are not scorpions at all, but really true bugs (Hemiptera) much more closely related to giant water bugs and stink bugs. Water scorpions are aquatic predators, using a long breathing tube on the ends of their abdomens for gas exchange and large raptorial (grabbing) forelegs for snatching prey. There are only about 13 species in the U.S. and 10 of those are in one common, widespread genus, Ranatra, the members of which are so thin as to resemble walkingsticks. Another two species are in the genus Curicta, restricted to a few localities in Texas and Arizona. The final species, Nepa apiculata, was the one I had just found. It is widely distributed in the eastern U.S. but is rather uncommonly seen, as evidenced by the paucity of photos on BugGuide and other websites. Strangely enough, Nepa is the most common water scorpion genus in Europe, whereas Ranatra is rare.

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The adult Nepa

Nepa apiculata is a rather awkward little animal that seems, at least to me, to be ill suited to its own lifestyle (but they continue to exist, so they must be doing something right). They are not good swimmers and if placed in a jar of water without something to climb up to acquire air from the surface, will soon drown (as I found out the hard way). Thus they seem restricted to very shallow water with lots of vegetation. The locality where I saw my first Nepa, and in fact the only place I’ve ever found them, is a large pond with extensive shallows. I had been visiting this pond for several years and never come across them, but after finding my first one I was alerted to their presence and later found them again in the same spot a few times. I found adults to be a bit more mobile and active than nymphs, but I never had them try to attack small insects I tried to feed to them. Adults have wings but are apparently loathe to use them–I certainly saw no evidence that they were willing to fly. I found them to be rather comical animals, with their funny little heads and their fierce looking forelimbs which they did not even want to use.

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Nepa face. Note the raptorial forelegs and the rostrum (beak) used for sucking the insides out of prey.

Cicadas of the Cornell University Campus

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The face of a Linne’s Cicada (Neotibicen linnei). The large “grill”-like bump on the front of the face is the clypeus, which contains the muscles that act like a pump to power the cicada’s mouthparts.

The sizzling calls of cicadas are a familiar sound to anyone who has spent time outdoors on hot sunny days in late summer. Most cicadas sing from high in trees, making finding them a challenge. While they may all sound similar at first, their songs are all distinct and can be used to recognize species. I believe it is useful and fun to learn the calls of species that exist in your area. At the very least, it is a handy bit of trivia to have, and it’s also helpful in documenting biodiversity. With that in mind, here are the cicadas of Cornell University’s campus in Ithaca, New York. I have linked to recordings of each species from InsectSingers.com, a fantastic resource for cicadas.

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A male (left) and female (right) of the Linne’s Cicada. 

Neotibicen linnei, the Linne’s Cicada, is one of the two most common cicadas to be heard at Cornell. This species sounds a bit like a salt-and-pepper shaker to me. Its rattling buzz can be heard here. Individuals are nicely patterned in green and black, and have a prominent bend in the forewings that is a helpful guide to distinguish them from similar species. However this is not definitive, as some populations have less of a bend than others, and this should be used in conjunction with other traits to conclusively identify a specimen.

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Two females of the Lyric Cicada. Left is N. lyricen lyricen and right is N. lyricen engelhardti

Neotibicen lyricen, the Lyric Cicada, is the second of the two most common cicadas of Cornell’s campus. Its call is similar to the Linne’s but lacks the pulsations (hence the “lyric” moniker). It has been described as a syrupy buzz and can be heard here. I find that since these often drone on and on, they can become ‘white noise’ and fade from one’s notice easily. There is quite a bit of variation in the coloring of individuals. Around Ithaca there are two main color forms, known as N. lyricen lyricen and N. lyricen engelhardti. The former is patterned with greens, browns, reds, and tans while the latter is usually black with a very small amount of color on the pronotum, often in the shape of an anchor. These are not true subspecies and are better described as clinal variations. There are often intermediates in transitional zones such as Ithaca.

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A male Dog-day Cicada (Neotibicen canicularis).

Neotibicen canicularis, the Dog-day Cicada, is present on Cornell’s campus, but is not as abundant as the first two species mentioned. This is a more northern cicada, found in Canada and the northern tier of U.S. states. Its call is a high-pitched whine sounding like a buzz saw, and can be heard here. Dog-day cicadas look very similar to Linne’s cicadas but are quite a bit smaller.

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A comparison between a male Neotibicen linnei (left) and a male N. canicularis (right). Note the obvious size difference.

A few other species that I have not been able to document well here (or photograph) deserve brief mention:

I have heard Okanagana canadensis, the Canadian Cicada, numerous times around Cornell, but have been unable to find any. This is a very northern species on the southern edge of its range here. Males call from high in conifers. The call is an extended, cricket-like series of clicks (song).

Neotibicen tibicen, the Swamp Cicada, is a species that I think I have heard twice at Cornell, but both times were from quite a distance away. It is possible that these may have been Linne’s cicadas, as they sound rather similar (song). I will be listening for more this fall.

Finally, I must mention Neotibicen winnemanna, the Eastern scissor-grinder cicada. I heard this animal but once, at the edge of Cayuga lake in the early evening. However, there is no mistaking this cicada’s crazy call for anything else in the region. True to its name, it resembles the loud grating sound made by grinding scissors (song).

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A teneral (newly emerged) Linne’s cicada. At this stage they are very soft and vulnerable to predation. After several hours, the normal coloration sets in and the exoskeleton hardens up.

Leptoglossus

And now, an interlude from the Gorongosa posts.

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Leptoglossus occidentalis, the Western conifer seed bug (Ithaca, NY).

This is an insect many people in the United States and Europe may be familiar with; perhaps not by name, but certainly by appearance. Known as Leptoglossus occidentalis, the Western conifer seed bug, its large (20 mm) size, tendency to wind up in houses, and habit of releasing a strong scent when disturbed or crushed have shocked many of us. However, there is no need to be concerned with these creatures, as they are completely harmless to humans and pets, and cannot reproduce indoors. The only reason they enter our homes is because they are looking for a warm place to spend the winter. Ordinarily they would overwinter under leaf litter or under bark, but human habitations are just too warm to resist; unfortunately for them, as most people do not appreciate their presence. During the summer months, their nymphs are high up in conifer trees, feeding on sap. Usually they do not cause much harm, but they sometimes damage conifer nurseries.

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A very young nymph, final instar nymph, and resulting adult of Leptoglossus occidentalis (Kennebunk, ME).

This is an insect on the move. It is originally native to western North America, but started spreading eastward in the 1950s and is now common coast to coast. It was reported in Italy in 1999 and has since taken up residence across much of the European continent as well. There, it has the potential to become a more serious pest because it has no native enemies.

L. occidentalis is a member of the family Coreidae, the leaf-footed bugs. This name refers to the expanded portions of the hind legs, which in some tropical species are expanded enough so that they really do look like leaves. Coreidae is a colorful and diverse family, with approximately 1,900 species worldwide. The genus Leptoglossus includes about 60 species, eleven of which can be found in the U.S. and Canada. I have been fortunate enough to see four species of Leptoglossus, although the overwhelming majority have been L. occidentalis.

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Leptoglossus oppositus. I have seen this species in Maryland and New York; this individual is from Bear Mountain State Park, NY. It feeds on many different plants but is partial to catalpa.

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Leptoglossus phyllopus. The straight white cross-bar identifies this species. Supposedly one of the most common eastern species, though I’ve only seen it once, in Florida. It can be a pest of many crops. 

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Leptoglossus gonagra. In my opinion the coolest of the Leptoglossus species I’ve encountered, these have bright yellow spots on the ventral surface and a bow-legged appearance. They are a pantropical species, sometimes damaging citron groves in Florida. This was one of a pair of individuals sent to me from Fort Lauderdale, FL.

Side note: I have recently acquired Photoshop, and this post was partially borne out of one of my first experiments, the L. occidentalis collage, the style of which is based upon Piotr Naskrecki’s collages on white (such as this one).

Chitengo Camp: First Impressions

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Chitengo Camp

I arrived in Gorongosa National Park’s Chitengo Camp late Tuesday night. Around me pulsed the calls of thousands of crickets and katydids that I did not recognize. After getting my luggage put away and having a quick dinner at the restaurant here (which is very nice, I might add), I was out patrolling the grounds. Immediately I started seeing some awesome stuff. I found several grasshoppers which were familiar to me from my work on this group on dead specimens. Seeing them alive and in their natural habitats, they looked familiar, but also not. The lights around the camp swarmed with insects of all sorts; an occasional large katydid or grasshopper, small crickets jumping and flying everywhere, colorful assassin bugs and rhyparochromids scuttling under the leaves. Scores of the big-headed ant, Pheidole megacephala, were ever-present, ready to attack and take away any insect that paused too long. It was heaven.

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One of my first Gorongosa katydids, a beautiful male Plangia compressa.

The interesting thing about Gorongosa in July and August (which is their dry season) is that the abundance of many insects is not extremely high, but the diversity is. For example, I found a total of 5 individual katydids the other night, all very widely spaced around the camp, and each one was a different species. In comparison, Piotr has told me that in the wet season (January/February is the peak) you cannot even sit at the restaurant, because there are just clouds of giant preying mantids and katydids everywhere. Problem then is that most of the roads are flooded and you are basically trapped in Chitengo. Piotr arrived on Thursday morning from a collecting trip on Mt. Gorongosa, and I had dinner with him and several of the other researchers after we tried to locate a bat hawk in Chitengo (a very interesting bird of prey that only hunts bats for about 30 minutes every dusk) Learned quite a bit about all sorts of things. You cannot exit the camp unless you are on a safari or with someone affiliated with the park, because while the camp is fully fenced off, the rest of the park is not as safe with lions and elephants roaming the area. However, there are two gates. One is guarded and you are only allowed through with the guard’s OK. The other gate is open and you can just walk right though and go down to the river. As Piotr described it, the park has an agreement with the lions and elephants. They attack people at the first gate, and they don’t attack people at the second gate. But in all seriousness, the large mammals could be anywhere, but they usually avoid the area around the second gate because of the heavy foot traffic. These and many other interesting tidbits I have been picking up the last few days. I already have several cool stories of insects to post about, but that will have to be another day. I also have tons of photos and I will share a few below.

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The first grasshopper I found in Gorongosa was this lovely female Metaxymecus gracillipes, a species with which I am very familiar from specimens.

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This odd little bug is a water measurer (Hydrometridae). As with many insects here, this one has only been identified to family. A species ID is not an easy process for most of these smaller bugs.

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Several species of larger mammals are common around the camp. These warthogs do not seem to mind people at all.

Tonight we are going collecting outside of the camp, at the “lion house”. Should be interesting…