Beneficial Insects and Spiders of Alaska PMC-10075

Beneficial Insects and

Spiders of Alaska PMC-10075 Cover photos, left to right: Top row: crab spider (Misumena vatia), Dave Guinn; three-banded lady beetle (Coccinella trifasciata perplexa) eating aphids, Aaron Hagerty; green lacewing (Chrysopidae), Dave Guinn Bottom row: parasitoid wasp (Ichneumonidae), Dave Guinn; aerial yellowjacket (Dolichovespula arenaria), Derek Sikes This printing was paid for by the Renewable Resources Extension Act (RREA).

www.uaf.edu/ces or 1-877-520-5211

Jessie Moan, Extension Integrated Pest Management Technician. Originally prepared by Michele Hébert, former Extension Agriculture and Horticulture Agent. Published by the University of Alaska Fairbanks Cooperative Extension Service in co- operation with the United States Department of Agriculture. The University of Alaska is an AA/EO employer and educational institution and prohibits illegal discrimina- tion against any individual: www.alaska.edu/nondiscrimination ©2019 University of Alaska Fairbanks. 6-07/MH/9-19 Revised September 2019 Table of Contents Introduction...... 1 Beneficial Spiders and Their Relatives...... 2 Daddy Longlegs or Harvestman (Order: Opiliones)...... 4 Wolf Spiders (Family: Lycosidae)...... 6 Crab Spiders (Family: Thomisidae)...... 8 Orbweaver Spiders (Family: Araneidae)...... 10 Beneficial Insects: Introduction...... 12 Damsel Bugs, Nabids (Family: Nabidae)...... 14 Lacewings (Order: Neuroptera)...... 16 Ground Beetles (Family: Carabidae)...... 20 Lady Beetles (Family: Coccinellidae)...... 22 Flower Flies (Family: Syrphidae)...... 26 Robber Flies (Family: Asilidae)...... 28 Yellowjackets (Family: Vespidae)...... 30 Parasitoid Wasps (Order: Hymenoptera)...... 32 Parasitoid Flies (Family: Tachinidae)...... 34 Photo Credits...... 36 Photo Identifications for Known Taxa...... 37 References...... 38 Acknowledgements...... 39

4 Introduction Gardens and agricultural systems sup- Predators hunt and consume other port a community of small invertebrates, species to survive. Insects may be preda- including pests and their natural enemies. tors in either the immature or adult stage Natural enemies are organisms that act or both. Adult parasitoids deposit eggs in, against other organisms in ways that gen- on or near the body of their host. When erally keep populations below damaging the eggs hatch, the larvae feed on the host’s levels. We consider these natural enemies body while it is still alive and eventually to be beneficial organisms in our environ- cause mortality. Adult parasitoids are ments and an important component of generally free-living, feeding on nectar or integrated pest management strategies. pollen. Pathogens are microorganisms Natural enemies are particularly impor- (fungi, bacteria or viruses) that produce tant in low-input and organic systems, disease and lead to death. where they may be a primary component Additional information on identifica- of a pest management program. tion of beneficial organisms and encourag- Natural enemies can be divided into ing and incorporating them into your pest three broad categories: predators, para- management program is available through sitoids, and pathogens. This booklet will your local Cooperative Extension Service cover common predators and parasitoids. office.

1 Beneficial Spiders and Their Relatives Identification actively pursue prey in a hunting manner. Spiders are characterized by having The spiders outlined in this booklet have four pairs of legs and two body regions, been included because of their likelihood the cephalothorax (head and thorax com- to be present in a garden or crop setting in bined) and abdomen, usually separated by Alaska. Exclusion of any family of spiders a waist constriction. does not indicate their absence from the Spiders are distinguished by spinnerets, state or a lack of beneficial qualities. the silk and web-spinning organs at the Attract spiders by providing a variety rear of the abdomen. Spinnerets may or of plant structures that offer harborage may not be immediately visible on all and habitat for them. spiders.

Habits All spiders in Alaska are predators, feeding on insects and other small arthropods. Most spiders are docile and harmless to humans. Some spiders construct webs to ensnare prey; others do not spin webs but

2 Beneficial Spiders and Their Relatives

1 3 Daddy Longlegs or Harvestman (Order: Opiliones) Identification glands that produce strong-smelling Harvestmen species are not true spi- secretions for defense. They deposit their ders but are close relatives of spiders. They eggs in soil, in cracks or crevices and lack a constricted waist and spinnerets. under bark. Harvestmen have a small, pea-sized There are several harvestman species in body and eight slender legs. Legs can be Alaska; they are most frequently found in either long or short. undisturbed forest sites. The upper surface of the body is usually a mottled grey and brown coloration, while the underside is a cream color.

Web Type Harvestmen do not spin a web.

Habits Harvestmen are generalist predators, feeding on soft-bodied insects, some beetle larvae, slugs and snails, and decaying organic matter. Harvestmen use special

4 Daddy Longlegs or Harvestman (Order: Opiliones)

4 5

5 Wolf Spiders (Family: Lycosidae) Identification rocks or cracks for retreat, while others are Wolf spiders have highly variable grey found in grass, leaf litter or stony areas. and brown color patterns to match their Female wolf spiders carry egg sacs surroundings. They are mostly moderately under their spinnerets. After hatching, the sized spiders with most being approxi- tiny spiderlings climb onto the abdomen mately one inch in length. of the mother, where they remain for a considerable amount of time. Web Type In Alaska, wolf spiders are encountered around the yard and garden and some- Wolf spiders do not spin webs, but times even in homes. females spin silk to make egg sacs. Attract wolf spiders by maintaining a few permanent plantings. Edging, wooden Habits walkways and mulch also provide shelter. Wolf spiders are fast and are often seen running from disturbances or danger. They have excellent eyesight and are active predators. Some species make tunnels in the ground or use natural depressions such as

6 Wolf Spiders (Family: Lycosidae)

7 Crab Spiders (Family: Thomisidae) Identification prey on the ground. This family of spiders Crab spiders have their first and second relies more on touch than eyesight to pairs of legs much longer than the last two detect prey. pairs, giving them a crab-like appearance. Some species may slowly change color Their abdomen is often much wider to match their flower perch. than it is high. They are usually light in color and rely on camouflage to hunt.

Web Type Crab spiders do not spin webs, snares or nests, but they do spin egg sacs.

Habits Crab spiders secure their prey by ambush and stealth and can often be found on flowers in the garden setting. Camouflaged, they lie in wait for prey — sometimes for days. They also stalk their

8 Crab Spiders (Family: Thomisidae)

8 9

9 Orbweaver Spiders (Family: Araneidae) Identification Habits Orbweavers are highly varied in size Orbweavers are most famous for their and coloration. The Alaska example shown web engineering. They and their webs are is a large species with a brightly patterned commonly found on or near plants in the abdomen and distinctive leg markings. garden and on the exteriors of homes and Males are often much smaller than decks. females. With greatly reduced eyes, orbweavers rely on the vibration of the web to indicate Web Type when prey has been captured. Orbweavers are so-named because they Females camouflage egg sacs within the construct a web made up of concentric web or sometimes bury them in leaf duff. circles of silk anchored to the surrounding Members of this group are some of the vegetation. largest spiders likely to be encountered in Most people are familiar with this Alaska gardens. “Charlotte’s Web” pattern.

10 Orbweaver Spiders (Family: Araneidae)

10 11

11 Beneficial Insects: Introduction Insects are characterized by three pairs Insect growth and development also of legs, three body regions — head, thorax vary. The beneficial insects described in and abdomen — and two antennae. this booklet, with the exception of damsel Insects are incredibly diverse. Body bugs, undergo complete metamorphosis. size and coloration vary dramatically, as They develop through four life stages in- do feeding habits. Insects may feed on cluding egg, larva, pupa and adult. Damsel plants, animals, fungi, detritus, etc. Most bugs undergo simple metamorphosis with insects are harmless to humans and our three life stages including egg, nymph and crops. adult. Each life stage is described for the Insects occupy a wide range of habitats beneficial groups presented. and possess a vast array of habits. Insects have colonized the great majority of Earth’s ecosystems with one main exception — salt water environments. A great many insects are beneficial or benign, pollinating both wild and cultivated plants, feeding on pest organisms, and serving as food sources for birds, fish and mammals. Others are important agricultural and human health pests.

12 Beneficial Insects: Introduction

13 13 Damsel Bugs, Nabids (Family: Nabidae) The mouthparts of damsel bugs (a.k.a. Eggs: Small, cream colored to white, nabids) are elongated into a beak and are laid on foliage or inserted in plant tissue. held folded under the head. When prey is captured, the beak is extended and sharp Habits stylets puncture the prey and then suck Damsel bugs are found in the garden, out the body contents. in tall grass and other vegetative cover. Damsel bugs are known to feed on Maintain natural grassy areas around the agricultural pests such as aphids, plant garden to encourage this predator. bugs, mites, moth eggs and small caterpillars. Although generally beneficial, damsel bugs can produce a painful bite if handled.

Identification Adults: (approx. 1 cm) Narrow-oval body, usually yellowish brown in color. Legs and antennae are long and head appears pointed. Immatures: (1-7 mm) Similar in appearance to the adults but lack wings.

14 Damsel Bugs, Nabids (Family: Nabidae)

16 19

Egg

Young nymph Adult

17 20 Older nymph Adult

18 15 Lacewings (Order: Neuroptera) Lacewings are part of a large order of with an overall greenish tint. Brown mostly predaceous insects. In Alaska, we lacewings are smaller (6-12 mm) and most commonly see green lacewings and brown in color. brown lacewings, which are important Pupae: Green lacewing: Small, predators of aphids, mites, whiteflies and round cocoon attached to foliage. Brown the eggs of some economically destructive lacewing: Small, elongate cocoon attached caterpillars. to foliage or under bark. Some species of lacewings can be dif- Larvae: Both green and brown ficult to tell apart. Fortunately, they are all lacewings are “alligator-like” in appearance beneficial and easy to identify as a group. with long sickle-shaped mandibles. The Lacewings are distinct because their wings body can vary from grey-green to red- contain many veins, which give them a brown in color with bumps or knobs. lacy appearance. Eggs: Small and cream colored. Green lacewing eggs are laid at the end of long, Identification delicate stalks attached to vegetation near Adults: Soft-bodied with four mem- prey. Brown lacewing eggs are oval and branous wings held roof-like over the laid directly on leaves. back; eyes are gold or copper metallic. Green lacewings are larger (15-25 cm)

16 Lacewings (Order: Neuroptera)

22 Brown Lacewing

Green Lacewing 21 17 Lacewings (Order: Neuroptera) Habits Adult green and brown lacewings are night flyers; immatures are found on plant foliage. Most adults are predators, although some may feed on honeydew, pollen or nectar. Immatures are predators and primarily feed on aphids and other soft-bodied insects. Green lacewings are commonly found around bushes, grasses and weeds while brown lacewings are common in more wooded areas.

18 Lacewings (Order: Neuroptera)

23 24 Eggs

Lacewing Larva 25

Lacewing Adult

19 Ground Beetles (Family: Carabidae) Ground beetles are a large group of Habits insects that can be found in a variety of As generalist predators, adults and habitats. Some sources note over 200 larvae actively hunt a variety of insect species in the state of Alaska. prey. Adults of some species feed on seeds, while the larvae are predaceous. Almost Identification any insect that spends a portion of its life Adults: Range in size from very small close to the ground is fair game for ground to about 3 cm. Body form is usually oval beetles. with long walking legs. Coloration is usu- Permanent plantings, wooden terraces, ally black or brown, but some beetles have walkways and mulch can provide shelter striking blue or green iridescence. and increase populations of ground beetles Larvae: Body resembles a flattened around the yard and garden. caterpillar with long legs; head with distinct mandibles. Eggs and pupae: Found in soil and under debris.

20 Ground Beetles (Family: Carabidae)

26 27

21 Lady Beetles (Family: Coccinellidae) Lady beetles are a well known and In recent years, it has been shown that diverse group of primarily predaceous introduction of non-native species can be beetles. The beneficial status of lady beetles detrimental to the ecosystem; some intro- has been known for hundreds of years, and duced lady beetles tend to out-compete they are considered a harbinger of good native species and reduce their numbers. tidings in many cultures. More than 20 species of predaceous Adults and immatures are voracious, lady beetles have been recorded from active predators of aphids, scale insects Alaska. and other soft-bodied pests. Since the early 1900s, their populations have been encouraged, and species have been introduced into new areas for control of agricultural and garden pests.

22 Lady Beetles (Family: Coccinellidae)

28 31

32 30

23 Lady Beetles (Family: Coccinellidae) Identification Habits Adults: (1-10 mm) Body convex, Lady beetles are commonly encoun- round to oval, often brightly colored red, tered in agricultural, garden and residen- orange or cream with dark spots or stripes. tial areas. Adults and immatures can be They can be distinguished from other found on grasses, bushes, trees and garden colorful beetles by their short, clubbed plants. antennae and hidden head. Lady beetles pass the winter as adults Pupae: (2-8 mm) Pupae are similar to under leaf litter and other debris. larvae in coloration and are found attached to plants. Larvae: Dark grey to black, often with bright bands or spots. Body flattened and “alligator-like” in appearance with spines or bumps on the back. Eggs: Oval to spindle shaped, yellow- orange in color, often laid in clusters on plants.

24 Lady Beetles (Family: Coccinellidae)

33 34

35 36

25 Flower Flies (Family: Syrphidae) Flower flies are familiar, colorful Habits insects that are often seen hovering around Adults are not predaceous but are flowers like helicopters. Although adults important as pollinators, feeding primarily closely resemble bees or wasps, they are on pollen and nectar. harmless and do not sting or bite. Eggs are laid singly or in groups, often The immatures of some species are among aphids. Immatures can be found beneficial, feeding on aphids and other on plants. soft-bodied insects. Attract adults with flowering plants Identification around the garden. Place dishes of sugar water out in the spring when flowers are Adults: Medium-to-large flies; bodies not blooming. usually brightly colored with yellow and Several species occur in Alaska, but the black bands that mimic wasps and bees. group is poorly studied. Pupae: Small and tan, attached to foliage. Larvae: Slug-like maggots, grey-green or creamy white with variable darker markings. Head end usually narrowed. Eggs: Small, oval and cream colored, often laid on foliage near aphid colonies

26 Flower Flies (Family: Syrphidae)

37 38 Larva

39 40

27 Robber Flies (Family: Asilidae) Robber flies are a predaceous group in color. Can be difficult to distinguish that feed on a wide variety of insects, from other soil-dwelling larvae. including wasps, bees, grasshoppers and Eggs: Variable between species. other flies. Several species are known to occur in Alaska, but the group is poorly Habits studied. Robber flies are found in a wide variety of habitats. However, they are most com- Identification monly encountered in grassy, open areas Adults: Medium-to-large flies. Eyes are or forest edges. Adults pursue and capture large with a characteristic notch or depres- prey in the air or capture prey resting on sion between them. Some have bristles foliage. Adults use piercing mouthparts to on their head that make them appear inject digestive saliva into prey and then bearded. Most species are elongate with suck out the body contents. narrow abdomens; others are more robust The immatures are poorly studied; they and hairy and mimic bumblebees. are thought to live in rotting wood, under Pupae: Not concealed within a cover- bark or fallen leaves or in loose soil, where ing. they are primarily predaceous. Larvae: Body is elongated and cylin- drical and can be creamy white to yellow

28 Robber Flies (Family: Asilidae)

41 43

42 44 45 29 Yellowjackets (Family: Vespidae) Yellowjackets are social wasps living Habits in colonial nests above or below ground. Yellowjacket colonies consist of a single Some species are nuisance pests when queen and daughter workers. They are ef- their stinging and scavenging behavior ficient pollinators and voracious predators. puts them in contact with humans. The Workers feed on nectar but will eat flies, group as a whole is considered beneficial aphids, caterpillars and other pests. The as pollinators and predators of other larvae are fed chewed insects by workers. insects. Overwintering queens emerge in the spring, construct a small nest, lay eggs and Identification care for the developing first brood of work- Adults: Medium-to-large wasps. Bod- ers. Once the workers emerge, they expand ies black with yellow or ivory markings. the nest, forage for food, care for the young Distinguished from bees by their relatively larvae and defend the colony. The queen hairless bodies, obvious waist constriction then devotes all her time to laying eggs. and wings that are held longitudinally over New queens and males are produced in abdomen. the fall. Males leave the colony, mate with Immature life stages: Not likely to be new queens and die. Only the new queen encountered unless removing a nest. overwinters; the remainder of the colony dies.

30 Yellowjackets (Family: Vespidae)

46 47

31 Parasitoid Wasps (Order: Hymenoptera) Parasitoid wasps belong to several structure looks impressive, it cannot be families of Hymenoptera and vary widely used to sting people. This appendage is in appearance and habits. Immature life used to deposit eggs into hosts. stages develop on or in insects or other Immature life stages: Rarely seen due invertebrates. to their parasitic habits. Many species of parasitoid wasps are host specific, making them useful Habits for pest control in natural settings and Some adults feed on pollen or nectar greenhouses. All insect life stages can and are beneficial as pollinators; others serve as hosts to parasitioids. Some species are predaceous. Adults lay eggs on or in are available commercially for release as potential host insects. biocontrol agents. The larvae develop inside the host, feeding on body fluids, fat deposits and Identification organs. Eventually, the host is killed once Adults: Vary in size from 1 mm to the parasitoid completes its development. several cm. Usually thin-bodied, elongate Some species form characteristic wasps, but some minute species are rather cocoons on or around the dead host. robust. Many parasitoid wasps have a very long, stinger-like ovipositor. While this 32 Parasitoid Wasps (Order: Hymenoptera)

49 51

50 33 Parasitoid Flies (Family: Tachinidae) Species of parasitoid flies most Habits commonly encountered belong to the fly Adult flies lay eggs directly on the family Tachinidae. Tachinid fly maggots host or on something the host will eat. develop inside the bodies of various When the eggs hatch, the parasitoid larvae species of insects. They most commonly enter the host through the body wall or attack caterpillars, true bugs, beetles and are consumed by the host as it feeds. The grasshoppers. larvae develop inside the host, feeding on body fluids, fat deposits and organs. Identification Once parasitoid development is Adults: Small-to-medium-sized flies, complete, the larvae will bore out of the often with many hairs or bristles. Many host body, killing it, and pupate in the soil. species appear very similar to common Most adult flies feed on honeydew, house or filth flies. nectar or pollen. Immature life stages: Rarely seen due to their parasitic habits.

34 Parasitoid Flies (Family: Tachinidae)

53 54

55 56

35 Photo Credits Joseph Berger, www.forestryimages.com. Photo: 24 David Cappaert, www.forestryimages.com. Photos: 44, 45, 54, 55 Whitney Cranshaw, Colorado State University, www.forestryimages.org. Photos: 16, 17, 19 Dave Guinn, [email protected]. Photos: 1, 2, 3, 4, 6, 8, 9, 10, 13, 14, 15, 22, 26, 28, 29, 31, 32, 36, 37, 39, 40, 42, 47, 48, 50, 51, 53, 56 Aaron Hagerty, USDA Agricultural Research Service. Photos: 30, 33, 34 Tim Haye, Universität Kiel, www.insectimages.org. Photo: 52 Bradley Higbee, Paramount Farming, www.forestryimages.org. Photo: 18 Gerald Lenhard, www.forestryimages.org. Photo: 11 D. McClenaghan, www.ento.csiro.au. Photo: 7 R.J. Reynolds Tobacco Company Slide Set, R.J. Reynolds Tobacco Company, www. insectimages.org. Photo: 49 Corlene Rose, UAF Cooperative Extension Service. Photo: 46 Derek S. Sikes, © 2007. Photos: 5, 25, 27, 38, 41, 53 Alton N. Sparks, Jr., University of Georgia, www.forestryimages.org. Photo: 20 Cathy Turner, UAF Cooperative Extension Service. Photo: 12 UAF Cooperative Extension Service Staff. Photos: 21, 23, 35

36 Photo Identifications for Known Taxa 1, 3, 10 Araneus trifolium 5 Phalangium opilio 8-9 Misumena vatia 13 Cicindella sp. 14 Syrphidae, Flower Fly Maggot 15 Dolichovespa arenaria, Aerial Yellowjacket 19-20 Nabis sp. 25 Chrysoperla sp. 26 Carabus vietinghoffi 27 Pterostichus adstrictus 28, 30 Anatis mali, Eye-Spotted Lady Beetle 29 Adalia bipunctata, Two-Spotted Lady Beetle 31 Coccinella trifasciata perplexa,Three-Banded Lady Beetle 32 Calvia quatuordecimguttata, Native Four-Spotted Lady Beetle 36 Hippodamia quinquesignata guinquesignata, Five-Spotted Lady Beetle 46 Dolichovespa maculata, Baldfaced Hornet 47 Vespula vulgaris, Common Yellowjacket 49 Brachonidae 50 Gasteruption sp. 51 Ammophila sp.

37 References Triplehorn, C. A. and N. F. Johnson. 2005. “Borror and Delong’s Introduction to the Study of Insects,” 7th Edition. Belmont, California: Thomson Brooks/Cole. 864 pp. Borror, D. J. and R. E. White, eds. 1970. “A Field Guide to Insects: America North of Mexico.” Peterson Field Guide Series. New York: Hougton Mifflin Co. 404 pp. Hoffmann, M. P. and A. C. Frodsham. 1993. “Natural Enemies of Vegetable Insect Pests.” Cooperative Extension, Cornell University, Ithaca, New York. 63 pp. Weeden, C. R., A. M. Shelton, Y. Li and M. P. Hoffmann, eds. 2006. “Biological Control: A Guide to Natural Enemies in North America.” www.nysaes.cornell.edu/ent/ biocontrol/ McGavin, George. 2000. “Insects, Spiders and Other Terrestrial Arthropods.” New York: Dorling Kindersley, Inc. Arnett Jr., Ross. 2000. “American Insects,” 2nd edition. New York: CRC Press. 1003 pp. Emerton, James. 1961. “The Common Spiders of the United States.” New York: Dover Publications. 220 pp.

38 Acknowledgements Michele Hébert, UAF-CES; Cathy Turner, UAF-CES; Susan Emmert, USDA-ARS; Aaron Hagerty, USDA-ARS; Alberto Pantoja, USDA-ARS

Originally produced as a cooperative project with the University of Alaska Fairbanks Cooperative Extension Service (UAF-CES) and United States Department of Agriculture Agricultural Research Service (USDA-ARS). This publication was developed with funds from the USDA Natural Resources Conservation Service.