Alaska IPM

Bug of the Week! In honor of Alaska’s Invasive Species Awareness Week, this week’s bug of the week is the Large Yellow Underwing, Noctua pronuba. This is a large showy moth commonly found in Southeast but occasionally into Southcentral. The moth when at rest is about 1”. They are brown, with some modeling on the wings and some darker small eye spots. When they fly or flutter you can see why they get their common name, as the rear wings are bright orange with a bold black bar. The caterpillar is a typical cutworm. They are brown with some dark lateral spots on each segment. They will curl up into a “C” when collected and can grow to about an inch as well. This species is of European origin and was originally introduced to the East Coast in the 1970’s. Since then, it has crept across the US finally reaching Alaska in 2005.

Once established it is a common moth and agricultural pest. Being a cutworm, they overwinter as a larger caterpillar, ready to consume those young seedlings just as they get going in the spring. They pupate shortly after and mature in July or August. Adults are quite fecund, with some papers citing 450 eggs per female. They were very abundant in Colorado when I was younger, but also in Southeast even though there are not large agricultural areas there. One of the reasons this is such a successful invasive species is the diversity of plants they will eat. Thankfully the species has not reached destructive numbers here, but the potential is there. Part of recognizing non-native species is the potential those species could have to be destructive, and this is one to watch as Alaska warms and our growing season lengthens.

Joey Slowik, IPM Technician
[email protected]

This image can be found at inaturalist.org

Bug of the Week! This week’s bug of the week is the larder beetle, Dermestes lardarius. I’ve done a bug of the week on the larder beetle before, so I’ll be brief in describing it, but most of us have seen one. They are a smaller beetle, about ¼ in length. Their head and pronotum are brown, and they have dark brown elytra broken by a light tan band. Dermestids are notable because these beetles are hairy. The larvae, like the adults, are hairy as well, and resemble an elongate lint ball. We find these beetles in many, if not most homes, and the beetles are adapted to living off our refuse. Specifically food stuffs with proteins and fats and our shed skin. So, anyone with pets or kids where food bits may hit the floor probably has them.

There are many species of dermestid beetle. Some are specialized in feeding on the rotting flesh of carcasses, but those are different species. I mention this beetle now as one of our retired farm employees mentioned how he picked up a bag of sunflower seeds at a local grocer and found the beetles there. If you think about it, this isn’t surprising as many stores with food likely have food bits hitting the floor providing fodder for the beetles. It also exposes one of the many ways the beetles get moved around or introduced into our home. Sometimes we wonder where bugs come from and it’s almost always from us, often an overlooked avenue we never thought of. But it’s not worth calling a pest company for this species. A good cleaning usually takes care of the problem or keeps the indoor populations so low we rarely see them. And we could even think they are doing us some good, eating all those shed skin bits we don’t even notice we drop.

Joey Slowik, IPM Technician
[email protected]

The photograph is from https://en.wikipedia.org/wiki/Dermestes_lardarius

🐝 New publication alert! The publication "HGA-00501, Building Pollinator Habitat into the Alaska Garden" covers twelve tips for attracting and supporting pollinators in your own yards and gardens. The publication is available from the UAF Cooperative Extension Service publication page in both web and pdf formats. https://www.uaf.edu/ces/publications/database/gardening/building-pollinator-habitats.php

🐞 New publication alert! 🐞 The publication "HGA-00500, Building Lady Beetle Habitat into the Alaska Garden" covers information about the life cycle and biology of lady beetles (aka "ladybugs"), tips for creating habitat for lady beetles in your yards and gardens, as well as a photo guide which covers ten native species of lady beetles found in Alaska and one invasive species. The publication is available from the UAF Cooperative Extension Service publication page in both web and pdf formats. https://www.uaf.edu/ces/publications/database/gardening/lady-beetle-habitat.php

Bug of the Week! This week’s bug of the week is the twisted wing parasite, Elenchus tenuicornis. This small and rarely noticed order of insects is truly one of the odd balls. This species is a parasite of a number of insects, but is most often associated with leafhoppers. Life begins with an egg which is laid by the mother inside the host hopper which she herself developed in. The first instar larvae leave that host through thin intersegment host membranes and are free living. They attach to vegetation and wait for a new host to come along. When one does, they burrow into the new host through those flexible membranes and take up residency, living off of the host tissues and eventually taking up much of the host's abdomen. When it comes time to mature, the pupa of males will protrude from the membrane in between the host’s abdominal segments. The male looks like a very small wasp but different. They have only one pair of fan shaped wings, and their one pair is the rear most pair of wings, a bit different than flies who also have one pair of wings but it’s the forward pair. If you want to find one you had better look very closely as they really are small, adult males are only about 1.5mm, and only live for a few days.

The females never leave the host leaf hopper, and they don’t quite develop into a regular looking insect either. Their head and thorax semi-fuse and they don’t develop functional legs or eyes. This ceplothorax as it’s called, protrudes from in between the abdominal segments of the host and functions for allowing the male to find the female and mate. She will then develop eggs in the host and the cycle repeats itself. Host bugs with females will die, but those with males may live on. Females are often found when looking at a leafhopper and noticing an odd bulge on their abdomen, males occasionally in a sweep net. This species is commonly found in Europe, but only rarely in the US. Being as small as they are, and as far out there as some of the collection sites have been, some think this is a native holarctic species rather than a European introduction. Either way, it’s a cool little bug with a very different way of living out its life.

Joey Slowik, IPM Technician
[email protected]

Photograph from inaturalist.org

Looking for a good book to jump start your gardening season? The book Insects and Gardens by entomologist Eric Grissell (2001) is full of insights into the lives of the insects in your garden. He covers the biological questions, such as which insects and other arthropods are you likely to encounter in the garden and what are they doing there, in addition to the philosophical questions of how to come to terms with the existence of insects in our gardens. While the book is full of factual information, Grissell has a knack for writing in a conversational tone, peppered with bits of humor, that is pleasurable to read.

If you've taken the Master Gardener course in recent years, you may recognize this book. I like to start my presentation on insect biology with a quote from his book that I think helps to reframe our perspective of insects in the garden:
“When an insect awakens, the first thought that comes to its puny mind is not how much trouble it can create for you, the gardener. The concept of trouble is confined entirely to the mind of the gardener and his philosophical outlook on such things.”

This is not to say that the author does not acknowledge that insects can cause damage in the garden. Rather, Grissell encourages gardeners to get to know the diverse roles of insects in their garden, so that the gardener can learn to appreciate and encourage the benefits that insects can provide for our gardens.

The book is available to borrow through Anchorage Public Library's interlibrary loan system, or through the Soldotna & Kodiak Public Libraries.

-Alex Wenninger, [email protected]

Bug of the Week! This week’s bug of the week is the rove beetle, Aleochara bilineate. I know it doesn’t seem like it this year, but spring is coming, and for many that is also when our beloved root maggot flies return. For those in the dark, root maggots are a major pest to many a backyard gardener who tries to grow any brassica plant, like turnips, kale, cabbage or broccoli. The maggots eat away the plant so it wilts and dies. The beetle A. bilineate is an interesting pest of the pest. It has adapted its lifecycle to that of the root maggot. Adult beetles lay eggs in the soil near where root maggots are likely to be found, so near brassica plants. The beetles hatch in about 10 days and then actively seek out a maggot pupa in the soil. They nibble into it and eat up the pupating maggot inside. After about 30-40 days they emerge as an adult. Then they mate, lay some eggs and do it again. The adults can live for about a month and are predators of both loose larvae and root maggot eggs, and probably the adult flies should they catch them.

The beetles overwinter like the maggots, in a pupa, only the pupa of the maggot. They have been found to emerge later than the flies. This ensures that when they are done mating and are laying eggs there are flies around for them and their future brood to eat. These beetles are not native to North America, and likely followed the root maggots which have moved around with us. Southcentral Alaska is about as far out there as the species has made it in North America. This species has been speculated to be a potential biocontrol for root maggots, as they can knock down a maggot population by 70-90%. But, they always let that first population get away, so the flies always come back and sometimes too many for the beetles to control. No silver bullet here, just another interesting bug.

Joey Slowik, IPM Technician
[email protected]

Don't forget to register your honey bee hives with the Alaska Division of Agriculture! Registration is quick and easy and is required annually by law. You can either fill out the form electronically and submit via email or can print and mail to the address on the form: https://dnr.alaska.gov/.../HB%20Registration%20Fillable...

Registration helps the Alaska Division of Agriculture understand the size of the industry in Alaska, and also allows them to notify nearby apiaries in the event of a nearby bee disease detection. The information provided remains confidential within the Division of Agriculture.

Bug of the Week! This week’s bug of the week is the Black Spruce Borer, Asemum striatum. Black Spruce Borers are a medium sized beetle, with adults growing to slightly less than an inch in length. They are all black, elongate, with noticeable forward directed antennae about as long as half their body length. They belong to the beetle family Cerambycidae, which are the long-horned beetles, but this species antennae are shorter than many others in the family. Though, they do share a similar body shape, in that they are an elongate oval. This species also has longitudinal ridges along their elytra. These help in separating them from other borer species. The larvae take several years to mature and feed in the stumps or lower parts of dead and freshly dead trees. They may bore into the wood of the tree, but spend much of their time feeding near the surface, under the bark.

Although the species common name implies it’s found in Black Spruce, it’s much more common in pine species and other spruce. They will feed on a variety of tree species such as the common landscape trees Mugo Pine and Norway Spruce, and they are even known to feed on Larch and Firs. Adults can be found all summer from May-August. They have a broad holarctic distribution, and in other places are attracted to light traps implying they are at least somewhat nocturnal. This species is rare in Alaska. The Museum only lists a few specimens collected from the 1950’s. It could be that we lack the tree species they really like, even though we have lots of black spruce. Or maybe it’s our long days. Who knows, but they are very likely out there and just unreported/noticed like many of our insects.

Joey Slowik, IPM Technician
[email protected]

Photo description: The photograph shows a Black Spruce Borer, Asemum striatum. The beetle is black, oval shaped, has long forward facing antennae, and 6 legs. It is resting on a section of tree bark.