Category Archives: Photography

Insects in the vegetable garden

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Here are some photographs I took in June at my allotment in town.

Spotted cucumber beetle (Diabrotica undecimpunctata howardi)

First up is a spotted cucumber beetle (Diabrotica undecimpunctata howardi), perhaps the most common insect in my garden every year. In addition to being defoliators, the beetles are important transmitters of the Erwinia tracheiphila, which causes wilting. I think some of my zucchini fruits might be suffering from this wilt, but I’m not positive. The insect can also eat corn roots during their larval phase (hence its other common name, southern corn rootworm). If any of my corn plants lodge (fall over) I’m going to attempt to find and photograph the little bastards. For a beetle with “cucumber” in the common name it’s stunning how many different types of plants this insect can survive on (per one estimate, over 40 different families). More information on the species can be found at BugGuide.

Mexican bean beetle (Epilachna varivestis)

This is a Mexican bean beetle (Epilachna varivestis) next to some of the damage it presumably caused. If you provoke them they apparently “reflex bleed”, and the blood is laced with a toxic alkaloid (Eisner et al. 1986). I haven’t yet seen their larvae (here‘s an excellent pic) but those have a different alkaloid in their glandular hairs (Attygalle et al. 1993). BugGuide has information on identification, distribution, and life cycle.

Phyllotreta striolata

This is some sort of Phyllotreta, I think, on radish. I spent several hours online trying to identify it to species but got stuck with three options that all are rather similar: Phyllotreta striolata, Phyllotreta zimmermanni, and Phyllotreta liebecki (links go to respective BugGuide pages). But the first option seems the best: “Antennae black, basal 3 segments yellow-brown, 5th segment usually 1/3 longer than 4th, its width 1/4 its length” (BugGuide). Here‘s the iNaturalist observation in the event that an expert is reading this and can help with an ID. These beetles sequester the glucosinolates of their cruciferous hosts (Beran et al. 2014).

Potato stalk borer (Trichobaris trinotata)

This weevil is Trichobaris trinotata, the potato stalk borer. The larvae get inside the stems courtesy of small notches that the female chews prior to oviposition. If any of my potatoes, eggplants, or tomatillo begins to wilt I’m going to dissect the stem in search of the larvae (I’m easily entertained). Adults are easy to ID because of their all-black head and presence of three black spots in between the thorax and elytra. More information is available on BugGuide.

Eggplant flea beetles (Epitrix fuscula)

This is one of hundreds of eggplant flea beetles (Epitrix fuscula) in my garden. In addition to defoliating my eggplants every year they are extremely small and thus hard to photograph and identify. And apparently they might be eating my beets, too, as larvae. BugGuide has cursory information on identification but for more extenstive treatments plus excellent photographs see Deczynski 2014 and Deczynski 2016.

Epitrix brevis

Epitrix brevis is even smaller than the eggplant flea beetle, above, and thus really at the limit of my camera gear and patience. They are all over my tomatillo, slowly skeletonizing some of the leaves through hundreds of tiny excavations like the one in the background of this photograph. Pestiferous, but also rather cute due to their small size. BugGuide has a page on the species but doesn’t have any interesting information. Likely too small.

Lady beetle larvae

These are the larvae of some sort of coccinellid (lady beetle), still hanging around their eggs and perhaps entertaining themselves by eating each other, as one does. I’m wondering whether they might be Harmonia axyridis (Asian lady beetle), an introduced beetle so common that is often a good guess. I need to go back and check on this location (on pole bean leaf) to find later instars or adults. Here’s my iNaturalist observation.

Clouded plant bug (Neurocolpus nubilus)

This menacing insect is a clouded plant bug (Neurocolpus nubilus) and I’ve seen several on my borlotti beans. In perhaps related news, several of my borlotti beans suddenly died this week (early July) and I’m wondering whether this bug is responsible. It’s a known pest of cotton but I can’t find any evidence in the literature that it eats legumes. More details on BugGuide.

Broad-headed sharpshooter (Oncometopia orbona)

This gorgeous leafhopper is a female broad-headed sharpshooter (Oncometopia orbona). Those white spots are chalky deposits (brochosomes) that are often found on females. Females use the substance to coat their eggs, though I’m not sure whether she uses the material from those spots. For the life of me I cannot locate a photograph of eggs protected by this chalk. I gather both males and females of this species (and other leafhoppers and planthoppers) also “anoint” themselves with this goop after each molt to better protect themselves from the elements and from sticky substances (Rakitov 1996). They are really hard to photograph because when they sense your proximity they will quickly move to the other side of the leaf. More on BugGuide.

Swift feather-legged fly (Trichopoda pennipes)

This is a swift feather-legged fly (Trichopoda pennipes), one of my favorite dipterans. I love it because (1) it’s beautiful, (2) not easily spooked, and (3) is a highly motivated parasitoid of squash bugs. I’ve never seen it in action, but they slap eggs right onto squash bugs (and several related bugs), and they do this all day long, sometimes effectively controlling the pest without any need for pesticides. They are so common that if you scroll through pics of squash bugs you’ll see the fly’s eggs regularly (e.g.). Here‘s a nice summary of its life cycle by Susan Mahr (University of Wisconsin). BugGuide.

Condylostylus caudatus

This is a male Condylostylus in the sipho group. My garden has thousands of these flies, all of them likely eating the aphids and other small insects that are present in large numbers. They are extremely skittish and hard to photograph. To make things worse, they also take flight when they detect a flash pulse, so 90% of my shots have only a leg or two. Here’s the iNaturalist observation in case you can help me with the identification. Caleb Scholtens has an excellent guide to the Condylostylus groups on iNaturalist .

Squash vine borer moth (Melittia cucurbitae)

Finally, here’s an early-instar larva of a squash vine borer moth (Melittia cucurbitae) inside a zucchini stem. I found it by examining leaf stems for surface damage caused by oviposition and early feeding by the larva (see pic #3 on my Inaturalist observation to see the damage). These are horrible pests of zucchini and yellow squash, so I tend to wrap the bases of my plants in tinfoil, plus patrol the leaves and fruit stalks for larval damage. The adult, by the way, is stunningly beautiful. BugGuide has identification help, which I recommend checking just to be sure it’s not Melittia calabaza, which looks very similar.

Finally, here’s a non-macro photograph that shows where all these insects are spending their lives, my little allotment at the Scott Arboretum Community Gardens.

Allotment at community vegetable garden

All of the above photographs, plus thousands more, are at https://colinpurrington.smugmug.com.

Photo tour of my insect hotel, 2022 edition

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Here are photographs of my insect hotel from Spring 2022. It has three levels and features nesting holes of varying diameters so that I can attract multiple species of bees and wasps. If you’d like to see what shows up this spring and summer, follow me on iNaturalist — I post photographs of everything that arrives, plus post photographs of what is inside the nesting tubes at the end of season. The latter is possible because all holes are lined with paper straws or are stems that can be split open. Having nests that can be dismantled also allows me to minimize the number of unwanted parasites and diseases that might otherwise thrive.

Starting from the top, in the attic space, are 7″ sections cut from a princess tree (Paulownia tomentosa) growing in my yard. The wood blocks have slightly smaller-diameter holes (1/2″) and are lined with 6″ lengths of paper bubble-tea straws. Together, these holes will likely attract grass-carrying wasps (Isodontia spp.), eastern carpenter bees (Xylocopa virginica), and sculptured resin bees (Megachile sculpturalis). And, probably, jumping spiders.

The middle section has more traditional offerings, with paper tubes inside nesting trays (I bought them online) and inside blocks with 6″ holes that I drilled. You can buy super-hard paper liners made for insect hotels, or you can be cheap like me and just use paper drinking straws. I found straws online that are a tad shy of 5/16″. There are dozens of bee and wasp species that will use holes of this size. Note that if you splurge on the trays, you’ll need a way to compress them; I use pipe clamps but luggage straps work, too.

The lower level has cavities that are slightly smaller still, to attract bees and wasps that have smaller body sizes. The blocks have 1/4″ holes fitted with paper drinking straws that are just shy of that. Stems to the left of the blocks are 7″ sections of swamp milkweed (Asclepias incarnata) from my garden (I also like bee balm). These smaller nests seem to attract Georgia mason bees (Osmia georgica) and my favorite wasp, Trypoxylon collinum (the male stays home to guard the nest).

Also on the lower level are square holes routered onto a pine board and covered with Plexiglas. This allows me to spy on the bees and wasps as they construct and provision their nests. It’s early in the season so there’s no real excitement in the photograph, but you can see horned-faced mason bees (Osmia cornifrons) in tunnels #2 and #8. They are both males and are waiting for the females to show up. This panel can be taken apart at the end of the season and cleaned.

Finally, I have an array of stems on both sides of the insect hotel to accommodate species that might prefer to nest vertically. I’m hoping to attract some leafcutting bees (Megachile), but they are said to dislike the commotion at large insect hotels. One can always dream.

Using paper straws to line nests

If you want to make your own insect hotel you’ll need to invest in some long drill bits so that your tunnels can be at least 6″ long. I purchased both a standard set (inches) and a metric set, plus two individual bits that I purchased separately. And you should make yourself a little floor brace so that you can drill without the block rotating wildly. For straws, there are dozens of online places to get paper ones, but I’ve also found them at local grocery stores. And when you get to the stage of inserting the straws into blocks, trim the lengths and then crimp the end (see pic, below) so that the inhabitants don’t extend their nesting materials into the block itself; this makes it easier to use a forceps to pull the straw out. Then during the winter, unroll the straw to reveal contents. Save the pupae you want (in small containers, outside, so they develop normally) and discard parasites such as Houdini flies.

Using stems

For making reeds, I highly recommend using a rotary tool with a cut off blade instead of pruners or saws, both of which leave jagged edges and sometimes cause fractures that can allow parasites to get inside the stem. When you’re ready to sort through the stems, use a knife to split open the stem, then use your thumbnail to continue the break to the end. Contents can be cleaned and sorted just as for those inside straws.

Identifying contents

Part of the fun of having an insect hotel is it provides a nice window to all the organisms you might not even know are in your yard. I’ve managed hotels for over a decade and there is always something new each year, and during a pandemic these surprises keep me going. E.g., I found a parasitic beetle last year. So I highly recommend taking photographs of your hotel guests and uploading them onto iNaturalist (free), a site that can often get your organisms identified by other like-minded folks. And I always recommend buying some books. Here are the titles I own:

  • Wasps: A Guide for Eastern North America (Heath Holm)
  • Bees: An Identification and Native Plant Forage Guide (Heather Holm)
  • Common Native Bees of the Eastern United States (Heather Holm)
  • The Bees in Your Backyard (Joseph S. Wilson & Olivia Messinger Carril)